Optimize control of your UPS with remote power off (RPO) and remote on/off (ROO)

Among the most practical features of UPS systems is the ability to manage emergency shutdowns and remote restarts of connected equipment. Many of Eaton’s models include RPO and ROO functions, particularly those designed for network, enterprise or industrial environments.

Remote power off (RPO)

The RPO connection is used to shut down the UPS remotely when the connection contact is open. This feature can be used for shutting down the equipment connected to the UPS and the UPS itself by thermal relay, for instance, in the event of room over-temperature.

Note: this feature is sometimes labeled EPO (emergency power off) or REPO (remote emergency power off). Check your model’s documentation for the correct specifications and instructions for use.

Remote on/off (ROO)

The Remote On/Off (ROO) connection allows you to remotely switch the UPS on or off. This can be handy if you need to control the UPS from a distance.

Primarily, the RPO function is for emergency shutdown. It consists of a two-position contact, with the circuit closed for normal operation. Opening the circuit activates an emergency shutdown.

When RPO is activated, the UPS shuts down the output and all its power converters immediately. The UPS internal control circuitry may remain active to support alarms and monitoring. The RPO circuit is an IEC 60950 safety extra-low voltage (SELV) circuit that must be separated from any hazardous voltage circuits by reinforced insulation.

The RPO must not be connected to any utility-connected circuits. Reinforced insulation to the utility is required. The RPO switch must be a dedicated latching-type switch not tied into any other circuit. The RPO signal must remain active for at least 250 ms for proper operation. To ensure the UPS stops supplying power to the load during any mode of operation, the input power must be disconnected from the UPS when the RPO function is activated. RPO does not disconnect utility or battery input; hazardous voltages may remain present inside the UPS even after RPO activation.

Note: in order to restart the UPS, manual intervention is required. This helps ensure the UPS does not restart during adverse conditions. (Restart behavior varies by model. Refer to your model’s documentation or contact support for specific restart procedures.)

The ROO allows the UPS to be switched on or off remotely. When the contact is changed from open to closed, the UPS is switched on (or stays on). When the contact is changed from closed to open, the UPS is switched off (or stays off). If the ROO is connected but in the OFF (open) state, the UPS will NOT restart automatically, even when utility power is restored. The UPS will wait for the ROO setting to be changed to ON (closed).

Like the RPO, the ROO uses a safety extra-low voltage (SELV) circuit.

Note: the on/off control via the unit’s power button has priority over remote control.

An ROO port is often hard-wired to a dry contact switch. This switch enables the ROO to be opened or closed from outside the area containing the UPS. For example, the operator could use a wall-mounted dry contact switch to turn the UPS on or off from outside a data room or electrical room, or use it to manually prevent the UPS from restarting automatically after a shutdown until safe conditions are verified. The switch simply opens or closes the ROO contact; no voltage is supplied by the switch itself.