ECN Forum Forums General Topics of the Trade General Discussion Area Underground wire connections

I am troubled by an installation I am currently working on. I have gleaned from this site that any/all conduits placed underground eventually fill with water no matter what installation procedure is used, period. Is it then a "no brainer" to assume that any splices located underground (Like in a PVC hand-hole) should be connected using a "rated" undergroung gel-filled wirenut to prevent corrosive effects?

Well that depends on the wire size - hand hole location - the way the hand hole is installed.

Whats the splice for? I am assuming since we are talking handholes and wirenuts that its some sort of outdoor branch circuit - like a lighting circuit ot similar?

The NEC assumes all underground conduits and enclosures are wet locations.

I personally always assume that these underground raceways will be filled with water.

IMO unless you can put crushed stone under the handhold, and keep the splices up at the top of the hand hole you need to use underground splice kits, not just gel filled wire nuts.

It is a large estate driveway lighting system. I was surprized to see regular old wire nuts being delivered to the job intended for the underground splices. How frustrating it is to try to make some people see the light. (i.e the boss) The customer is certainly capable of paying for the right components. The boss doesn't see the need, and I'm getting tired of being the "overinformed persnickety apprentice"

You are not being nitepickey. I was a former 3rd year apprentice who recentley left the field. You are trying to do the right thing. I cant count how many times box fill was wrong, conduit fill was way too much and so on. I would check with the AHJ. If you do it the bosses way and then he finds out that you have to go back with the proper wirenuts he may very well get the right stuff to begin with rather than pay you again to go out and fix what he knew was wrong in the first place. Its a wet location. Use the proper wirenuts.The money he will pay to fix it will be more than just buying the right wirenuts. CHEAP> is what I see here. Along with future problems down the road for the customer.

[This message has been edited by steve ancient apprentice (edited 11-20-2006).]

If all you have is standard wirenuts, try filling them with silicone caulk. It's pretty effective on small wire. Taping them is a waste of time. Keeping the wirenuts to the top is a very good idea.

The boss is the boss. It's his warranty and his reputation at stake. Sometimes the customer doesn't want to pay more, even if they have the money.

And yeh, every underground pipe and box will fill with water. I've seen the French drains (rock in the bottom) fill, and even those with sumps will eventually fail when the sump goes bad.

I have two practices where the connections will get wet.

For areas like laws -remember, this is in a desert area- I will usually just dip the wire nuts in Scotch-Kote, aim them up (so they drain), and keep to the top of the handhole. This is a connection that can be taken apart later. Say, if the fool backs over his pole light.

For more demanding areas, say, in sump pump float connection boxes, I will slip the entire wire nut assembly into a plastic packet of a compound made for underground splices. This is a permanent connection - so you might want to make sure everything works before you do!

Code issues aside, I prefer to always use a proper handhole. Direct burial may be allowed, but those connections are then impossible to find. many will use 'bell' boxes, but I have found that even properly gasketed ones will soon fill with mud - and the ground corrodes them severely. There's never enough room to work with UF in them, and the cables are never run deep enough, either!

My 'handhole of choice' is called an N-9. It is fiberglass, about the size of a 5-gallon bucket, and has worked well for me.