Industrial and commercial power distribution systems; main service entrance protection for 600 V, 3-phase systems; feeder-circuit protection in heavy-manufacturing facilities; large HVAC and refrigeration installations; any application requiring 800 A of bolt-on overcurrent protection with high interrupting capacity.

The breaker employs a molded composite case for structural integrity and insulation. Internally, it uses high-conductivity copper alloy for the current-carrying path, a bimetallic strip for thermal sensing, and an electromagnetic coil for instantaneous magnetic trip action. The contacts are designed for arc interruption under high fault current.

Three-pole, bolt-on molded case form factor. The case is constructed of durable thermoset composite material. The front face provides access to the thermal-magnetic trip adjustment and the operating handle. Bolt-on terminals at the rear ensure a secure mechanical and electrical connection to the bus.

Under normal load, current flows through the bimetallic strip and electromagnetic coil with minimal heating. During an overload, the bimetallic strip heats and bends, mechanically releasing the trip mechanism after a time inversely proportional to the overload magnitude (long-time characteristic). During a short circuit, the sudden high current energizes the electromagnetic coil, which instantaneously attracts an armature to trip the mechanism (instantaneous characteristic). Both actions open the contacts, interrupting the current and protecting downstream equipment.

Install in a compatible GE K1200-line switchboard or panel designed for bolt-on THKM frames. De-energize the entire panel before mounting. Securely bolt the breaker to the bus bar using the specified torque values to ensure a low-resistance connection. Verify proper phase alignment across the three poles. Confirm the trip unit is set to the correct rating and characteristics for the protected circuit. Ensure the ambient temperature does not exceed the 40 °C rating; if higher, apply the appropriate derating.

As with all molded case circuit breakers, the THKM836F000C must be applied within its 35 kAIC @ 480 V interrupting rating—do not apply where available fault current exceeds this value. Periodically inspect the bolted connections for tightness, as loose connections generate heat and accelerate deterioration. The breaker is sold as a frame-only assembly; ensure a compatible trip unit is installed before energizing. This is a legacy product; verify availability and lead time with suppliers. Replace the breaker if the operating handle becomes stiff, the trip indicator shows a fault that cannot be reset, or if there is any sign of case cracking or terminal overheating. Always follow lockout/tagout procedures during maintenance.