Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T 7122-1993
Basic requirements for AC vacuum contactors
Published on October 8, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on January 1, 1994
Mechanical Industry Standard of the People's Republic of China
Basic requirements for AC vacuum contactors
1 Subject content and scope of application
JB/T7122-1993
This standard specifies the basic rules and requirements for vacuum contactors for general purposes (hereinafter referred to as contactors). Including: terminology; characteristics; normal working and installation conditions; structural and performance requirements; test methods and rules for verifying the requirements for properties and performance; marking, packaging, transportation and storage of contactors, etc.
This standard applies to contactors with an AC frequency of 50Hz (or 60Hz) and a rated working voltage of 6300V or less. The contactor can be used to connect and disconnect the circuit, and can be used with appropriate thermal relays or electronic protectors and other related protection devices to form an electromagnetic starter, especially suitable for forming a flameproof electric starter.
Note: ① Derivatives of contactors, except for special requirements, should still comply with the provisions of this standard. ② For contactors with a rated working voltage of 10kV, this standard can be used as a reference. 2 Reference standards
GB14048.1
GB14048.4
GB14048.5
IEC664-1
GB/T 4942.2
GB/T2900.18
3 Terms, symbols and codes
General provisions for low-voltage switchgear and controlgear
Low-voltage electromechanical contactors and motor starters Low-voltage switchgear and controlgear
Low-voltage switchgear and controlgear
Control circuit appliances and switching elements Part 1 Electromechanical control circuit appliances
Basic principles and requirements for insulation coordination of low-voltage systems Insulation coordination of high-voltage power transmission and transformation equipment
Rated voltage
Rated current of electrical equipment
Degree of protection of low-voltage electrical enclosures
Electrical terminology Low-voltage electrical appliances
3.1 Terms
For terms not specified in this standard, refer to the relevant terms and their definitions in GB/T2900.18. 3.1.1 Vacuum contactor
See Article 4.4.11 of GB/T2900.18.
3.1.2 Limit breaking capacity
The maximum breaking capacity of vacuum contactor under specified parameters. 3.1.3 Overcurrent
See Article 3.1.1.2 of GB14048.1.
3.1.4 Overload
See Article 3.1.1.3 of GB14048.1,
3.1.5 Overload current
See Article 3.1.1.4 of GB14048.1.
3.1.6 Making contact, "a\contact
Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
See Article 3.1.3.2 in GB14048.1.
3.1.7 Breaking contact, "b\contact
See Article 3.1.3.3 in GB14048.1.
3.1.8 Short-time withstand current
See Article 3.1.5.3 in GB14048.1.
3.1.9 Impulse withstand voltage, impulse withstand voltage
See Article 3.1.5.9 in GB14048.1.
0 rated withstand voltage, rated withstand voltage
see Article 3.1.5.10 of GB14048.1.
rated working voltage
rated insulation voltage
connection voltage
recovery voltage after breaking
rated impulse withstand voltage
conventional thermal current
conventional closed thermal current
rated working current
rated short-time withstand current
connection current
breaking current
power-on time
power factor
rated control voltage Source voltage
Short-circuit protection device
Comparative tracking index
Alternating damp heat test
Oscillation frequency
Over-oscillation coefficient
Use category code of contactor main circuit
Non-inductive or slightly inductive load, resistance furnace
JB/T7122-1993
Starting of wound-rotor induction motor, starting of disconnecting squirrel-cage induction motor, starting of disconnecting squirrel-cage induction motor during operation , reverse braking or reverse operation, inching transformer switching
capacitor switching
3.3.2 Contactor auxiliary contact usage category code AC-12
Control resistive load and solid-state load isolated by optical coupler Control transformer-isolated solid-state load
Control small-capacity electromagnet load
4 Classification
Control AC electromagnet load
JB/T7122-1993
Control electric DC electromagnets with resistive loads and solid-state loads isolated by optocouplers
DC electromagnet loads with economical resistance in the control circuit 4.1
Classification by number of poles in the main circuit
4.1.1 Single pole
4.1.2 Double pole
4.1.3 Three poles
4.1.4 Multi-pole
4.2 Classification by operating mechanism
4.2.1 Electromagnetic holding type
DC magnetic system
4. 2. 1. 1
AC/DC magnetic system
AC magnetic system
4. 2. 1. 3
4.2.2 Locking type
4.2.2.1 DC magnetic system
4.2.2.2 AC magnetic system
4.2.3 Pneumatic type
4.3 According to the action mode of the operating mechanism
4.3.1 Rotary type
4.3.2 Direct-acting type
5 Characteristics
5.1 Rated value
5.1.1 Rated rate
Rated operating frequency is: 50Hz (60Hz) 5.1.2 Rated operating voltage (U.)
The determination of the rated operating voltage value shall comply with the provisions of GB156. The combination of the rated working voltage and rated working current of the contactor determines the purpose of the contactor, and various use categories and corresponding tests are related to it. In order to be applicable to different working systems and use categories, several combinations of rated working voltage and rated working current (or power) or rated working voltage and associated connection and disconnection capacity can be specified. For multi-phase circuits, the rated working voltage refers to the line voltage. For single-pole contactors, the voltage across the poles when the contacts are in the disconnected position is the rated working voltage.
