WNB1-63 3P MCB 6kA Three Pole Circuit Breaker

The Westhomes WNB1-63 3P MCB is a three-pole miniature circuit breaker designed for three-phase low-voltage electrical systems. It provides thermomagnetic protection against overloads and short circuits across three phase conductors, making it suitable for commercial and light industrial applications.

3P means the circuit breaker has three poles and is designed to switch and protect three phase conductors, typically L1, L2, and L3. It is commonly used in three-phase systems where a neutral conductor does not need to be switched.

The WNB1-63 series is available with a rated short-circuit breaking capacity of up to 6kA. The appropriate breaking capacity should be selected according to the prospective short-circuit current at the installation point.

The WNB1-63 series provides multiple rated current options from 1A to 63A, including 6A, 10A, 16A, 20A, 25A, 32A, 40A, 50A, and 63A. The correct rating should be selected according to the load current and cable carrying capacity.

The WNB1-63 series has a rated operational voltage of 240/415V AC and operates at 50/60Hz, making it suitable for common three-phase low-voltage distribution systems.

The WNB1-63 series is available with B, C, and D magnetic tripping characteristics:

B Curve: 3–5 × In

C Curve: 5–10 × In

D Curve: 10–20 × In

B curve is generally suitable for low-inrush loads, C curve for general-purpose loads, and D curve for high-inrush loads such as motors and transformers.

Yes. The WNB1-63 3P MCB can be used for three-phase motor applications. For motors with high starting currents, the D-curve version is generally more suitable because its magnetic tripping range is higher and can help reduce nuisance tripping during motor startup.

A 3P MCB protects and switches three phase conductors, while a 4P MCB adds a fourth pole for the neutral conductor. A 3P breaker is generally suitable when only the three phases need to be switched, while a 4P configuration may be selected when neutral switching or isolation is required.

The WNB1-63 is designed for installation on a standard 35mm DIN rail, making it suitable for modular distribution boards and electrical switchgear. It supports cable and pin-type busbar connections, with terminals that can be connected from the top or bottom.

Selection should consider the system voltage, load current, cable capacity, prospective short-circuit current, load characteristics, and required tripping curve. The rated current should be coordinated with the protected cable, while the 6kA breaking capacity must be suitable for the available fault current.

For general three-phase loads, a C-curve version is commonly considered. For motors, pumps, transformers, and other high-inrush loads, a D-curve version may be more appropriate.