Help! Faulty apartment wiring.

[SavageHenry]

I suspect that not one, but two outlets in my apartment are ungrounded. And I say that I suspect this because while they do have the typical "3-hole" outlet, both have caused serious problems with the appliances attached to them (I suspect that hole number 3 is not connected to anything). One of them was a cheap microwave and many fireworks resulted, but no big loss. Unfortunately the other was my friend's $300 PA amp which not only shocked the crap out of me, but seems to have killed the amp as well. Before I take all of this up with my landlord, I am hoping I can prove the wiring is faulty (possibly with a multi-meter?). Can someone with some electrical experience please offer their suggestions? Thanks.

[Rich Greenberg]

Do you have a known good ground? If your plumbing is copper, you can usually use the plumbing as a ground for these tests.

Make up a test light. A light socket with 2-3 foot lengths of #14 wire is good. Use a 100 watt bulb. If the KNOWN good ground is not handy to the outlets, extend a length of #14 from a ground to the outlet in question.

Make these tests on a known good outlet so you can verify that it is good and your ground is good. Then the suspect outlets.

The bulb should light fully for the following connections:

Between the two flat blades. between the smaller flat blade and the u-ground (the #3 hole). between the smaller flat blade and your known ground.

Anything less than fully lighted indicates a problem.

The bulb should not light at all for the following connections:

Between the wider flat blade and the u-ground. Between the wider flat blade and your known ground. Between the u-ground and your known ground.

Any light at all indicates a problem.

Good hunting.

[Howard]

Or just get one of these at HD or Lowes

They just plug in and the lights tell the story. Easy for landlord to understand. ABout $10 and a bit sfaer than a test light.

Rich Greenberg wrote:

[RBM]

I would suggest hiring a professional to verify your suspicions. If indeed your outlets are ungrounded and caused this damage and you expect to get reimbursed by your landlord, a professional's word would be harder to refute

[Pat]

I agree with both Rich and Howard but there is a but. Even if the outlet is ungrounded, that wouldn't cause otherwise properly working items to spontanteously combust, so to speak.

A "hot ground" might cause some problems. It could short to ground and cause massive overheating. But it would also likely pop a breaker. It might also shock YOU. So check to make sure you don't have seriously oversized breakers, nickels in the fuse box, etc. (but which is very unlikely).

Reversing the polarity might also cause the problem, but that to is unlikely. It is common enough that most appliances can handle it.

If you have a rats nest of extension cords or an undersized lead cord, that could also cause a problem.

Another possibility is that the voltage is wrong. Plug in a regular incandecent light and see if it looks right. If it is REALY bright, you might have 220 there. That would cause a problem. Just out of curiosity, what does the outlet look like? One of the flat holes doesn't have a let off of it to make it look like a sideways"T" does it? Sort of:

| | | | | |-------- | | | | __ |__|

Sorry for the image, but I hope you get the point.

Remember, it might just be dumb luck, too. Sometimes a coincidence is just a coincidence.

Good luck. More infor would be useful.

Pat.

Owner:Sibernet-L

[mm]

I don't see why the lack of a ground would cause problems with a microwave. Maybe someone could tell me if and why I'm wrong.

Are you sure you didn't have something metal in the microwave? Even metal decoration on a plate, or tin foil?

I don't think cheap microwave ovens are any different from more expesnive ones, except possibly the expensive one is less likely to be broken. My brother put the wrong metal shelf in one -- I guess there's is some special alloy? -- and he blew a glass fuse in the oven. My Amana model 2 didn't have a fuse. I don't know about others.

This on the ohter hand does sound like it might be an ungrounded outlet. That is, if there were a grounded outlet and it was a strong shock representing 110 volts, it would have blown the fuse if the outlet were grounded. Was there a 3-prong plug on the PA amp???

but seems to have

[mm]

I haven't tried it but wouldn't 220 burn out 110 volt bulbs? More below.

The image above does not represent 220. It means 110 on a 20 amp circuit.

[mm]

I meant the expensive one is less likely to be broken after it was run with metal in it, although I had a little sparking in my cheap one and it's still running.