5.1.3 Rated insulation voltage (U.)
The rated insulation voltage of the contactor is related to the dielectric performance test voltage, creepage distance, etc. In any case, the maximum value of the rated working voltage should not exceed the rated insulation voltage value.
Note: If the rated insulation voltage is not clearly specified, the maximum value of the specified working voltage can be considered as its rated insulation voltage. 5.1.4 Rated impulse withstand voltage (Uim) The contactor can withstand the impulse voltage peak with specified waveform and characteristics without failure under specified test conditions. The rated impulse withstand voltage is related to electrical clearance, etc.
The rated impulse withstand voltage of the contactor shall be equal to or greater than the specified value of the decompression overvoltage that may be generated in the circuit where the contactor is located. 3
JB/T7122-1993
5.1.5 Rated working current (L) or rated control power The determination of the rated working current value shall give priority to the specified value in GB762. The rated working current of the contactor is determined during the design and development, taking into account the rated working voltage, rated frequency, rated working system and use category.
The rated working current of the contactor that directly switches a single motor can be replaced or supplemented by the maximum rated output power of the expected controlled motor at the rated working voltage. The manufacturer shall provide the relationship between current and power. 5.1.6 Conventional heating current (la)
The conventional heating current is the maximum test current of the unenclosed contactor used for temperature rise test under atmospheric conditions. Atmospheric conditions are understood as normal indoor air conditions without ventilation and external radiation. The conventional heating current is at least equal to the maximum rated working current of the unenclosed contactor in an eight-hour working system. 5.1.7 Conventional enclosed thermal current (Iae) 5.3.2.2 of GB14048.1 applies.
5.1.8 Rated duty
Under normal circumstances, the contactor should consider the following rated duty. 5.1.8.1 Eight-hour working system
Eight-hour working system is a working system in which the main contact of the contactor remains closed and carries a stable current for a long enough time for the electrical appliance to reach thermal equilibrium, but the current must be disconnected after 8 hours.
Eight-hour working system is the basic working system, and the agreed heating current and agreed closed heating current of the contactor are determined by this basic working system. 5.1.8.2 Uninterrupted working system
Uninterrupted working system is a working system without a no-load period, that is, the main contact of the contactor remains closed and carries a stable current for more than 8 hours (weeks, months or years) without disconnecting the current. Since the main contacts of the vacuum contactor are sealed in a vacuum, no oxide layer and dust accumulation will form on the contacts, so it can be considered according to the eight-hour working system. 5.1.8.3 Intermittent cycle working system (repeated short-time working system or intermittent working system for short) Intermittent cycle working system means that the load time of the main contact of the contactor (remaining closed) and its no-load time have a specified ratio. A duty system in which neither time is sufficient for the appliance to reach thermal equilibrium. Intermittent cycle duty system is characterized by three parameters: current value, number of on-off operation cycles per hour and load factor (duration of power on). Load factor is the ratio of power on time (t) to on-off operation cycle (t.), usually expressed as a percentage. The standard values of load factor (duration of power on) are 15%, 25%, 40% and 60%; a.
b. Contactors can be divided into the following levels according to the number of on-off operation cycles they can perform per hour: Level 1
Level 120
Level 300
(Level 600)
Level 1200
1 time/hour
3 times/hour
12 times/hour
30 times/hour
120 times/hour
300 times/hour
(600 times/hour)
1200 times/hour
For intermittent cycle working systems with a large number of on-off operation cycles per hour, the development should be based on the known actual number of on-off operation cycles or according to regulations. The rated working current value is specified by the number of on-off operation cycles, and the following formula should be satisfied: edt≤X (or Xt)
Note: The above formula does not take into account the arc energy during on-off operation. JB/T7122-1993
is applicable to the characteristic (parameter) representation method of the contactor of the intermittent cycle working system. For example, the intermittent cycle working system with a current of 100A and a power supply of 2min every 5min can be expressed as 100A, 12 levels, 405.1.8.4 Short-time working system
The short-time working system is a working system in which the main contact of the contactor remains energized for a time that is not enough for the contactor to reach thermal equilibrium, and the no-load time is enough for the contactor temperature to return to the temperature of the surrounding medium. The standard values of the power-on time of the short-time working system are 3, 10, 30, 60 and 90min. 5.1.8.5 Cycle working system
The cycle working system is a working system that always runs regularly and repeatedly regardless of whether the load is stable or variable. 5.1.9 Normal load and overload characteristics
Article 5.3.5 of GB14048.1 is applicable, supplemented as follows: 5.1.9.1 The ability to withstand the overload current of the motor, see Article 7.2.4.4 for specific requirements. 5.1.9.2 The requirements for the rated making capacity and rated breaking capacity corresponding to different use categories (5.2) are shown in Article 7.2.4.1. The rated making capacity and rated breaking capacity are valid only when the contactor is operated according to the requirements of 7.2.1.
5.1.9.3 Agreed operating performance
The requirements for the agreed operating performance corresponding to different use categories (5.2) are shown in Article 7.2.4.2. 5.1.9.4 Rated limiting short-circuit current
Article 5.3.6.4 of GB14048.1 is applicable.
