Dear Doctor Livejournal (Electrical Dept.)

[eub]

One electrical box in the kitchen stopped working, both outlets of it. It definitely worked until the day or two before.

My little outlet tester says hot/ground reversed. I'm not 100% certain but I'm pretty sure I tested every three-prong outlet in the house (to find the ones that aren't actually grounded), and there was sure no hot/ground reversal. Which sounds like a weird condition to have, ever, plus extra-weird to spontaneously develop. I o_Oed and breakered that circuit off.

Now I ask Dear Doctor Internet (Electrical Dept.) and it sounds like that reading probably means "open neutral" and a load somewhere else on the circuit. The "backstabbed outlets" that the Doctor mentions seem to be described here.

I ♥ Doctor Internet (all her Departments), but I like a second opinion from Doctor Livejournal on electrical work. Also... if I find these are backstab, I'll probably change them all over to screwed, but I'm curious if there's also a way to debug which one went bad before opening them all -- it should be either the last *working* one in the circuit chain (if the fault's in the "outbound" neutral), or the first non-working one (if fault's in the "inbound" neutral), I believe?

Comments

[hattifattener]

Dr. Internet seems to be busy helping another caller at the moment but the diagnosis sounds reasonable to me.

You could use one of the simpler outlet testers (the kind that's just a neon bulb with two probes) to compare the outlet's neutral against a neutral or ground brought in on an extension cord.

[randomdreams.livejournal.com]

I was thinking the same. Find an outlet that you know is working, figure out if neutral's gone hot. I agree with your diagnostic technique, with the proviso that the problem might not be in an outlet box, but in somewhere else that people have joined neutrals: a light or a switch-with-power.

Also, afaik, if people wire the ground to the neutral per-outlet, the outlet testers will show the outlet as grounded without actually being grounded: people do that if the wiring in the house is only two-strand but they want three-prong outlets.

[eub.livejournal.com]

Looking, I think this circuit contains only two outlet boxes on opposite walls of the room with another circuit interspersed. I dunno, man.

Re the afaik: interesting, that is a definite possibility in this house. Though it would be a different electrical-work style that what I know we have, which is three-prong outlets with open ground.

[3smallishmagi.livejournal.com]

My suggestions are all variations of 'have you plugged it in and switched it on?'
Do you know the path electricity takes from outside into you house and to the kitchen electrical box?
Have you flipped all the circuit breakers on the path to the kitchen? (flip them off, then back on again to make sure it doesn't just look like it is on but has actually tripped)
Do you have any earth leakage breakers on any of your plugs (they're commonly in bathroom outlets, but I've been fooled by having them scattered about the house. when one trips, the whole circuit doesn't work. If its still set, pressing the 'test' button trips it (and you have to press it in to reset)
Is power reaching the kitchen box or is it just not leaving it (don't know how to test that)
Does the problem go away for some plugs if you turn off all but one breaker in the kitchen electrical box?

It may be that the power supply of an appliance plugged into the kitchen circuit has failed and has tripped a breaker (this is how I know about the earth leakage breakers)

If there's a short somewhere, you could troubleshoot it with the power off using a multimeter, but don't want to give specific steps (you could electrocute yourself or wreck your meter with great surprise.)

[eub.livejournal.com]

Good thoughts. I did try toggling the breaker off and on. There are some earth leakage breakers (Americanised as ground fault interrupters) in the kitchen, but not on this circuit. All but the one outlet box are delivering juice, BTW.

I'm betting I'll find a continuity break in the circuit's neutral, which I can then binary search on (with the whole kitchen off, which is why I'm waiting for daylight).

[brokengoose.livejournal.com]

The "open neutral" theory makes some sense, and it sounds easy to check: just unplug everything else on the circuit.

Personally, I'd take a close look at BOTH the last working box and the first non-working one. We live in a house with stunningly bizarre wiring, and I've seen a few cases where they did two things wrong that canceled each other out. I'd fix one problem and things would get worse until I found and fixed the other. I've learned to go over every inch of the wiring between known good and known bad, even when there "couldn't possibly" be a problem in between.

As for the "connect ground to neutral to make 3-prong plugs work", we have some of that, too. I've been disconnecting the fake grounds. When I need a 3-prong outlet on a non-grounded circuit, I throw together a short, brightly colored "WTF is this?" adapter cord. That way, nobody will make false assumptions about the circuit that's in the wall.