# 100 amp sub panel for garage



## halfblank

I just got my restricted license and my first official job involves wiring a garage. I want to send 100 amps to it and the existing panel is 200 amps. The garage will only have a deep freezer, a water heater, one bathroom, and a couple of other branch circuits. I want to do this right and I'm just looking for tips, ideas, etc. If you've done a similar operation before, what size breaker did you use in the main panel? What size wire did you (and how did you) send to the garage? Thanks in advance for you ideas. I'm just making sure that I'm thinking of everything.


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## JohnJ0906

Well, why don't you tell us how you plan on doing it, and what materials you plan on using, and perhaps we can point out anything you missed.

Welcome to the forum.


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## kbsparky

Attached, or detached garage? Heat or A/C in the bathroom? etc?


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## waco

assuming it is detached, you could pull in 6-3 with ground to a four place subpanel, then wire the HW heater with 10-2 and the rest of the branch circuits with 12-2. Use a 60 amp breaker at the main.

You could go bigger, using #4 or #2, and a sub-panel with more spaces, but I don't see why you'd need them.

Another way is to go to a replaceable lug meter socket (if the house doesn't already have one) and run a 100 amp service to the garage from the meter socket. You'd need to check with the utility provider and make certain their existing service drop or lateral is large enough to handle both the house and the garage. A separate service wil require its own grounding.


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## halfblank

Sorry, should've been a little more specific. The garage is detached and the tenant is still deciding on ac/heat options. I can't run the power feed from the meter, it's going to have to come from the main panel inside the existing house. I was thinking of using a 60 amp breaker and installing a 100 amp panel in the garage in case.


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## 480sparky

halfblank said:


> Sorry, should've been a little more specific. The garage is detached and the tenant is still deciding on ac/heat options. I can't run the power feed from the meter, it's going to have to come from the main panel inside the existing house. I was thinking of using a 60 amp breaker and installing a 100 amp panel in the garage in case.


Until you find out what you're going to power out there, we can't help you much. 60amps should be plenty, however.

Welcome to contracting! It's a great job ruined by people called customers. :icon_wink:


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## John Valdes

Okay, Here goes.

Install a 100 amp 2 pole breaker in the main service panel.
If using conduit, Run 3 # 3's/cu and 1 #8/cu green THWN conductors to the sub panel. 4 wire circuit. 
Use a 100 amp main breaker panel for the sub. (since you are not sure how many circuits you will need).
Seperate neutrals and grounds at the sub. 
Drive at least one 96" electrode (see AHJ) at the sub and connect a bare #6 conductor from the rod to the ground bus.
Bury conduit 18' below grade. (exceptions exist)

Make sure you pull a permit, and ask the AHJ if he has any special requirements for sub panels in unattached structures.

If you are not going to use conduit let us know.


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## jbfan

Welcome halfblank to the forum and to the contracting world.
What part of GA?


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## Raverill

I'm a little suprised that you got some kind of electrical license and are asking what are to me some pretty fundamental questions about electrical construction. It seems to me in order to get whatever licensse you have you should be at least minimaly conversant with whatever code applies in your state, which would answer all your questions. Given what seems to me to be a vast ignorance of electrical construction, I recommend you look into casrpentry as a career.


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## cdnelectrician

Well put Raverill (aside from changing careers to be a carpenter, at least he is trying)....I don't mean to offend anyone here but I have first and second year apprentices who work under me that can figure something like this out on their own...I was a little surprised when I first read this post but I wanted to see where it went before I made any comments


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## bigA26

John Valdes said:


> Bury conduit 18' below grade. (exceptions exist)


Dude! Eighteen feet below grade! That's gonna cost extra to get the hole that deep...lol


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## bigA26

Raverill said:


> I'm a little suprised that you got some kind of electrical license and are asking what are to me some pretty fundamental questions about electrical construction.


I agree...I'm calling shenanigans on this so-called 'restricted' license.


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## cdnelectrician

Hmmm electrician or homeowner?:glare:


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## sparks134

John Valdes said:


> Okay, Here goes.
> 
> Install a 100 amp 2 pole breaker in the main service panel.
> If using conduit, Run 3 # 3's/cu and 1 #8/cu green THWN conductors to the sub panel. 4 wire circuit.
> Use a 100 amp main breaker panel for the sub. (since you are not sure how many circuits you will need).
> Seperate neutrals and grounds at the sub.
> Drive at least one 96" electrode (see AHJ) at the sub and connect a bare #6 conductor from the rod to the ground bus.
> Bury conduit 18' below grade. (exceptions exist)
> 
> Make sure you pull a permit, and ask the AHJ if he has any special requirements for sub panels in unattached structures.
> 
> If you are not going to use conduit let us know.


could have used #8 for ground rod!


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## Magnettica

The minimum for a ground rod is #6 no matter what size the service/ feeder is.


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## Dennis Alwon

Magnettica said:


> The minimum for a ground rod is #6 no matter what size the service/ feeder is.


I disagree. Art. 250.66(A) says the connection to the rod need not be larger than a #6 however art. 250.66 first paragraph states the GEC to be based on 250.66. I take this to be if you use #2 copper than a #8 can be used to the rod.


