Why anyone would pass aluminum wire as safe is beyond explanation.

When aluminum wire was allowed, many structures used them, with passing inspections, and fire resulted. Spring loaded connectors etc. aren't the long answer as corrosion will eventually cause problems, plus more contact points. Aluminum just isn't that good.

I for one would never use aluminum wire unless Forced to.

Positron



Quote Originally Posted by skeptic
I don't know what your are referring to about UL approving products which failed their tests but aluminum wiring was approved by the National Electrical Code which is a subchapeter of the National Fire Code. The people who review and change these codes are experts in the areas of fire safety, electrical safety, and loss prevention. Their main customers are the insurance companies which pay off when there is an accident resulting in injury, death, or loss of property. They have a vested interest in preventing any such losses. Municipalities have the option to approve these codes as part of their own laws or as in the case of New York City, to write their own codes.

Aluminum wiring is pefrectly safe when used the way it was intended. However, the alloys used in the era when they were approved were relatively soft and underwent "plastic deformation" over time. Switches, receptacles, and other devices approved for use with aluminum wiring had springs which maintained adequate pressure to keep good contact over the years. But many homeowners and perhaps inexperienced or untrained Saturday afternoon electricians and handyman types used the hardware intended for copper wire instead. Over time, these connections became loose and would arc causing the aluminum to burn which further increased contact resistance, causing them to get even hotter from further arcing, and eventually could cause a fire. BTW, this can happen even with copper wire. Today large companies "thermoscan" all electrical connections during routine annual maintenance or when a problem is suspected. I saw a 200 amp GE safety swich melt down due to loose connections, the obvious result of long term inattention to maintenance. Luckly, it was discovered before an accident. As for UL, they merely verify that the equipment will safely do what the manufacturer claims it will under the conditions of use he specifies. They cannot protect people from themselves if they do not know what they are doing and screw up.

It might interest you to know that aluminum wire is still used today by utilities for high voltage feeder cables but the people who use it are well trained tradesmen and professionals who know exactly what they are doing. Aluminum has been taken away from the homeowner for his own protection from lack of knowledge and skill.