100A subpanel Installation

[ajm2688]

I'm wanting to install a 100A subpanel off of the 200A Service Panel to the house. The 100A will have 7 Receptacle circuits inside a shed, 1 outdoor lighting circuit, and 1 indoor lighting circuit. It is a 12 ft. X 32 ft. shed. It will be 120ft-125ft panel to panel and the wire i believe im going to use is 3-3-3-5 copper (as was suggested per another site) to run underground through PVC Conduit. 2 questions:

1) Is this the correct wire size for this layout?

2) What size PVC Conduit should I use?

This is the Panel I intended to get. It will be Installed inside the shed.
Home Depot
Homeline 100A 20-Space 40 Circuit Indoor Main Plug-on Neutral Breaker Load Center with Cover (Internet#204836397) (SKU#1000040024)

 

[pattenp]

I would use 2-2-2-4 aluminum Mobile Home Feeder (MHF) and cut the feeder breaker amps back to 90A. This will save you a lot of $$. Use 2" PVC conduit.






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[ajm2688]

Ok thank you.

 

[soob]

That 3-3-3-5 is SER which you can't run underground, anyway.

I mean, I don't think there's any good reason you can't run copper SER underground in a conduit (as opposed to aluminum) but apparently you can't.

 

[wyliesdiesels]

If the panel doesnt include a ground bar then u will need to purchase that separately. U will also need 2 ground rods....

 

[theoldwizard1]

MHF does not require conduit, except above ground and in buildings.

 

[pattenp]

That 3-3-3-5 is SER which you can't run underground, anyway.

I mean, I don't think there's any good reason you can't run copper SER underground in a conduit (as opposed to aluminum) but apparently you can't.

He didn't say SER, but stating 3-3-3-5 could lead you to that assumption. I was just thinking individual THHN/THWN.

 

[justind]

You will need a separate ground bar and do not bond the neutral bar to the panel. Run the ground from the house to the separate ground bar and then run a ground wire of at least #6 to a 8' ground rod outside the building. You may need another 6 feet away from the first with a continuous wire from the panel to both rods. I was going to use aluminum for my sub panel but for ease of installation I used dual rated copper in sch 80 pvc conduit. I used a electric supply house and for a 100 foot run I spent 350 for everything between the 2 panels.

 

[soob]

He didn't say SER, but stating 3-3-3-5 could lead you to that assumption. I was just thinking individual THHN/THWN.

I just did this project, and he mentioned Home Depot--they sell a 3-3-3-5 copper SER that they erroneously recommended to me for an underground conduit install. I guess I did assume he meant the same stuff, but I wanted to warn him.

 

[pattenp]

I just did this project, and he mentioned Home Depot--they sell a 3-3-3-5 copper SER that they erroneously recommended to me for an underground conduit install. I guess I did assume he meant the same stuff, but I wanted to warn him.

Oh.. it's good that you stated this because there have been people that have used SER under ground in conduit on the recommendation of an employee at the big box store.

 

[alfredeneuman]

I've never heard of #5 wire.
Does it even exist?

It's certainly not a standard size

 

[pattenp]

I've never heard of #5 wire.
Does it even exist?

It's certainly not a standard size

Not as individual wire. Apparently only in the Cu SER cable assembly.

 

[soob]

Oh.. it's good that you stated this because there have been people that have used SER under ground in conduit on the recommendation of an employee at the big box store.

I actually had a guy at a bonafide electrical supply house recommend aluminum SER for that. In fact he said I could direct bury it. And no it wasn't MHF.

Anything for a sale I guess.

 

[wyliesdiesels]

I actually had a guy at a bonafide electrical supply house recommend aluminum SER for that. In fact he said I could direct bury it. And no it wasn't MHF.

Anything for a sale I guess.

Wow! Guess these counter people need better training and education on the stuff theyre selling!

 

[Aceman]

Wow! Guess these counter people need better training and education on the stuff theyre selling!

You have to remember they are SALES people, not tradesmen. They are not in the business of knowing how to install products, only to sell them. With that said, they should NOT be giving installation advice just to sell products.

Same story, you wouldn't believe how many people call our shop and ask our office guy what they need to install a new service panel themselves or ask him what wire size they need for a project?!?!

 

[my58dodge]

I actually had a guy at a bonafide electrical supply house recommend aluminum SER for that. In fact he said I could direct bury it. And no it wasn't MHF.

Anything for a sale I guess.

I have this SER installed underground for about 35 feet in 2" PVC conduit, on the advice of the local well respected supply house....so much for the "good" advice from the supply house vs. the big box store...will be replacing it in the spring with MHF.

 

[my58dodge]

You have to remember they are SALES people, not tradesmen. They are not in the business of knowing how to install products, only to sell them. With that said, they should NOT be giving installation advice just to sell products.

Same story, you wouldn't believe how many people call our shop and ask our office guy what they need to install a new service panel themselves or ask him what wire size they need for a project?!?!

I would think though that these "sales people" who are around the trade every day for years would at least have an understanding of basic application of their products.

 

[bmxdad]

I just finished something like this, but not near as far. As pattenp suggested... run individual wire if you can. I used individual THHN/THWN, three #2 with a #4 for ground, all copper run through Schedule 40. Its a full 100amp service too.

If you do use Conduit, make sure the Bell mouth faces the direction the wire is coming from ... so your feeding into the bell mouth. Makes getting by the joints a snap.

Another thing ... get the biggest panel you can fit. Mine is filling up way to fast ... in wire, not in breakers. Just having a little more room would be nice.

 

[akpolaris]

I ran 1/0 1/0 1/0 alum, buriable wire, without conduit, for an approx 95" run from a 125 amp breaker in a 200 amp service to a 36 slot box in my shop.

 

[wyliesdiesels]

You have to remember they are SALES people, not tradesmen. They are not in the business of knowing how to install products, only to sell them. With that said, they should NOT be giving installation advice just to sell products.

Same story, you wouldn't believe how many people call our shop and ask our office guy what they need to install a new service panel themselves or ask him what wire size they need for a project?!?!

Installing products is one thing. I wouldnt expect a salesman to know how to install something. But were not talking installation. On the other hand, I WOULD AND DO expect a salesman to KNOW the product theyre selling. A good salesperson knows the product theyre selling!!

I ran 1/0 1/0 1/0 alum, buriable wire, without conduit, for an approx 95" run from a 125 amp breaker in a 200 amp service to a 36 slot box in my shop.

95" run? Man thats short!

And when did u install this? After 2008? If so, u used the wrong wire.