CHINT NM1-250S/3300 MCCB | 3 Pole 225A Circuit Breaker

The CHINT NM1-250S/3300 Molded Case Circuit Breaker (MCCB), 3-Pole, 225-Amp is a reliable and high-performance circuit protection device. This MCCB is standard breaking type (‘S’ type) and is meant to safeguard electrical circuits from overload and short-circuit and ensure continuity of operation in tough situations. Large switchboard, motor control centre or maritime distribution panel, engineers know they can rely on the uncompromising durability and quick thermal-magnetic responsiveness of the NM1 series.

Model Nomenclature Breakdown: NM1-250S/3300

• NM1: Series Code (Molded Case Circuit Breaker)
• 250: Frame Size (Up to 250A maximum capacity)
• S: Breaking Capacity Level (Standard Capacity)
• 3: Number of Poles (3 Poles)
• 300: Release Type & Internal Accessories

Technical Details:

Our Engineer’s Insight:

1. In the engine room, ambient temperatures can fluctuate drastically. The NM1-250S/3300 handles thermal stress exceptionally well, but remember that its trip characteristics are calibrated at a standard ambient temperature (usually 40°C). When mounting this inside a tightly packed, non-air-conditioned engine room panel, always apply the appropriate temperature derating factors to prevent nuisance tripping.
2. Torque Settings: Marine vibrations are notorious for loosening electrical connections. When installing and doing the annual surveys, always use a calibrated torque wrench and torque the terminal lugs to the exact specifications specified by CHINT. Loose connections lead to micro-arc overloads and localized heating.
3. Insulation Resistance(IR) Test Megger the insulation before commissioning or after a long layup. Take off the circuit breaker. If retrofitted, do not apply test voltages to any electronic auxiliary components.