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## sparks134

Dennis Alwon said:


> I disagree. Art. 250.66(A) says the connection to the rod need not be larger than a #6 however art. 250.66 first paragraph states the GEC to be based on 250.66. I take this to be if you use #2 copper than a #8 can be used to the rod.


thats how I read it too!:nerd:


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## Magnettica

Ok, let me know how that goes for the inspection. :thumbsup:

250.53(E)


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## sparks134

ive done a dozen times, and has passed!!!


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## sparks134

im not saying the inspector isnt gonna fight you on it....


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## Magnettica

The ground rods are supplemental to the metal underground water pipe. 

For a 100 amp service a #8 copper could be run to the water pipe, but often #6 is run because #6 does not need to be guarded against physical damage.


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## sparks134

ok, in chicago, everything has to be in rigid, emt or imc


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## Magnettica

The physical damage portion can be found in 250.64(B)


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## sparks134

ok ill look it up... ,but the conduit would protect the wire from pysical damage,right? there for you would be able to use #8 for 100a service!


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## Magnettica

Yes, #8 is ok for the metal underground water pipe, but not for the ground rods.


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## user5941

Magnettica said:


> Yes, #8 is ok for the metal underground water pipe, but not for the ground rods.


Table 250.66 ungrounded conductor 2 or smaller GEC 8


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## RIVETER

*100amp sub panel*



Magnettica said:


> The ground rods are supplemental to the metal underground water pipe.


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## Magnettica

rewire said:


> Table 250.66 ungrounded conductor 2 or smaller GEC 8


(B) Securing and Protection Against Physical Damage. 
Where exposed, a grounding electrode conductor or its enclo- 
sure shall be securely fastened to the surface on which it is 
carried. A 4 AWG or larger copper or aluminum grounding 
electrode conductor shall be protected where exposed to 
physical damage. A 6 AWG grounding electrode conductor 
that is free from exposure to physical damage shall be permit- 
ted to be run along the surface of the building construction 
without metal covering or protection where it is securely fas- 
tened to the construction; otherwise, it shall be in rigid metal 
conduit, intermediate metal conduit, rigid nonmetallic conduit, 
electrical metallic tubing, or cable armor. *Grounding electrode 
conductors smaller than 6 AWG shall be in rigid metal con- 
duit, intermediate metal conduit, rigid nonmetallic conduit, 
electrical metallic tubing, or cable armor.*


Mmmmm kay?


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## waco

Interesting. Why would anybody use anything smaller than #6 for a GEC?


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## Dennis Alwon

Magnettica said:


> The ground rods are supplemental to the metal underground water pipe.
> 
> For a 100 amp service a #8 copper could be run to the water pipe, but often #6 is run because #6 does not need to be guarded against physical damage.


We were responded to your statement not the physical protection -- that's a different issue. You made a blanket statement that said you could not use smaller than #6 to a ground rod. I disagree with that-


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## user5941

waco said:


> Interesting. Why would anybody use anything smaller than #6 for a GEC?


 because you can


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## user5941

Magnettica said:


> (B) Securing and Protection Against Physical Damage.
> Where exposed, a grounding electrode conductor or its enclo-
> sure shall be securely fastened to the surface on which it is
> carried. A 4 AWG or larger copper or aluminum grounding
> electrode conductor shall be protected where exposed to
> physical damage. A 6 AWG grounding electrode conductor
> that is free from exposure to physical damage shall be permit-
> ted to be run along the surface of the building construction
> without metal covering or protection where it is securely fas-
> tened to the construction; otherwise, it shall be in rigid metal
> conduit, intermediate metal conduit, rigid nonmetallic conduit,
> electrical metallic tubing, or cable armor. *Grounding electrode *
> *conductors smaller than 6 AWG shall be in rigid metal con- *
> *duit, intermediate metal conduit, rigid nonmetallic conduit, *
> *electrical metallic tubing, or cable armor.*
> 
> 
> Mmmmm kay?


 so you have to protect #8 GEC ,you can still use it


Mmmmm Kay?


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## Magnettica

Penny wise, dollar foolish.

Mmmmmm kay.


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## sparks134

i knew i was right!arty::detective::tt2::bangin:


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## user5941

Magnettica said:


> Penny wise, dollar foolish.
> 
> Mmmmmm kay.


 Not really









Mmmmm Kay


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## nolabama

waco said:


> Interesting. Why would anybody use anything smaller than #6 for a GEC?


to save 35 cents on a job


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## electrocop

*Informative only*

HELLO HALFABLANK :First of all any outside underground electrical work has too be done through the( AHJ) planning department get your permit out and ask all the questions every municipality works with codes according to geographical area what is permitted in California may not be permitted in Illinois but lets remember basics CEC/ is based on NEC and NEC is adopted every where for example 120 VOLT circuit in conduit in a driveway has to be burried 18 inches below grade. But 12 inches deep its OK in conduit and G.F.C.I protected and if not below a drive way. If in Illinois where the temperature drops below zero you might go below the frost line if the frost line is at 12 inches below grade you might be asked to go 14 inches deep and G.F.C.I protected to meet code..last of all your wire has to be according to temperature and if approved for out side use weather resistant etc,, see N.E.C annex..tables:jester::laughing:


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## Magnettica

#6 to the ground rods.


