A remote suppression unit retains a first set of surge suppression modules. A base suppression unit retains a second set of surge suppression modules. An over voltage protection (OVP) board in the remote suppression unit includes power strips that couple the first set of surge suppression modules to remote ends of DC power cables. A configurable terminal assembly in the base suppression unit couples the second set of suppression modules to local ends of the DC power cables. The surge suppression modules in combination with the OVP board and terminal assembly provide more suppression protection in both the remote and base suppression units. A remote voltage monitor circuit in the remote suppression unit measures voltages on remote ends of the DC power cables and transmits the voltages and alarm status to a monitor circuit in the base suppression unit.