About a year ago I buried some aluminum 2-2-2 rated for underground sevice. It is about 100 ft to the shop from the service source which is the breaker in the house box. I buried at 18" and have had no problems until about a day ago when I notice it dropped one of the hots and I only had 110v in the shop. I double and triple checked all breakers and connections. I found that one of the hot wires somewere underground is no longer conducting. I also eliminated the possibility of a bad breaker by switching the two hots and rechecking with a volt meter. That same wire stays dead no matter what I switch around or do. What is strange though is the fact that on the good wire out in the shop it reads 120v and the "bad" one reads anywere from 50v to 100v but as soon as I put any load to it, it drops to 0v. I dont understand where the 50v-100v is comming from. Has the voltage went to ground? why hasn't the breaker thrown itself? And also how do I find the bad spot? is there any tricks? I tryed to be real careful when I filled the dirt back in and used my bare hands for the begining of the fill in so I would not cut the wires with the shovel. Any help would be appreciated. I am not looking forward to redoing this job. Any ideas on fixing this would be welcomed. Thanks

Are you a electrican? If you do not know what is going on in the situation you out line in your question then you should seek a electrical contractor before you get killed.

All you can do is trace the break. You may be able to find an electrician in you area that has an undergroud circuit tracer. It may keep you from having to re-trench the whole feeder.

And yes you can have a broken wire and the breaker will still hold due to a lack of resistance to ground or lack of proper grounding.

Maybe your local Power company can help, they should have a cable fault locator unit.

just say no to direct burial.....

Direct buried cables are required to be 24".

Call an electrician before someone gets killed and or something gets destroyed.

Just my opinion.

Aluminum wire sucks by the way.

Wait 'till the first snowfall then look for the green spot. I've found many bad tornado magnet feeders this way.

Tom

Regardless of where the break is underground, you will need to replace the whole wire.

Turn the power off, start digging and this time use conduit.

Tom, LOL Heh heh... "tornado magnet"... too funny!

Good point, George.

bayala13, Pipe it (but over-size the pipe for an easier pull, i.e. 2" for 100A, or 3" for 200A). It'll be more resilient and if it does fail, it'll be easier to replace (ideally).

For what it's worth, ya got a break in one leg. Probably had a "nick" in the insulation, moisture/water got to the Al conductor. Water, al, soil; mix it all together & bingo.....you wind up with an "open". It's OK with no load, cause the "open" didn't burn far enough apart yet.
I believe in pipe.....but there can be problems there also. Check that depth, direct burial is 24", right.
Personally, I would not "patch" it; if it happened once it can happen again, then you put patches on the patches.

Dig it, pipe it, pull it, & it's done.
100 amp feeder, 100', my shop, damn if it wouldn't be pipe & COPPER.

PS: Ypour profile says "sales" as a profession, I strongly suggest that you call a qualified ELECTRICAL CONTRACTOR. BE SAFE.
John

One of the things that I like most about this site is that its members are both helpful AND polite. If Bayala had posted this question on Mike Holts NEC forum, he would have been ridiculed and belittled.

I'm proud to be a member of this site.

Pearlfish you are absolutley correct. I always save my wrath for the Mike Holt site. May have something to do with those rather expensive videos I purchaed over there. <bitter> Anyway have a wonderful evening fella.

[This message has been edited by Electricmanscott (edited 11-01-2002).]

I like pipe also, even for line voltage (120) yard lighting you still have to dig a trench, and the first cost is a little bit more, but if you oversize the conduit you can add a new circuit, or replace a bad wire without digging again. I believe the only use for ½" conduit is so large commercial electrical bidders can save money on large jobs.

I work for one of those in which you refer to and as far as I am concerned 1/2" PVC does not exist! (Well, you do have to use it for certain step lights and such. That is how big the hub is.)