——Part 8: Control units for built-in thermal protection (PTC) for rotating electrical machines.
This part is Part 5-1 of the Low-voltage switchgear and controlgear.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 14048.5-2008 Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices.
The following main technical changes have been made with respect to GB/T 14048.5-2008:
——The characteristic requirements related to making and breaking operational overvoltages are deleted (see 4.9 of Edition 2008);
——The requirements related to the polarity of contact elements are added (see 4.10);
——The content of information that shall be given by the manufacturer is added [see 5.1o)~5.1p)];
——The requirements for the marking of terminals, emergency stop, etc. are modified (see 5.2.1~5.2.4; and 5.2.1~5.2.4 of Edition 2008);
——The requirements for glow-wire testing and test based on flammability category are added (see 7.1.2.2 and 7.1.2.3);
——The requirements for clearances and creepage distances are modified, and the corresponding provisions in IEC 60947-1 are directly quoted (see 7.1.4; 7.1.3 of Edition 2008);
——The requirements related to maximum recovery time are added (see 7.2.8);
——The requirements related to immunity are modified (see 7.3.2; 7.3 of Edition 2008);
——The kinds of special tests that can be carried out, including damp heat, salt mist, vibration and shock tests, are added (see 8.1.5);
——The requirements for electrical performance and ageing test of screwless-type clamping units are added (see 8.2.4.7~8.2.4.8);
——The requirements for velocity of movement rotary switches are added (see 8.3.2.1);
——The requirements for expected current adjustment in test circuit and test quantities are modified (see 8.3.4.3; 8.3.4.3 of Edition 2008);
——The tests for EMC are added (see 8.4);
——Figure 10 "Voltage drop measurement at contact point of the clamping unit or terminal" is added (see 8.4.4);
——Annex D "Clearances and creepage distances of control circuit devices" is deleted and left vacant;
——The requirements for the pulling force of cable in pull-out test are modified (see G.8.2.2; G.8.1.1 of Edition 2008);
——The general requirements for the verification test of electromagnetic compatibility and immunity test of control circuit devices with semiconductor switch elements are modified (see H.8.7.1~H.8.7.2; H.8.7.1~H.8.7.2 of Edition 2008);
——The requirements related to colour of lens are deleted (see Annex J);
——The requirements for terminal marking, distinctive number and distinctive letter for control circuit devices are added (see Annex M);
——"Procedure to determine reliability data for electromechanical devices in control circuits used in functional safety applications" is added (see Annex N).
This part has been redrafted and modified in relation to IEC 60947-5-1:2016 Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching elements - Electromechanical control circuit devices.
The main technical differences with respect to IEC 60947-5-1:2016 and the reasons are as follows:
——As for the normative references, adjustments of technical differences are made to this part to keep them in line with the technical conditions in China. The adjustments are embodied in a concentrated way in Clause 2 "Normative references", specifically as follows:
The national standard GB/T 14048.1-2012 Low-voltage switchgear and controlgear - Part 1: General rules is added.
——The requirements for humidity resisting qualities of materials are modified to "as specified in GB/T 14048.1-2012, Annex K" in 7.1.2.1 "General materials requirements". As IEC 60947-5-1:2016 does not gives specific requirements, but only states that "special attention shall be called", which cannot meet the needs of actual test verification in China, this requirement is modified.
——8.2.1.2 "Humidity resistance test" is added to the content of materials in Clause 8 "Tests". This subclause is added because the specific requirements for humidity resisting qualities of materials have been modified in 7.1.2.1.
This standard was proposed by the China Electrical Equipment Industrial Association.
This part is under the jurisdiction of SAC/TC 189 National Technical Committee on Low-voltage Apparatus of Standardization Administration of China.
The previous editions of this part are as follows:
——GB 14048.5-1993, GB 14048.5-2001, and GB/T 14048.5-2008.
Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices
1 General
1.1 Scope and object
This part of Low-voltage switchgear and controlgear applies to control circuit devices and switch elements intended for controlling, signalling, interlocking, etc., of switchgear and controlgear.
It applies to control circuit devices having a rated voltage not exceeding 1,000V a.c. (at a frequency not exceeding 1,000Hz) or 600V d.c.
However, for operational voltages below 100V a.c. or d.c., see 4.3.2.2.
This part applies to specific types of control circuit devices such as:
——manually operated control switches, for example push-buttons, rotary switches, foot switches, etc.;
——electromagnetically operated control switches, either time delayed or instantaneous, for example contactor relays;
——pilot switches, for example pressure switches, temperature sensitive switches (thermostats), programmers, etc.;
——position switches, for example control switches operated by part of a machine or mechanism;
——associated control circuit device, for example indicator lights, etc.
Note 1: A control circuit device includes (a) control switch(es) and associated devices such as (an) indicator light(s).
Note 2: A control switch includes (a) switch element(s) and an actuating system.
Note 3: A switch element may be a contact element or a semiconductor element.
It also applies to specific types of switch elements associated with other devices (whose main circuits are covered by other standards) such as:
——auxiliary contacts of a switching device (e.g. contactor, circuit breaker, etc.) which are not dedicated exclusively for use with the coil of that device;
——interlocking contacts of enclosure doors;
——control circuit contacts of rotary switches;
——control circuit contacts of overload relays.
Contactor relays also comply with the requirements and tests of IEC 60947-4-1:2009 +A1:2012 except for the utilization category which comply with this part.
This part does not include the relays covered in GB/T 14598 or in the IEC 61810 series, nor automatic electrical control devices for household and similar purposes.
The colour requirements of indicator lights, push-buttons, etc., are found in GB/T 4025-2010 and also in CIE S 0004/E-2001 from the International Commission on Illumination (CIE).
The object of this part is to state:
a) the characteristics of control circuit devices;
b) the electrical and mechanical requirements with respect to:
1) the various duties to be performed;
2) the significance of the rated characteristics and of the markings;
3) the tests to verify the rated characteristics.
c) the functional requirements to be satisfied by the control circuit devices with respect to:
1) environmental conditions, including those of enclosed equipment;
2) dielectric properties;
3) terminals.
