Choosing the Right MCB for Your Electrical Panel
MCB ratings, curve types, and pole counts explained — what actually matters when specifying protection for a commercial or industrial panel.
Miniature Circuit Breakers (MCBs) are the most common protection device in any distribution board, but getting the spec wrong is one of the most frequent mistakes we see on incoming BOQs.
Curve Type Matters More Than Amperage
A 32A Type C breaker and a 32A Type B breaker aren't interchangeable. Type B trips on lower inrush current and suits resistive loads like lighting and heating. Type C tolerates higher inrush and is the standard choice for motors, transformers, and most general power circuits. Specifying the wrong curve type causes nuisance tripping — not a fault, just an undersized trip threshold for the load's startup current.
Pole Count and System Type
Single-phase circuits need single-pole MCBs; three-phase distribution boards need triple-pole (or four-pole with neutral switching, depending on your earthing system). Mixing this up at the design stage is a common source of late-stage panel rework.
RCCB and SPD Pairing
An MCB alone protects against overcurrent and short-circuit, not earth leakage. Pairing with an RCCB (residual current device) is standard practice for final circuits, and a Type 2 surge protection device at the board level is increasingly specified for sites with sensitive electronic equipment.
What We Stock
Our MCB range covers single and triple-pole configurations from 6A to 63A, C-curve as standard, alongside RCCBs and SPDs sized to match. All units ship with full batch traceability for your compliance records.