American Power Conversion Redundant Switch operation manual

Operation
Emergency	You can use a remotely operated Emergency Power Off (EPO)
Power Off	switch to turn off the UPS and disconnect power to the
	equipment load. When you turn off the UPS through the
	Emergency Power Off system, it will turn off immediately
	without switching to battery operation.

Electrical Hazard

Use only a licensed electrician to perform the following procedure to connect the Redundant Switch and its attached UPSs to your Emergency Power Off system.

1.Use the EPO connector.

2.Use a normally-open contact to connect the +24 terminal to the IN terminal.

3.Wire the external blue four-pin female connector to the emergency power off system.

The EPO interface is a Safety Extra Low Voltage (SELV) circuit. Connect it only to other SELV circuits.

The EPO interface monitors circuits that have no determined voltage potential. Such closure circuits may be provided by a switch or relay

Caution	properly isolated from the utility. To avoid
	damage to the Redundant Switch, do not connect
	the EPO interface to any circuit other than a
	closure type circuit.

16 APC Redundant Switch: Installation and Operation Manual