Conduit over fill!

Status
Not open for further replies.
B

brother

Senior Member
Location
"I have learned, in whatsoever STATE I am, therewi
Ok, maybe Im just being to strict in 'NEC' code following, but I just got done helping a guy on a job (was done with mine) where the conduit is overfilled. This is 1" emt, it has 15 #10's 4 #12's Thhn insulation. You can double check my math but I come up with too many wires in this pipe. (this why the pull was too hard) and yet it was forced in there anyways. Have any of you run into this where there were too many wires and they just 'force more in there'???

Oh by the way we wont even go into the derating that nots being done, even though i know alot of guys dont derate. Those #12's either should be #10's or on a 15amp breaker. I counted 10 ccc and this is not counting the neutrals (dont know it they have nonlinear loads). I also discovered that the #10's that were pulled are spliced into #12's at another j box down stream just before they get to the deivices (mostly receptacles, light etc). This should be #10's all the way.

I didnt realize this error in his stuff until it was done. The over fill just looked funny to me at first until I double checked my math. I feel Ive been suckered into being a HACK!! What do you think??
 
Last edited:
You're right about the overfill. Doesn't sound like the guy doing the job really cares about derating or overfill. For what it's worth I see this quite a bit. Conduit's too small or not enough of them so they get crammed full of wire.
 
brother said:
Ok, maybe Im just being to strict in 'NEC' code following, but I just got done helping a guy on a job (was done with mine) where the conduit is overfilled. This is 1" emt, it has 15 #10's 4 #12's Thhn insulation. You can double check my math but I come up with too many wires in this pipe. (this why the pull was too hard) and yet it was forced in there anyways. Have any of you run into this where there were too many wires and they just 'force more in there'???

Oh by the way we wont even go into the derating that nots being done, even though i know alot of guys dont derate. Those #12's either should be #10's or on a 15amp breaker. I counted 10 ccc and this is not counting the neutrals (dont know it they have nonlinear loads).

I didnt realize this error in his stuff until it was done. The over fill just looked funny to me at first until I double checked my math. I feel Ive been suckered into being a HACK!! What do you think??
Click to expand...

Looks to me to be .02 in? over. Now lets talk derating.:D
 
Did you pull in a ground wire? Conduit sounds tight, when I come behind you later on and need to pull some more circuits in I'll probably use that as a pull string...;)

Like Rob said, it's definitely not uncommon.:roll:
 
Well , you could just look at as taking some load off of the central heating
system. BTW I don't think your a HACK. A Hack doesn't question if a install
is compliant or not.
 
Brother,

Maybe he did pull the #10's (that splice to the #12's) for derating purposes, normally the

recpts. are 20a circuits and 20a circuits for lighting is also common. Do you feel a little bit

better ? :)
 
Cow said:
Did you pull in a ground wire? Conduit sounds tight, when I come behind you later on and need to pull some more circuits in I'll probably use that as a pull string...;)

Like Rob said, it's definitely not uncommon.:roll:
Click to expand...
Yes a ground wire was pulled, (required cause its in a hospital!!!) This is why it BOTHERS me soo much. You most likely will end up installing more conduit in this job.
 
brother said:
This is 1" emt, it has 15 #10's 4 #12's Thhn insulation.

I counted 10 ccc and this is not counting the neutrals (dont know it they have nonlinear loads).
Click to expand...

If you have 19 conductors, no travelers, EGC's, or control wires and a wye, in a perfect world, you would have 14 ccc and 5 neutrals. But your right in that 10 or 14 ccc, your 10's are good for 20A and your 12's are good for 15A.
 
benaround said:
Brother,

Maybe he did pull the #10's (that splice to the #12's) for derating purposes, normally the

recpts. are 20a circuits and 20a circuits for lighting is also common. Do you feel a little bit

better ? :)
Click to expand...

Not really!! those spliced on #12's are still suppose to be #10s to the device according to code. Its suppose to be derated for # of conductors, not for distance/length of run (the run was not that long). So it would fly if it was just for 'voltage drop' but not for the overcrowding.
 
brother said:
Yes a ground wire was pulled,
Click to expand...

chris kennedy said:
in a perfect world, you would have 14 ccc and 5 neutrals.
Click to expand...

Let my correct this before someone corrects me.

Brother states an ECG was pulled, that leaves 18 other conductors. So assuming a 4-wire 3-phase wye, linear loads:

A,B,C-N

A,B,C-N

A,B,C-N

A,B,C-N

A or B or C with N

This would be 14 ccc's
 
chris kennedy said:
Let my correct this before someone corrects me.

Brother states an ECG was pulled, that leaves 18 other conductors. So assuming a 4-wire 3-phase wye, linear loads:

A,B,C-N

A,B,C-N

A,B,C-N

A,B,C-N

A or B or C with N

This would be 14 ccc's
Click to expand...


That sounds right. If the #10's are protected at 20 amps and the #12's at 15 amps then the derating is compliant. Fill is another issue.

#10's do not need to go all the way to the device for a 20 amp circuit.
 
brother said:
Not really!! those spliced on #12's are still suppose to be #10s to the device according to code. Its suppose to be derated for # of conductors, not for distance/length of run (the run was not that long). So it would fly if it was just for 'voltage drop' but not for the overcrowding.
Click to expand...

Brother, After they spliced to #12, was the conduit still over filled?
 
benaround said:
Brother, After they spliced to #12, was the conduit still over filled?
Click to expand...

Ok, let me see if I can make this a little clearer. As far as I can tell, the 1" emt goes from the panel to a 4'11 box. Then from there they spliced the #10's to #12's . Maybe then they are ok from that 4'11 on to the device (maybe no #10's needed to the receptacle as I had originally thought), Im not sure how many wires are in that final run, but I do know they drop off. But the 1" is still over crowed and the #12's in that 1" (this is a different set of #12's from the ones spliced to the #10 in the 4'11) needs a 15amp breaker , or be upgraded to #10.
 
Last edited:
Just to add to my concern, In the past I have seen where some electricians didnt double check the reason why a #10 wire was on a 20 amp breaker. They just go ahead and put a 30 amp on it and that #10 is spliced to a #12 down stream. Ive had to correct others work over this issue before. This is one of the main reasons I dont like to see this type of work/done even though in reality they may not be any fires!
 
Status
Not open for further replies.
Top