5.2 Use category
Article 5.4 of GB14048.1 is applicable and supplemented as follows; if the contactor has been tested for a use category or other parameter combination (such as maximum working voltage and current), it can be applied to other use categories without testing as long as the following conditions are met. This condition is: the test current, voltage, power factor, number of operation cycles, closing and opening time and other customer parameters given in Tables 6 and 7 and the test circuit of the selected use category are not more severe than the use category of the contactor that has been tested, and the current of the verification temperature rise test that has been carried out is not lower than the rated working current of the selected use category under the long-term working system.
5.3 Control circuit
Article 5.5 of GB14048.1 applies
5.4 Auxiliary circuit
Article 5.6 of GB14048.1 applies
5.S Coordination with short-circuit protection device (SCPD) The coordination between contactor and short-circuit protection device (SCPD) is indicated by the type, rated value and characteristic value of SCPD. Specific requirements are given in Article 7.2.5.1 of this standard and Article 5.8 of GB14048.1. 5.6 Overvoltage of switching operation
Article 5.9 of GB14048.1 applies.
5.7 Limit breaking capacity
The limit breaking capacity of contactor enables contactor to have certain ability to protect circuit from overload or fault, so that it is easy to coordinate with short-circuit protection device (SCPD) in terms of protection characteristics. 6 Normal working conditions and installation cases
6.1 Normal working conditions
6.1.1 Ambient air temperature
a. Upper limit, not more than +40℃;
b. Lower limit, not less than -5℃;
c. 24h average value, not more than +35℃. JB/T7122-1993
Note: The lower limit of ambient air temperature is -10℃ and below, and the working conditions of the upper limit of ambient air temperature exceeding +40℃ shall be specified separately by specific products. 6.1.2 Altitude
The altitude of the contactor installation site shall not exceed 2000m, but the contactor with voltage above 1200V shall not exceed 1000m. 6.1.3 Atmospheric conditions
The relative humidity of the air shall not exceed 50% when the maximum temperature is +40℃. Higher relative humidity is allowed at lower temperatures. For example, when the average minimum temperature of the wettest month is +25℃, the average maximum relative humidity is 90%. Taking into account the dew on the surface of the product due to temperature changes,
6.1.4 Pollution level
The pollution level of the contactor is specified as level 3, but it can also be specified as other pollution levels. This depends on the micro-environment of all factors affecting insulation in the contact, and will also affect the selection of the electrical clearance and creepage distance of the contactor. 6.2 Installation conditions
6.2.1 Installation category (overvoltage category)
The installation category of the contactor is specified as the sub-category, but it can also be specified as other categories. 6.2.2 Installation requirements
The installation requirements of the contactor are specified by the specific product standards. 7 Structural and performance requirements
7.1 Structural requirements
7.1.1 Materials
Article 7.1.1 of GB14048.1 is applicable
7.1.2 Current-carrying parts and their connections
Article 7.1.2 of GB14048.1 is applicable
7.1.3 Electrical clearance and creepage distance
This standard recommends that the electrical clearance be determined by the rated impulse withstand voltage and the installation category, and the electrical clearance be determined by the rated insulation voltage (or actual working voltage), pollution degree and insulation material group. For contactors with rated impulse withstand voltage values specified in specific product standards, the minimum values of electrical clearance and creepage distance are shown in 3.1.2 and 3.2.3 of IEC664-1. For contactors with rated impulse withstand voltage values not specified in specific product standards, the values of electrical clearance and creepage distance are shown in Appendix A of this standard. For the classification of insulating material groups and their comparative tracking index (CTI), please refer to Article 7.1.3.2 of GB14048.1. The above provisions do not include the interior of the vacuum interrupter. 7.1.4 Terminals
It is recommended that the terminals can be connected to the conductors with screws, or they can be connected to the conductors with elastic connections or other equivalent measures to ensure that the necessary contact pressure is maintained permanently without damaging the wires and terminals. The position of the terminals should ensure that the heat dissipated by the contactor does not damage the insulation of the external connecting wires. The structure of the terminals should not allow the connecting wires to shift, or produce movements that are harmful to the operation of the contactor or reduce the insulation level of the specified installation category. 7.1.5 Grounding requirements
The metal housing of the contactor must have a protective grounding terminal, which should be placed in a place that is easy to wire, and the contactor should remain grounded when the movable part of the contactor is moved away. The grounding terminal should have appropriate anti-corrosion protection, and the grounding terminal should be marked with a clear, firm and durable grounding symbol③. The minimum size of the grounding screw should not be less than the provisions in Table 1. 6
Contactor's agreed heating current
200<≤630
6301000
7.1.6 Contactor housing
Article 7.1.10 of GB14048.1 applies
Contactor housing protection levelbzxZ.net
JB/T7122-1993
Table 1 Minimum size of grounding screw
If the contactor has a housing, its protection level and test method are shown in GB/T4942.2 . 7.1.8 Vibration and shock resistance requirements for contactors Article 7.1.12 of GB14048.1 applies.
7.2 Performance requirements
7.2.1 Action (operation) conditions
Minimum size of grounding screw
Electromagnetic operation and electro-pneumatic operation contactors should be able to reliably attract in the ambient air temperature range of -5℃ to +40℃. The control power supply voltage is 85% to 110% of the rated value (U.). This action range is applicable to AC and DC. Pneumatic contactors and electro-pneumatic contactors should be reliably attracted in the range of 85% to 110% of the rated pressure. When the attraction action range is as specified above, the value of 85% should be used to indicate the lower limit of the attraction action range, and the value of 110% should be used as the upper limit.
