Feeder from main panel to detatched Garage

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Strahan

Strahan

Senior Member
Location
Watsontown, PA
Just want to make sure I'm not missing something. I believe I'm right. When running a 4-wire feeder to a detatched garage a grounding electrode (ground rod) is required per 250.32. There would be no bond between the grounded conductor and equipment ground as this would violate 250.6(A). Comments or correct me if I'm missing something. Thanks guys:D
 
Pierre C Belarge said:
You can also reference 250.24(A)(5). Take note of the FPN that follows this subsection.
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Ok FPN refers me to250.30(A) separately derived systems; which is not the case, 250.32 which basically tells me exactly what I have suggested (except in existing premises with only grounded conductor run) or now we have 250.142 and within this article I am not seeing any alternative the only place that may permit the grounded conductor to be used as the grounding means would be 250.142(A)(2) and this points me right back to 250.32(B) which states an equipment grounding conductor must be run. Pierre maybe I totally missed what you were trying to refer me too I'm not sure but please elaborate.
 
Most people who read the NEC do not pay much attention to the FPNs. I was not refering you to the FPN to state you had done something wrong. I did it strictly to bring it to your attention. One of the features of this FPN, is it does help one to locate the other sections of the NEC that relate to the topic, without having to find them through a search or trial and error.
 
Pierre C Belarge said:
Most people who read the NEC do not pay much attention to the FPNs. I was not refering you to the FPN to state you had done something wrong. I did it strictly to bring it to your attention. One of the features of this FPN, is it does help one to locate the other sections of the NEC that relate to the topic, without having to find them through a search or trial and error.
Click to expand...

Ok I see just trying to confuse me :D just kidding thanks it did cause me to put more effort into it and more research which in the end caused me to learn something!! Thanks:D
 
Strahan said:
Ok I see just trying to confuse me :D just kidding thanks it did cause me to put more effort into it and more research which in the end caused me to learn something!! Thanks:D
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Don't sweat it...I have installed a new program on my computer. It automatically debits anyones account if I respond to a post. You will notice this on your next statement. ;):cool:

P.S.
There is an additional charge if you actually learn something.:grin:
 
Pierre C Belarge said:
Don't sweat it...I have installed a new program on my computer. It automatically debits anyones account if I respond to a post. You will notice this on your next statement. ;):cool:

P.S.
There is an additional charge if you actually learn something.:grin:
Click to expand...

Oh man it looks like I'm in for some overtime this evening!!:D
 
is this right?

is this right?

If I run a 4 wire feed[2 hots 1 netural 1 grd] to a subpanel in a garage do I need a ground rod at the subpanel?
 
Dennis Alwon said:
Yes, a ground rod or two is necessary if the garage is detached.
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Or a CEE if the garage in question has footings with 20 feet or more #4 rebar.

In my area 2 #4 continious re-bar are required to be installed in most residential footings including detached garages and sheds.

Chris
 
raider1 said:
Or a CEE if the garage in question has footings with 20 feet or more #4 rebar.

In my area 2 #4 continious re-bar are required to be installed in most residential footings including detached garages and sheds.

Chris
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This is correct and I wish everyone would make it as you say. :smile: I am all for the CEE.
 
Dennis Alwon said:
This is correct and I wish everyone would make it as you say. :smile: I am all for the CEE.
Click to expand...

I live in a high seismic zone and the seismic requirements for footings and foundations require substantial reinforcing in the concrete. This makes it very easy, as the rebar is always there in the footing, all we have to do is connect to it.

In fact I have a luxury in my area, as the footing steel packages that come from the supply houses include a rebar clamp and typically 40' of solid #4 copper.:)

Chris
 
raider1 said:
In fact I have a luxury in my area, as the footing steel packages that come from the supply houses include a rebar clamp and typically 40' of solid #4 copper.:)

Chris
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Nice upsell for the rebar companies. Great idea- makes it hard for the GC to forget.
 
250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.

Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non?current-carrying metal
parts of equipment.

note the exception. according to my ahj a ground rod @ the other building with 3 conductors feeding, or 4 conductors feeding. my company does four conductors to ensure a more effective path. the earth is not an effective means of grounding. i have seen voltage on the ground rod with this setup
 
vinster888 said:
250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.

Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non?current-carrying metal
parts of equipment.

note the exception.
Click to expand...
The exception is addressing a single branch circuit, not a feeder

vinster888 said:
according to my ahj a ground rod @ the other building with 3 conductors feeding, or 4 conductors feeding.
Click to expand...
And he is correct for a feeder, when FL adopts the 08 (if they haven't already) the feeder will have to have an EGC.

vinster888 said:
my company does four conductors to ensure a more effective path. the earth is not an effective means of grounding. i have seen voltage on the ground rod with this setup
Click to expand...
To be correct, the earth is the only effective means of grounding, it is not an effective ground fault clearing path. In a three wire 120/240 volt feeder to a detached building the neutral is the fault clearing conductor.

BTW, Welcome to the forum


Roger
 
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