contact miniature circuit breaker current arc molded case circuit breaker trip unit rated current breaking capacity breaker failure protection reclosing three-phase voltage bolt low-voltage circuit breaker air switch household appliances electrical appliances common error vacuum circuit breaker motor overvoltage transformer high voltage circuit breaker pressure relay hydraulic principle limit switch safety valve leakage switch circuit breaker selection circuit breaker classification circuit breaker purpose sulfur hexafluoride opening coil operating mechanism iron core circuit breaker failure protection resistance preventive test trip sf6 circuit breaker low voltage circuit breaker energy storage vacuum environment short-circuit current short-circuit capacity wiring plastic case circuit breaker motor controller MCB neutral wires power calculate current relay frame voltage level rated short-time withstand current high-voltage circuit breaker ampacity neutral wire live wire vacuum interrupter insulation class welding arc energy zero line low-voltage circuit breakers battery universal circuit breaker ground wire insulation resistance brand protection substation disconnect switch tripping device household release set current rated voltage phase line high voltage switch cabinet low-voltage electrical appliances control box modulus 1p 2p power supply trip units air switches arc extinguishing principle oil-less circuit breaker electric motor automatic air switch opening time electric motors delay switches circuit breaker maintenance refused to close leakage protection switch electric current tripper three-phase four-wire schematic diagram direct current dc circuit breaker ac circuit breaker circuit loop short circuit delay delay protection 50Hz LCD NDW3-2500 ACB CCC NDW2 AC1000V RoHS CE MCCB NDM5Z DC1200V AC690V NDM5 60Hz NDM5E NDM3 NDM3Z NDM3E NDM3L NDM3G NDM2 DC250V NDM2Z 630A NDM2ZB dc mccb new energy industrial control real estate telecom rail transportation AC400V NDM2E ATS NDQ PIC NDB5 DC80V HMCB UL NDB3-30 NDB6-125 civil buildings communication infrastructure NDB6Z NDB2-63 NDB2-40 NDB2T-63 NDB2Z Reliable wiring Accessories NDB2 NDM1 NDB1-63 NDB1-32 NDB1-40 NDB1-125 CB NDB1L-32 440V NDA high gloss ABS NDP3A NDP3 1.2mm NDP1A NDU SPD 35mm dc mcb ac mcb