Q. The home we just bought is 45 years old and has aluminum wiring for the outlets and lights. Our home inspector said this could be unsafe, so we hired an electrician. He attached short copper wires to all of the aluminum wire ends and fastened them with regular wire nuts. Our home inspector said the electrician should have used special connectors made for joining copper and aluminum wires. But the electrician assured us the connections are very tight and will not be a problem. We want to be sure about this. Whom should we believe?
A. You have good reason to be concerned. Aluminum wire connections can pose fire hazards, and special connectors are needed when retrofitting them with copper ends.
Aluminum wire was commonly used for 110-volt circuits in homes from the late 1960s through the early 1970s. Its use came to an abrupt end when loose and improper connections became overheated and caused house fires. Fortunately, rewiring is not necessary to eliminate this problem.
Aluminum wires can be safe and functional, but there is a tendency for the connections to become loose. The solution is to attach copper ends, known as "pigtails," at all of the terminals on lights, outlets, switches, and other fixtures. But this retrofit must be done properly, with connectors that are specially designed and approved for joining these dissimilar metals. Common wire nuts do not meet this standard.
The building department in your area may require a permit for this work. You should consult one of their building inspectors to see what they require for the retrofitting of aluminum wires. Have them inspect to ensure that the pigtails are safe and in full compliance with applicable requirements.
Q. We just purchased a 15-year-old home and have two concerns about the electrical system. First, we noticed the wires in the attic are not protected. They just lie exposed on the framing. Is this OK, or should the wires be run in pipes? Also, the main service panel is located on the far side of the attached garage. Therefore, wires that go to the other end of the house have to run a long distance. Could these long runs cause a loss of power?
A. The wiring in your attic is probably a non-metallic type that typically consists of three or four wires contained in a plastic sheathing, usually white, black or yellow. This wiring in an attic is acceptable in many areas of the U.S., if it is fastened to the framing in ways that comply with applicable safety standards. Some municipalities require wiring in protective piping, known as conduit, but running non-metalic wires, rather than conduit wiring, through an attic complies with standards set forth in the National Electrical Code, provided that your local building department approves such use.
As for the long run from the main panel to the far end of the house, significant voltage reductions can occur when wires extend for considerably long distances, such as between separate buildings. Wire runs extending from one end of your home to the other should not pose a problem in this regard. However, if there are symptoms that concern you, such as dimming lights, have the system checked by a licensed electrician.
• To write to Barry Stone, visit him on the web at www.housedetective.com, or write AMG, 1776 Jami Lee Court, Suite 218, San Luis Obispo, CA 94301.
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