NF32-SV2P5A Molded Case Circuit Breaker NF32SV2P5A 2P 5A Amp 200V AC Brand New

AF (Ampere Frame) and AT (Ampere Trip) are two distinct ratings. AF refers to the maximum current the breaker's frame, bus connections, and contacts can physically carry and interrupt — the NF32-SV2P5A's 30AF frame is physically rated for 30A. AT refers to the calibrated trip setting — the current level at which the thermal and magnetic elements will trip. The 5AT setting means the NF32-SV2P5A protects a 5A circuit. Both ratings are needed to fully specify an MCCB.

Mitsubishi NF-S series MCCBs are primarily rated for AC applications. DC circuit breakers require specific arc interruption capability since DC arcs do not self-extinguish at current zero crossings the way AC arcs do. If a DC application is planned, confirm from the Mitsubishi NF-S series data sheet whether the NF32-SV2P5A is DC-rated and at what DC voltage the rating applies. Do not assume AC-rated MCCBs are suitable for DC applications without this confirmation.

The thermal element is a bimetallic strip in series with the circuit. Sustained current above the 5A trip rating heats the bimetal, causing it to deflect. When deflection reaches the trip threshold, the mechanism releases and the breaker opens. This response is intentionally time-delayed — it allows brief overloads (motor starting current, inrush) to pass without nuisance tripping while responding to sustained overloads that indicate a real fault.

No tools are required. After a trip, the handle moves to an intermediate position between ON and OFF, indicating a tripped state. To reset, move the handle fully to the OFF position (to reset the mechanism), then back to ON. Before resetting, confirm the fault cause has been identified and corrected — resetting a breaker onto an uncleared fault will cause an immediate re-trip.

The NF32-SV2P5A is a fixed trip unit with a 5AT setting — the trip current is factory-set at 5A and cannot be field-adjusted. Some larger MCCB families offer adjustable thermal and magnetic trip settings through dial or slide adjusters on the front face, but the NF-S standard frame series uses fixed trip units matched to the rated current specified in the ordering code.