Sleeve a conduit in a concrete floor?

Status
Not open for further replies.
hockeyoligist2

hockeyoligist2

Senior Member
Location
close to greenville sc
Is there anything on the market to sleeve conduit? A 60' run. I have done a web search and talked to our suppliers. No luck. We have had to replace the wire 4 times in the last 2 years. The short was in the same place every time, about 8' from the motor. It is in a suspended concrete floor and we don't have any good options for running new conduit. If we run it overhead we can't get it around an overhead crane. If we run along the floor it is a tripping hazard. Our only option is to bore 2 holes in to the lower level and run about 200' of pipe or go overhead as far as we can and run about 300' of pipe (Ocal because harsh environment, hard to work with).

It is 1" pipe with 4 # 12's so a sleeve of some sort wouldn't be hard to do. I have been tempted to pull in some MC cable.....
 
Buck Parrish

Buck Parrish

Senior Member
Location
NC & IN
[quote=hockeyoligist2;1119731]Is there anything on the market to sleeve conduit? A 60' run. I have done a web search and talked to our suppliers. No luck. We have had to replace the wire 4 times in the last 2 years. The short was in the same place every time, about 8' from the motor. It is in a suspended concrete floor and we don't have any good options for running new conduit. If we run it overhead we can't get it around an overhead crane. If we run along the floor it is a tripping hazard. Our only option is to bore 2 holes in to the lower level and run about 200' of pipe or go overhead as far as we can and run about 300' of pipe (Ocal because harsh environment, hard to work with).

It is 1" pipe with 4 # 12's so a sleeve of some sort wouldn't be hard to do. I have been tempted to pull in some MC cable.....[/quote]
We use bigger conduit. Or cast iorn water pipe.
 
ultramegabob

ultramegabob

Senior Member
Location
Indiana
is there a burr inside the conduit at a coupling or somthing? maybe you can get a SeeSnake or similar tool and look inside and see what is causing the failure. why cant you just cut the floor and repair the conduit that is there?
 
C

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
Pierre C Belarge said:
How about installing parking deck MC cable inside of the 1" pipe?
Click to expand...

This sounds like the easiest most cost effective solution.

Everything else would probably require cutting the concrete to get to the burr in the conduit or running a whole new conduit like you mentioned.
 
hockeyoligist2

hockeyoligist2

Senior Member
Location
close to greenville sc
infinity said:
What exactly is causing the conductors to fail?
Click to expand...

We think it is a burr in the pipe or something. It is an easy pull every time we re-pull the wire. The wires don't show any damage anywhere else. Not even a tiny nick on any wire any where else. But all four wires show damage at the same point.

The machine does cause a lot of vibration, but there are 4 of them and this one is the only one with problems. The first failure was about 3 months after the building was constructed and put on line.

We have had a lot of problems in other buildings that were built during this upgrade. We had another short in a concrete pad and couldn't re-pull the wires. After looking at it there is no way that it could have had less than 7 90's. No boxes in between unless they were under the concrete with no access.
 
H

hurk27

Senior Member
Location
Portage, Indiana NEC: 2008
If you know the distance to the problem area, tape a piece of smurf tubing or even a piece of garden hose on the wires covering it in this area, then just pull it to the bad area when you pull in the wires, I'm sure 1/2" smurf will go in a 1" conduit easy?

Just put a note in the J-box so the next guy who comes along and trys to add more circuits to the conduit will know about it being in there.:D

I have also seen a pipe cleaner type of system that is like a Snake with a spinning head that cleans out rust in pipe before, but I never found out where they got it, it was kind of like having a brake honer on the end of a speedometer cable?
 
S

sameguy

Senior Member
Location
New York
Occupation
Master Elec./JW retired
we used roto rooter once in the 80's, put a 200' fish in one end of a 300+ run and another in the other end and couldn't get them to touch. Couldn't blow,suck a mouse in or a bag called roto rooter and they hooked the one fish we left in for the price of a service call. We had already wasted much more time and money trying the rest. Rooter guy said to call him any time, so not that uncommon.
 
ohmhead

ohmhead

Senior Member
Location
ORLANDO FLA
Well they make a mandrel for 1 inch conduit . The company is Inwestco it has metal washers and its not your typical type it actually rips out burning or concrete issues .

But that said if it was installed by a EC who did not ream out your pipes if it is i assume its emt in the deck then if you know were its at chip it out fix it or last option .

But just because its there in that same spot doesnt mean its that spot damaging the wire it might be a coupling or fitting any place before that spot ?

Before you install wire use stranded thhn only wire and use shrink tube over a 5 or 6 foot area of that bad spot shrink tube each or shrink tube the whole bundle .

You can buy 12 wire shrink tube or smaller.

Everytime it shorts out that spot is going to get a build up of copper weld metal on the walls of that emt this is just adding to the problem .

Did you megg it before you turned it on at 1000 volts ?

Last option shrink tube the bundle its cheap and go to a hardware store get a gallon of mineral oil when you pull it in next time pour a gallon of that inside the run it will make a non conductive wire soap and protect your wires better then the soap that old greenlee sells us .

Take care







.
 
Status
Not open for further replies.
Top