A double pole 24 volt DC relay and enclosure that Backwoods uses in grid-tie AC coupled configurations.
AC coupled systems use a control signal from the battery-based inverter to trigger the relay to disconnect AC power to the grid-tie inverter when there is a utility black-out, AND solar power is not needed to run loads or charge batteries. The battery-based inverter then sustains the loads using battery power. As the battery bank voltage drops, the relay is triggered to close, re-engaging the array to charge the batteries, and support the household loads.
The metallic enclosure covers and protects the live electrical contact points of the relay.