For lock-type contactors, the attraction action limit value shall be negotiated by the supply and demand parties. The release voltage of electromagnetically operated and electrically controlled pneumatically operated contactors shall not be higher than 75% of the rated control power supply voltage (U.), and its release voltage shall not be lower than 20%U. at AC and rated frequency, and shall not be lower than 10%U for DC. Pneumatic or electrically controlled pneumatic contactors shall be released within the range of 75% to 10% of the rated air pressure. When the release action range is as specified above, the value of 20% or 10% shall be used to indicate the upper limit of the release action range, and the value of 75% shall be used as the lower limit.
For the action line circle, the release voltage limit value applicable when the line medical circuit resistance is equal to the resistance obtained at -5°C can be verified by calculation based on the resistance measured at normal ambient temperature. When the contactor is used in other specific occasions such as mines, its action conditions are specified by specific product standards. For example, contactors used in coal mines should be able to reliably attract when the control power supply voltage is within the range of 75% to 110% of the rated value. For AC and DC magnetic systems, the DC magnetic system conditions shall be evaluated. 7.2.2 Temperature rise
The temperature rise of each component of the contactor shall not exceed the following relevant specified values when the temperature rise test is carried out under specified conditions. The temperature rise of the contactor components under normal use conditions may differ from the test values, depending on the installation conditions and the size of the connecting conductors.
The temperature rise limits specified below apply to new and intact contactors. If there are differences in the test conditions or the size (or volume) of the device is very small, the product standard may specify different temperature rise limits, but not exceeding the temperature rise limit value of 10K specified in Table 2. 7.2.2.1 Temperature rise of the wiring terminals
The temperature rise of the wiring terminals shall not exceed the specified values in Table 2. Bare copper
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver-plated or nickel-plated
Other metals
JB/T7122—1993
Temperature rise limit of terminal
Note: 1) The temperature rise limit of terminal 70K is determined based on PVC cable, 2) The temperature or limit is determined based on the use experience and life test, but should not exceed 65K. 7.2.2.2 Ambient air temperature
Temperature rise limit
The temperature rise limit specified in Table 2 is only applicable to the ambient air temperature within the range specified in Article 6.1.1. 7.2.2.3 Main circuit temperature rise
The main circuit of the contactor should be able to carry its agreed heating current and be tested according to the specified test method. Its temperature rise should not exceed the temperature rise limit specified in Table 2.
7.2.2.4 Temperature rise of control circuit
The control circuit of the contactor fuse (including the control circuit appliances used for closing and opening operations) should be allowed to operate normally under the rated working system. The temperature rise should not exceed the temperature rise limit specified in Table 2 when tested according to the specified test method. 7.2.2.5 Temperature rise of coil and electromagnet windings The coil and electromagnet windings should be able to withstand their rated voltage (AC at rated frequency) when the main circuit is energized. The temperature rise should not exceed the temperature rise limit specified in Table 3 when tested according to the specified test method. Note: This requirement does not apply to pulse-operated coils, whose operating conditions shall be specified separately by the manufacturer. Table 3 Temperature rise limit of insulated coils
Insulating material
Heat resistance grade
Temperature rise limit measured by resistance method
Wire in air
Note: The temperature rise limit of the wire in air is recommended under the condition of an annual average air temperature of +20°C. For insulated coils under conditions where the annual average temperature exceeds +20°C, the supply and demand parties shall negotiate.
7.2.2.6 Temperature rise of auxiliary circuits
The auxiliary circuit (including auxiliary switch) of the contactor shall be able to carry its agreed heating current and be tested according to the specified test method. Its temperature rise shall not exceed the temperature rise limit specified in Table 2. If the auxiliary circuit becomes a component of the contactor (already equipped in operation), its test can be carried out together with the main electrical appliance, but the actual current used is passed.
7.2.2.7 Other components
The temperature rise obtained by testing other components of the contactor according to the specified test method should not endanger the current-carrying parts and adjacent parts of the contactor, especially when it comes to insulating materials. The relevant product standards should refer to the heat resistance classification of insulating materials (see Table 3) to determine the temperature rise limit of other components of the contactor.
7.2.3 Dielectric properties
JB/T7122-1993
Contactor It should be able to withstand the dielectric test requirements specified in Article 8.2.3.3 of this standard. 7.2.3.1 Requirements for rated impulse withstand voltage The rated impulse withstand voltage of the contactor is used to verify the dielectric properties of the contactor. The rated impulse withstand voltage of the contactor should be determined according to the highest relative voltage to ground in the expected power supply system and the highest installation category. The recommended rated impulse withstand voltage values for contactors with installation category II are selected from Table 4. For other installation categories, Article 7.1.3.1.2 of IEC664-1 applies. For ungrounded systems or one-phase grounded systems, the relative phase voltage should be considered as the relative ground voltage. Table 4 has a pass In the insulation coordination system with overvoltage limitation usually specified, for installation category II, the corresponding relationship between the relative ground voltage determined by the rated voltage of the power supply system and the rated impulse withstand voltage is the maximum relative ground voltage (effective value) determined by the power supply system
The priority value of impulse withstand voltage is determined by the clause
(1.2/50μS of Ume) kV
Note: The rated impulse withstand voltage values in Table 4 refer to the priority values at an altitude of 2000m for power supply systems of 1200V and below, and to the priority values at an altitude of 1000m for power supply systems above 1200V. For the correction methods at different altitudes, refer to IEC664-1 and GB311.1, the provisions of GB14048.1 7.2.3.1 for impulse withstand voltage waveform are applicable. 7.2.3.2 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify the rated impulse withstand voltage (U) but clearly specify that the power frequency withstand voltage is allowed. The relationship between the test voltage value of the power frequency withstand voltage and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
60) should be able to be reliably attracted within the range of 85% to 110% of the rated pressure. This action range is applicable to AC and DC. Pneumatic contactors and electric pneumatic contactors should be reliably attracted within the range of 85% to 110% of the rated pressure. When the attraction action range is as specified above, the value of 85% should be used to indicate the lower limit of the attraction action range, and the value of 110% should be used as the upper limit.