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## sparks134

Here we go again!


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## SparkYZ

electrocop said:


> HELLO HALFABLANK :First of all any outside underground electrical work has too be done through the( AHJ) planning department get your permit out and ask all the questions every municipality works with codes according to geographical area what is permitted in California may not be permitted in Illinois but lets remember basics CEC/ is based on NEC and NEC is adopted every where for example 120 VOLT circuit in conduit in a driveway has to be burried 18 inches below grade. But 12 inches deep its OK in conduit and G.F.C.I protected and if not below a drive way. If in Illinois where the temperature drops below zero you might go below the frost line if the frost line is at 12 inches below grade you might be asked to go 14 inches deep and G.F.C.I protected to meet code..last of all your wire has to be according to temperature and if approved for out side use weather resistant etc,, see N.E.C annex..tables:jester::laughing:


Uhhhh..no. 

Schedule 80 or Rigid can be less than 18'' deep. Not Schedule 40. Only way you can hit 12'' is if you're under atleast 2'' concrete
And where does NEC state that an underground conduit run for a sub panel has to be GFCI protected?

Aww crap I just realized I contributed to a zombie thread. This thread was 4 months old


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## Shockdoc

2 #2 al xlpe, 1 # 4 al xlpe, 1# 8 cu bare in 1 1/2 pvc, some inspectors if they are a hard ass will want to see a 90 amp breaker in main panel. Don't forget ground rod at new panel.


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## Shockdoc

Magnettica said:


> #6 to the ground rods.


Always get a kick out of those huys that run 3/0 to a ground rod on a 400 amp service.:jester:


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## Ohmbre

sparks134 said:


> Here we go again!


Where are you looking it up in the Chicago code book or NEC


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## Ohmbre

Supplemental ground cobductor is never smaller than a #6.


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## sparks134

NEC: look at table 250.66


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## sparks134

Shockdoc said:


> Always get a kick out of those huys that run 3/0 to a ground rod on a 400 amp service.:jester:


the largest is a copper #6 , but for a 100A service a #8 is OK!


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## sparks134

Ohmbre said:


> Supplemental ground cobductor is never smaller than a #6.


 I can't find that in the codebook, give me a referance.


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## NolaTigaBait

sparks134 said:


> the largest is a copper #6 , but for a 100A service a #8 is OK!


#8 copper...YEAH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Lovin IT!!!!!!!!!!!!!!!!!!!! I love electrical work!!!!!!!


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## NolaTigaBait

sparks134 said:


> I can't find that in the codebook, give me a referance.


If you use the water pipe as an electrode it must be supplemented by a ground rod, ring, blah blah blah!!!!!!...Not sure about teh not smaller than #6 though!!!!


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## sparks134

NolaTigaBait said:


> If you use the water pipe as an electrode it must be supplemented by a ground rod, ring, blah blah blah!!!!!!...Not sure about teh not smaller than #6 though!!!!


I am fuuly aware of that, I was talking about #8 to the ground rod


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## NolaTigaBait

sparks134 said:


> I am fuuly aware of that, I was talking about #8 to the ground rod


I know you were!!...Thats why I said I wasn;t sure where he got that from!!


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## sparks134

:thumbsupk!


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## NolaTigaBait

:thumbsup:Okay!!!


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## electricmanscott

Shockdoc said:


> 2 #2 al xlpe, 1 # 4 al xlpe, 1# 8 cu bare in 1 1/2 pvc, some inspectors if they are a hard ass will want to see a 90 amp breaker in main panel. Don't forget ground rod at new panel.


Why would asking to have a conductors OCPD be the correct size be considered being a "Hard ass"?


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## Shockdoc

electricmanscott said:


> Why would asking to have a conductors OCPD be the correct size be considered being a "Hard ass"?


 #2 al is not rated for 100 amps after the service equipment. Many inspectors want to see #1 al for a clean 100 amp sub after the main breaker since there is no 80% rule.


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## sparks134

Shockdoc said:


> #2 al is not rated for 100 amps after the service equipment. Many inspectors want to see #1 al for a clean 100 amp sub after the main breaker since there is no 80% rule.


 yep,yep!


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## Shockdoc

Ohmbre said:


> Supplemental ground cobductor is never smaller than a #6.


 That is only if the conductor is not in a approved raceway and is secured openly.


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## electricmanscott

Shockdoc said:


> #2 al is not rated for 100 amps after the service equipment. Many inspectors want to see #1 al for a clean 100 amp sub after the main breaker since there is no 80% rule.


Yeah no kidding that's the point of my reply. You said the inspector would be a hard ass for not allowing #2 al on a 100 amp breaker. Why is that being a hard ass? I would call it enforcing the code.

