Allen-Bradley 809-A05E Instantaneous Trip Relay

Allen-Bradley 809-A05E Instantaneous Trip Relay is a Bulletin 809 current-relay device designed for instantaneous overcurrent protection in motor circuits. As an Open Type member of the 809 family, it is magnetically operated and intended for use in motor protection schemes to trip quickly when the sensed current exceeds the preset threshold. The A05E variant offers an adjustable instantaneous trip current range from 6.3 to 18.1 amperes, enabling protection to be tailored to specific motor sizes and wiring configurations. The relay supports operation in both AC and DC applications, providing a compact, rugged means of interrupting fault current in industrial controls. In normal operation, it trips at the preset current and resets at defined percentages of that setting: 70–85 percent for AC service and 62–82 percent for DC service, allowing reliable restart after faults. The 809-A05E embodies Allen-Bradley’s legacy Bulletin 809 instantaneous trip relays, combining straightforward adjustment with a robust construction to meet protective requirements across diverse panels and installations.