Sunday, February 20, 2011

Guick way to a fire


One of the things I am glad to see changed in Electrical devices is the quick wire Push in terminals on receptacles, they can no longer except number 12# gauge 20 amp copper wire they will now only except 14# gauge 15 amp wire and with good reason .
As a Trouble Shooting Electrician many times I have been called to homes and businesses
to find that an electrical receptacle has burned up due to poorly made electrical connections and of these poorly made connections 80+% of these connections I find causing this problem are what as known as a quick wire terminal which is located on the rear of most electrical receptacles and switches you would find in the average home and small business. Instead of the traditional way of making a receptacle connect to copper wire by stripping the wire bending it around and then tightening down a screw , the quick wire terminal allows that you only need strip the wires insulation off about 3/4" and push the exposed copper into the quick wire terminal .Simple enough but all too often incorrectly done especially when inserting larger12# gauge wire which allows resistance to build up in the receptacle, and if this receptacle is also being used to feed thru to other receptacles or has a heavy load running thru it the situation gets worse with time. One of 2 things ends up happening the connection burns up blowing the fuse and ruining all the wiring with in the receptacle enclosure box or as in the case with Plastic boxes now commonly used in residences
often times it leads to fires. Although the receptacles at the time were UL listed and approved by the National Electrical Code NFPA both agencies failed to take into consideration the fatal human error factor that allowed 12# gauge wire to be simply pushed into the receptacles and if the connection was not double checked leads to problems. typically 12# gauge circuits are wired for heavier circuits which means higher resistance and temperatures and unfortunately many millions of these older receptacles are still in every day use waiting to tick off like a bomb .
Finally in 1996 the NEC took another look at these receptacles and redesigned them that
quick wire terminals can now only allow the smaller 14# wire into them and the connectors have been better reinforced.
But the original design considerations have never been addressed and like split main panels and several other dangerous electrical designs there still out there.

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