BTW It doesn't matter what they "want to see". Just do it right. :thumbsup:


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## Shockdoc

electricmanscott said:


> Yeah no kidding that's the point of my reply. You said the inspector would be a hard ass for not allowing #2 al on a 100 amp breaker. Why is that being a hard ass? I would call it enforcing the code.
> 
> BTW It doesn't matter what they "want to see". Just do it right. :thumbsup:


It's those grey areas.. I recently sub divided a warehouse into five sections , adding three 200 amp thee phase unit panels. The inspector allowed us to run 4/0,4/0,4/0,4/0,6 aluminum MC overhead in the girders for our subfeeds( this was a job I was not proud of but needed to fit the dollar requirement to get it) 4/0 al thhn has a rating of 195 amps, we fused them at 200. Some inspectors would have required 250 mcm al. Some leeway should always be given for the circumstances, like driving 65 mph in a 55 mph zone.


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## raider1

Shockdoc said:


> It's those grey areas.. I recently sub divided a warehouse into five sections , adding three 200 amp thee phase unit panels. The inspector allowed us to run 4/0,4/0,4/0,4/0,6 aluminum MC overhead in the girders for our subfeeds( this was a job I was not proud of but needed to fit the dollar requirement to get it) 4/0 al thhn has a rating of 195 amps, we fused them at 200. Some inspectors would have required 250 mcm al. Some leeway should always be given for the circumstances, like driving 65 mph in a 55 mph zone.


4/0 Aluminum THHN has an ampacity of 180 amps at 75 degrees C not 195 according to Table 310.16.

Now provided that the calculated load of the feeder was not more than 180 amps you could use the next size up rule in 240.4(B) and protect the feeder with a 200 amp breaker. I don't see how an insepctor would require you to use 250 Kcmil aluminum MC cable if you followed the rules in 240.4(B).

Chris


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## electricmanscott

Shockdoc said:


> It's those grey areas.. I recently sub divided a warehouse into five sections , adding three 200 amp thee phase unit panels. The inspector allowed us to run 4/0,4/0,4/0,4/0,6 aluminum MC overhead in the girders for our subfeeds( this was a job I was not proud of but needed to fit the dollar requirement to get it) 4/0 al thhn has a rating of 195 amps, we fused them at 200. Some inspectors would have required 250 mcm al. Some leeway should always be given for the circumstances, like driving 65 mph in a 55 mph zone.


 
So you don't feel like answering the question?


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## Shockdoc

raider1 said:


> 4/0 Aluminum THHN has an ampacity of 180 amps at 75 degrees C not 195 according to Table 310.16.
> 
> Now provided that the calculated load of the feeder was not more than 180 amps you could use the next size up rule in 240.4(B) and protect the feeder with a 200 amp breaker. I don't see how an insepctor would require you to use 250 Kcmil aluminum MC cable if you followed the rules in 240.4(B).
> 
> Chris


Commercial Service load calculations must be 100% over residential 80%. My bad, I was thinking 2/0 cu with the 195a. NY is kind of funny, aluminum is highly frowned upon here on Long Island, most inspectors enforce the ultimate full size aluminum conductor in these parts.


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## Shockdoc

electricmanscott said:


> So you don't feel like answering the question?


there's what works, then there's whats safe, theres whats logical and then there s code. Sometimes discretion needs to be used . The NEC NFPA lost my respect when they accepted payoffs to mandate AFI breakers.


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## NolaTigaBait

Shockdoc said:


> there's what works, then there's whats safe, theres whats logical and then there s code. Sometimes discretion needs to be used . The NEC NFPA lost my respect when they accepted payoffs to mandate AFI breakers.


It's always about the $$$$$...Tamper proof, arc faults, blah blah blah...Money first, peoples safety second.


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## sparks134

NolaTigaBait said:


> It's always about the $$$$$...Tamper proof, arc faults, blah blah blah...Money first, peoples safety second.


 YEP! the almighty $


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## electricmanscott

Shockdoc said:


> there's what works, then there's whats safe, theres whats logical and then there s code. Sometimes discretion needs to be used . The NEC NFPA lost my respect when they accepted payoffs to mandate AFI breakers.


 

Great. Now about the question I asked.


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## sparks134

Shockdoc said:


> there's what works, then there's whats safe, theres whats logical and then there s code. Sometimes discretion needs to be used . The NEC NFPA lost my respect when they accepted payoffs to mandate AFI breakers.


 Thats how it got mandate. Wow buncha crooks!


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## Dennis Alwon

Ohmbre said:


> Supplemental ground cobductor is never smaller than a #6.





> 250.66(A) Connections to Rod, Pipe, or Plate Electrodes. Where the grounding electrode conductor is connected to rod, pipe, or plate electrodes as permitted in 250.52(A)(5) or (A)(7), that portion of the conductor that is the sole connection to the grounding electrode *shall not be required to be m larger than 6 AWG copper wire or 4 AWG aluminum wire.*


 If you look at T250.66 a #8 copper may be used as the grounding electrode conductor when using #2 as the service conductors.


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## JohnJ0906

Ohmbre said:


> Supplemental ground cobductor is never smaller than a #6.





Dennis Alwon said:


> If you look at T250.66 a #8 copper may be used as the grounding electrode conductor when using #2 as the service conductors.


I agree with Dennis. The reason, IMO, that #8 is rarely used is the requirement for protection- 250.64(B)


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## Shockdoc

NolaTigaBait said:


> It's always about the $$$$$...Tamper proof, arc faults, blah blah blah...Money first, peoples safety second.