1.2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2423.4-2008 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle) (IEC 60068-2-30:2005, IDT)
GB/T 2423.22-2012 Environmental testing for electric and electronic products - Part 2: Test methods - Test N: Change of temperature (IEC 60068-2-14:2009, IDT)
GB/T 4025-2010 Basic and safety principles for man-machine interface, marking and identification - Coding principles for indicators and actuators (IEC 60073:2002, IDT)
GB/T 14048.1-2012 Low-voltage switchgear and controlgear - Part 1: General rules (IEC 60947-1:2011, MOD)
GB/T 17464-2012 Connecting devices - Electrical copper conductors - Safety requirements for screw-type and screwless-type clamping units - General requirements and particular requirements for clamping units for conductors from 0.2mm2 up to 35mm2 (included) (IEC 60999-1:1999, IDT)
GB/T 17626.11-2008 Electromagnetic compatibility - Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests (IEC 61000-4-11:2004, IDT)
IEC 60068-2-6:2007 Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal)
IEC 60068-2-27:2008 Environmental testing - Part 2-27: Tests - Test Ea and guidance: Shock
IEC 60417-DB:2002 Graphical symbols for use on equipment
IEC 60617-DB:2012 Graphical symbols for diagrams
IEC 60695-2-10:2013 Fire hazard testing - Part 2-10: Glowing/hot-wire based test methods - Glow-wire apparatus and common test procedure
IEC 60695-2-11:2014 Fire hazard testing - Part 2-11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products (GWEPT)
IEC 60695-2-12:2010 Fire hazard testing - Part 2-12: Glowing/hot-wire based test methods - Glow-wire flammability index (GWFI) test method for materials
IEC 60695-2-12:2010/A1:2014 Amendment 1, 2014
IEC 60947-1:2007 Low-voltage switchgear and controlgear - Part 1: General rules
IEC 60947-1:2007/A1:2010 Amendment 1, 2010
IEC 60947-1:2007/A2:2014 Amendment 2, 2014
IEC 60947-4-1:2009 Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters
IEC 60947-4-1:2009/A1:2012 Amendment 1, 2012
IEC 60947-5-5:1997 Low voltage switchgear and controlgear - Part 5-5: Control circuit devices and switching elements - Electrical emergency stop device with mechanical latching function
IEC 60947-5-5:1997/A1:2005 Amendment 1, 2005
IEC 60947-5-5:1997/A2:2016 Amendment 2, 2016
IEC 61000-3-2 Electromagnetic compatibility ( EMC) - Part 3-2: Limits - Limits for harmonic current emissions (equipment input current <16A per phase)
IEC 61000-3-3 Electromagnetic compatibility (EMC) - Part 3-3: Limits - Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current <16A per phase and not subject to conditional connection
IEC 61000-4-2:2008 Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test
IEC 61000-4-3:2006 Electromagnetic compatibility (EMC) - Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-3:2006/A1:2007 Amendment 1, 2007
IEC 61000-4-3:2006/A2:2010 Amendment 2, 2010
IEC 61000-4-4:2012 Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques - Electrical fast transient/burst immunity test
IEC 61000-4-5:2014 Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test
IEC 61000-4-6:2013 Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-8:2009 Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test
IEC 61000-4-13:2002 Electromagnetic compatibility (EMC) - Part 4-13: Testing and measurement techniques - Harmonics and interharmonics including mains signalling at a.c. power port, low frequency immunity tests
IEC 61000-4-13:2002/A1:2009 Amendment 1, 2009
IEC 61000-4-13:2002/A2:2015 Amendment 2, 2015
IEC 61140:2016 Protection against electric shock - Common aspects for installation and equipment
CISPR 11:2015 Industrial, scientific and medical equipment - Radio-frequency disturbance characteristics - Limits and methods of measurement
CIE S 004/E-2001 Colours of light signals
2 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60947-1:2007+A1:2010+A2:2014 and the following apply.
2.1 Basic terms and definitions
2.1.1
control circuit device
an electrical device intended for the controlling, signalling, interlocking, etc., of switchgear and controlgear
Note: Control circuit devices can include associated devices dealt with in other standards, such as instruments, potentiometers, relays, in so far as associated devices are used for the purposes specified above.
2.1.2
control switch (for control and auxiliary circuit)
a mechanical switching device which serves the purpose of controlling the operation of switchgear or controlgear, including signalling, electrical interlocking, etc.
Note 1: A control switch consists of one or more contact elements with a common actuating system.
Note 2: A control switch may include semiconductor elements or contact elements (see 2.3.2 and 2.3.3).
Note 3: IEC 60050-441:1984, 441-14-46, modified.
2.1.3
control switch suitable for isolation
a control switch which, in the open position, complies with the requirements specified for the isolating function (see IEC 60947-1:2007, 2.1.19 and 7.1.7)
Note: Such control switches are intended to provide a higher degree of safety to personnel when working on the equipment controlled. For this reason, they have to be manually actuated relying on the intelligence of instructed persons to react in case they would fail to operate, e.g. in case of insufficiently opened contacts.
2.1.4
control station
an assembly of one or more control switches fixed on the same panel or located in the same enclosure
Note: A control station panel or enclosure may also contain related equipment, e.g. potentiometers, signal lamps, instruments, etc.
[IEC 60050-441:1984, 441-12-08]
2.2 Control switches
2.2.1
automatic control switches
Note: Automatic control switches are operated by automatic control (see IEC 60947-1:2007, 2.4.5). They are also designated as pilot switches (see IEC 60947-1:2007, 2.2.18).
2.2.1.1
instantaneous contactor relay
a contactor relay operating without any intentional time delay
Note: Unless otherwise stated, a contactor relay is generally an instantaneous contactor relay.
[IEC 60050-441:1984, IEV 441-14-36]
2.2.1.2
time-delay contactor relay
a contactor relay with specified time-delay characteristics
Note 1: The time-delay may be associated with energization (e-delay) or with de-energization (d-delay) or both.
Note 2: A time-delay contactor relay may also incorporate instantaneous contact elements.
Note 3: IEC 60050-441:1984, 441-14-37, modified.
2.2.1.3
position switch
a pilot switch the actuating system of which is operated by a moving part of the machine, when this part reaches a predetermined position
[IEC 60050-441:1984, EV 441-14-49]
2.2.1.4
programmer
a control switch having a multiplicity of switch elements which, after initiation, operates in a defined sequence
2.2.2
manually operated control switches
Note: Manually operated control switches are operated by manual control (see IEC 60947-1:2007, 2.4.4).
2.2.2.1
push-button
a control switch having an actuator intended to be operated by force exerted by a part of the human body, usually the finger or palm of the hand, and having stored energy (spring) return
[IEC 60050-441:1984, 441-14-53]
2.2.2.2
pull-button
a control switch having an actuator intended to be operated by manual pull, and having stored energy (spring) return
2.2.2.3
push-pull button
a control switch having an actuator intended to be operated by manual push and returned to its initial position by manual pull, or vice versa
Note: There are also “push-push” or “push-turn” or other combinations of buttons.
2.2.2.4
rotary button
a combination of push-button type switch elements having an actuator operated by a manual rotation (see also 2.2.2.15 to 2.2.2.18 inclusive)
Example: A selector switch.
Note: A rotary push-button may have more than two positions; it may or may not have a spring return.
2.2.2.5
latched push-button
a push-button with spring return, but which remains in the actuated position until a latch is released by a separate action
Note: The latching may be released by subsequent actuation (such as pushing, turning, etc.) of the same or of an adjacent push-button or by the action of an electromagnet, etc.
2.2.2.6
locked push-button
a push-button which may be secured in one or more of its positions by a separate action
Note: The locking may be obtained by turning the button, by turning a key, by operating a lever, etc.
2.2.2.7
key-operated push-button
a push-button which can only be operated as long as a key remains inserted
Note: Key withdrawal may be provided at any position.
2.2.2.8
time-delay push-button
a push-button the contacts of which return to the initial position only after a pre-determined interval of time following the release of the actuating force
2.2.2.9
delayed action push-button
a push-button in which the switching operation does not occur until after the force on the button has been maintained for a pre-determined interval of time
2.2.2.10
illuminated push-button
a push-button incorporating a signalling lamp in the button
2.2.2.11
covered push-button
a push-button in which the button is protected against inadvertent operation by a lid or a cover
2.2.2.12
shrouded push-button
a push-button in which the button is protected against inadvertent operation in certain directions
2.2.2.13
free push-button
a push-button in which the rotation of the actuator around its axis is not limited
2.2.2.14
guided push-button
a push-button in which the rotation of the actuator around its axis is prevented
Note: Examples of guided push-buttons: the actuators of which are keyed, square or rectangular, etc.
2.2.2.15
rotary control switch
rotary switch (abbreviation)
a control switch having an actuator intended to be operated by rotation
2.2.2.16
key-operated rotary switch
a rotary switch where a key is used as the actuator
Note: Key withdrawal may be provided at any position.
