ALCRs and Rapid Power Cycling

The Automatic Load Control Relay (ALCR) is powered by the “EMERGENCY” source connected to the unit. In the event of an extremely rapid power cycle, on > off > on, of around 1 second or less, the internal power supply of the ALCR will shut down to protect itself. The ALCR will then appear to be off but will pass power to Emergency loads regardless of the state of the normal sense and external contact input.

The solution to this problem is to power cycle the emergency power feed to the ALCR when it is safe to do so. The power should be turned off for at least two seconds before turning it on again. The LEDs on the ALCR will restore, and normal operation via switch sense and external contact input will be resumed.