It took the NEC nearly ten years to mandate the use of GFI receptacles, by the time they where approved, they were a proven safety device. AFI breakers were
mandated before they even hit the market, they even state they do not prevent a heat arcing fire. As the economy worsened, the mandate for these and other more costly material increased, you are going to tell me that the lobbyist and corporations did not play a hand in this. We are the ones who got hurt when we presented the estimates for panels containing 25 to 30 AFI breakers in our bids.


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## Shockdoc

Dennis Alwon said:


> If you look at T250.66 a #8 copper may be used as the grounding electrode conductor when using #2 as the service conductors.


As long as it is in a raceway, otherwise no smaller than #6 may be run openly.


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## Shockdoc

electricmanscott said:


> Great. Now about the question I asked.


Does a police officer ticket you for driving 57 mph in a 55 mph zone, if so, he is a ball breaker. I got stopped for doing 83 in a 55 yesterday, with my kid... Cop let me off , told me I should be ashamed of myself.


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## NolaTigaBait

Shockdoc said:


> Does a police officer ticket you for driving 57 mph in a 55 mph zone, if so, he is a ball breaker. I got stopped for doing 83 in a 55 yesterday, with my kid... Cop let me off , told me I should be ashamed of myself.


Does "suffolk county pba" mean anything to you?


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## Shockdoc

NolaTigaBait said:


> Does "suffolk county pba" mean anything to you?


Yea but I got NYPD pba cards.


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## NolaTigaBait

Shockdoc said:


> Yea but I got NYPD pba cards.


Ok, i googled it and it came with suffolk county police benevolent association. A friend sent me a gold pullover and that was stitched on it, I was just curious if thats what it was for.:thumbsup:


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## electrocop

*the sub panel wiring reply to Sparkz*

First of all thank you very much for your info and second of all i seen in Chapter 3 wiring methods table 300-5 where it shows for residential underground wiring and it shows different conditions and situations with different materials and allowed burial depths of pvc/conduit etc that is where i saw the GFCI protection requirement option for underground wiring. Also the IRC book one condition this same table stating in chapter 37 it shows gfci protected and in a trench below 2 inch thick concrete 6 inches below grade:thumbsup:


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## electricmanscott

Shockdoc said:


> Does a police officer ticket you for driving 57 mph in a 55 mph zone, if so, he is a ball breaker. I got stopped for doing 83 in a 55 yesterday, with my kid... Cop let me off , told me I should be ashamed of myself.


Yeah, that's exactly like enforcing a clear code rule. :no: 



BTW, the cop is an idiot and he should be ashamed of himself too.


Just for my amusement, tell me what size wire you would run for the 100 amp sub panel in a garage.


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## electricmanscott

Shockdoc said:


> Yea but I got NYPD pba cards.


Yet you bitch about the crooked NEC. Please.


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## NolaTigaBait

electricmanscott said:


> Yeah, that's exactly like enforcing a clear code rule. :no:
> 
> 
> 
> BTW, the cop is an idiot and he should be ashamed of himself too.


All cops are idiots:thumbsup:


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## electricmanscott

NolaTigaBait said:


> All cops are idiots:thumbsup:


Well yeah, that's why they're cops.


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## Shockdoc

electricmanscott said:


> Yet you bitch about the crooked NEC. Please.


If an officer extends courtesy how does that make him crooked ??? It's not like accepting payoffs from corporations to create laws that would profit corporations. If the cop knew me or accepted a cash bribe then that would be another story.


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## Shockdoc

electricmanscott said:


> Yeah, that's exactly like enforcing a clear code rule. :no:
> 
> 
> 
> BTW, the cop is an idiot and he should be ashamed of himself too.
> 
> 
> Just for my amusement, tell me what size wire you would run for the 100 amp sub panel in a garage.


 #2 aluminum, #4 aluminum neutral, # 8 bare cu inside a 1 1/4 pvc conduit at a depth of 24" fused at 100 amps at main panel , Scottshoe, excuse me .


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## Shockdoc

NolaTigaBait said:


> All cops are idiots:thumbsup:


I work for a large number of police officers from various departments. It's all about respect, it's a two way street . I can honestly say I get along much better with them when they are not in uniform.


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## Shockdoc

electricmanscott said:


> Well yeah, that's why they're cops.


Did you fail the test Scott, those bennies and the 3/4 is well worth it.


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## NolaTigaBait

Shockdoc said:


> Did you fail the test Scott, those bennies and the 3/4 is well worth it.


I'd become a cop as a last resort.


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## Dennis Alwon

Shockdoc said:


> #2 aluminum, #4 aluminum neutral, # 8 bare cu inside a 1 1/4 pvc conduit at a depth of 24" fused at 100 amps at main panel , Scottshoe, excuse me .


I say violation as the code reads now. #2 alum at 75C is only good for 90amps.


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## raider1

Dennis Alwon said:


> I say violation as the code reads now. #2 alum at 75C is only good for 90amps.


I agree, #2 aluminum has an ampacity of 90 amps from the 75 degree column of Table 310.16.

240.4(B) can't be used as a 90 amp breaker is a standard sized breaker listed in 240.6(A).

Chris


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## Shockdoc

Dennis Alwon said:


> I say violation as the code reads now. #2 alum at 75C is only good for 90amps.


