Quck answer
To wire a 220 to a fuse box, follow these steps:
1. Turn off the power supply to the fuse box.
2. Locate the main breaker and turn it off as well.
3. Identify the fuse that will be used for the 220 circuit.
4. Connect the black wire from the 220 circuit to the fuse terminal.
5. Connect the white wire to the neutral bus bar in the fuse box.
6. Connect the green or bare copper wire to the ground bar in the fuse box.
7. Install a double-pole circuit breaker in the fuse box for the 220 circuit.
8. Connect the red wire from the 220 circuit to one terminal of the circuit breaker.
9. Connect the black wire to the other terminal of the circuit breaker.
10. Turn on the main breaker and test the 220 circuit to ensure it is working properly.
Remember to follow all safety precautions and consult a professional if you are unsure about any step.
The term “fuse box” is outdated. It refers to the electrical control centers in older houses that used screw-in fuses that would blow when the current draw exceeded their rating. If your house still has a fuse box, rather than a breaker box, it is advisable to have an electrician evaluate it before attempting to connect a 220-volt outlet. There is no guarantee that the fuse box can handle the high amperage required. Many older fuse boxes are only rated for 60 amps and have limited connection slots, which is insufficient for modern houses, even without adding a new circuit.
The electrician will likely recommend upgrading to a 100- or 200-amp breaker box. While this may not be what you want to hear, it is the safest option. If you decide to keep the fuse box and the electrician determines that adding a 220-volt circuit is possible, there are two options. The first is to connect the wires to two available slots. However, if you have a six-slot fuse box, this means that only four slots will remain for all your other electrical needs. The second option is to install a sub-panel.
Wiring a Fuse Panel: The Basics
Since fuse boxes are becoming obsolete, wiring them is becoming a lost skill. The two hot legs from the line transformer, which have a voltage of 240 volts (220 volts is somewhat inaccurate) between them, are connected to a pair of lugs, and a return wire leads back to the transformer. Each 110-volt circuit makes contact with one of these lugs and the return lug, but a 220-volt circuit must make contact with both hot lugs. To achieve this, you need to connect wires to a pair of fuses, and since they must be on different lugs, the fuses are usually on opposite sides of the fuse box.
Most fuse boxes have a cartridge containing larger 30-amp fuses for servicing a single 220-volt circuit. If available, you can use this, but you cannot exceed its current rating to power a large modern appliance, such as a 50-amp stove. An alternative is to wire a subpanel to the fuse box and route the new 220-volt circuit through it. However, it is important to have a thorough inspection and recommendation from a licensed electrician before doing this.
Breaker Boxes: Easier and Safer
A breaker box simplifies 220-volt wiring. Instead of lugs, the breaker box has a pair of bus bars, and the breakers are designed to snap onto them. The bus bars are not straight; they have a squiggly shape, resembling continuous S’s, so that each adjacent breaker contacts a different bus. This means that wires attached to a pair of stacked breakers have a voltage of 240 volts between them.
To connect a 220-volt circuit, use one of these stacked breakers, also known as a double-pole breaker, with the amperage rating required for the device you want to power. Each breaker accepts a hot wire, typically one red and one black. The neutral wire connects to the neutral bus, and the ground wire connects to the ground bus. This requires a total of four wires, so you will need three-conductor cable (the ground wire does not count as a conductor). The recommended wire gauge depends on the current rating: use 12 AWG cable for 20-amp service, 10 AWG for 30 amps, 8 AWG for 40 amps, and 6 AWG cable for 50-amp service.
Fuse Boxes Lack Grounding
In accordance with the current electrical code, it is mandatory for all circuits, including those operating at 220 volts, to have grounding. However, older fuse boxes typically do not possess this feature. This serves as yet another compelling reason to upgrade from a fuse box to a breaker box. Grounding plays a crucial role in preventing electrical shocks and fires, as well as safeguarding delicate equipment from potential damage. Although there is no legal requirement to replace your old fuse box, disregarding this could have grave consequences if you overload the fuse box with a new 220-volt circuit, causing it to overheat and ultimately ignite your residence.
