Questionable Install (CEC)

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Old 02-12-14, 05:05 PM
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Questionable Install (CEC)

So long story short, the company I work for does some questionable work sometimes.
I have a few questions for anyone fluent in commercial installs, preferably with CEC knowledge.

There is a roughly 150'-200' run of 1" EMT feeding a 100A RTU.
There are pull boxes at about 50', and 100'.
My boss chose 2 AWG RW90 wire to compensate for voltage drop.
Three 2AWG wires are being pulled.
The plan was to pull to the RTU from the 50' box, then spool off the last 50' to the panel.
4 of us had a hell of a time making it from the 50' box to the 100' box. The guess is that the guy who ran it forgot to do up a coupling. There is also 240 degrees worth of offsets in that 50'.
So the boss says "we'll just do joints. pull box to box, box to RTU".
Now, at the 100'-RTU box, we only made it maybe 1/3 of the way through the run before we couldn't budge the wire. I went and followed the parts of the run that weren't behind walls and bulkheads, and could see just under 500 degrees worth of bends in the run (and thats only what I could see). The guy who ran it went nuts with offsets on the last 50ish feet and didn't put any pull boxes in.
So now the boss says "pull it all back and i'll bring 3AWG tomorrow. we're close enough now that voltage drop doesn't matter".
I also asked him about maybe using barrel splices. He said the company would just use split bolts wrapped in a layer of splicing tape and another layer of electrical tape after.
So now that you know the story...

-In a roughly 150' - 200' run, can you downsize your wire in the last 50' and still maintain your voltage drop compensation?

-Is the "split bolt and tape" method acceptable when splicing larger wire?

-How would you personally go about splicing 2AWG wire in a box?

-Is it worth arguing with my journeyman, who would have to argue with his superior in the office who ultimately provides us with our parts, over better resolutions?
 
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Old 02-12-14, 05:56 PM
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As you know already, I am not fully versed in CEC, but I can tell you what I know per NEC.

You didn't mention how many wires you are pulling in but I will assume this is a 3 phase unit. You also didn't mention what the full load of the unit is as that will affect voltage drop, as will voltage.

-In a roughly 150' - 200' run, can you downsize your wire in the last 50' and still maintain your voltage drop compensation?
Yes. Voltage drop is also affected by wire size. You can go here: Voltage Drop Calculator and do the calculation for each section of wire run.

-Is the "split bolt and tape" method acceptable when splicing larger wire?
Yes. It is kind of old school, but it is acceptable.

-How would you personally go about splicing 2AWG wire in a box?
Make your splice with the split bolt. Tape with rubber tape. Wrap with good electrical tape. Stuff the wires in the box. Hopefully your boxes are big enough.

-Is it worth arguing with my journeyman, who would have to argue with his superior in the office who ultimately provides us with our parts, over better resolutions?
I can tell you this, I know way your having a tough time with the wire pull. 240 degrees of offsets and 500?!?! Code limits bends to 360 degrees max and even than that can be tough. Also your pipe is too small for 3 #2 wires. IIRC you can only get 3 #3 THHN wires in a 1" pipe EMT.
 
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Old 02-12-14, 06:07 PM
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-In a roughly 150' - 200' run, can you downsize your wire in the last 50' and still maintain your voltage drop compensation?
You can downsize the wire. but I wouldn't because you have a motor load to get started on that circuit. Can't say for sure about the CEC, but as far as I know, the NEC doesn't get into voltage drop or how to calculate it. That's a design issue that the NEC isn't supposed to be concerned with.

-Is the "split bolt and tape" method acceptable when splicing larger wire?
Perfectly acceptable, but may not be cost effective when considering the labor involved. Most companies wouldn't use split bolts if Polaris type connectors were available.

-How would you personally go about splicing 2AWG wire in a box?
I'd use Polaris insulated connectors, ILSCO makes a similar connector and is priced a little more competitively.

-Is it worth arguing with my journeyman, who would have to argue with his superior in the office who ultimately provides us with our parts, over better resolutions?
It's normally the foreman's job to talk to the project manager in the office. There may be a reason, such as the specification book, that requires the split bolt use. As far as downsizing the wire, it's just plain not a good idea, but the project manager usually makes the decision unless overruled by the company engineer, if there is one.
 
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Old 02-12-14, 06:12 PM
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Also your pipe is too small for 3 #2 wires. IIRC you can only get 3 #3 THHN wires in a 1" pipe EMT.
I totally missed the conduit size in the original post. Yes, definitely too small for #2s. I would have instructed my foreman to use 1 1/2" EMT for that circuit.

Is wire and conduit size not shown on your drawings? These issues are precisely why accurate drawings should be on the job.
 
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Old 02-12-14, 06:17 PM
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The wires enter comfortably. CEC says Three 2AWG RW90 in 1'' EMT is max. I know the bends are the issue. CEC also says 360 degrees max. The guy who piped the run took a foolish path and ignored bends.
My jman disagrees about the bends being a problem though. He figures it should still be smooth sailing even with 500 degrees within the last 50'.
The split bolt tape thing still sounds sketchy to me, but I guess I'll roll with it.
Thanks Tolyn!
 
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Old 02-12-14, 06:23 PM
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Joe,

I fully agree it should be bigger, but according to our rules it squeaks by on a pass.
No we have little info on our prints for this job. Just what devices they want and where. Not even any circuit numbers.
I have yet to even see a print with our conduit and wire mapped out. That is left to us. Even telco, security, audio, etc. pipes are left for us to figure out. They just tell us where they want to enter, and where they want to end up. The in between is on us.
 
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Old 02-12-14, 06:43 PM
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He figures it should still be smooth sailing even with 500 degrees within the last 50'.
You'll not get the last 50 feet pulled in without possibly destroying both the conduit and wire. Not gonna happen.

The split bolt tape thing still sounds sketchy to me, but I guess I'll roll with it.
It's a good splice when done correctly, but labor intensive and not cost effective with electrician rates in this country.
 
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Old 02-12-14, 07:14 PM
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You'll not get the last 50 feet pulled in without possibly destroying both the conduit and wire. Not gonna happen.
That part he accepted. But only after he hooked his fish tape to his lift and tried pulling it with the lift. The arse end of the lift started coming up. Thats where the idea to downsize came from.
 
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Old 02-12-14, 07:37 PM
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That part he accepted. But only after he hooked his fish tape to his lift and tried pulling it with the lift. The arse end of the lift started coming up. Thats where the idea to downsize came from.
Still with 500 degrees of bends? Even with downsizing the wire it's not gonna happen. You'll need to install more pull boxes or even C-Fittings to pull from. Where did your journeyman get his card, from KMart?
 
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Old 02-13-14, 04:26 PM
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No Kmart here, perhaps Cheerios.
I did convince him to at least cut in a 10x10 box. Made the pull much easier.
 
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