I know its a violation, it's like driving 65 mph in a 55 zone. Anyway, when I sell a job like that I intend to sell it as a 100 amp meanwhile fusing it at 90 amps. The 10 amp difference on the breaker if fused at 100 amps is not dangerous. If you consider the panel feeding the detach building as service equipment and apply the 80% rule then a 100 amp breaker would be legit, the problem is it falls downstream of the main service. We have used #2 copper in the past when prices were down fused at 100 amps. These are the situations where leeway should be applied.


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## Shockdoc

Dennis Alwon said:


> I say violation as the code reads now. #2 alum at 75C is only good for 90amps.


My code book is in my office, not available but what is the 90c rating type xhhw ?


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## Dennis Alwon

Shockdoc said:


> I know its a violation, Anyway, when I sell a job like that I intend to sell it as a 100 amp meanwhile fusing it at 90 amps.


You never mentioned fusing it at 90 amps. I agree that 90 amps is usually more than enough for a garage.

I did a garage once that had it's own 400 amp service. It was beautiful.


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## Dennis Alwon

Shockdoc said:


> My code book is in my office, not available but what is the 90c rating type xhhw ?


100 amps


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## NolaTigaBait

Shockdoc said:


> My code book is in my office, not available but what is the 90c rating type xhhw ?


Doesn't matter you can't use the 90 except for derating...


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## Shockdoc

Dennis Alwon said:


> 100 amps


So #2 xhhw and a whole lotta yellow 77


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## raider1

Shockdoc said:


> My code book is in my office, not available but what is the 90c rating type xhhw ?


You can't use the 90c ampacity most likely due to the fact that the terminals and equipment that you will be using most likely won't be rated at 90c.

Chris


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## raider1

> If you consider the panel feeding the detach building as service equipment and apply the 80% rule then a 100 amp breaker would be legit,


Please expound on this "80% rule" that would allow a 100 amp breaker on a #2 aluminum.

Chris


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## Shockdoc

Dennis Alwon said:


> You never mentioned fusing it at 90 amps. I agree that 90 amps is usually more than enough for a garage.
> 
> I did a garage once that had it's own 400 amp service. It was beautiful.


I bid a job last year with a 320 ug at the street, 200 to the house and 100 to the garage. The homeowner got cheap and hired a fly by night that reused the existing 1970's # 2 u/g feed ,upgraded to 200 via meterpan and panel and ran 100 amp direct burial under driveway. They get what they pay for...


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## electricmanscott

Shockdoc said:


> #2 aluminum, #4 aluminum neutral, # 8 bare cu inside a 1 1/4 pvc conduit at a depth of 24" fused at 100 amps at main panel , Scottshoe, excuse me .


 
Violation. :laughing:


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## XCasper

My only opinion here is that I would not run less than a 100a sub to garage or any other resi sub panel unless I was certain that the sub had a finite load (specific HVAC or Pool equip for example). It has been our experience that the HO will almost always want to add something later so I want to be prepared for whatever future expansions may come.


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## electricmanscott

XCasper said:


> My only opinion here is that I would not run less than a 100a sub to garage or any other resi sub panel unless I was certain that the sub had a finite load (specific HVAC or Pool equip for example). It has been our experience that the HO will almost always want to add something later so I want to be prepared for whatever future expansions may come.


That may be a good way to look at it but history proves it is not necessary.

There are a gazillion houses that have 60 or 100 amp services that are just fine. In fact I would bet that the majority of 200 amp services on a dwelling are WAY over sized.


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## RIVETER

Shockdoc said:


> Does a police officer ticket you for driving 57 mph in a 55 mph zone, if so, he is a ball breaker. I got stopped for doing 83 in a 55 yesterday, with my kid... Cop let me off , told me I should be ashamed of myself.


I would be glad to be let off easy. Around here they would charge you with CHILD ENDANGERMENT.


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## Forgery

XCasper said:


> My only opinion here is that I would not run less than a 100a sub to garage or any other resi sub panel


That's an awfully large expense. 

When rewiring houses I'll often run 6-3 to supply 40A 240V to an attic subpanel to handle the second floor of the house. It's all 120V, what could possibly require more than 80A on the second floor in a typical house?


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## XCasper

electricmanscott said:


> That may be a good way to look at it but history proves it is not necessary.
> 
> There are a gazillion houses that have 60 or 100 amp services that are just fine. In fact I would bet that the majority of 200 amp services on a dwelling are WAY over sized.


 
Your history is obviously far different than ours. More often than not the "Can you add power to my garage?" conversation starts out for us with simple lights and receps that could be handled with a mere 20a circuit or two but then later turns into "Can you add a circuit for my freezers?" Then comes the work bench, irrigation system, 220v well pump, and surprisingly often a welder needing a 250V 50A outlet. "Oh, can I add a reverse cycle window unit also?" So yes I would rather start with a 100A 12/24 loadcenter and know that when I get the next call I won't have to rework anything we have already done.

Regarding that bet about the 200amp services. I would suggest that anyone who bet against you there was soon to be parted from their money. I'm still much more likely to install a 200A before I'd install a 150A. The cost difference is minimal in most cases and I would rather have the expansion room for future additions to the system.


