Critique my plan for 100 amp sub feeders.

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stickboy1375

stickboy1375

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Litchfield, CT
frizbeedog said:
I just read that text preceeding the table and I am stumped. I have always installed #2 al. to out buildings with a 100 amp OCPD and have never once been called ont this. From what I think you are saying, I've been wrong all this time and every inspector that has approved these installations is also wrong.

That disturbs me..... :-?
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Check out the 2008 code, they reworded it so it makes more sense.
 
brantmacga

brantmacga

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Georgia
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frizbeedog said:
I just read that text preceeding the table and I am stumped. I have always installed #2 al. to out buildings with a 100 amp OCPD and have never once been called ont this. From what I think you are saying, I've been wrong all this time and every inspector that has approved these installations is also wrong.

That disturbs me..... :-?
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me too. its not a dwelling, but is a detached garage any different than an attached garage? i'm just saying for load calc purposes. . . i don't think you're going to have any problems. . .but it is against code i guess. . .i'll just have to start charging for and installing #1 i reckon.
 
brantmacga

brantmacga

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stickboy1375 said:
You need a ground rod at the building no matter what.
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of course you do. i guess i wrote that in case the OP wanted to know where the 'ground' was going to come from.
 
frizbeedog

frizbeedog

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Oregon
stickboy1375 said:
Check out the 2008 code, they reworded it so it makes more sense.
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I did read 2008. And the highlighted change says ...all loads that are part or associated with the dwelling unit."
 
brantmacga

brantmacga

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iwirehouses said:
i will be using 2-2-2-4 in addition to the ground rod, so I'm looking good. I plan on using a pvc jbox. I'll probably have to hole saw the knockouts, right?
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why not 2-2-4?
 
brantmacga

brantmacga

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stickboy1375 said:
What if he wants a phone or catv? then its a problem.
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alright you've got me there. . . .what is it that i don't know?
why can't the phone/catv/dish be grounded to electrode at the garage? it is connected to the electrode at the main.
 
stickboy1375

stickboy1375

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Location
Litchfield, CT
brantmacga said:
alright you've got me there. . . .what is it that i don't know?
why can't the phone/catv/dish be grounded to electrode at the garage? it is connected to the electrode at the main.
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Check out 250.32 (B)(2) Besides all that, 2008 is not even going to allow 3 wire feeders anymore.
 
brantmacga

brantmacga

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stickboy1375 said:
Check out 250.32 (B)(2) Besides all that, 2008 is not even going to allow 3 wire feeders anymore.
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hmm. i'm not sure i follow. i'm reading that as "don't connect the neutral to the ground bar" & vice versa in a 4 wire feeder. what am i missing?
 
iwire

iwire

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Location
Massachusetts
iwirehouses said:
yeap, the inspector told me to use #2 alum.
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I know it is not going to hurt anything but you should be aware that it is still a NEC violation and your name will always be attached to it. (It is also a very common violation.)
 
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haskindm

Senior Member
Location
Maryland
brantmacga said:
hmm. i'm not sure i follow. i'm reading that as "don't connect the neutral to the ground bar" & vice versa in a 4 wire feeder. what am i missing?
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If there is any other metallic path between the buildings (such as CATV, Phone Line, or water line) that is bonded in both buildings then you MUST install an equipment grounding conductor between the buildings and keep the neutrals and grounds separate in the garage so that multiple paths for neutral currents are not established. In the 2008 NEC the permission to install only three conductors and using the neutral as a ground return path from the garage has been removed. You must install a grounding conductor to the garage under the 2008 code.
 
brantmacga

brantmacga

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Location
Georgia
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Former Child
haskindm said:
If there is any other metallic path between the buildings (such as CATV, Phone Line, or water line) that is bonded in both buildings then you MUST install an equipment grounding conductor between the buildings and keep the neutrals and grounds separate in the garage so that multiple paths for neutral currents are not established. In the 2008 NEC the permission to install only three conductors and using the neutral as a ground return path from the garage has been removed. You must install a grounding conductor to the garage under the 2008 code.
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oh okay. i just couldn't grasp that last night. thanks for the reply.
 
S

SiddMartin

Senior Member
Location
PA
I just caught wind of this,... are you saying that for a subpanel it is required to run 3 cond. (2 hots, 1 neu) and then have a seperate grounding means at the subpanel ie. ground rod, and not connect the neu to the ground? Is this soley for detached subpanels? Anyone have a link that I could read up on? Thank you
 
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