Turning Off Power at the Fuse Box

At your fuse box, shut off power by unscrewing and removing a fuse. Test the device to make sure the power is off before doing any work. If a fuse has blown, replace it with a new one.

To turn off power to the entire house, pull out the main fuse block, which looks like a rectangular block with a handle. It is usually located at the top of the panel. Tug hard and straight out on the handle. Use caution; the metal parts may be hot.

A main block or 240-volt circuit may have a fuse block that has cartridge fuses inside. Remove an individual cartridge fuse by pulling it out from the holders. Test the fuse and, if necessary, replace it.

When a fuse blows frequently, it's tempting to replace it with one of a greater amperage. This is dangerous -- house wires could burn up before the fuse blows. Instead, remove some of the load from the circuit.

The wire gauge in the circuit determines how large a fuse or circuit breaker it can have. A 15-amp circuit should have 14-gauge or larger wire; a 20-amp circuit, 12-gauge or larger; and a 30-amp circuit, 10-gauge or larger.

Checking the wire gauge is easy if you have nonmetallic cable running into the box. Examine the sheathing for a stamped or printed identification, which includes the gauge. With armored sheathing or conduit, open a receptacle on the circuit. Check the insulation on the wires for a gauge marking or compare it with a wire of known gauge.