Instead of your plug of your PDU going into a receptacle, the wires that would go into the plug are hardwired to a panel circuit breaker. This is less common i

Instead of your plug of your PDU going into a receptacle, the wires that would go into the plug are hardwired to a panel circuit breaker. This is less common in DCs historically but more and more as folks do 208v 3phase 100A circuits.