subpanel info needed

[soxrule]

Good morning,
This is my 1st post - let me know please if I am not following procedure:

Detached garage (12x28) is only 20 feet from house.

I am running 8/3 from main panel to garage.
Electrical needs are minimal: 6 overhead flourescent shop lights (2 switches), 1 outside outlet, 3 outside lights, garage door opener, 4-6 outlets (will run typical power tools on occasion).

I'd like to pick out the correct subpanel capable of 6-8 circuits. (Will run the 8/3 off 40 amp breaker)

Can someone please throw suggestions my way?

Thank you.

Tony Soxrule

 

[pattenp]

First thing I suggest to do 50A as a minimum and use 6/3. Also use a main breaker panel so you are not limited to just 6 circuits.

Use something like this... http://www.homedepot.com/p/Square-D...lue-Pack-HOMVP5/100197589?N=12l2#.Uk8BFtJONY4

 

[soxrule]

Thx for the suggestion... unfortunately, I already ran 80 ft of 8/3 cable through the house. Can I still use this box?

 

[pattenp]

You can still use that panel. If you know for sure you won't ever need more that 6 circuits then you can use this.....http://www.homedepot.com/p/Square-D...th-Cover-HOM612L100SCP/100190554#.Uk8LMdJONY4 . But code requires a main disconnect once you have more than 6 breakers to turn off all the power.

Edit: You can use a back fed 2pole 40A breaker in the main lug panel as a disconnect if needed.

 

[theoldwizard1]

You can still use that panel. If you know for sure you won't ever need more that 6 circuits then you can use this.....http://www.homedepot.com/p/Square-D...th-Cover-HOM612L100SCP/100190554#.Uk8LMdJONY4 . But code requires a main disconnect once you have more than 6 breakers to turn off all the power.

Edit: You can use a back fed 2pole 40A breaker in the main lug panel as a disconnect if needed.

Just to be clear ...

Use a 40A breaker in the main panel and use a 2 pole 40A breaker in the first 2 slot on the left

That only leaves you 4 slots, but if you use tandem breakers you can have 8 circuits.

 

[pattenp]

Yes, but use a HOM240 in that panel not a QO240.

Just to be clear ...

Use a 40A breaker inthe main panel and use a 2 pole 40A breaker in the first 2 slot on the left

 

[soxrule]

Thanks everyone for the help.

Will this unit also safely work?
Siemens 100 Amp 30-Space 30-Circuit Indoor Main Breaker Load Center
P3030B1100CU

Also, the 8/3 wire that I am running is copper. Does that make a difference with an AL box?

soxrule (they won today!)

 

[theoldwizard1]

Thanks everyone for the help.

Will this unit also safely work?
Siemens 100 Amp 30-Space 30-Circuit Indoor Main Breaker Load Center
P3030B1100CU

Why do you want such a big box when you said you only need 6 or 8 circuits. Plus the wire you have install so far (#8 copper) would never carry near enough current for 30 circuits.

Also, the 8/3 wire that I am running is copper. Does that make a difference with an AL box?

The box can be made out of any approved material. The connections inside the box (and the breakers) should be compatible with both aluminum and copper wire.

The biggest difference between aluminum and copper wire is the amount of current that can safely be carried for a given distance. My recommendations were based on copper wire over a distance of 110' from panel to panel. 80', 20' underground, plus 10' to play with. Is this correct ?

 

[soxrule]

80', 20' underground plus 10 is correct.
I thought if I used this box, I would have a turn-off at the subpanel. That's what I would like... don't really need that big box.

 

[Kevin C]

Any 240 volt circuits will use up two spaces. You can get some that are paired with 120V breakers, allowing three circuits in two slots.

A larger panel is nice if you ever decide to expand and run a larger feed circuit. Lowes has a couple of smaller panels with a 100 amp main breaker that can be used as a disconnect.

Siemens 24-Circuit 12-Space 100-Amp Main Breaker Load Center
Item #: 374128 | Model #: P1224B1100CU

$64

http://www.lowes.com/pd_374128-1318-P1224B1100CU_1z0yt2q+1z10wgm+1z140f2__?productId=3532944&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar%7C1%26page%3D1&facetInfo=Main%20breaker|Siemens


OR

Siemens 20-Circuit 10-Space 100-Amp Main Breaker Load Center (Value Pack)
Item #: 94657 | Model #: E1020MB1100FCGP
3.5 / 5

2 reviews | Write a review
$62.00

http://www.lowes.com/pd_94657-1318-E1020MB1100FCGP_1z0yt2q+1z10wgm+1z140f2__?productId=3129843&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar%7C1%26page%3D1&facetInfo=Main%20breaker|Siemens

 

[ishiboo]

Given 40A max and limited circuit needs, I'd go with a 6/12 as wizard said.

If you anticipate future 240v needs, a 20-circuit may be the safe way to go as you essentially are left little capacity without filling the remaining 4 slots with tandems.

I would have went with 2-2-2-4 aluminum for a similar price and had more capacity, but what's done is done

 

[theoldwizard1]

80', 20' underground plus 10 is correct.
I thought if I used this box, I would have a turn-off at the subpanel. That's what I would like... don't really need that big box.

I was afraid you would not understand pattenp and my posts !

Edit: You can use a back fed 2pole 40A breaker in the main lug panel as a disconnect if needed.

Just to be clear ...

Use a 40A breaker in the main panel and use a 2 pole 40A breaker in the first 2 slot on the left ...

The 2 pole 40A breaker on the left side of that small panlel become the "main breaker" for that panel. The incoming power attaches to that breaker, which is why pattenp used the term "back fed", because the current is following backwards compared to what a typical breaker would see. Breaker don't care which way the current is actually flowing.

This gives you the very nice ability to "turn off" (electricians term is "disconnect") the entire subpanel for adding additional wiring. It is also a code requirement if you have over 6 circuits.

 

[theoldwizard1]

Yes, but use a HOM240 in that panel not a QO240.

Yep, I missed that detail that it was a Homeline.

Different tandem breakers also.

 

[Aceman]

Detached garage (12x28) is only 20 feet from house.

I am running 8/3 from main panel to garage.

Thx for the suggestion... unfortunately, I already ran 80 ft of 8/3 cable through the house. Can I still use this box?

Did you run Romex out to your detached garage?

 

[Norcal]

Did you run Romex out to your detached garage?

Good question, if the OP did run Romex® all the way there he has a big problem.

 

[wyliesdiesels]

80', 20' underground plus 10 is correct.
I thought if I used this box, I would have a turn-off at the subpanel. That's what I would like... don't really need that big box.

Is the wire that u ran Romex? And if so is it UF-B? In other words, is it rated for underground/wet locations?

EDIT: whoops, i see that all 3 of us posted this at the same time....

 

[pattenp]

Well if he's got all NM-b (Romex) it's not all bad news. He can put in a couple of junction boxes and use UF for the 20 feet under ground.

Did you run Romex out to your detached garage?

Good question, if the OP did run Romex® all the way there he has a big problem.