> G wrote: > Out of a present inventory of 42 houses ... 30 of them have had > low voltage at the service entrance. Of those 30 only 2 were > not aluminum main cable from power company. > > The aluminum entry cables, with use, heat up more than copper. > With each heat, the aluminum embeds due to expansion, further > into the clamp screws. When it is unloaded [AC cycles off, for > example] it cools and retracts from the clamp screw, leaving a > slight air gap.
Unless it's covered it grease. There is special grease just for aluminum electrical connections, but my standby of wheel bearing grease works rather well and is sure better than nothing. Using grease does not prevent this problem, it just drastically decreases the speed that a problem will occur. I have seen similar even with copper - which I also grease. *smiles* > The first indication this has happened is usually found with a > meter at a wall socket, for 110 or by checking each leg of a 220 > plug. > > I have found, on some houses, as low as 85 volts at a 110 wall > socket. It's so common from my experience, I've now made it part > of any "pre-buy inspection". The voltage drop caused by a high resistance connection will be dependent on the current draw. Meaning - if there is nothing using electricity in the house, even a really bad connection will read full voltage. The voltage drop will _increase_ as the draw goes up. Ideal would be a known and repeatable load of, say 50 A. Then the amount of voltage drop will directly relate to the state of the connections. _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
