WESTINGHOUSE HC series molded case circuit breaker

Core accessory system

The HC series provides a complete field adaptation accessory system, which is easy to install, safe and reliable, and can meet diverse needs such as remote control, signal feedback, and safety locking

Accessory category, specific type, functional description, adaptation framework

Signal feedback auxiliary switch 1NO+1NC conversion contact, used for the full frame of signal feedback for opening/closing status

Alarm switch 1NO contact, output alarm signal when fault trips, full frame

Remote control type shunt release device for remote control of circuit breaker opening, supporting AC/DC multi voltage level full frame

When the voltage of the undervoltage release is insufficient, it automatically opens to protect the equipment from undervoltage damage to the entire frame

Electric opening and closing of motor operating mechanism, supporting local/remote switching operation, with ON/OFF/TRIPPED status indication full frame

The safety lock type padlock handle locks the ON/OFF position to prevent accidental operation, and can hang 3 padlocks (6mm lock tongue) on the entire frame

Install auxiliary plug-in adapters to simplify plug-in installation, including line/load end adapters and installation board F/J/K/L/N frames

Pull out cassette, specifically designed for pull-out installation, includes a secondary terminal block and automatically opens J/K/L/N frame when pulled out

Operation auxiliary rotating handle mechanism for changing operation direction, suitable for cabinet door installation, with a shaft length of 290mm and a full frame

Protective terminal cover with anti misoperation design, reaching IP30 protection level, including short/long specifications for the entire frame

Maintenance and upkeep system

（1） Maintenance cycle and core projects

Key operational points for core projects in the maintenance cycle

Daily appearance inspection+status confirmation check: The appearance of the circuit breaker is free of damage and rust, and the handle position is consistent with the operating status

Weekly current/temperature monitoring records three-phase operating current to ensure no overload; Use an infrared thermometer to measure the terminal temperature. A temperature of ≤ 70 ℃ is considered normal

Mechanical operation inspection+manual opening and closing of terminals 3-5 times per month, with flexible and non jamming movements; Tighten the terminal bolts to prevent loosening and overheating

Insulation resistance testing should be conducted quarterly using a 500VDC megohmmeter to measure insulation resistance, which should be ≥ 100M Ω (calibrated at 40 ℃)

Annual comprehensive functional testing simulates overload and short circuit conditions to verify the reliability of the tripping mechanism action; Check the function of accessories (auxiliary switch, release)

Thoroughly maintain and clean the dust inside the circuit breaker every 3 years; Check the status of bimetallic strips/electronic components and replace them if necessary; Replace aging parts

（2） Key component maintenance details

Maintenance of the release mechanism:

Thermal magnetic type: Regularly clean the dust on the surface of the bimetallic sheet to avoid affecting heat conduction; Check that the magnetic release mechanism is not stuck and operates flexibly.

Electronic: Keep electronic components dry to avoid condensation damage; Regularly verify the tripping accuracy to ensure accurate protection.

Terminal maintenance: Regularly tighten the terminal bolts, especially the copper aluminum conductor connection parts, to prevent oxidation from increasing contact resistance and overheating overload.

Accessory maintenance: Regularly test the reliability of the action of the shunt/undervoltage release device; Clean the contacts of the auxiliary switch to ensure accurate signal feedback; The motor operating mechanism was checked for loose wiring terminals and no abnormal noise during operation.

Environmental maintenance: Keep the installation environment of the circuit breaker dry and ventilated, and avoid the accumulation of dust and oil stains; Strengthen heat dissipation measures in high temperature environments to ensure that equipment operates within the rated temperature range.

Selection Guide and Application Scenarios

（1） Selection core logic

Current matching: Select the rated current of the circuit breaker based on 1.2 times the rated current of the load, ensuring that there is overload redundancy (such as selecting a 63A circuit breaker for a 50A load).

Breaking capacity matching: Select the breaking capacity based on the level of short-circuit current in the distribution system (such as workshop short-circuit current of 30kA, select models with breaking capacity ≥ 36kA).

Buckling type matching: Choose F-type for load stability, T/TM type for load fluctuation, and LSIG type for precision equipment/important loads.

Installation method matching: Choose fixed type for compact space, insert type for regular maintenance, and pull-out type for important circuits.

Environmental adaptation: Select the 55 ℃ series for high temperature scenarios and the 40 ℃ series for normal scenarios; Strengthen protection in humid environments and choose models with terminal protective covers.