The MK Sentry range features solid neutral type single pole RCBOs in one module format. The one module MK Sentry RCBOs are a combination of a Type B/C MCB and a Residual Current Device. This enables both overcurrent protection and earth fault current protection to be provided by a single unit.

This combination allows earth fault protection to be restricted to a single circuit, thus ensuring that only the circuit with the fault is interrupted. (When groups of circuits are protected by an RCD, all circuits would be interrupted under fault conditions, which may cause unnecessary inconvenience).

The operating switch on all MK Sentry RCBOs may be locked in either the ON or OFF position without affecting the ability of the trip mechanism to operate.

MK Sentry RCBOs feature tunnel terminals of generous capacity, with 25mm2 for live supply terminals and 10mm2 for live and neutral load terminals. The neutral supply (blue) and earth supply (white/cream) are provided via flying leads.