Homeruns

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Alwayslearningelec

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Ok, let's saya spec limits (3) cicruits to a conduit and says all homeruns must be #10 wire. If you have say (12) circuits in an area about 150' away why would you ever run a homerun out to that location? Would'nt you run the homerun 10-20' feet out then run the #12's to the location.......keeping the homeruns as short as possible? THanks.
 
If I had 12 circuits 150 feet away I believe I would run a feeder and set a sub panel.

I think you are trying to cheat here. A homerun is the wire between the first device and the panel. Setting a JB and getting by that way is not the intent of what is being specified. The purpose of a #10 homerun is for Voltage Drop. To do what you suggest would not help with this issue.
 
Dennis Alwon said:
If I had 12 circuits 150 feet away I believe I would run a feeder and set a sub panel.

I think you are trying to cheat here. A homerun is the wire between the first device and the panel. Setting a JB and getting by that way is not the intent of what is being specified. The purpose of a #10 homerun is for Voltage Drop. To do what you suggest would not help with this issue.
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Besides setting a sub panel, if you ran #10 you would almost have to transition to #12 to land on some devices wouldn't you?
 
No more than three circuits to a conduit seems to deal with derating issues (maybe). The #10 AWG conductors as Dennis suggested are for voltage drop. 150' homeruns are pretty common in commercial applications when panels are located in a central electric closet.
 
Yes, the receptacles would be wired with #12's but can't that branch circuit be run close to the panel to a box then splice with #10's for the dhort home run. My question is why would the #10 homerun have to be run out(about 150') to the area near the receptacles? Thanks.
 
horsegoer said:
Yes, the receptacles would be wired with #12's but can't that branch circuit be run close to the panel to a box then splice with #10's for the dhort home run. My question is why would the #10 homerun have to be run out(about 150') to the area near the receptacles? Thanks.
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Dennis answered that question in post #2. You would use larger conductors for voltage drop compensation.
 
infinity said:
Dennis answered that question in post #2. You would use larger conductors for voltage drop compensation.
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Yes, but I am saying that I think #12's would be fine to run 150'.... i think?? Hence my question about a short homerun..and no need to run it 150'
 
horsegoer said:
Yes, but I am saying that I think #12's would be fine to run 150'.... i think?? Hence my question about a short homerun..and no need to run it 150'
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It doesn't matter what you think the engineer specified it so running a short piece of #10 will not satisfy his request, IMO.
 
What do you base your comment on that #12 is okay. If there is a 20 amp load on the circuit then a #12 would not be okay. What is the circuit feeding?
 
horsegoer said:
Yes, but I am saying that I think #12's would be fine to run 150'.... i think?? Hence my question about a short homerun..and no need to run it 150'
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Well if you're in a position to perform value engineering and save some money then do it. But if I'm writing the spec for 3 circuit, #10 homeruns in a raceway then I would not accept anything less.

Just curious, what method are you using to determine that the #12's may be sufficient for a 150' run? I'm not saying that they aren't just wondering how you would go about determining that.
 
Dennis Alwon said:
It doesn't matter what you think the engineer specified it so running a short piece of #10 will not satisfy his request, IMO.
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How would that not satisy his request? Because a "homerun" is from the last device? From what I have seen, and the engineer is okay with it in the past, you can run from the "last device" to a homerun box then to the panel. So like I was saying that homerun box would be right outside the electrical closet.
 
infinity said:
Well if you're in a position to perform value engineering and save some money then do it. But if I'm writing the spec for 3 circuit, #10 homeruns in a raceway then I would not accept anything less.

Just curious, what method are you using to determine that the #12's may be sufficient for a 150' run? I'm not saying that they aren't just wondering how you would go about determining that.
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MH vd calculator but I think I entered wrong.
 
OK. But nobody agrees with you.
What is the point of a #10 home run if it changes to #12 right outside the closet? Why bother with #10 at all?
 
horsegoer said:
How would that not satisy his request? Because a "homerun" is from the last device? From what I have seen, and the engineer is okay with it in the past, you can run from the "last device" to a homerun box then to the panel. So like I was saying that homerun box would be right outside the electrical closet.
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I sincerely doubt that would be acceptable to the engineer that specified this. You can't just put a jbox 10' from the panel and say that after that 10', it's no longer a home run. The intent is obviously to use #10s for the majority of the run length in order to minimze voltage drop.

I would caution you to avoid just assuming the voltage drop will be "fine" at 150'. It only takes 7 amps at 150' with #12s to exceed 3%.
 
DetroitEE said:
I sincerely doubt that would be acceptable to the engineer that specified this. You can't just put a jbox 10' from the panel and say that after that 10', it's no longer a home run. The intent is obviously to use #10s for the majority of the run length in order to minimze voltage drop.

I would caution you to avoid just assuming the voltage drop will be "fine" at 150'. It only takes 7 amps at 150' with #12s to exceed 3%.
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Yes I just saw that on the calculator.
 
Adding to post #14 and #15, you would gain practically nothing by doing as you suggest other than pulling the wool over someones eyes by making them think you had a #10 home run from the general area of the load.
If you truly had a 20 amp load, the voltage drop on a #12 for the full 150 ft would be 11.88 volts, far in excess of the 3.6 desirable. If you just ran the #10 for 20 ft and then changed to #12 you would still have 10 volts drop.
With a full 20 amp load, even a #10 for the full length gives you a 7 volt drop.
 
DetroitEE said:
I sincerely doubt that would be acceptable to the engineer that specified this. You can't just put a jbox 10' from the panel and say that after that 10', it's no longer a home run. The intent is obviously to use #10s for the majority of the run length in order to minimze voltage drop.

I would caution you to avoid just assuming the voltage drop will be "fine" at 150'. It only takes 7 amps at 150' with #12s to exceed 3%.
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So if you have a circuit with say (6) 20a general receptacles feeding computer, printers etc. I would say each might draw 1-2 amps. So then #10 homerun....
 
horsegoer said:
So if you have a circuit with say (6) 20a general receptacles feeding computer, printers etc. I would say each might draw 1-2 amps. So then #10 homerun....
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Correct, I would definitely want those #10s for the home run for a circuit feeding workstations that contain computers and printers.
 
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