CJM1-250L/3300 250A 400V/690V China Factory Electric MCCB Moulded Case Circuit Breaker

Application CJMM1 series moulded case circuit breaker(hereinafter referred to as circuit breaker) is pplicable for AC 50/60HZ power distribution network circuit with rated insulation voltage of 800V, rated operation voltage of 690V and rated operation current from 10A to 630A, it's used to distribute power and prevent circuit and power supply equipment from damage due to overload, short circuit, under voltage and other faults, it's also used for infrequent start of motor as well as overload, short circuit and under voltage protection.This circuit breaker owns advantages of small volume, high breaking capacity, short arcing (or noarcing)etc, it can be equipped with accessories like alarm contact, shunt release, auxiliary contact etc, it's an ideal product for user. The residual current circuit breaker can either be vertically installed (vertical installation) or be horizontally installed (horizontal installation) The product is in accordance with the standards of IEC60947-2 and Gb140482

Products Details

Product Model

CJ:Enterprise code M:Moulded case circuit breaker 1:Design No □:Rated current of frame □:Breaking capacity characteristic code/S denotes standard type (S can be omitted)H denotes higher type Note: There are four types of neutral pole (N pole) for four phases product.The neutral pole of type A is not equipped with over-current tripping element, its always switched on, and it is not switched on or off together with other three poles. The neutral pole of type B is not equipped with over-current tripping element, and it's switched on or off together with other three poles(the neutral pole is switched on before being switched off)The neutral pole of type C is equipped with over-current tripping element, and it's switched on or off together with other three poles(the neutral pole is switched on before being switched off) The neutral pole of type D is equipped with over-current tripping element, it's always switched on and is not switched on or off together with other three poles.

Table 1

Accessory name Electronic release Compound release
Auxiliary contact,under voltage release,alam contact 287 378
Two auxiliary contact sets,alarm contact 268 368
Shunt release, alarm contact, auxiliary contact 238 348
Under voltage release,alarm contact 248 338
Auxiliary contact alarm contact 228 328
Shunt release alarm contact 218 318
Auxiliary contact under-voltage release 270 370
Two auxiliary contact sets 260 360
Shunt release under-voltage release 250 350
Shunt release auxiliary contact 240 340
Under-voltage release 230 330
Auxiliary contact 220 320
Shunt release 210 310
Alarm contact 208 308
No accessory 200 300


  • By breaking capacity: a standard type(type S) b higher breaking capacity type(type H)
  • By connection mode: a front board connection, b back board connection, c plugin type
  • By operation mode: a direct handle operation, b rotation handle operation,c electrical operation
  • By number of poles: 1P, 2P, 3P, 4P
  • By accessory: alarm contact, auxiliary contact, shunt release, under voltage release

Normal Service Condition

  • The altitude of the installation site shall not exceed 2000m
  • Ambient air temperature
  • The ambient air temperature shall not exceed +40℃
  • The average value shall not exceed +35℃ with in 24 hours
  • The ambient air temperature shall not be less than -5℃
  • Atmosphere condition:
  • 1There lative humidity of atmosp here shall not exceed 50% at highest temperature of +40℃,and it can be higher atalower temperature,when theaver agelowest temperature in the wettest month doesn't exceed 25℃ can be 90%,conden sationon product surfacedue to temperature change must be takenin to account.
  • The pollution level is class 3

Main Technical Parameter

1 Rated value of circuit breakers
Model Imax (A) Specifications (A) Rated Operation Voltage(V) Rated Insulation Voltage(V) Icu (kA) Ics (kA) Number of Poles (P) Arcing Distance (mm)
CJMM1-63S 63 6,10,16,20 25,32,40, 50,63 400 500 10* 5* 3 ≤50
CJMM1-63H 63 400 500 15* 10* 3,4
CJMM1-100S 100 16,20,25,32 40,50,63, 80,100 690 800 35/10 22/5 3 ≤50
CJMM1-100H 100 400 800 50 35 2,3,4
CJMM1-225S 225 100,125, 160,180, 200,225 690 800 35/10 25/5 3 ≤50
CJMM1-225H 225 400 800 50 35 2,3,4
CJMM1-400S 400 225,250, 315,350, 400 690 800 50/15 35/8 3,4 ≤100
CJMM1-400H 400 400 800 65 35 3
CJMM1-630S 630 400,500, 630 690 800 50/15 35/8 3,4 ≤100
CJMM1-630H 630 400 800 65 45 3
Note: When the test parameters for the 400V, 6A without heating release
2 Inverse time breaking operation characteristic when each pole of overcurrent release for power distribution is powered on at the same time
Item of test Current (I/In) Test time area Initial state
Non-tripping current 1.05In 2h(n>63A),1h(n<63A) Cold state
Tripping current 1.3In 2h(n>63A),1h(n<63A) Proceed immediately after No.1 test
3 Inverse time breaking operation characteristic when each pole of over- current release for motor protection is powered on at the same time.
Setting Current Conventional time Initial State Note
1.0In >2h Cold State
1.2In ≤2h Proceeded immediately after the No.1 test
1.5In ≤4min Cold State 10≤In≤225
≤8min Cold State 225≤In≤630
7.2In 4s≤T≤10s Cold State 10≤In≤225
6s≤T≤20s Cold State 225≤In≤630
4 The instantaneous operation characteristic of circuit breaker for power distribution shall be set as 10in+20%, and the one of circuit breaker for motor protection shall be set as12ln±20%

Characteristics of MCCBs

MCCBs are designed with several functions that help protect electrical systems in a safe and reliable manner. Some key features of the MCCB include: High breaking capacity: Molded case circuit breakers are capable of breaking currents up to thousands of amperes, making them ideal for high-power applications. Thermal-magnetic trip mechanism: Molded case circuit breakers use a thermal-magnetic trip mechanism to detect and respond to overcurrent and short circuits. Thermal trip elements respond to overloads, while magnetic trip elements respond to short circuits. Adjustable Trip Setting: MCCBs have an adjustable trip setting, which allows them to be set to the appropriate level for the desired application. Wide range of frame sizes: MCCBs are available in a variety of frame sizes, which allows them to be used in a variety of applications.Working principle of molded case circuit breaker The operating principle of the MCCB is based on a thermal-magnetic tripping mechanism. The thermal trip element senses the heat generated by the flow of current in the circuit and trips the circuit breaker when the current exceeds the trip rating. The magnetic trip element senses the magnetic field generated by a short circuit in the circuit, tripping the circuit breaker almost immediately.Structure of molded case circuit breaker The MCCB consists of a molded plastic housing that houses the trip mechanism, contacts and current carrying parts. The contacts are made of a highly conductive material such as copper, while the trip mechanism consists of a bimetallic strip and a magnetic coil.  

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