2.2.2.17
limited movement rotary switch
a rotary switch with a restricted angular movement of its actuator
2.2.2.18
unidirectional movement rotary switch
a rotary switch in which the actuating system allows rotation in one direction only
2.2.2.19
joy stick
a control switch having an actuator consisting of a pin or stick projecting essentially at a right angle from the panel or enclosure when in one of its positions and intended to be operated by angular displacement
Note 1: A joy stick may have more than two positions associated with different directions of the displacement of the stick and operating the contact elements differently: such a joy stick is referred to as a joy stick selector.
Note 2: The pin or stick may or may not have a spring return.
2.2.2.20
wobble stick
a joy stick which operates all contact elements alike, whatever be the direction of the displacement
2.2.2.21
foot switch (pedal)
a control switch having an actuator intended to be operated by force exerted by a foot
Note: IEC 60050-441:1984, 441-14-52, modified.
2.3 Parts of control switches
2.3.1
switch element
a switch element may be a semiconductor element (see 2.3.2) or a contact element (see 2.3.3)
2.3.2
semiconductor element
an element designed to switch the current of an electric circuit by means of the controlled conductivity of a semiconductor
2.3.3
contact element
the parts, fixed and movable, conducting and insulating, of a control switch necessary to close and open one single conducting path of a circuit
Note 1: The contact element and the actuating system may form an indivisible unit, but frequently one or more contact elements may be combined with one or more actuating system or systems. The actuating systems may be different.
Note 2: Terms and definitions relating to various kinds of contact elements are given in 2.3.3.1 to 2.3.3.10 inclusive.
Note 3: This definition does not include control coils and magnet systems.
The following definitions refer to a single contact element of a control switch:
2.3.3.1
single gap contact element
a contact element which opens or closes the conducting path of its circuit on one location only
Note: See Figures 4a) and 4c).
2.3.3.2
double single gap contact element
a contact element which opens or closes the conducting path of its circuit in two locations in series
Note: See Figures 4b), 4d) and 4e).
2.3.3.3
make-contact element (normally open)
a contact element which closes a conducting path when the control switch is actuated
2.3.3.4
break-contact element (normally closed)
a contact element which opens a conducting path when the control switch is actuated
2.3.3.5
change-over contact elements
a contact element combination which includes one make-contact element and one break-contact element
Note: See Figures 4c), 4d) and 4e).
2.3.3.6
pulse (fleeting) contact element
a contact element which opens or closes a circuit for a part of the travel during the transition of the actuator from one position to another
2.3.3.7
electrically separated contact elements
contact elements belonging to the same control switch, but adequately insulated from each other so that they can be connected into electrically separated circuits, which can be either same polarity or opposite polarity
Note: IEC 60050-441:1984, 441-15-24, modified.
2.3.3.8
independent (snap) action contact element
a contact element of a manual or automatic control device in which the velocity of contact motion is substantially independent of the velocity of motion of the actuator
2.3.3.9
dependent action contact element
a contact element of a manual or automatic control device in which the velocity of contact motion depends on the velocity of motion of the actuator
2.3.3.10
contact unit
a contact element or contact element combination which can be combined with similar units operated by a common actuating system
2.3.4
button
the external end of the actuator of a push-button, to which the actuating force is applied
2.3.4.1
flush-button
a button which is substantially level with the adjacent fixed surrounding surface when in its initial position and is below this surface when it is operated
2.3.4.2
recessed button
a button which is below the adjacent fixed surrounding surface in both its initial and operated positions
2.3.4.3
extended button
a button which protrudes above the adjacent fixed surrounding surface in both its initial and operated positions
2.3.4.4
mushroom button
a button, the protruding end of which has an enlarged diameter
2.3.5
locating mechanism
that part of the actuating system which retains the actuator and/or the contact elements in their positions
Note: Other devices (e.g. a push-button with two positions, or an emergency stop) may also have such a function.
2.3.6
end stop
a device that limits the travel of a moving part
Note: An end stop may relate either to the actuator or to the contact element.
2.4 Operation of control switches
2.4.1 Operation of contactor relays
2.4.1.1
e-delay
a delay in the operation of a contact element of a contactor relay, following the energization of the coil of the electromagnet of this contactor relay
Example: Delay to close make-contacts (ON delay).
Note: The terms "e-delay” and "d-delay" may be applied to any kind of contact elements (see 2.3.3).
2.4.1.2
d-delay
a delay in the operation of a contact element of a contactor relay, following the de-energization of the coil of the electromagnet of this contactor relay
Example: Delay to open make-contacts (OFF delay).
Note: The terms "e-delay” and "d-delay" may be applied to any kind of contact elements (see 2.3.3).
2.4.1.3
fixed delay
a delay in the operation of a contact element of a contactor relay, which is not intended to be adjusted in value
2.4.1.4
adjustable delay
a delay in the operation of a contact element of a contactor relay, which is intended to be adjusted to different values after the installation of the contactor relay
2.4.2 Operation of pilot switches
2.4.2.1
actuating quantity
the physical quantity, the value of which is decisive for the actuation or non-actuation of a pilot switch
2.4.2.2
operating value
the value of the actuating quantity which is sufficient to cause a pilot switch to be actuated
2.4.2.3
return value
the value of the actuating quantity which has to be re-established in order to cause an actuated pilot switch to return to its position of rest
2.4.2.4
different value
the difference between the operating value and the return value
2.4.3 Operation of rotary switches
2.4.3.1
definite position (of a rotary switch)
a position into which the locating mechanism pulls the rotary switch and retains it as long as the actuating moment does not exceed a certain value
2.4.3.2
position of rest
a stable (definite) position into which the locating mechanism tends to move back and retain the rotary switch by stored energy
2.4.3.3
transit position
a (definite) position in which the locating mechanism produces an intended marked change in the operating moment, but in which the actuator cannot remain by itself
2.4.3.4
biased position
a (definite) position of a rotary switch in which the actuator is pulled against a stop from which it will return to a position of rest by means of stored energy (for example, by means of a spring)
Note: During the transfer from a biased position to the adjacent position of rest, the rotary switch may pass through one or more transit positions.
2.4.3.5
latched position
a biased position in which the return mechanism is held by a latching arrangement
Note: The latching arrangement may be released manually or otherwise.
2.4.3.6
locked position
a (definite) position in which a rotary switch is secured by separate action
Note: The locking may be obtained by turning a key, operating a lever, etc.
2.4.3.7
operating diagram
the representation of the intended order in which the contact elements of a rotary switch operate as a result of actuation
2.4.4 Operation of mechanically operated control switches
2.4.4.1
pre-travel of the actuator
the maximum travel of the actuator which causes no travel of the contact elements
Note: See Dimension a on Figure 2.
2.4.4.2
over-travel of the actuator
the travel of the actuator after all the contacts have reached their closed (open) position
2.4.4.3
direct drive
a connection between actuator and contact element that excludes any pre-travel of the actuator
2.4.4.4
positive drive
a connection between actuator and contact element such that the force applied to the actuator is directly transmitted to the contact element
2.4.4.5
limited drive
a connection between actuator and contact element that limits the force transmitted to the contact element
2.4.4.6
minimum starting force (or moment)
the minimum value of force (or moment) initiating the pre-travel of the actuator
2.4.4.7
minimum actuating force (or moment)
the minimum value of the force (or moment) to be applied to the actuator that will cause all contacts to reach their closed (open) position
2.4.4.8
pre-travel of the contact element
the relative movement which occurs within the contact element before the contacts make (break)
Note: See Dimension b on Figure 2.
2.4.4.9
over-travel of the contact element
the relative movement which occurs within the contact element after the contacts have reached the make (break) position
Note: See Dimension d on Figure 2.
