3 Pole MCBs for Three-Phase Circuit Protection
3 pole MCBs provide overcurrent and short-circuit protection across all three live phases of a three-phase supply. They are used in commercial boards, industrial panels, machinery circuits and distribution systems where all phases must disconnect together during a fault.
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Designed for three-phase loads, these breakers ensure simultaneous isolation of L1, L2 and L3, preventing phase imbalance and equipment damage. They are available in a wide range of current ratings and tripping curves to support motors, pumps, compressors, HVAC systems, heating equipment and plant machinery.
- Three-phase protection for balanced and unbalanced loads
- Simultaneous tripping across all three phases
- B and C curve options for different startup behaviours
- High breaking capacities for industrial fault levels
- DIN-rail compatible modules for commercial and industrial boards
3 Pole MCBs are essential wherever three-phase equipment is used and are a standard requirement in workshops, factories, plant rooms and commercial buildings.
WKC 3 Pole 10kA MCB – 40A B Curve (WKC340B)
£21.30
The WKC340B 3 Pole 10kA MCB is a 40A B Curve breaker providing short-circuit and overload protection for three-phase circuits. Built with a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it’s trusted in industrial boards, EV charging setups, and solar PV...
WKC 3 Pole 10kA MCB – 6A C Curve (WKC306C)
£21.30
The WKC306C 3 Pole 10kA MCB is a 6A C Curve breaker designed for protecting three-phase circuits against overload and short-circuit faults. Rated at 10kA breaking capacity and compliant with BS 7671 (18th Edition), it’s ideal for small inductive loads such as EV chargers, motors,...
WKC 3 Pole 10kA MCB – 6A B Curve (WKC306B)
£21.30
The WKC306B 3 Pole 10kA MCB is a compact B Curve breaker rated at 6A, designed to protect three-phase circuits from overload and short-circuit faults. Built with a 10kA breaking capacity, it’s ideal for commercial and industrial distribution boards, EV chargers, and solar PV systems....
WKC 3 Pole 10kA MCB – 63A C Curve (WKC363C)
£21.30
The WKC363C 3 Pole 10kA MCB is a 63A C Curve breaker designed for heavy three-phase circuits that need reliable overload and short-circuit protection. With a 10kA breaking capacity and full compliance with BS 7671 (18th Edition), it’s a trusted choice for industrial boards, EV...
WKC 3 Pole 10kA MCB – 63A B Curve (WKC363B)
£21.30
The WKC363B 3 Pole 10kA MCB is a 63A B Curve breaker engineered to protect heavy-duty three-phase circuits from short-circuit and overload faults. With a robust 10kA breaking capacity and full compliance to BS 7671 (18th Edition), it’s trusted in industrial distribution boards, EV charger...
What Is a 3 Pole MCB?
A 3 pole MCB disconnects all three live conductors at the same time when an overcurrent or short-circuit occurs. This protects three-phase motors and equipment from imbalance damage and ensures safe isolation of the entire circuit.
Where 3 Pole MCBs Are Used
- Three-phase distribution boards in commercial and industrial buildings
- Motors, pumps and compressors with significant startup demands
- HVAC and ventilation systems requiring stable three-phase supply
- Machinery circuits in workshops, factories and processing plants
- Heaters, welders and plant equipment with fluctuating load profiles
B Curve vs C Curve 3 Pole MCBs
B Curve: Trips at 3–5 × rated current; suitable for light-duty three-phase loads and predictable startup current.
C Curve: Trips at 5–10 × rated current; ideal for motor-driven loads, compressors, pumps and equipment with noticeable inrush.
Benefits of 3 Pole Protection
Three-phase equipment can suffer serious mechanical and electrical damage if only one or two phases disconnect. A 3 pole MCB avoids this by tripping all phases together, ensuring full isolation and preventing phase-loss faults.
- Balanced disconnection prevents equipment strain and overheating
- Reliable performance under heavy or surge-prone loads
- Correct coordination with motor and machinery characteristics
Compliance & Standards
All 3 Pole MCBs in this category comply with BS EN 60898 and meet the requirements of the 18th Edition Wiring Regulations. They are suitable for new installations, commercial upgrades and equipment protection in three-phase environments.
Installer Benefits
3 Pole MCBs give electricians dependable protection for industrial and commercial systems. Their robust construction, predictable tripping characteristics and wide rating options make them ideal for plant equipment, three-phase motors and multi-phase distribution boards.