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## XCasper

Forgery said:


> That's an awfully large expense.
> 
> When rewiring houses I'll often run 6-3 to supply 40A 240V to an attic subpanel to handle the second floor of the house. It's all 120V, what could possibly require more than 80A on the second floor in a typical house?


Typically here the 2nd floor will have it's own airhandler with an 8kw or 10kw heat strip in the attic. Another common 250V load lately is electric on demand (tankless) water heaters. Everything else then is _usually_ 120V.

Note: This is not an absolute. I did quantify my original remark with "...unless I was certain that the sub (panel) had a finite load." A subpanel for a specific purpose that has no reasonable chance of future expansion is a waste if oversized.


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## Shockdoc

electricmanscott said:


> You are f'n priceless. Driving like an asshole, ignoring the code, blaming inspectors, flat out lying to your customers, and lying to us then flip flopping like a fish out of water when called on it.
> 
> Well done.


You sound bitter, try doing it once by getting it right the first time.....Have a nice day.


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## electricmanscott

Shockdoc said:


> You sound bitter, try doing it once by getting it right the first time.....Have a nice day.


Bitter, not really. Just not afraid to say what I think.


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## geo5509

What is a restricted license? We don't have those around here. 
Are you a Jman, Master,Class A,B,C Contractor?

The first code reference that comes to mind is
Art. 100 Qualified Persons.
One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved.


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## Shockdoc

XCasper said:


> Your history is obviously far different than ours. More often than not the "Can you add power to my garage?" conversation starts out for us with simple lights and receps that could be handled with a mere 20a circuit or two but then later turns into "Can you add a circuit for my freezers?" Then comes the work bench, irrigation system, 220v well pump, and surprisingly often a welder needing a 250V 50A outlet. "Oh, can I add a reverse cycle window unit also?" So yes I would rather start with a 100A 12/24 loadcenter and know that when I get the next call I won't have to rework anything we have already done.
> 
> Regarding that bet about the 200amp services. I would suggest that anyone who bet against you there was soon to be parted from their money. I'm still much more likely to install a 200A before I'd install a 150A. The cost difference is minimal in most cases and I would rather have the expansion room for future additions to the system.


Everytime I do a new build , I'll run 3/4 PVC u/g and through the directly to the panel for detached garages for expansion purposes. Even though I'll pull 3 #14s as a code feed, it can be upgraded either as a sub panel or have additional feeds pulled through later for a pool or equipment.


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## Shockdoc

geo5509 said:


> What is a restricted license? We don't have those around here.
> Are you a Jman, Master,Class A,B,C Contractor?
> 
> The first code reference that comes to mind is
> Art. 100 Qualified Persons.
> One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training on the hazards involved.


We have them around here for HVAC/ communications type businesses. They are not supposed to enter the panel of install new work outside of their scope of business even though they do.


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## Shockdoc

electricmanscott said:


> Bitter, not really. Just not afraid to say what I think.


I think you should go up to a cop on duty and tell him/her exactly how you feel about them....


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## electricmanscott

Shockdoc said:


> I think you should go up to a cop on duty and tell him/her exactly how you feel about them....


Dude, you were wrong and shown to be so. Get over it. :laughing:


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## electricmanscott

Shockdoc said:


> Everytime I do a new build , I'll run 3/4 PVC u/g and through the directly to the panel for detached garages for expansion purposes. Even though I'll pull 3 #14s as a code feed, it can be upgraded either as a sub panel or have additional feeds pulled through later for a pool or equipment.


Oh boy here we go again. Lets start with this. What's a "code feed"?


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## JohnJ0906

Shockdoc said:


> Everytime I do a new build , I'll run 3/4 PVC u/g and through the directly to the panel for detached garages for expansion purposes. Even though I'll pull 3 #14s as a code feed, it can be upgraded either as a sub panel or have additional feeds pulled through later for a pool or equipment.


 Additional feeds would be a violation. 225.30


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## electricmanscott

JohnJ0906 said:


> Additional feeds would be a violation. 225.30


Fun spoiler! :jester:


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## Shockdoc

electricmanscott said:


> Dude, you were wrong and shown to be so. Get over it. :laughing:


 ****boy, why do you do things twice ??? I do it once and then I'm on to the next.


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## Shockdoc

electricmanscott said:


> Oh boy here we go again. Lets start with this. What's a "code feed"?


Minimum requirements D I C Kboy


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## electricmanscott

Shockdoc said:


> Minimum requirements D I C Kboy


Would you care to address the violation that was pointed out.


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## electricmanscott

Shockdoc said:


> Minimum requirements D I C Kboy


Who's minimum requirements?


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## electricmanscott

Shockdoc said:


> ****boy, why do you do things twice ??? I do it once and then I'm on to the next.


It's called a joke silly.


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## Shockdoc

electricmanscott said:


> Would you care to address the violation that was pointed out.


Using a conduit run for multiple circuits is not a violation, for say a 3/4 run to a detach garage with a 14 feed for a gfi, light and switch and at the termination box a #12 feed out to a shed with a pool pump in it. Where's the violation, please explain.


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## Shockdoc

electricmanscott said:


> It's called a joke silly.


You fit me as the simple kind that runs a two wire to every switch end.