2.4.4.10
bounce time
for a contact which is closing/opening its circuit, time interval between the instant when the contact circuit first closes/opens and the instant when the circuit is finally closed/opened
Note: IEC 60050-444:2002, 444-05-04, modified.
3 Classification
3.1 Contact elements
Contact elements may be classified as follows:
a) Utilization categories (see 4.4);
b) Electrical ratings based on utilization categories (see Annex A);
c) One of the following form letters (see Figure 4):
1) Form A – Single gap make-contact element;
2) Form B – Single gap break-contact element;
3) Form C – Single gap make-break three terminal change-over contact element;
4) Form X – Double gap make-contact element;
5) Form Y – Double gap break-contact element;
6) Form Z – Double gap make-break four terminal change-over contact element.
d) Other types not included in c).
Note 1: Regarding Figure 4e), the two moving contact elements are electrically separated (see 2.3.3.7).
Note 2: Distinction is made between make before break (overlap) change-over contact elements where the two circuits are both closed for a part of the travel of the moving contacts from one position to the other, and break before make (non-overlap) change-over contact elements where the two circuits are both open for a part of the travel of the moving contacts from one position to the other. Unless otherwise stated, change-over contact elements are generally break before make.
3.2 Control switches
Control switches may be classified according to the contact element and the nature of the actuating system, e.g. push-buttons, form X.
3.3 Control circuit devices
Control circuit devices may be classified according to the control switch and the associated control circuit equipment, e.g. push-buttons plus indicator lights.
3.4 Time-delay switch elements
Distinction is made according to how the time delay of a switch element is achieved, e.g. electrical delay, magnetic delay, mechanical delay, or pneumatic delay.
3.5 Control switch mounting
The control switch mounting may be classified by the mounting hole size, e.g. D12, D16, D22, D30 (see 6.3.1).
4 Characteristics
4.1 Summary of characteristics
4.1.1 General
The characteristics of control circuit devices and switch elements shall be stated in the following terms, where such terms are applicable:
——type of equipment (see 4.2);
——rated and limiting values for switch elements (see 4.3);
——utilization categories of switch elements (see 4.4);
——normal and abnormal load characteristics (see 4.3.6).
4.1.2 Operation of a control switch
The principal application of a control switch is the switching of loads as indicated for the various utilization categories in Table 1.
Other applications, e.g. the switching of tungsten filament lamps, small motors, etc., are not dealt with in detail in this part, but are mentioned in 4.3.6.2.
4.1.2.1 Normal conditions of use
The normal use of a control switch is to close, maintain and open circuits in accordance with the utilization category shown in Table 1. Also refer to Table 4.
4.1.2.2 Abnormal conditions of use
Abnormal conditions may arise, for example, when an electromagnet, although energized, has failed to close. Refer to Table 5.
A control switch shall be able to break the current corresponding to such conditions of use.
4.2 Type of control circuit device or switch element
4.2.1 Kind of control circuit device
The kind of control circuit device shall be stated:
——manually operated control switches, e.g. push-buttons, rotary switches, foot switches, etc.;
——electromagnetically operated control switches, either time delayed or instantaneous, e.g. contactor relays;
——pilot switches, e.g. pressure switches, temperature sensitive switches (thermostats), programmers, etc.;
——position switches;
——associated control circuit devices, e.g. indicator lights, etc.
4.2.2 Kind of switch elements
The kind of switch elements shall be stated:
——auxiliary contacts of a switching device (e.g. contactor, circuit breaker, etc.) which are not dedicated exclusively for use with the coil of that device;
——interlocking contacts of enclosure doors;
——control circuit contacts of rotary switches;
——control circuit contacts of overload relays.
4.2.3 Number of poles
The number of poles shall be stated.
4.2.4 Kind of current
The kind of current shall be stated:
——alternating current;
——direct current.
4.2.5 Interrupting medium
The interrupting medium shall be stated:
——air;
——oil;
——gas;
——vacuum, etc.
4.2.6 Operating conditions
4.2.6.1 Method of operation
The method of operation shall be stated:
——manual;
——electromagnetic;
——pneumatic;
——electro-pneumatic.
4.2.6.2 Method of control
The method of control shall be stated:
——automatic;
——non-automatic;
——semi-automatic.
4.3 Rated and limiting values for switch elements
4.3.1 General
The rated values established for the switch elements of a control circuit device shall be stated in accordance with 4.3.2 to 4.3.6 inclusive but it is not necessary to specify all the values listed.
4.3.2 Rated voltages (of a switch element)
4.3.2.1 General
A switch element is defined by the rated voltages described in 4.3.2.2 to 4.3.2.4.
4.3.2.2 Rated operational voltage (Ue)
IEC 60947-1:2007, 4.3.1.1 applies with the following additions:
For three-phase circuits, Ue is stated as r.m.s. voltage between phases.
Note: A switch element can be assigned a number of combinations of rated operational voltage and rated operational current.
Control switches dealt with in this part are not normally intended to be used at very low voltages and they may not be suitable for such a service. It is therefore recommended to seek the advice of the manufacturer concerning any application with a low value of operational voltage, e.g. below 100V a.c. or d.c.
Foreword II 1 General 2 Terms and definitions 3 Classification 4 Characteristics 5 Product information 6 Normal service, mounting and transport conditions 7 Constructional and performance requirements 8 Tests Annex A (Normative) Electrical ratings based on utilization categories (see 3.1) Annex B (Normative) Example of inductive test loads for d.c. contacts Annex C (Normative) Special tests – Durability tests Annex D Annex E (Normative) Items subject to agreement between manufacturer and user Annex F (Normative) Class II control circuit devices insulated by encapsulation Requirements and tests Annex G (Normative) Additional requirements for control circuit devices with integrally connected cables Annex H (Normative) Additional requirements for semiconductor switch elements for control circuit devices Annex J (Normative) Special requirements for indicator lights and indicating towers Annex K (Normative) Special requirements for control switches with direct opening action Annex L (Normative) Special requirements for mechanically linked contact elements Annex M (Normative) Terminal marking, distinctive number and distinctive letter for control circuit devices Annex N (Normative) Procedure to determine reliability data for electromechanical devices in control circuits used in functional safety applications Bibliography
The Low-voltage switchgear and controlgear consists of the following parts:
——Part 1: General rules;
——Part 2: Circuit-breakers;
——Part 3: Switches, disconnectors, switch-disconnectors and fuse-combination units;
——Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters (Including motor protector);
——Part 4-2: Contactors and motor-starters - AC semiconductor motor controllers and starters (including soft-starters);
——Part 4-3: Contactors and motor-starters - AC semiconductor controllers and contactors for non-motor loads;
——Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices;
——Part 5-2: Control circuit devices and switching elements - Proximity switches;
——Part 5-3: Control circuit devices and switching elements - Requirements for proximity devices with defined behaviour under fault conditions (PDDB);
——Part 5-4: Control circuit devices and switching elements - Method of assessing the performance of low-energy contacts - Special tests;
——Part 5-5: Control circuit devices and switching elements - Electrical emergency stop device with mechanical latching function;
——Part 5-6: Control circuit devices and switching elements - DC interface for proximity sensors and switching amplifiers (NAMUR);
——Part 5-7: Control circuit devices and switching elements - Requirements for proximity devices with analogue output;
——Part 5-8: Control circuit devices and switching elements - Three-position enabling switches;
——Part 5-9: Control circuit devices and switching elements - Flow rate switches;
——Part 6-1: Multiple function equipment - Transfer switching equipment;
——Part 6-2: Multiple function equipment - Control and protective switching devices (or equipment) (CPS);
——Part 7-1: Ancillary equipment - Terminal blocks for copper conductors;
——Part 7-2: Ancillary equipment - Protective conductor terminal blocks for copper conductors;
——Part 7-3: Ancillary equipment - Safety requirements for fuse terminal blocks;
——Part 8: Control units for built-in thermal protection (PTC) for rotating electrical machines.
