commercial pipe run

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bikeindy

bikeindy

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Location
Indianapolis IN
There is a fitness center that I will be installing 4 new 20A circuits for tred mills. the run is 190' has three 90 degree bends. I plan to use #12 THHN wire 4 ungrounded and two grounded conductors for power. I was thinking to put in 4 pull boxes to make things simple use 3/4" EMT. I don't do a lot of commercial so if anyone has suggestions I would like to hear them. oh power is 120/240 single phase. receptacles are 120V twist lock. tred mills are rated at 10.5 Amps.

Thanks
 
77401 said:
Why 3/4"?
Why so many Pull boxes?
No GEC? Just the conduit?
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yes I will have a GEC I was planning to make it easy on myself thats why 3/4" and so many pull boxes. I am charging plenty and thought that it might come in handy for future use to have space in the conduit and boxes to make future additions. I tend to do things with the next guy in mind incase that guy is me.
 
If that makes it easier - then do it.

Not many EC's care about the next guy - there is little profit in the "next guy"...unless YOU are the next guy :)
 
Sometimes tread mills can be a hard start. Should you not use #10 for voltage loss? They may be rated 10.5 amps but it seem like they take a while to get up to speed. Just a thought.
 
I'd like to offer another option:

Use that 3/4" EMT to pull a run for, say, a 60a, 240/120v sub-panel, using #6 wire. This will allow for less voltage-drop upon starting (unless they happen to start more than one at a time) and expansion.

I have always felt that sub-panels are preferable over several single circuits run the same length for the above reasons, and can even be more economical in the (pardon the pun) long run.
 
LarryFine said:
I'd like to offer another option:

Use that 3/4" EMT to pull a run for, say, a 60a, 240/120v sub-panel, using #6 wire. This will allow for less voltage-drop upon starting (unless they happen to start more than one at a time) and expansion.

I have always felt that sub-panels are preferable over several single circuits run the same length for the above reasons, and can even be more economical in the (pardon the pun) long run.
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That would put the panel in the fitness room which is not wanted this place is long and narrow and no place for a sub panel. that too would have been preferable to me. I figure since #12 THHN is rated 25 Amps it should be ok and they never have more that six of the twelve tred mills on at the same time. right now they are running 8 on 4 circuits and don't have a problem but the manufacture and service guys told them to get seperate circuits for them.
 
Your voltage drop with #12 AWG conductors would be 5.8%. A little high for a motor load IMO. Given that the run is 190' I would use #10 AWG. With only 3-90's I would install one pull box in the middle and use stranded wire. With the #12's, you should be able to pull it in with one hand.
 
bikeindy said:
That would put the panel in the fitness room which is not wanted this place is long and narrow and no place for a sub panel. that too would have been preferable to me. I figure since #12 THHN is rated 25 Amps it should be ok and they never have more that six of the twelve tred mills on at the same time. right now they are running 8 on 4 circuits and don't have a problem but the manufacture and service guys told them to get seperate circuits for them.
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If they can only have 6 on at the same time, why do they have 12?
If I'm understanding correctly, the end result will be 8 circuits for 12 machines and each pulls 10.5 Amps, correct? If that's true, it averages to 17 amps per circuit if they ever decide to run all of them at once. I'm with infinity, I would install #10 conductors. I also would use the EMT for equipment grounding (as mtnelectrical suggested). If you use the #10 thhn you'll need the 3/4" EMT (and still have room for 2 more circuits). You really can get by with less pull boxes, but if you sold the customer on "handy for future additions", then that's exactly what I would give them. I'd first make sure that I had enough "juice" for the job at hand.
steve
 
I am on the 10 AWG bandwagon.

Generally we step up to 10 AWG for 20 amp circuits longer than 100'.

If it is up to me I would most likely include a copper EGC (it would have to be 10 AWG as well)

This puts you at seven 10 AWGs in 3/4" EMT which is a fairly easy pull.

Is there any reason you must run EMT?

Is 10/3 MC a possibility?

Much less labor and costs.

