Need advise with installation of 100 amp breaker panel

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  #1  
Old 09-23-11, 09:41 PM
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Need advise with installation of 100 amp breaker panel

Hi. I having an electrician wire a 100 amp service to my shop.
He is tapping at the house main breaker panel and running 4/0-4/0-2/0 wire from the house panel to the new panel in the shop. My question is that My panel seem really load already. I have 200 amp service to the house panel.
On the house breaker panel. i have the following circuts already.
3 30amp 220
2 40amp 220
1 50amp 220
15 20amp 120

Can my house breaker afford to add an additional 100amp service feeder for the shop. The 100 amp at the shop will have the following loads.
2 30amp 220
1 40amp 220
4 20amp 120

Any advise would be greatly appreciated.
 
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  #2  
Old 09-23-11, 11:10 PM
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You are detailing the sizes of the various circuit breakers, not the actual load. For what it's worth, my 200 ampere service has about 900 amperes worth of circuit breakers installed but the LOAD is probably never more than 50 amperes at the maximum.

So, instead of telling us what the circuit breaker ratings are please tell us what those various circuit breakers are connected to. Tell us also what items are likely to be operating at the same time.

He is tapping at the house main breaker panel and running 4/0-4/0-2/0 wire from the house panel to the new panel in the shop.
This bothers me. How far from the service (main) panel is the shop panel? Is it in a separate building or is the shop attached to the same building as the service panel? If it is a separate, detached building then the feeder needs to have FOUR conductors total, not three.
 
  #3  
Old 09-24-11, 06:30 AM
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1 30amps run the water pump
1 30 amp runs water heater
1 30amp runs dryer
1 40amp runs heating
1 50 amp run stove
the 20 amps run lights and electrical plugs throught out the house.

The panel will be in a seperate building 100 feet from panel to panel. Which wire should he use.
I'll talk to him this morning as I may be confuse on the wire size. it may be 2/0-2/0-4/0
 
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Old 09-24-11, 07:12 AM
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I'll talk to him this morning as I may be confuse on the wire size. it may be 2/0-2/0-4/
It's not the wire size it is the number of wires. Normally you would use PVC conduit which means four wires, two hots, a neutral, and a ground.
 
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Old 09-24-11, 07:17 AM
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Will there be a permit taken out for this work and will it be inspected? Is your electrician a real electrician or a handyman type guy? My first thought was he needs to take some code classes.
 
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Old 09-24-11, 07:45 AM
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I Just talked to the electrician and it is a 4 connector feed wire he's using. Two hot, one nuatral, one ground. That makes sense? I'm not and electrician and only know basic stuff about it. One, it can kill you! two, it can burn your house down. Yes there is a permit and yes he has a license.
I'm just want to make sure everything is ok, i seen guys with license screw up. So that doesn't mean it's going to be done right. I personaly pulled the permit yesterday.
 
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Old 09-24-11, 07:59 AM
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Originally Posted by CasualJoe View Post
Will there be a permit taken out for this work and will it be inspected? Is your electrician a real electrician or a handyman type guy? My first thought was he needs to take some code classes.
Joe,I'm a home owner and just writing what I remember him telling me, I may have not given the right info. I spoke with him this morning and he explained it to me in better language. I have post the new info. He is a license contractor since 2000. I've checked his license and has no complains on file. I'm not questioning his ability,trying to educate myself and for peace of mind checking on here for suggestions and advise. This way I can talk to him, if you guys suggest a different route. I pulled a permit yesterday,work being started today and maybe turned on Monday or Tuesday after inspections.
It's being run in conduit 30" deep,thou he said it's not required by code in this County.
 

Last edited by dale002; 09-24-11 at 08:22 AM.
  #8  
Old 09-24-11, 09:29 AM
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Why are you pulling the permit? Generally the permit is pulled by the person actually doing the work.

The 100 ampere feeder to the shop is likely well within the capacity of the 200 ampere service panel. Of the specific loads listed (not counting the 120 volt loads) you would have about 120 amperes IF everything were operating at once.

The size of conductors you cite either are way larger than necessary or simply don't make sense. It is possible that the electrician is using something that he has left over from a different job.
 
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Old 09-24-11, 10:48 AM
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Originally Posted by Furd View Post
Why are you pulling the permit? Generally the permit is pulled by the person actually doing the work.

The 100 ampere feeder to the shop is likely well within the capacity of the 200 ampere service panel. Of the specific loads listed (not counting the 120 volt loads) you would have about 120 amperes IF everything were operating at once.

The size of conductors you cite either are way larger than necessary or simply don't make sense. It is possible that the electrician is using something that he has left over from a different job.
Probably left over. He works for a large electrical contractor and doesside work on the weekends. I pulled the permits cause my wife works at the department and he is giving me a great deal. Half of what the other guys bid lowest bid. So if it's left overs i don't care as long as it's passes inspection and it's withing codes.
 

Last edited by dale002; 09-24-11 at 01:10 PM.
  #10  
Old 09-24-11, 10:52 AM
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If I were to install a 100A subpanel in a detached garage, this is what I would do. (You can use this to keep half an eye on his work)

100A breaker in the main panel. PVC conduit from the main panel, underground, at least 24" deep, long sweep underground on both ends into an LB (right angle connector with an access panel) going into each structure.
4 conductors, two hots and one neutral of 3ga copper or 1ga aluminum. Also a ground (I forget off the top of my head what size).