This part is Part 5-1 of the Low-voltage switchgear and controlgear.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 14048.5-2008 Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices.
The following main technical changes have been made with respect to GB/T 14048.5-2008:
——The characteristic requirements related to making and breaking operational overvoltages are deleted (see 4.9 of Edition 2008);
——The requirements related to the polarity of contact elements are added (see 4.10);
——The content of information that shall be given by the manufacturer is added [see 5.1o)~5.1p)];
——The requirements for the marking of terminals, emergency stop, etc. are modified (see 5.2.1~5.2.4; and 5.2.1~5.2.4 of Edition 2008);
——The requirements for glow-wire testing and test based on flammability category are added (see 7.1.2.2 and 7.1.2.3);
——The requirements for clearances and creepage distances are modified, and the corresponding provisions in IEC 60947-1 are directly quoted (see 7.1.4; 7.1.3 of Edition 2008);
——The requirements related to maximum recovery time are added (see 7.2.8);
——The requirements related to immunity are modified (see 7.3.2; 7.3 of Edition 2008);
——The kinds of special tests that can be carried out, including damp heat, salt mist, vibration and shock tests, are added (see 8.1.5);
——The requirements for electrical performance and ageing test of screwless-type clamping units are added (see 8.2.4.7~8.2.4.8);
——The requirements for velocity of movement rotary switches are added (see 8.3.2.1);
——The requirements for expected current adjustment in test circuit and test quantities are modified (see 8.3.4.3; 8.3.4.3 of Edition 2008);
——The tests for EMC are added (see 8.4);
——Figure 10 "Voltage drop measurement at contact point of the clamping unit or terminal" is added (see 8.4.4);
——Annex D "Clearances and creepage distances of control circuit devices" is deleted and left vacant;
——The requirements for the pulling force of cable in pull-out test are modified (see G.8.2.2; G.8.1.1 of Edition 2008);
——The general requirements for the verification test of electromagnetic compatibility and immunity test of control circuit devices with semiconductor switch elements are modified (see H.8.7.1~H.8.7.2; H.8.7.1~H.8.7.2 of Edition 2008);
——The requirements related to colour of lens are deleted (see Annex J);
——The requirements for terminal marking, distinctive number and distinctive letter for control circuit devices are added (see Annex M);
——"Procedure to determine reliability data for electromechanical devices in control circuits used in functional safety applications" is added (see Annex N).
This part has been redrafted and modified in relation to IEC 60947-5-1:2016 Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching elements - Electromechanical control circuit devices.
The main technical differences with respect to IEC 60947-5-1:2016 and the reasons are as follows:
——As for the normative references, adjustments of technical differences are made to this part to keep them in line with the technical conditions in China. The adjustments are embodied in a concentrated way in Clause 2 "Normative references", specifically as follows:
The national standard GB/T 14048.1-2012 Low-voltage switchgear and controlgear - Part 1: General rules is added.
——The requirements for humidity resisting qualities of materials are modified to "as specified in GB/T 14048.1-2012, Annex K" in 7.1.2.1 "General materials requirements". As IEC 60947-5-1:2016 does not gives specific requirements, but only states that "special attention shall be called", which cannot meet the needs of actual test verification in China, this requirement is modified.
——8.2.1.2 "Humidity resistance test" is added to the content of materials in Clause 8 "Tests". This subclause is added because the specific requirements for humidity resisting qualities of materials have been modified in 7.1.2.1.
This standard was proposed by the China Electrical Equipment Industrial Association.
This part is under the jurisdiction of SAC/TC 189 National Technical Committee on Low-voltage Apparatus of Standardization Administration of China.
The previous editions of this part are as follows:
——GB 14048.5-1993, GB 14048.5-2001, and GB/T 14048.5-2008.
Low-voltage switchgear and controlgear - Part 5-1: Control circuit devices and switching element - Electromechanical control circuit devices
1 General
1.1 Scope and object
This part of Low-voltage switchgear and controlgear applies to control circuit devices and switch elements intended for controlling, signalling, interlocking, etc., of switchgear and controlgear.
It applies to control circuit devices having a rated voltage not exceeding 1,000V a.c. (at a frequency not exceeding 1,000Hz) or 600V d.c.
However, for operational voltages below 100V a.c. or d.c., see 4.3.2.2.
This part applies to specific types of control circuit devices such as:
——manually operated control switches, for example push-buttons, rotary switches, foot switches, etc.;
——electromagnetically operated control switches, either time delayed or instantaneous, for example contactor relays;
——pilot switches, for example pressure switches, temperature sensitive switches (thermostats), programmers, etc.;
——position switches, for example control switches operated by part of a machine or mechanism;
——associated control circuit device, for example indicator lights, etc.
Note 1: A control circuit device includes (a) control switch(es) and associated devices such as (an) indicator light(s).
Note 2: A control switch includes (a) switch element(s) and an actuating system.
Note 3: A switch element may be a contact element or a semiconductor element.
It also applies to specific types of switch elements associated with other devices (whose main circuits are covered by other standards) such as:
——auxiliary contacts of a switching device (e.g. contactor, circuit breaker, etc.) which are not dedicated exclusively for use with the coil of that device;
——interlocking contacts of enclosure doors;
——control circuit contacts of rotary switches;
——control circuit contacts of overload relays.
Contactor relays also comply with the requirements and tests of IEC 60947-4-1:2009 +A1:2012 except for the utilization category which comply with this part.
This part does not include the relays covered in GB/T 14598 or in the IEC 61810 series, nor automatic electrical control devices for household and similar purposes.
The colour requirements of indicator lights, push-buttons, etc., are found in GB/T 4025-2010 and also in CIE S 0004/E-2001 from the International Commission on Illumination (CIE).
The object of this part is to state:
a) the characteristics of control circuit devices;
b) the electrical and mechanical requirements with respect to:
1) the various duties to be performed;
2) the significance of the rated characteristics and of the markings;
3) the tests to verify the rated characteristics.
c) the functional requirements to be satisfied by the control circuit devices with respect to:
1) environmental conditions, including those of enclosed equipment;
2) dielectric properties;
3) terminals.
