Miniature Circuit Breakers (MCB)
MK Circuit Protection MCBs are of the thermo-magnetic, current limiting type and are available with either Type B or Type C operating characteristics.
The thermal component is carefully calibrated, thermally operated bi-metal element. Larger overloads and fault current situations are dealt with using the magnetic tripping mode of the MCB. This acts very quickly, overriding the thermal operation.
BS EN 60898 requires the tripping to occur within 100 milliseconds and when short circuit happens and the design of the MK Sentry MCB allows fault currents of up to 6000A (M6) to be safely interrupted within this time-scale.
Positive contact status indication
When the green indicator is visible, then a contact gap of 4mm has been achieved. MK Sentry MCBs may therefore be used as single pole isolating switches where appropriate.
The operating dolly may be locked in either the ON or OFF position without affecting the ability of the trip mechanism to operate. The contacts themselves are manufactured from carefully chosen materials, selected specifically for their low electrical resistance and low propensity to weld under fault conditions.
