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GE THJK436F000-250A
Product Name: GE THJK Series 250A Thermal-Magnetic Molded Case Circuit Breaker
Product Overview: The THJK436F000-250A is an industrial-grade thermal-magnetic molded case circuit breaker (MCCB) produced by GE with a rated current of 250A. It is used for circuit protection in low-voltage power distribution systems, providing both overload and short-circuit protection functions. It is suitable for motor circuits, feeder circuits, and main distribution circuits.
Detailed content
Technical Specifications:
- Brand: GE
- Model: THJK436F000-250A
- Series: THJK Series
- Rated Current: 250 A
- Poles: 3-Pole (3P)
- Rated Insulation Voltage: 690 V AC
- Rated Operating Voltage: 600 V AC
- Rated Short-Circuit Breaking Capacity (Icu): 65 kA @ 480 V AC
- Rated Service Short-Circuit Breaking Capacity (Ics): 50 kA @ 480 V AC
- Trip Unit Type: Thermal-Magnetic
- Overload Trip Setting Range: 160 A ~ 250 A (adjustable)
- Short-Circuit Trip Setting: Fixed, approximately 10×In (2500 A)
- Frame Size: N-Frame (compact molded case circuit breaker)
- Power Consumption: < 15 W at full load
- Mechanical Life: 20,000 operations
- Electrical Life: 10,000 operations at rated load
Functional Features:
- Thermal-magnetic dual trip protection: Thermal trip provides long-delay overload protection, magnetic trip provides instantaneous short-circuit protection
- Overload trip current is field-adjustable to adapt to different load requirements
- Equipped with electric operator interface supporting remote opening/closing
- Front panel clearly displays open/close status and trip cause indication
Structural Features:
- Housing Material: Flame-retardant thermoplastic material (UL94 V-0)
- Front Panel: Open/close handle, trip indicator window, overload setting knob
- Terminals: Top and bottom wiring, bolt connection, maximum conductor size 3/0 AWG (85 mm²)
- Installation: Vertical mounting, supports DIN rail or screw fixing
Working Principle:
- During normal operation, current passes through the thermal trip bimetallic strip and magnetic trip coil
- During overload, the bimetallic strip bends from heating and triggers the trip mechanism to disconnect the circuit
- During short circuit, the magnetic trip coil generates strong magnetic force, instantly pushing the trip mechanism to disconnect the circuit
Installation Requirements:
- Install vertically inside the distribution cabinet with consistent top-bottom wiring direction
- Connect the power supply side to the input terminal and load side to the output terminal
- The grounding terminal must be reliably connected to protective earth
- Sufficient heat dissipation space must be maintained around, with vertical spacing not less than 50 mm
- Operating environment temperature: -25°C to +70°C
- Altitude not exceeding 2000 m (derating required above this)
Usage Notes:
- Regularly check the tightness of terminal connections to prevent excessive contact resistance
- The trip setting must never exceed the rated current of 250 A
- After short-circuit breaking, the contact condition must be checked before reclosing
- Applicable Industries: Power plant auxiliary power systems, industrial distribution, building distribution, petrochemical plant distribution, data center distribution