1.2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2423.4-2008 Environmental testing for electric and electronic products - Part 2: Test method - Test Db: Damp heat, cyclic (12h+12h cycle) (IEC 60068-2-30:2005, IDT)
GB/T 2423.22-2012 Environmental testing for electric and electronic products - Part 2: Test methods - Test N: Change of temperature (IEC 60068-2-14:2009, IDT)
GB/T 4025-2010 Basic and safety principles for man-machine interface, marking and identification - Coding principles for indicators and actuators (IEC 60073:2002, IDT)
GB/T 14048.1-2012 Low-voltage switchgear and controlgear - Part 1: General rules (IEC 60947-1:2011, MOD)
GB/T 17464-2012 Connecting devices - Electrical copper conductors - Safety requirements for screw-type and screwless-type clamping units - General requirements and particular requirements for clamping units for conductors from 0.2mm2 up to 35mm2 (included) (IEC 60999-1:1999, IDT)
GB/T 17626.11-2008 Electromagnetic compatibility - Testing and measurement techniques - Voltage dips, short interruptions and voltage variations immunity tests (IEC 61000-4-11:2004, IDT)
IEC 60068-2-6:2007 Environmental testing - Part 2-6: Tests - Test Fc: Vibration (sinusoidal)
IEC 60068-2-27:2008 Environmental testing - Part 2-27: Tests - Test Ea and guidance: Shock
IEC 60417-DB:2002 Graphical symbols for use on equipment
IEC 60617-DB:2012 Graphical symbols for diagrams
IEC 60695-2-10:2013 Fire hazard testing - Part 2-10: Glowing/hot-wire based test methods - Glow-wire apparatus and common test procedure
IEC 60695-2-11:2014 Fire hazard testing - Part 2-11: Glowing/hot-wire based test methods - Glow-wire flammability test method for end-products (GWEPT)
IEC 60695-2-12:2010 Fire hazard testing - Part 2-12: Glowing/hot-wire based test methods - Glow-wire flammability index (GWFI) test method for materials
IEC 60695-2-12:2010/A1:2014 Amendment 1, 2014
IEC 60947-1:2007 Low-voltage switchgear and controlgear - Part 1: General rules
IEC 60947-1:2007/A1:2010 Amendment 1, 2010
IEC 60947-1:2007/A2:2014 Amendment 2, 2014
IEC 60947-4-1:2009 Low-voltage switchgear and controlgear - Part 4-1: Contactors and motor-starters - Electromechanical contactors and motor-starters
IEC 60947-4-1:2009/A1:2012 Amendment 1, 2012
IEC 60947-5-5:1997 Low voltage switchgear and controlgear - Part 5-5: Control circuit devices and switching elements - Electrical emergency stop device with mechanical latching function
IEC 60947-5-5:1997/A1:2005 Amendment 1, 2005
IEC 60947-5-5:1997/A2:2016 Amendment 2, 2016
IEC 61000-3-2 Electromagnetic compatibility ( EMC) - Part 3-2: Limits - Limits for harmonic current emissions (equipment input current <16A per phase)
IEC 61000-3-3 Electromagnetic compatibility (EMC) - Part 3-3: Limits - Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current <16A per phase and not subject to conditional connection
IEC 61000-4-2:2008 Electromagnetic compatibility (EMC) - Part 4-2: Testing and measurement techniques - Electrostatic discharge immunity test
IEC 61000-4-3:2006 Electromagnetic compatibility (EMC) - Part 4-3: Testing and measurement techniques - Radiated, radio-frequency, electromagnetic field immunity test
IEC 61000-4-3:2006/A1:2007 Amendment 1, 2007
IEC 61000-4-3:2006/A2:2010 Amendment 2, 2010
IEC 61000-4-4:2012 Electromagnetic compatibility (EMC) - Part 4-4: Testing and measurement techniques - Electrical fast transient/burst immunity test
IEC 61000-4-5:2014 Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement techniques - Surge immunity test
IEC 61000-4-6:2013 Electromagnetic compatibility (EMC) - Part 4-6: Testing and measurement techniques - Immunity to conducted disturbances, induced by radio-frequency fields
IEC 61000-4-8:2009 Electromagnetic compatibility (EMC) - Part 4-8: Testing and measurement techniques - Power frequency magnetic field immunity test
IEC 61000-4-13:2002 Electromagnetic compatibility (EMC) - Part 4-13: Testing and measurement techniques - Harmonics and interharmonics including mains signalling at a.c. power port, low frequency immunity tests
IEC 61000-4-13:2002/A1:2009 Amendment 1, 2009
IEC 61000-4-13:2002/A2:2015 Amendment 2, 2015
IEC 61140:2016 Protection against electric shock - Common aspects for installation and equipment
CISPR 11:2015 Industrial, scientific and medical equipment - Radio-frequency disturbance characteristics - Limits and methods of measurement
CIE S 004/E-2001 Colours of light signals
2 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60947-1:2007+A1:2010+A2:2014 and the following apply.
2.1 Basic terms and definitions
2.1.1
control circuit device
an electrical device intended for the controlling, signalling, interlocking, etc., of switchgear and controlgear
Note: Control circuit devices can include associated devices dealt with in other standards, such as instruments, potentiometers, relays, in so far as associated devices are used for the purposes specified above.
2.1.2
control switch (for control and auxiliary circuit)
a mechanical switching device which serves the purpose of controlling the operation of switchgear or controlgear, including signalling, electrical interlocking, etc.
Note 1: A control switch consists of one or more contact elements with a common actuating system.
Note 2: A control switch may include semiconductor elements or contact elements (see 2.3.2 and 2.3.3).
Note 3: IEC 60050-441:1984, 441-14-46, modified.
2.1.3
control switch suitable for isolation
a control switch which, in the open position, complies with the requirements specified for the isolating function (see IEC 60947-1:2007, 2.1.19 and 7.1.7)
Note: Such control switches are intended to provide a higher degree of safety to personnel when working on the equipment controlled. For this reason, they have to be manually actuated relying on the intelligence of instructed persons to react in case they would fail to operate, e.g. in case of insufficiently opened contacts.
2.1.4
control station
an assembly of one or more control switches fixed on the same panel or located in the same enclosure
Note: A control station panel or enclosure may also contain related equipment, e.g. potentiometers, signal lamps, instruments, etc.
[IEC 60050-441:1984, 441-12-08]
2.2 Control switches
2.2.1
automatic control switches
Note: Automatic control switches are operated by automatic control (see IEC 60947-1:2007, 2.4.5). They are also designated as pilot switches (see IEC 60947-1:2007, 2.2.18).
2.2.1.1
instantaneous contactor relay
a contactor relay operating without any intentional time delay
Note: Unless otherwise stated, a contactor relay is generally an instantaneous contactor relay.
[IEC 60050-441:1984, IEV 441-14-36]
2.2.1.2
time-delay contactor relay
a contactor relay with specified time-delay characteristics
Note 1: The time-delay may be associated with energization (e-delay) or with de-energization (d-delay) or both.
Note 2: A time-delay contactor relay may also incorporate instantaneous contact elements.
Note 3: IEC 60050-441:1984, 441-14-37, modified.
2.2.1.3
position switch
a pilot switch the actuating system of which is operated by a moving part of the machine, when this part reaches a predetermined position
[IEC 60050-441:1984, EV 441-14-49]
2.2.1.4
programmer
a control switch having a multiplicity of switch elements which, after initiation, operates in a defined sequence
2.2.2
manually operated control switches
Note: Manually operated control switches are operated by manual control (see IEC 60947-1:2007, 2.4.4).
2.2.2.1
push-button
a control switch having an actuator intended to be operated by force exerted by a part of the human body, usually the finger or palm of the hand, and having stored energy (spring) return
[IEC 60050-441:1984, 441-14-53]
2.2.2.2
pull-button
a control switch having an actuator intended to be operated by manual pull, and having stored energy (spring) return
2.2.2.3
push-pull button
a control switch having an actuator intended to be operated by manual push and returned to its initial position by manual pull, or vice versa
Note: There are also “push-push” or “push-turn” or other combinations of buttons.
2.2.2.4
rotary button
a combination of push-button type switch elements having an actuator operated by a manual rotation (see also 2.2.2.15 to 2.2.2.18 inclusive)
Example: A selector switch.
Note: A rotary push-button may have more than two positions; it may or may not have a spring return.
2.2.2.5
latched push-button
a push-button with spring return, but which remains in the actuated position until a latch is released by a separate action
Note: The latching may be released by subsequent actuation (such as pushing, turning, etc.) of the same or of an adjacent push-button or by the action of an electromagnet, etc.
2.2.2.6
locked push-button
a push-button which may be secured in one or more of its positions by a separate action
Note: The locking may be obtained by turning the button, by turning a key, by operating a lever, etc.
