The 1X30 relay is comprised of two electromechanical relays which are wired across the protection trip contact and the circuit breaker 52a and 52b pallet switches. This results in the alarm relay being normally energized provided the trip supply, the trip circuit and the circuit breaker coil are all healthy. Failure of the trip supply, the circuit under supervision or the CB coil will cause the alarm relay to be de-energized providing a remote warning signal and the front panel alarm LED changing state. The 1X30 relay incorporates an electronic time delay to avoid nuisance alarm signals during normal operation of the circuit breaker between the open and closed state. An important characteristic of the design is the low level of current required to flow through the CB coil for correct operation of the supervision scheme. This results in low power dissipation in the 1X30 circuit and the CB coil which avoids the possibility of nuisance tripping. Constant supervision is maintained irrespective of the CB being in the open or closed position.Two supervision schemes are available to provide a range of visual alarm and output contact options. The relay is designed for flush mounting utilizing asingle 25mm diameter mounting holewhich also houses the LED indicator. Electrical termination is made via ten (10) screw terminals on the rear of the case. This terminal block is of a plug in type further simplifying installation.