How to Wire a Fuse Box | DoItYourself Step 2 - Purchase Correct Fuse Box. Knowing your current, and future, amperage load will help you choose the correct fuse box. Choose the correct box based on need rather than cost. Step 3 - Disconnect Power From Main Meter. To get started with wiring a new fuse box you want to make sure that the power is first disconnected.Author: DIY Staff Wiring Basics for Electrical Disconnect Switches - The Spruce The electrical wiring to the disconnect is fed from the "load" side, or outgoing side, of the electric meter. The side of the meter that receives incoming power from the utility service lines is called the "line" side. There are two hot wires and a neutral wire. The hot wires each carry 120 volts and are different phases.