For lock-type contactors, the attraction action limit value shall be negotiated by the supply and demand parties. The release voltage of electromagnetically operated and electrically controlled pneumatically operated contactors shall not be higher than 75% of the rated control power supply voltage (U.), and its release voltage shall not be lower than 20%U. at AC and rated frequency, and shall not be lower than 10%U for DC. Pneumatic or electric pneumatic contactors should be released within the range of 75% to 10% of the rated pressure. When the release action range is as specified above, the value of 20% or 10% shall be used to indicate the upper limit of the release action range, and the value of 75% shall be used as the lower limit.
For the action line circle, the release voltage limit value applicable when the line medical circuit resistance is equal to the resistance obtained at -5°C can be verified by calculation based on the resistance measured at normal ambient temperature. When the contactor is used in other specific occasions such as mines, its action conditions are specified by specific product standards. For example, the contactor used in coal mines should be able to reliably attract when the control power supply voltage is 75% to 110% of the rated value. For AC and DC magnetic systems, the DC magnetic system conditions shall be assessed. 7.2.2 Temperature rise
The temperature rise of each component of the contactor under the specified conditions shall not exceed the following relevant specified values. The temperature rise of the contactor components under normal use conditions may differ from the test values, depending on the installation conditions and the size of the connecting conductors.
The temperature rise limits specified below apply to new and intact contactors. If there are differences in test conditions or the size (or volume) of the device is very small, the product standard may specify different temperature rise limits, but the temperature rise limit value specified in Table 2 shall not exceed 10K. 7.2.2.1 Temperature rise of terminals
The temperature rise of terminals shall not exceed the value specified in Table 2. Bare copper
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver-plated or nickel-plated
Other metals
JB/T7122—1993
Temperature rise limit of terminals
Note: 1) The temperature rise limit of 70K for terminals is determined based on PVC cables, 2) The temperature or limit is determined based on usage experience and life tests, but should not exceed 65K. 7.2.2.2 Ambient air temperature
Temperature rise limit
The temperature rise limit specified in Table 2 is only applicable to the ambient air temperature within the range specified in 6.1.1. 7.2.2.3 Main circuit temperature rise
The main circuit of the contactor should be able to carry its agreed heating current. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 2.
7.2.2.4 Control circuit temperature rise
The control circuit of the contactor (including the control circuit electrical appliances used for closing and opening operations) should be allowed to operate normally under the rated working system. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 2. 7.2.2.5 Coil and electromagnet winding temperature rise The coil and electromagnet winding should be able to withstand its rated voltage (AC at rated frequency) when the main circuit is energized. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 3. Note: This requirement does not apply to pulse-operated coils, whose operating conditions shall be specified separately by the manufacturer. Table 3 Temperature rise limits of insulated coils
Insulating materials
Heat resistance grade
Temperature rise limits measured by resistance method
Wire in air
Note: The temperature rise limits of wires in air are recommended under the condition that the annual average temperature of the air is +20°C. For insulated coils under the condition that the annual average temperature exceeds +20°C, the supply and demand parties shall negotiate
7.2.2.6 Temperature rise of auxiliary circuits
The auxiliary circuits (including auxiliary switches) of contactors shall be able to carry their agreed heating currents and be tested according to the specified test methods. The temperature rise shall not exceed the temperature rise limits specified in Table 2. If the auxiliary circuit becomes a component of the contactor (already equipped in operation), its test can be carried out together with the main electrical appliance, but the actual current used is passed.
7.2.2.7 Other components
The temperature rise obtained by testing other components of the contactor according to the specified test method should not endanger the current-carrying parts and adjacent parts of the contactor, especially when it comes to insulating materials. The relevant product standards should refer to the heat resistance classification of insulating materials (see Table 3) to determine the temperature rise limit of other components of the contactor.