2.2.2.7
key-operated push-button
a push-button which can only be operated as long as a key remains inserted
Note: Key withdrawal may be provided at any position.
2.2.2.8
time-delay push-button
a push-button the contacts of which return to the initial position only after a pre-determined interval of time following the release of the actuating force
2.2.2.9
delayed action push-button
a push-button in which the switching operation does not occur until after the force on the button has been maintained for a pre-determined interval of time
2.2.2.10
illuminated push-button
a push-button incorporating a signalling lamp in the button
2.2.2.11
covered push-button
a push-button in which the button is protected against inadvertent operation by a lid or a cover
2.2.2.12
shrouded push-button
a push-button in which the button is protected against inadvertent operation in certain directions
2.2.2.13
free push-button
a push-button in which the rotation of the actuator around its axis is not limited
2.2.2.14
guided push-button
a push-button in which the rotation of the actuator around its axis is prevented
Note: Examples of guided push-buttons: the actuators of which are keyed, square or rectangular, etc.
2.2.2.15
rotary control switch
rotary switch (abbreviation)
a control switch having an actuator intended to be operated by rotation
2.2.2.16
key-operated rotary switch
a rotary switch where a key is used as the actuator
Note: Key withdrawal may be provided at any position.
2.2.2.17
limited movement rotary switch
a rotary switch with a restricted angular movement of its actuator
2.2.2.18
unidirectional movement rotary switch
a rotary switch in which the actuating system allows rotation in one direction only
2.2.2.19
joy stick
a control switch having an actuator consisting of a pin or stick projecting essentially at a right angle from the panel or enclosure when in one of its positions and intended to be operated by angular displacement
Note 1: A joy stick may have more than two positions associated with different directions of the displacement of the stick and operating the contact elements differently: such a joy stick is referred to as a joy stick selector.
Note 2: The pin or stick may or may not have a spring return.
2.2.2.20
wobble stick
a joy stick which operates all contact elements alike, whatever be the direction of the displacement
2.2.2.21
foot switch (pedal)
a control switch having an actuator intended to be operated by force exerted by a foot
Note: IEC 60050-441:1984, 441-14-52, modified.
2.3 Parts of control switches
2.3.1
switch element
a switch element may be a semiconductor element (see 2.3.2) or a contact element (see 2.3.3)
2.3.2
semiconductor element
an element designed to switch the current of an electric circuit by means of the controlled conductivity of a semiconductor
2.3.3
contact element
the parts, fixed and movable, conducting and insulating, of a control switch necessary to close and open one single conducting path of a circuit
Note 1: The contact element and the actuating system may form an indivisible unit, but frequently one or more contact elements may be combined with one or more actuating system or systems. The actuating systems may be different.
Note 2: Terms and definitions relating to various kinds of contact elements are given in 2.3.3.1 to 2.3.3.10 inclusive.
Note 3: This definition does not include control coils and magnet systems.
The following definitions refer to a single contact element of a control switch:
2.3.3.1
single gap contact element
a contact element which opens or closes the conducting path of its circuit on one location only
Note: See Figures 4a) and 4c).
2.3.3.2
double single gap contact element
a contact element which opens or closes the conducting path of its circuit in two locations in series
Note: See Figures 4b), 4d) and 4e).
2.3.3.3
make-contact element (normally open)
a contact element which closes a conducting path when the control switch is actuated
2.3.3.4
break-contact element (normally closed)
a contact element which opens a conducting path when the control switch is actuated
2.3.3.5
change-over contact elements
a contact element combination which includes one make-contact element and one break-contact element
Note: See Figures 4c), 4d) and 4e).
2.3.3.6
pulse (fleeting) contact element
a contact element which opens or closes a circuit for a part of the travel during the transition of the actuator from one position to another
2.3.3.7
electrically separated contact elements
contact elements belonging to the same control switch, but adequately insulated from each other so that they can be connected into electrically separated circuits, which can be either same polarity or opposite polarity
Note: IEC 60050-441:1984, 441-15-24, modified.
2.3.3.8
independent (snap) action contact element
a contact element of a manual or automatic control device in which the velocity of contact motion is substantially independent of the velocity of motion of the actuator
2.3.3.9
dependent action contact element
a contact element of a manual or automatic control device in which the velocity of contact motion depends on the velocity of motion of the actuator
2.3.3.10
contact unit
a contact element or contact element combination which can be combined with similar units operated by a common actuating system
2.3.4
button
the external end of the actuator of a push-button, to which the actuating force is applied
2.3.4.1
flush-button
a button which is substantially level with the adjacent fixed surrounding surface when in its initial position and is below this surface when it is operated
2.3.4.2
recessed button
a button which is below the adjacent fixed surrounding surface in both its initial and operated positions
2.3.4.3
extended button
a button which protrudes above the adjacent fixed surrounding surface in both its initial and operated positions
2.3.4.4
mushroom button
a button, the protruding end of which has an enlarged diameter
2.3.5
locating mechanism
that part of the actuating system which retains the actuator and/or the contact elements in their positions
Note: Other devices (e.g. a push-button with two positions, or an emergency stop) may also have such a function.
2.3.6
end stop
a device that limits the travel of a moving part
Note: An end stop may relate either to the actuator or to the contact element.
2.4 Operation of control switches
2.4.1 Operation of contactor relays
2.4.1.1
e-delay
a delay in the operation of a contact element of a contactor relay, following the energization of the coil of the electromagnet of this contactor relay
Example: Delay to close make-contacts (ON delay).
Note: The terms "e-delay” and "d-delay" may be applied to any kind of contact elements (see 2.3.3).
2.4.1.2
d-delay
a delay in the operation of a contact element of a contactor relay, following the de-energization of the coil of the electromagnet of this contactor relay
Example: Delay to open make-contacts (OFF delay).
Note: The terms "e-delay” and "d-delay" may be applied to any kind of contact elements (see 2.3.3).
2.4.1.3
fixed delay
a delay in the operation of a contact element of a contactor relay, which is not intended to be adjusted in value
2.4.1.4
adjustable delay
a delay in the operation of a contact element of a contactor relay, which is intended to be adjusted to different values after the installation of the contactor relay
2.4.2 Operation of pilot switches
2.4.2.1
actuating quantity
the physical quantity, the value of which is decisive for the actuation or non-actuation of a pilot switch
2.4.2.2
operating value
the value of the actuating quantity which is sufficient to cause a pilot switch to be actuated
2.4.2.3
return value
the value of the actuating quantity which has to be re-established in order to cause an actuated pilot switch to return to its position of rest
2.4.2.4
different value
the difference between the operating value and the return value
2.4.3 Operation of rotary switches
2.4.3.1
definite position (of a rotary switch)
a position into which the locating mechanism pulls the rotary switch and retains it as long as the actuating moment does not exceed a certain value
2.4.3.2
position of rest
a stable (definite) position into which the locating mechanism tends to move back and retain the rotary switch by stored energy
2.4.3.3
transit position
a (definite) position in which the locating mechanism produces an intended marked change in the operating moment, but in which the actuator cannot remain by itself
2.4.3.4
biased position
a (definite) position of a rotary switch in which the actuator is pulled against a stop from which it will return to a position of rest by means of stored energy (for example, by means of a spring)
Note: During the transfer from a biased position to the adjacent position of rest, the rotary switch may pass through one or more transit positions.
2.4.3.5
latched position
a biased position in which the return mechanism is held by a latching arrangement
Note: The latching arrangement may be released manually or otherwise.
2.4.3.6
locked position
a (definite) position in which a rotary switch is secured by separate action
Note: The locking may be obtained by turning a key, operating a lever, etc.
