The BT51 safety / expansion relay from ABB is designed to connect safety devices directly in the voltage supply circuit to the relay. It has 4 NO safety outputs, a test input and complete internal supervising.
The test input of the BT51 is intended to monitor when contactors or valves have dropped/returned before a new start is permitted. The test input can also be used for starting and the start button can be supervised. The relay functions safely in the event of component failure, short circuit or loss of power supply.
The BT51 can be connected to a safety relay or PLC to increase the number of safe outputs. Therefore, an unlimited number of dangerous machine operations and functions can be stopped from one safety relay or PLC.
Single and dual channel
Test/reset input
Width 22.5 mm
LED indication
4 NO relay outputs
Quick release connector blocks