Wow bad wiring in the AC outlet - expensive failure!

[DanglinModifiers]

Donald Puryear wrote:

You are lucky the CTB08D was not in a grounded metal enclosure. You may have been fried instead of the Laptop.

The CTB08D was in a grounded metal enclosure.... I guess that makes me very lucky.

I wound up tracing the whole thing back to some electrical work done by the previous owner. At some point my house had two three way switched for this circuit. By the time I moved in, those two switches were replaced with standard 2-way switches for some reason. Some additional electrical work I did, assuming everything was right, compounded the problem.

It's actually pretty scary. I tested everything with one of those three light outlet testers. And it always indicated this outlet was wired correctly! I guess they never planned that some bozo would be using them on an outlet as screwed up as mine. Somebody needs to make an outlet tester with LEDs or something else than can measure not only relative voltage, but polarity.

Anyway, I identified all the wiring related to the original three way switch set up, and was able to trace it to a common junction box. I installed a new junction box right near the outlet in question. I was able to cut the wire leading up to the outlet, and join it with a new run of wire straight from my breaker. I'll remove all the wiring related to the switch at some point, but for now it's all disconnected.

I still can't believe I've lived with wiring like this for almost four years and never had a single problem with it until last week. Like I said... Very lucky.

[webbie]

May I recommend a apc battery backup. Speaking from experience, MID Our electrical company has bought me a few for free. My street blew a transformer and when they can back to install a new one, they somehow revesed the wires and blam, apc destroyed . All my computers and servers were 100 percent ok. They will even warn you if you have a open ground or wiring fault! Just a tip. =) Saves you a headache in the long run.

[-klb-]

I do like, and use a lot of APC UPS's around the house, (including two for the entertainment system) but I am not sure it would have detected this either...

Speaking of scary grounding issues, there is a reason that code calls for old ungrounded circuits to be upgraded to grounded all the way back to the circuit panel. As an interim step, someone I know had extended a circuit, and upgraded part of it, but had not replaced the run back to the panel, because they were waiting until a newer (much larger) main panel was installed, and the fuse box that fed this circuit was retired..

Unfortunately, somehow in one of the boxes, the insulation on the hot wire had been nicked, and came into contact either with the ground wire or ground screw on one of the outlets. As a result, all the ground pins on the outlets on that circuit were hot. I found it when I accidentally brushed a cable TV coax across a galvanized power strip that was plugged into one of those outlets, and it drew a spark.. Not good when two supposedly grounded pieces of metal draw an arc.... I can't tell you how many times I had grabbed that power strip when plugging or unplugging stuff from it.. I'm glad I was apparently always insulated from ground!!!!:shock: Glad I was never touching the coax ground and the power strip at the same time!!!

- Kevin

P.S. The entertainment system has two UPS's for a reason. Most of it is on an 1100VA UPS, but the DirecTV system is on it's own.. There are still copper paths between the satellite dish and the rest of the system, but I figured I would at least put in some isolation, by putting it on a separate UPS... Really kind of odd to have a power outage, but still be watching TV...