Upgrading to three-wire circuitry is worth the trouble.
The U.S. National Electrical Code has required grounded circuitry in new construction since the early 1960s. If your house still has two-wire circuitry, upgrading to three-wire circuitry is more than prudent. The electrical code requires grounding to prevent electrocution and fires. Since the requirement has been in force for a half-century, any two-wire circuitry is probably too old to be efficient. Upgrading to three-wire circuitry involves pulling new wires to replace the old ones and changing out all outlets and switches. The work begins at the source of your home's electricity, the main panel. Does this Spark an idea?
Instructions
1. Disconnect the power from your panel. There are two ways to do this. One is to have a qualified electrician disconnect the panel from the electric meter; the other is to call the power company and have them shut off the service.
2. Disconnect and replace the service panel. Whether your existing panel is an old fuse box or a more modern circuit-breaker box, a new, larger breaker box will give you more flexibility for adding circuits. Moreover, all modern panels are designed to be grounded, eliminating the need to retrofit grounding onto an old panel that wasn't designed for it.
3. Ground the panel. Pound one or more copper or metal rods 8 feet into the earth as close to the panel as practical, and connect the rods to the ground bus bar in the panel with 10-gauge or heavier bare copper wire. If you have metal water pipes, you should also ground them by connecting them to a ground rod. The number of rods you need depends on your electricity use. If you're not sure how many rods you need, consult an electrician.
4. Disconnect all electric outlets, switches, lights, and appliances, and discard any devices that do not have grounding capability.
5. Pull out the old cables. If you plan to keep the circuitry the way it is, you can save much time and trouble by attaching a length of new non-metallic sheathed (NM) cable to the far end of each old one before you pull it. This way, the new cable will be pulled into place as the old cable is removed. Run cable for any new circuits by making holes in the studs or floorboards where needed and fishing it through with fish tape. The amount of difficulty you'll have doing this depends on whether the walls are covered.
6. Install all the electrical devices in the circuits, using only groundable outlets, switches, and light fixtures. Wire each device by connecting black wires to brass terminals, white wires to silver ones, and bare ground wires to the green grounding screw on the device.
7. Feed all the circuit cables into the panel. Connect the white wire from each cable to the silver bus bar and the bare wire to the ground bus. Connect the black wire from each cable to a circuit breaker and snap the breaker into the front of the panel. Label each circuit clearly on the front of the panel.
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