7.2.3 Dielectric properties
JB/T7122-1993
Contactor It should be able to withstand the dielectric test requirements specified in Article 8.2.3.3 of this standard. 7.2.3.1 Requirements for rated impulse withstand voltage The rated impulse withstand voltage of the contactor is used to verify the dielectric properties of the contactor. The rated impulse withstand voltage of the contactor should be determined according to the highest relative voltage to ground in the expected power supply system and the highest installation category. The recommended rated impulse withstand voltage values for contactors with installation category II are selected from Table 4. For other installation categories, Article 7.1.3.1.2 of IEC664-1 applies. For ungrounded systems or one-phase grounded systems, the relative phase voltage should be considered as the relative ground voltage. Table 4 has a pass In the insulation coordination system with overvoltage limitation usually specified, for installation category II, the corresponding relationship between the relative ground voltage determined by the rated voltage of the power supply system and the rated impulse withstand voltage is the maximum relative ground voltage (effective value) determined by the power supply system
The priority value of impulse withstand voltage is determined by the clause
(1.2/50μS of Ume) kV
Note: The rated impulse withstand voltage values in Table 4 refer to the priority values at an altitude of 2000m for power supply systems of 1200V and below, and to the priority values at an altitude of 1000m for power supply systems above 1200V. For the correction methods at different altitudes, refer to IEC664-1 and GB311.1, for the provisions on impulse withstand voltage waveform, Article 7.2.3.1 of GB14048.1 is applicable. 7.2.3.2 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify the rated impulse withstand voltage (U) but clearly specify that the power frequency withstand voltage is allowed.
The relationship between the test voltage value of the power frequency withstand voltage and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
60) should be able to be reliably attracted within the range of 85% to 110% of the rated pressure. This action range is applicable to AC and DC. Pneumatic contactors and electric pneumatic contactors should be reliably attracted within the range of 85% to 110% of the rated pressure. When the attraction action range is as specified above, the value of 85% should be used to indicate the lower limit of the attraction action range, and the value of 110% should be used as the upper limit.
For lock-type contactors, the attraction action limit value shall be negotiated by the supply and demand parties. The release voltage of electromagnetically operated and electrically controlled pneumatically operated contactors shall not be higher than 75% of the rated control power supply voltage (U.), and its release voltage shall not be lower than 20%U. at AC and rated frequency, and shall not be lower than 10%U for DC. Pneumatic or electric pneumatic contactors should be released within the range of 75% to 10% of the rated pressure. When the release action range is as specified above, the value of 20% or 10% shall be used to indicate the upper limit of the release action range, and the value of 75% shall be used as the lower limit.
For the action line circle, the release voltage limit value applicable when the line medical circuit resistance is equal to the resistance obtained at -5°C can be verified by calculation based on the resistance measured at normal ambient temperature. When the contactor is used in other specific occasions such as mines, its action conditions are specified by specific product standards. For example, the contactor used in coal mines should be able to reliably attract when the control power supply voltage is 75% to 110% of the rated value. For AC and DC magnetic systems, the DC magnetic system conditions shall be assessed. 7.2.2 Temperature rise
The temperature rise of each component of the contactor under the specified conditions shall not exceed the following relevant specified values. The temperature rise of the contactor components under normal use conditions may differ from the test values, depending on the installation conditions and the size of the connecting conductors.
The temperature rise limits specified below apply to new and intact contactors. If there are differences in test conditions or the size (or volume) of the device is very small, the product standard may specify different temperature rise limits, but the temperature rise limit value specified in Table 2 shall not exceed 10K. 7.2.2.1 Temperature rise of terminals
The temperature rise of terminals shall not exceed the value specified in Table 2. Bare copper
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver-plated or nickel-plated
Other metals
JB/T7122—1993
Temperature rise limit of terminals
Note: 1) The temperature rise limit of 70K for terminals is determined based on PVC cables, 2) The temperature or limit is determined based on usage experience and life tests, but should not exceed 65K. 7.2.2.2 Ambient air temperature
Temperature rise limit
The temperature rise limit specified in Table 2 is only applicable to the ambient air temperature within the range specified in 6.1.1. 7.2.2.3 Main circuit temperature rise
The main circuit of the contactor should be able to carry its agreed heating current. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 2.
7.2.2.4 Control circuit temperature rise
The control circuit of the contactor (including the control circuit electrical appliances used for closing and opening operations) should be allowed to operate normally under the rated working system. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 2. 7.2.2.5 Coil and electromagnet winding temperature rise The coil and electromagnet winding should be able to withstand its rated voltage (AC at rated frequency) when the main circuit is energized. When tested according to the specified test method, its temperature rise should not exceed the temperature rise limit specified in Table 3. Note: This requirement does not apply to pulse-operated coils, whose operating conditions shall be specified separately by the manufacturer. Table 3 Temperature rise limits of insulated coils
Insulating materials
Heat resistance grade
Temperature rise limits measured by resistance method
Wire in air
Note: The temperature rise limits of wires in air are recommended under the condition that the annual average temperature of the air is +20°C. For insulated coils under the condition that the annual average temperature exceeds +20°C, the supply and demand parties shall negotiate
7.2.2.6 Temperature rise of auxiliary circuits
The auxiliary circuits (including auxiliary switches) of contactors shall be able to carry their agreed heating currents and be tested according to the specified test methods. The temperature rise shall not exceed the temperature rise limits specified in Table 2. If the auxiliary circuit becomes a component of the contactor (already equipped in operation), its test can be carried out together with the main electrical appliance, but the actual current used is passed.
7.2.2.7 Other components
The temperature rise obtained by testing other components of the contactor according to the specified test method should not endanger the current-carrying parts and adjacent parts of the contactor, especially when it comes to insulating materials. The relevant product standards should refer to the heat resistance classification of insulating materials (see Table 3) to determine the temperature rise limit of other components of the contactor.
