DC power supply distribution unit DCPD7, installed in the cabinet and connected between - 48 V DC power supply and equipment, is a class C drawer type surge protective power supply cabinet. It is suitable to indoor low-voltage DC power distribution system for protection of equipment from surge and transient over-voltage caused by outside environment (such as lightning, EMI, switching effects of the system) or internal environment (power on and off, startup or shut off of inductance and capacitance loads, etc.)