2.4.3.7
operating diagram
the representation of the intended order in which the contact elements of a rotary switch operate as a result of actuation
2.4.4 Operation of mechanically operated control switches
2.4.4.1
pre-travel of the actuator
the maximum travel of the actuator which causes no travel of the contact elements
Note: See Dimension a on Figure 2.
2.4.4.2
over-travel of the actuator
the travel of the actuator after all the contacts have reached their closed (open) position
2.4.4.3
direct drive
a connection between actuator and contact element that excludes any pre-travel of the actuator
2.4.4.4
positive drive
a connection between actuator and contact element such that the force applied to the actuator is directly transmitted to the contact element
2.4.4.5
limited drive
a connection between actuator and contact element that limits the force transmitted to the contact element
2.4.4.6
minimum starting force (or moment)
the minimum value of force (or moment) initiating the pre-travel of the actuator
2.4.4.7
minimum actuating force (or moment)
the minimum value of the force (or moment) to be applied to the actuator that will cause all contacts to reach their closed (open) position
2.4.4.8
pre-travel of the contact element
the relative movement which occurs within the contact element before the contacts make (break)
Note: See Dimension b on Figure 2.
2.4.4.9
over-travel of the contact element
the relative movement which occurs within the contact element after the contacts have reached the make (break) position
Note: See Dimension d on Figure 2.
2.4.4.10
bounce time
for a contact which is closing/opening its circuit, time interval between the instant when the contact circuit first closes/opens and the instant when the circuit is finally closed/opened
Note: IEC 60050-444:2002, 444-05-04, modified.
3 Classification
3.1 Contact elements
Contact elements may be classified as follows:
a) Utilization categories (see 4.4);
b) Electrical ratings based on utilization categories (see Annex A);
c) One of the following form letters (see Figure 4):
1) Form A – Single gap make-contact element;
2) Form B – Single gap break-contact element;
3) Form C – Single gap make-break three terminal change-over contact element;
4) Form X – Double gap make-contact element;
5) Form Y – Double gap break-contact element;
6) Form Z – Double gap make-break four terminal change-over contact element.
d) Other types not included in c).
Note 1: Regarding Figure 4e), the two moving contact elements are electrically separated (see 2.3.3.7).
Note 2: Distinction is made between make before break (overlap) change-over contact elements where the two circuits are both closed for a part of the travel of the moving contacts from one position to the other, and break before make (non-overlap) change-over contact elements where the two circuits are both open for a part of the travel of the moving contacts from one position to the other. Unless otherwise stated, change-over contact elements are generally break before make.
3.2 Control switches
Control switches may be classified according to the contact element and the nature of the actuating system, e.g. push-buttons, form X.
3.3 Control circuit devices
Control circuit devices may be classified according to the control switch and the associated control circuit equipment, e.g. push-buttons plus indicator lights.
3.4 Time-delay switch elements
Distinction is made according to how the time delay of a switch element is achieved, e.g. electrical delay, magnetic delay, mechanical delay, or pneumatic delay.
3.5 Control switch mounting
The control switch mounting may be classified by the mounting hole size, e.g. D12, D16, D22, D30 (see 6.3.1).
4 Characteristics
4.1 Summary of characteristics
4.1.1 General
The characteristics of control circuit devices and switch elements shall be stated in the following terms, where such terms are applicable:
——type of equipment (see 4.2);
——rated and limiting values for switch elements (see 4.3);
——utilization categories of switch elements (see 4.4);
——normal and abnormal load characteristics (see 4.3.6).
4.1.2 Operation of a control switch
The principal application of a control switch is the switching of loads as indicated for the various utilization categories in Table 1.
Other applications, e.g. the switching of tungsten filament lamps, small motors, etc., are not dealt with in detail in this part, but are mentioned in 4.3.6.2.
4.1.2.1 Normal conditions of use
The normal use of a control switch is to close, maintain and open circuits in accordance with the utilization category shown in Table 1. Also refer to Table 4.
4.1.2.2 Abnormal conditions of use
Abnormal conditions may arise, for example, when an electromagnet, although energized, has failed to close. Refer to Table 5.
A control switch shall be able to break the current corresponding to such conditions of use.
4.2 Type of control circuit device or switch element
4.2.1 Kind of control circuit device
The kind of control circuit device shall be stated:
——manually operated control switches, e.g. push-buttons, rotary switches, foot switches, etc.;
——electromagnetically operated control switches, either time delayed or instantaneous, e.g. contactor relays;
——pilot switches, e.g. pressure switches, temperature sensitive switches (thermostats), programmers, etc.;
——position switches;
——associated control circuit devices, e.g. indicator lights, etc.
4.2.2 Kind of switch elements
The kind of switch elements shall be stated:
——auxiliary contacts of a switching device (e.g. contactor, circuit breaker, etc.) which are not dedicated exclusively for use with the coil of that device;
——interlocking contacts of enclosure doors;
——control circuit contacts of rotary switches;
——control circuit contacts of overload relays.
4.2.3 Number of poles
The number of poles shall be stated.
4.2.4 Kind of current
The kind of current shall be stated:
——alternating current;
——direct current.
4.2.5 Interrupting medium
The interrupting medium shall be stated:
——air;
——oil;
——gas;
——vacuum, etc.
4.2.6 Operating conditions
4.2.6.1 Method of operation
The method of operation shall be stated:
——manual;
——electromagnetic;
——pneumatic;
——electro-pneumatic.
4.2.6.2 Method of control
The method of control shall be stated:
——automatic;
——non-automatic;
——semi-automatic.
4.3 Rated and limiting values for switch elements
4.3.1 General
The rated values established for the switch elements of a control circuit device shall be stated in accordance with 4.3.2 to 4.3.6 inclusive but it is not necessary to specify all the values listed.
4.3.2 Rated voltages (of a switch element)
4.3.2.1 General
A switch element is defined by the rated voltages described in 4.3.2.2 to 4.3.2.4.
4.3.2.2 Rated operational voltage (Ue)
IEC 60947-1:2007, 4.3.1.1 applies with the following additions:
For three-phase circuits, Ue is stated as r.m.s. voltage between phases.
Note: A switch element can be assigned a number of combinations of rated operational voltage and rated operational current.
Control switches dealt with in this part are not normally intended to be used at very low voltages and they may not be suitable for such a service. It is therefore recommended to seek the advice of the manufacturer concerning any application with a low value of operational voltage, e.g. below 100V a.c. or d.c.
Contents of GB/T 14048.5-2017
Foreword II
1 General
2 Terms and definitions
3 Classification
4 Characteristics
5 Product information
6 Normal service, mounting and transport conditions
7 Constructional and performance requirements
8 Tests
Annex A (Normative) Electrical ratings based on utilization categories (see 3.1)
Annex B (Normative) Example of inductive test loads for d.c. contacts
Annex C (Normative) Special tests – Durability tests
Annex D
Annex E (Normative) Items subject to agreement between manufacturer and user
Annex F (Normative) Class II control circuit devices insulated by encapsulation Requirements and tests
Annex G (Normative) Additional requirements for control circuit devices with integrally connected cables
Annex H (Normative) Additional requirements for semiconductor switch elements for control circuit devices
Annex J (Normative) Special requirements for indicator lights and indicating towers
Annex K (Normative) Special requirements for control switches with direct opening action
Annex L (Normative) Special requirements for mechanically linked contact elements
Annex M (Normative) Terminal marking, distinctive number and distinctive letter for control circuit devices
Annex N (Normative) Procedure to determine reliability data for electromechanical devices in control circuits used in functional safety applications
Bibliography
