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#124143 08/12/06 06:59 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
I was called to fix some parking lot lights. In tracing the circuit - with toner and marking paint - I found a place where the lines seemed to cross. Under the seamless asphalt, I found a junction box.
[Linked Image]


Now, until recently, there was no reference in the NEC to boxes, or methods, for mounting in the ground. What I found was a single gang "Bell" box, set in a custom-made concrete block. The contractor even bevelled the edges of the block!
[Linked Image]


Here is another view of the completely excavated block. Please note the UF coming out... it exited the box through a rigid nipple, then got caught up in the pour.
[Linked Image]

#124144 08/12/06 07:15 PM
Joined: Jan 2003
Posts: 4,391
I
Moderator
You can buy bell boxes precast in concrete as well.

[Linked Image]


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#124145 08/12/06 08:41 PM
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
I didn't know that!

Zinc, (or aluminum)... which is what they're made of... don't handle alkalai very well. They quickly degrade to little more than white dust. I am surprised they're actually sold in concrete- an alkalai.

The one in the pics was certainly in poor shape. Every such box I have seen, either buried in concrete, or just buried in dirt,
has been seriously corroded, and filled with mud. This is true even when the cover appears to have a gasket, and be properly installed.

I replaced this arrangement with a handhole, and traffic-rated cover.

#124146 08/13/06 06:49 AM
Joined: Jan 2003
Posts: 4,391
I
Moderator
Quote
I didn't know that!

That makes two of us, I never saw one till I dug this one up.

This one had to many 10 AWGs.

Story here

Quote
Zinc, (or aluminum)... which is what they're made of... don't handle alkalai very well. They quickly degrade to little more than white dust. I am surprised they're actually sold in concrete- an alkalai.

I agree and the one I dug up is only a few years old. It is already junk as far as any threaded holes.

Quote
The one in the pics was certainly in poor shape. Every such box I have seen, either buried in concrete, or just buried in dirt,
has been seriously corroded, and filled with mud. This is true even when the cover appears to have a gasket, and be properly installed.

Again I agree.

Quote
I replaced this arrangement with a handhole, and traffic-rated cover.

Cool.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
#124147 08/16/06 09:19 PM
Joined: Apr 2002
Posts: 7,381
Likes: 7
Member
As a side note to this sbject:
Had a no lights call in a shop ctr. Power was 'out' at 15-20 poles; all circuits in store on, contactors OK. ??? Started the trace process. Store mgr comes out & said ' we see smoke rising from the traffic island when the irrigation sprinklers are on' Hmmmm!

Traced a few circ. back to that island area, said OK, grab a shovel. Under 12" of mulch, a PVC box (30x30) with the cover concaved in.

Talk about major meltdown; cover crushed the conductors against the ruff PVC stubs & all heck broke loose, add some water & ??

BTW, manager guy said it was smoking for about two weeks, but he waited for a Friday at 3:30 to call HQ.

John


John
#124148 08/21/06 08:58 PM
Joined: Nov 2005
Posts: 187
Member
That box almost looks like a pre-cast "lick and stick" (stone veneer) box for lights and outlets.


Hank
#124149 08/25/06 06:32 AM
Joined: Dec 2005
Posts: 869
Likes: 4
R
Member
Good photo's.

We have similar problems here in Auckland too.
With a lot of road widening for extra buslanes etc streetlights circuits are usually first affected by botch up jobs, or hide it and she'll be right.

Within a few weeks, months the problems start appearing by intermittend blowing of section fuses on these streetlight circuits.

Then I go on site for a cable fault locate and mark out, and the new asphalt road will be cut open and poorly made breach joints are found, crushed j boxes, or just linetaps with some almalgamating tape around it.
Heads should roll here but it never seems to happen.

With these road widening projects I maintain that a complete new S.L. supply is run on the outer verge of the road feeding the new lights prior to disableing the old supply.
Also no breach joints underground which usually give troubles later on on when not properly done by subcontractors.
Then cables in, out of S.L. poles to complete the streetlight strings.

but,
cheap is very attractive short term,

and becomes
very expensive and inconvenient later on when faults will happen.

Why not do the jobs properly in the first place.


The product of rotation, excitation and flux produces electricty.
#124150 08/26/06 05:56 PM
Joined: Jul 2005
Posts: 73
S
Member
I like handholes myself.Down here in florida you need something that lets the water drain away.


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