Miguel_Cruz@ub.cc.umich.edu (03/21/89)
At work today, one of our many phones (which are pretty abused - people are always tripping over the cords and pulling them off desks) stopped working. If you picked it up, you heard nothing. If you called it, it rang. I was busy so I forewent my usual 'telephone repairman' role at the office. Then, I was sitting at the desk where this particular phone sat, jotting down some notes. I noticed a particularly noxious odor, and followed it to the phone in question. Strange, I said to myself. About to turn the phone over to take the cover off (this is a perfectly standard touch-tone desk telephone), I pulled on the cord to get some slack. It was hot. Very hot. I pulled the clip/plug out of the phone, and the two middle wires were glowing orange, the tiny plastic divider tooth between them was black and melted, and the whole thing smelled horribly. As I watched, the plug defiantly sent a little spark flying towards me. Needless to say, I unplugged the other end from the wall. Now, I have accidentally shorted phone lines across my body, even through my face when I didn't have wire clippers and was stripping a live wire with my teeth. It tingled, but certainly didn't hurt. Is there enough power in a phone line to melt plastic and make wires glow? This struck me as extremely odd. I plugged in another phone and cord and they worked perfectly, so I don't think something else was shorted across the phone line. Why did this happen? If it happens again, what if a fire starts? Could it be cheap phones/cords?
jbn@glacier.stanford.edu (John B. Nagle) (03/22/89)
NO WAY can you make wires glow red with any power level normally applied to a phone line; not even with ringing power is there enough energy to make that happen. Somehow, power line voltage is getting into your phone wiring. This is serious and needs to be tracked down. It may be necessary to examine all relevant punch blocks with a voltmeter. If you have wiring maintenance from your telco, have them do it; if not, it's probably better to have a licenced electrician with telephone expertise do it. You have a major fire and electric shock hazard. John Nagle
decom@dgp.toronto.edu (Jonathan Haruni) (03/24/89)
In article <telecom-v09i0102m08@vector.UUCP> "John B. Nagle" <glacier!jbn @labrea.stanford.edu> writes: > NO WAY can you make wires glow red with any power level normally >applied to a phone line; not even with ringing power is there enough >energy to make that happen. Somehow, power line voltage is getting into... >[etc.] > John Nagle Any amount of power will make a thin enough wire glow red. And the tinsel-wrapped-around-nylon wires they're using in phone wires these days are about as thin as practically possible. However, it seems unlikely that the problem would be with too-thin wires. In all likeliness, you are right, and as you say, an electrician should look into it. (This problem was occuring at someone's workplace, right ?) Jon Haruni.