7.2.3 Dielectric properties
JB/T7122-1993
Contactor It should be able to withstand the dielectric test requirements specified in Article 8.2.3.3 of this standard. 7.2.3.1 Requirements for rated impulse withstand voltage The rated impulse withstand voltage of the contactor is used to verify the dielectric properties of the contactor. The rated impulse withstand voltage of the contactor should be determined according to the highest relative voltage to ground in the expected power supply system and the highest installation category. The recommended rated impulse withstand voltage values for contactors with installation category II are selected from Table 4. For other installation categories, Article 7.1.3.1.2 of IEC664-1 applies. For ungrounded systems or one-phase grounded systems, the relative phase voltage should be considered as the relative ground voltage. Table 4 has a pass In the insulation coordination system with overvoltage limitation usually specified, for installation category II, the corresponding relationship between the relative ground voltage determined by the rated voltage of the power supply system and the rated impulse withstand voltage is the maximum relative ground voltage (effective value) determined by the power supply system
The priority value of impulse withstand voltage is determined by the clause
(1.2/50μS of Ume) kV
Note: The rated impulse withstand voltage values in Table 4 refer to the priority values at an altitude of 2000m for power supply systems of 1200V and below, and to the priority values at an altitude of 1000m for power supply systems above 1200V. For the correction methods at different altitudes, refer to IEC664-1 and GB311.1, the provisions of GB14048.1 7.2.3.1 for impulse withstand voltage waveform are applicable. 7.2.3.2 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify the rated impulse withstand voltage (U) but clearly specify that the power frequency withstand voltage is allowed. The relationship between the test voltage value of the power frequency withstand voltage and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
601 Temperature rise of the terminal
The temperature rise of the terminal shall not exceed the value specified in Table 2. Bare copper
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver-plated or nickel-plated
Other metals
JB/T7122—1993
Temperature rise limit of terminal
Note: 1) The temperature rise limit of the terminal 70K is determined based on PVC cable, 2) The temperature or limit is determined based on the use experience and life test, but should not exceed 65K. 7.2.2.2 Ambient air temperature
Temperature rise limit
The temperature rise limit specified in Table 2 is only applicable to the range where the ambient air temperature meets the requirements of Article 6.1.1. 7.2.2.3 Temperature rise of main circuit
The main circuit of the contactor shall be able to carry its agreed heating current. When tested according to the specified test method, its temperature rise shall not exceed the temperature rise limit specified in Table 2.
7.2.2.4 Temperature rise of control circuit
The control circuit of the contactor (including the control circuit electrical appliances used for closing and opening operations) shall be allowed to operate normally under the rated working system. When tested according to the specified test method, its temperature rise shall not exceed the temperature rise limit specified in Table 2. 7.2.2.5 Temperature rise of coil and electromagnet windings The coil and electromagnet windings shall be able to withstand their rated voltage (AC at rated frequency) when the main circuit is energized. When tested according to the specified test method, their temperature rise shall not exceed the temperature rise limit specified in Table 3. Note: This requirement does not apply to pulse-operated coils, whose operating conditions shall be specified separately by the manufacturer. Table 3 Temperature rise limits of insulated coils
Insulating materials
Heat resistance grade
Temperature rise limits measured by resistance method
Wire in air
Note: The temperature rise limits of wires in air are recommended under the condition that the annual average temperature of the air is +20°C. For insulated coils under the condition that the annual average temperature exceeds +20°C, the supply and demand parties shall negotiate
7.2.2.6 Temperature rise of auxiliary circuits
The auxiliary circuits (including auxiliary switches) of contactors shall be able to carry their agreed heating currents and be tested according to the specified test methods. The temperature rise shall not exceed the temperature rise limits specified in Table 2. If the auxiliary circuit becomes a component of the contactor (already equipped in operation), its test can be carried out together with the main electrical appliance, but the actual current used is passed.
7.2.2.7 Other components
The temperature rise obtained by testing other components of the contactor according to the specified test method should not endanger the current-carrying parts and adjacent parts of the contactor, especially when it comes to insulating materials. The relevant product standards should refer to the heat resistance classification of insulating materials (see Table 3) to determine the temperature rise limit of other components of the contactor.
7.2.3 Dielectric properties
JB/T7122-1993
Contactor It should be able to withstand the dielectric test requirements specified in Article 8.2.3.3 of this standard. 7.2.3.1 Requirements for rated impulse withstand voltage The rated impulse withstand voltage of the contactor is used to verify the dielectric properties of the contactor. The rated impulse withstand voltage of the contactor should be determined according to the highest relative voltage to ground in the expected power supply system and the highest installation category. The recommended rated impulse withstand voltage values for contactors with installation category II are selected from Table 4. For other installation categories, Article 7.1.3.1.2 of IEC664-1 applies. For ungrounded systems or one-phase grounded systems, the relative phase voltage should be considered as the relative ground voltage. Table 4 has a pass In the insulation coordination system with overvoltage limitation usually specified, for installation category II, the corresponding relationship between the relative ground voltage determined by the rated voltage of the power supply system and the rated impulse withstand voltage is the maximum relative ground voltage (effective value) determined by the power supply system
The priority value of impulse withstand voltage is determined by the clause
(1.2/50μS of Ume) kV
Note: The rated impulse withstand voltage values in Table 4 refer to the priority values at an altitude of 2000m for power supply systems of 1200V and below, and to the priority values at an altitude of 1000m for power supply systems above 1200V. For the correction methods at different altitudes, refer to IEC664-1 and GB311.1, for the provisions on impulse withstand voltage waveform, Article 7.2.3.1 of GB14048.1 is applicable. 7.2.3.2 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify the rated impulse withstand voltage (U) but clearly specify that the power frequency withstand voltage is allowed.
