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Is a Sub-panel Necessary?

OldracerJones

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Jan 20, 2012
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Chico, Texas
I've completed my 50' x 30' metal building and have a 200 amp Panel installed by an electrician. My question is, my panel,is in the corner of the building, 50 ft away from where I am going to build my offices. Should I run a sub-panel off the main panel or just run the wire for the offices from the main panel?
 
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pattenp

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Virginia - USA
Depends on the number of circuits that the offices will have. With the high cost of copper wire these days it may be cheaper to put in the sub so you will have shorter runs for the office circuits.
 

Aceman

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Eastern Oregon
Depends on the number of circuits that the offices will have. With the high cost of copper wire these days it may be cheaper to put in the sub so you will have shorter runs for the office circuits.

Exactly.

We've wired quite a few shops and the offices usually end up getting their own panels. From a commercial point of view, this makes it easier for the office staff to find breakers and keeps the mechanics/shop folks from messing with the office power.

Subpanels are pretty inexpensive, it's pretty hard to beat a main lug sub fed with 10/8/6-3 versus a whole bunch of 12-2's ran over to the office area individually. Plus you save panel space in your main shop panel.

Personally, I use subs as much as I can. I always price them either way, but if using a sub is break even or even costs just a little more, I'll use them. I like having extra breaker space. Makes adding more circuits easier too in the future.
 

Falcon67

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Merkel, TX
Shoulda done that here. Look at how you plan your circuit layout and decide from that. Live and learn - I did most of my stuff home run from the main panel at the corner of my 24x40 shop. More of the terminations ended up on the other end of the building than I really expected, and I underestimated the amount of wire chewed up to get there, while trying to run things neatly. I have 5 outlet runs, two light circuits and 3 20A 240V circuits. I'm approaching 1000' of 12-2 used.
 
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ishiboo

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It depends on how much wiring you buy. Romex gets significantly cheaper the more of it you buy.

Where do you find the big price savings?

Our electrical suppliers are the same or higher than the big box stores on NM-B. A 1000' reel is the same price per foot as the 250' reels at the BORG stores as well, and given the weight of a 250' 12-2 or 12-3 I usually prefer to haul the 250' packs around anyway.

I'd love to get a quantity discount.
 

ishiboo

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Exactly.

We've wired quite a few shops and the offices usually end up getting their own panels. From a commercial point of view, this makes it easier for the office staff to find breakers and keeps the mechanics/shop folks from messing with the office power.

Subpanels are pretty inexpensive, it's pretty hard to beat a main lug sub fed with 10/8/6-3 versus a whole bunch of 12-2's ran over to the office area individually. Plus you save panel space in your main shop panel.

Personally, I use subs as much as I can. I always price them either way, but if using a sub is break even or even costs just a little more, I'll use them. I like having extra breaker space. Makes adding more circuits easier too in the future.

I agree, but I've found the easiest way is to run 2-2-2-4 SER, which is a bit cheaper than 6/3 copper with ground.
 

Falcon67

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I have $284 in my 1000' of 12-2. All bought at HD. Fiddled with the numbers using 2-2-2-4 and a panel - if I saved only 250', buying the 250' 12-2 would still be cheaper. Mental exercise only now LOL.
 

ishiboo

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I have $284 in my 1000' of 12-2. All bought at HD. Fiddled with the numbers using 2-2-2-4 and a panel - if I saved only 250', buying the 250' 12-2 would still be cheaper. Mental exercise only now LOL.

50' run I figure would need at least 65-70 feet of cable, at $1.79 for SER that's $125.

At 4 circuits it would be much cheaper, at 6-8 it becomes closer, and you have to look at future expansion. IMO it's a horse a piece either way. I just went with a sub at the house as my walls are finished and I would have had to fish 7-8 circuits and be unable to expand for the future the way my house is setup. Now, the new sub services my second floor at 90A and I have an empty 1.5" conduit I can pull new circuits up into the attic and drop down anywhere needed. :)
 

matt151617

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New Jersey
Where do you find the big price savings?

Our electrical suppliers are the same or higher than the big box stores on NM-B. A 1000' reel is the same price per foot as the 250' reels at the BORG stores as well, and given the weight of a 250' 12-2 or 12-3 I usually prefer to haul the 250' packs around anyway.

I'd love to get a quantity discount.

I meant for smaller amounts: 25 feet is twice the price per foot of 250 feet. I haven't priced per foot for over 250 feet.

The advantage of the big box stores is you can buy a Lowes 10% off coupon on eBay (and Home Depot will accept it).
 

Norcal

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I meant for smaller amounts: 25 feet is twice the price per foot of 250 feet. I haven't priced per foot for over 250 feet.

The advantage of the big box stores is you can buy a Lowes 10% off coupon on eBay (and Home Depot will accept it).

If your a veteran, HD will give you a 10% discount. (I am not)...
 
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