Power distribution unit

A power distribution unit comprising:

• a main branching box;
• and
• a sub-branching box,
• wherein the main branching box includes a first power supply input portion, a plurality of main output portions, and a main branching circuit that branches power inputted into the first power supply input portion to the plurality of main output portions,
• the sub-branching box includes a sub-input portion connected to one of the plurality of main output portions, a plurality of sub-output portions, and a sub-branching circuit that branches power inputted into the sub-input portion to the plurality of sub-output portions;
• the main branching circuit includes a main circuit protection unit, which is constructed by a semiconductor relay mounted on a printed circuit board and prevents an overcurrent from flowing into the main output portions aside from the main output portion to which the sub-input portion is connected, and
• the sub-branching circuit includes a sub-circuit protection unit constructed by a mechanical fuse that prevents an overcurrent from flowing into the sub-output portions.