The relationship between the test voltage value of the power frequency withstand voltage and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
601 Temperature rise of the terminal
The temperature rise of the terminal shall not exceed the value specified in Table 2. Bare copper
Bare brass
Copper (or brass) tinned
Terminal material
Copper (or brass) silver-plated or nickel-plated
Other metals
JB/T7122—1993
Temperature rise limit of terminal
Note: 1) The temperature rise limit of the terminal 70K is determined based on PVC cable, 2) The temperature or limit is determined based on the use experience and life test, but should not exceed 65K. 7.2.2.2 Ambient air temperature
Temperature rise limit
The temperature rise limit specified in Table 2 is only applicable to the range where the ambient air temperature meets the requirements of Article 6.1.1. 7.2.2.3 Temperature rise of main circuit
The main circuit of the contactor shall be able to carry its agreed heating current. When tested according to the specified test method, its temperature rise shall not exceed the temperature rise limit specified in Table 2.
7.2.2.4 Temperature rise of control circuit
The control circuit of the contactor (including the control circuit electrical appliances used for closing and opening operations) shall be allowed to operate normally under the rated working system. When tested according to the specified test method, its temperature rise shall not exceed the temperature rise limit specified in Table 2. 7.2.2.5 Temperature rise of coil and electromagnet windings The coil and electromagnet windings shall be able to withstand their rated voltage (AC at rated frequency) when the main circuit is energized. When tested according to the specified test method, their temperature rise shall not exceed the temperature rise limit specified in Table 3. Note: This requirement does not apply to pulse-operated coils, whose operating conditions shall be specified separately by the manufacturer. Table 3 Temperature rise limits of insulated coils
Insulating materials
Heat resistance grade
Temperature rise limits measured by resistance method
Wire in air
Note: The temperature rise limits of wires in air are recommended under the condition that the annual average temperature of the air is +20°C. For insulated coils under the condition that the annual average temperature exceeds +20°C, the supply and demand parties shall negotiate
7.2.2.6 Temperature rise of auxiliary circuits
The auxiliary circuits (including auxiliary switches) of contactors shall be able to carry their agreed heating currents and be tested according to the specified test methods. The temperature rise shall not exceed the temperature rise limits specified in Table 2. If the auxiliary circuit becomes a component of the contactor (already equipped in operation), its test can be carried out together with the main electrical appliance, but the actual current used is passed.
7.2.2.7 Other components
The temperature rise obtained by testing other components of the contactor according to the specified test method should not endanger the current-carrying parts and adjacent parts of the contactor, especially when it comes to insulating materials. The relevant product standards should refer to the heat resistance classification of insulating materials (see Table 3) to determine the temperature rise limit of other components of the contactor.
7.2.3 Dielectric properties
JB/T7122-1993
Contactor It should be able to withstand the dielectric test requirements specified in Article 8.2.3.3 of this standard. 7.2.3.1 Requirements for rated impulse withstand voltage The rated impulse withstand voltage of the contactor is used to verify the dielectric properties of the contactor. The rated impulse withstand voltage of the contactor should be determined according to the highest relative voltage to ground in the expected power supply system and the highest installation category. The recommended rated impulse withstand voltage values for contactors with installation category II are selected from Table 4. For other installation categories, Article 7.1.3.1.2 of IEC664-1 applies. For ungrounded systems or one-phase grounded systems, the relative phase voltage should be considered as the relative ground voltage. Table 4 has a pass In the insulation coordination system with overvoltage limitation usually specified, for installation category II, the corresponding relationship between the relative ground voltage determined by the rated voltage of the power supply system and the rated impulse withstand voltage is the maximum relative ground voltage (effective value) determined by the power supply system
The priority value of impulse withstand voltage is determined by the clause
(1.2/50μS of Ume) kV
Note: The rated impulse withstand voltage values in Table 4 refer to the priority values at an altitude of 2000m for power supply systems of 1200V and below, and to the priority values at an altitude of 1000m for power supply systems above 1200V. For the correction methods at different altitudes, refer to IEC664-1 and GB311.1, for the provisions on impulse withstand voltage waveform, Article 7.2.3.1 of GB14048.1 is applicable. 7.2.3.2 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify the rated impulse withstand voltage (U) but clearly specify that the power frequency withstand voltage is allowed.
The relationship between the test voltage value of the power frequency withstand voltage and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
602 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify rated impulse withstand voltage (U) but clearly specify that power frequency withstand voltage is allowed.
The relationship between the power frequency withstand voltage test voltage value and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
602 Requirements for power frequency withstand voltage
Power frequency withstand voltage is applicable to verify the dielectric properties of contactors that do not specify rated impulse withstand voltage (U) but clearly specify that power frequency withstand voltage is allowed.
The relationship between the power frequency withstand voltage test voltage value and the rated insulation voltage a.
U. of the main circuit of the contactor and the control circuit and auxiliary circuit connected to the main circuit is listed in Table 5.
Rated insulation voltage
60
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