Larry is a great guy, I think he sells panels for a living. :D

Of course if your customer looks like they will be adding more equipment in the same area than that may be a smart way to go.

If I was to go the panel route it would not be less than a 100 amp feeder in MC if possible. But any panel install is a major jump in price from 2 MWBCs.
 
hillbilly said:
If they can only have 6 on at the same time, why do they have 12?
If I'm understanding correctly, the end result will be 8 circuits for 12 machines and each pulls 10.5 Amps, correct? If that's true, it averages to 17 amps per circuit if they ever decide to run all of them at once. I'm with infinity, I would install #10 conductors. I also would use the EMT for equipment grounding (as mtnelectrical suggested). If you use the #10 thhn you'll need the 3/4" EMT (and still have room for 2 more circuits). You really can get by with less pull boxes, but if you sold the customer on "handy for future additions", then that's exactly what I would give them. I'd first make sure that I had enough "juice" for the job at hand.
steve
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I wasn't exactly clear about the 12 tred mills. there are curently two rows one row of 4 tred mills and a row of 8 the row of 8 are run on 4 circuits and the row of 4 are run on 4 circuits. so I am adding the 4 circuits to the row of 8.


Bob said "
I am on the 10 AWG bandwagon.

Generally we step up to 10 AWG for 20 amp circuits longer than 100'.

If it is up to me I would most likely include a copper EGC (it would have to be 10 AWG as well)

This puts you at seven 10 AWGs in 3/4" EMT which is a fairly easy pull.

Is there any reason you must run EMT?

Is 10/3 MC a possibility?

Much less labor and costs.

Larry is a great guy, I think he sells panels for a living.

Of course if your customer looks like they will be adding more equipment in the same area than that may be a smart way to go.

If I was to go the panel route it would not be less than a 100 amp feeder in MC if possible. But any panel install is a major jump in price from 2 MWBCs."

There will not likely be any more additions that a sub would help and they requested EMT. I am leaving in 30 minutes to get started to work after they close. I have decided to go with #10 and will be running EGC. I cut back to two pull boxes. I'll let you know how it goes I think it will be pretty easy, but the ceiling is 14' high 2' drop cieling below that and the room is crowded.
 
bikeindy said:
Every thing went well had to sadle two beams I was unaware, of but that is the only thing I ran into unexpected. Thanks for the advice.
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Good :)

How did the pull go?

Saddles can really add some drag when pulling.
 
bikeindy said:
I figure since #12 THHN is rated 25 Amps it should be ok and they never have more that six of the twelve tred mills on at the same time. right now they are running 8 on 4 circuits and don't have a problem but the manufacture and service guys told them to get seperate circuits for them.
Click to expand...

You said in your first post "I plan to use #12 THHN wire 4 ungrounded and two grounded conductors for power." Since this is 4-6 current carrying conductors don't you derate by 80%? This would make the capacity of #12 THHN be 21 amps.
 
iwire said:
Good :)

How did the pull go?

Saddles can really add some drag when pulling.
Click to expand...

The pull went well I added back in my two pull boxes that I was planning to delete as I ran the pipe. so having 4 pull points helps if the wire "slows down" pulled it all by hand with a fish tape. you need a box for every 270 degrees of bend right? As I stated I do commercial work but not a lot.
 
bikeindy said:
The pull went well I added back in my two pull boxes that I was planning to delete as I ran the pipe. so having 4 pull points helps if the wire "slows down" pulled it all by hand with a fish tape. you need a box for every 270 degrees of bend right? As I stated I do commercial work but not a lot.
Click to expand...
It's equivalent to (4) 90 degree turns (or 360 total) between pull points.
I don't have my code book with me right now, so I can't cite you a number.
steve
 
I too would opt for #10...
EGC optional, but not a bad idea considering the evironment of a gym. Sweaty lightly clothed people on electric squirrel runners, getting thier exersize like lab rats..... A more reliable solid ground not a bad idea. Also lets you use it as a pull wire in the future if needed.
 
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