When a feeder is de-energized or experiences a momentary outage, any connected DERs are required to comply with IEEE-1547 disconnect rules. If the DER is not capable of operating in island mode, it must, for safety reasons, disconnect and stay off-line until voltage and frequency have been restored. Once the DER is re-energized it must remain disconnected for a period of time (typically 5 minutes) before re-connecting to the network. This behavior is modeled in the Power Flow applications so that correct voltage and load can be determined.

When a DER unit is in this disconnected state, a condition is applied to the device to alert operators that the condition is temporary.