The panel in the garage must have a main disconnect. (there are a few exceptions, but with a 100A service, this is what you want). The ground bus in the garage panel should be bonded (screwed) directly to the pan. The neutral bar should be electrically isolated from the ground. Grounds and neutrals from the circuits need to be kept separate.

You'll also need an 8' long 1/2" copper ground rod driven at the garage, ground wire attached with an acorn clamp. The rod should be driven an inch or two underground so the whole rod is buried.

I don't know what state you're in, but in NJ, it's prohibited for a homeowner to obtain a permit if they are not the ones doing the work. Additionally, some amount (usually 10%) of the final payment is legally supposed to be withheld by the homeowner until the work passes final inspection. States vary though.
Hope this helps
 
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Old 09-24-11, 12:16 PM
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Originally Posted by Zorfdt View Post
If I were to install a 100A subpanel in a detached garage, this is what I would do. (You can use this to keep half an eye on his work)

100A breaker in the main panel. PVC conduit from the main panel, underground, at least 24" deep, long sweep underground on both ends into an LB (right angle connector with an access panel) going into each structure.
4 conductors, two hots and one neutral of 3ga copper or 1ga aluminum. Also a ground (I forget off the top of my head what size).

The panel in the garage must have a main disconnect. (there are a few exceptions, but with a 100A service, this is what you want). The ground bus in the garage panel should be bonded (screwed) directly to the pan. The neutral bar should be electrically isolated from the ground. Grounds and neutrals from the circuits need to be kept separate.

You'll also need an 8' long 1/2" copper ground rod driven at the garage, ground wire attached with an acorn clamp. The rod should be driven an inch or two underground so the whole rod is buried.

I don't know what state you're in, but in NJ, it's prohibited for a homeowner to obtain a permit if they are not the ones doing the work. Additionally, some amount (usually 10%) of the final payment is legally supposed to be withheld by the homeowner until the work passes final inspection. States vary though.
Hope this helps
That help a bunch. He's out there working now, In the Florida heat! I'm in Florida,but was born in Northwest Jersey! He has strenched down to 24" give or take and inch and is putting the conduit grey pipe in now. The panel at the shop is a simmen 100amp 20 spaces with its own 100amp breaker,but there will be a 100amp at the main panel as well. I guess the one at the shop panel will act a a disconnect and the one on the main panel will be the one to cut off power to the shop.I don't see a grounding bar yet,but next time he takes a break,I go out there and ask. I'm inspecting via a set of Binos from the comfort of my house. I've only given him half the money and the remainer at when the inspector,inspects and the power is on.. I'm paying $800 for this work.It's a thrid fron other bids. Is this fair or were the other guys bidding high.
 
  #12  
Old 09-24-11, 04:28 PM
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The feed wires are 4 conductors, two hot 2 gauge, a 4 gauge neutral and a 6 gauge ground. Ground and neutral are seperate and attached to the panel. The subpanel is a siemen 100amp 20 space run of the mill panel,similar to the main panel. Does have the two grey elbows with access cover.
 
  #13  
Old 09-25-11, 01:30 PM
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Sounds pretty good to me!
 
  #14  
Old 09-26-11, 07:30 AM
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Inspector suppose to be here this afternoon,then he can cover and continue with installing wall sockets,lighting,and connection for air compresor. So far evrything is pretty much as per you guys advise. Our code are a little more relaxed than in other places.
 
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Old 09-26-11, 09:41 AM
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Your outbuilding receptacles will require GFI protection for the 120 volt circuits.
 
  #16  
Old 09-28-11, 09:00 PM
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Originally Posted by Zorfdt View Post
If I were to install a 100A subpanel in a detached garage, this is what I would do. (You can use this to keep half an eye on his work)

100A breaker in the main panel. PVC conduit from the main panel, underground, at least 24" deep, long sweep underground on both ends into an LB (right angle connector with an access panel) going into each structure.
4 conductors, two hots and one neutral of 3ga copper or 1ga aluminum. Also a ground (I forget off the top of my head what size).

The panel in the garage must have a main disconnect. (there are a few exceptions, but with a 100A service, this is what you want). The ground bus in the garage panel should be bonded (screwed) directly to the pan. The neutral bar should be electrically isolated from the ground. Grounds and neutrals from the circuits need to be kept separate.

You'll also need an 8' long 1/2" copper ground rod driven at the garage, ground wire attached with an acorn clamp. The rod should be driven an inch or two underground so the whole rod is buried.

I don't know what state you're in, but in NJ, it's prohibited for a homeowner to obtain a permit if they are not the ones doing the work. Additionally, some amount (usually 10%) of the final payment is legally supposed to be withheld by the homeowner until the work passes final inspection. States vary though.
Hope this helps
Thanks for your advise on what to look for,other than the wire size,everything else was as per your advise/suggestions. Final inspection was this afternoon and we have power and lights. No more of trying to work in a 26x36 workshop using ext: cords.
Thanks!
 
  #17  
Old 09-29-11, 06:29 AM
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Thanks for letting us know how it worked out.
 
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