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## sparks134

Get a room you two!


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## Dennis Alwon

Shockdoc said:


> Using a conduit run for multiple circuits is not a violation, for say a 3/4 run to a detach garage with a 14 feed for a gfi, light and switch and at the termination box a #12 feed out to a shed with a pool pump in it. Where's the violation, please explain.


I am curious about this install. Can you explain it better?


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## Shockdoc

Dennis Alwon said:


> I am curious about this install. Can you explain it better?


I had done an install for an above ground pool (2003) on a home where I previously ran a 3/4 " 15 amp conductors to a detached. My conduit terminated in the garage in a 5" box, and ran continuously to the main panel. I came back out of the 5" box and back to back installed a gfi receptacle and then ug about 20' feet to a post w/ a timeclock and twistlock . I pulled 3 sets of 12 through my existing garage conduit leaving my grounds isolated from each other since the garage had a ground rod terminating and connecting to the egc for the garage. I believe in conduit installations.


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## Dennis Alwon

It sounds to me that you have a problem with 225.30 or am I reading this wrong. Do you have a panel in each detached structure or are you feeding it with more than one MWBC. I still can't tell.


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## Shockdoc

Dennis Alwon said:


> It sounds to me that you have a problem with 225.30 or am I reading this wrong. Do you have a panel in each detached structure or are you feeding it with more than one MWBC. I still can't tell.


In conduit to garage, 1) #12 wh, 2) #12 green, 1) #14 green 1)#14 black, 1) #12 red . conduit out from garage, 1) #12 green (unspliced in pull box), #12 white(spliced to garage neutral) #12 red(unspliced in garage pull box. I am not familiar with225.30. My inspector passed this and complemented me on it. can you please paste 225.30


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## Dennis Alwon

Shockdoc said:


> In conduit to garage, 1) #12 wh, 2) #12 green, 1) #14 green 1)#14 black, 1) #12 red . conduit out from garage, 1) #12 green (unspliced in pull box), #12 white(spliced to garage neutral) #12 red(unspliced in garage pull box. I am not familiar with225.30. My inspector passed this and complemented me on it. can you please paste 225.30



Here it is


> 225.30 Number of Supplies.
> Where more than one building or other structure is on the same property and under single management, each additional building or other structure that is served by a branch circuit or feeder on the load side of the service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.


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## Shockdoc

Dennis Alwon said:


> Here it is


 Alright so , thank you for pasting that. My work still fell within parameters of that section since only one circuit terminated in the garage and the other at the pool. Using the same conduit run to a common pull box to branch off is an acceptable method , there is no condition that states that circuits need to be run in seperate conduits, only that no more than one circuit can be used individually .


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## Bob Badger

Shockdoc said:


> Alright so , thank you for pasting that. My work still fell within parameters of that section since only one circuit terminated in the garage and the other at the pool. Using the same conduit run to a common pull box to branch off is an acceptable method , there is no condition that states that circuits need to be run in seperate conduits, only that no more than one circuit can be used individually .


I will give you an A for effort, that is some serious hair splitting.:laughing:


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## Shockdoc

Bob Badger said:


> I will give you an A for effort, that is some serious hair splitting.:laughing:


Well the code stated structures or buildings, one item was a pool...I got an underwriters on it so the inspector felt I did the right thing.


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## Shockdoc

Dennis Alwon said:


> Here it is


Originally I gave the customer the option of pulling 10s and installing a six ckt sub in the garage and then feed out to the pool. I'm competing against a community that 1/2 would just run uf off the garage feed and install the gfi 5' from the pool and promise the cust he'll get his underwriters in 30 days.


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## Dennis Alwon

Shockdoc said:


> Originally I gave the customer the option of pulling 10s and installing a six ckt sub in the garage and then feed out to the pool. I'm competing against a community that 1/2 would just run uf off the garage feed and install the gfi 5' from the pool and promise the cust he'll get his underwriters in 30 days.


Sometime we need to be more forcefull and say "NO". I t must be done this way. Why would you leave yourself suseptible to future litigation. To be honest I still don;t have a full understanding of the wiring but that okay. I seem to read that their are ground rounds but no panels,, oh well.


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## Shockdoc

Dennis Alwon said:


> Sometime we need to be more forcefull and say "NO". I t must be done this way. Why would you leave yourself suseptible to future litigation. To be honest I still don;t have a full understanding of the wiring but that okay. I seem to read that their are ground rounds but no panels,, oh well.


According to 225.30, only one circuit (or multi) is to be used to supply detached building, my method incorporated running multiple circuits to a pull box and then having one feed the garage and the other , an above ground pool. the ground rod installed was linked to the ground wire serving the garage(detached bldg). My belief is to make the most of the least, and wire for the future. There is no violation hence the second circuit does not feed anything with the confines of that building, it just shares the same raceway back to the main loadcenter.


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## Sparkee

What's a "restricted license"?


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## Dennis Alwon

I think I see what you have., You have a total of 2 circuits in a conduit that enter the detached structure. From here you drop one circuit to feed the garage and then carry the other circuit thru the garage to feed the pool. 
Is this correct? I see it as compliant however there was no need for a GEC to be run in the conduit.


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