Allen-Bradley 809-A04E is a Phase/Voltage Loss Relay used to detect loss of a single phase or abnormal supply voltage and trigger protection in industrial control circuits. It is cataloged as an instantaneous-trip relay with a 6 A maximum contact rating, a single normally open output, and automatic reset, making it suitable for simple phase/voltage fault detection in motor or power-distribution schemes. Rockwell Automation lists the 809-A family as obsolete, with official notices indicating these relays are no longer manufactured.
