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Old 01-30-2010, 02:27 PM   #16
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Without a neutral I don't know how this works

Are you sure there aren't 3 wires coming out of that conduit ?

A sub by code needs 4 wires, so you can't install a sub without having 4 wires



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Old 01-30-2010, 04:23 PM   #17
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There's only 2 that I see. Ill check again, but 99% sure its only the two #6 hots from the 40A 240v.
And I reread all the posts, if Im correct in understanding, all I need to do is replace on of my 20A with a 30A (and 10/3 romex) to get another 10A of power.
This also shouldnt throw the 40A 240V since the load on either HOT wouldnt reach 40A (only 20A and 30A).
Is this right?
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Old 01-30-2010, 04:59 PM   #18
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I was wrong, I didnt notice it but there's another #6 coming in from the conduit that is wrapped with white tape to indicate neutral I believe.
It goes over and connects to the metal bar for neutral and ground connections.
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Old 01-31-2010, 03:54 PM   #19
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I was thinking some more and I think I get it now.
That's why you told me to put in a 100Amp subpanel... because its capable of it! (on 120v)

That went totally over my head lol.

So the best bet would be to get a 100A subpanel and then outfit it with breakers however needed.

And I agree!
That means all the 120v outlet wiring can stay how it is and be hooked to a 20a breaker.
The GFCI's can each have their own 20A.
And if I need a welding outlet I can drop a nice fat 50A in there just for it!

I should be fine with my grounding/nuetral wire being a #6 as well correct?
I understand its usually 1 size smaller.
I also assume that what you mean by a subpanel needing 4 wires is the 2 positive, neutral, and ground.

I'd love at least one more confirming post from you Scuba!
(p.s. Amazing job on your house)

Last edited by wtfh4xx; 01-31-2010 at 03:56 PM.
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Old 01-31-2010, 06:07 PM   #20
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Yes, if you leave the existing wires you can only stay with the 2 existing breakers
You can't upgrade to 30a breakers - no such thing as a 30a outlet circuit
20a outlets can't be installed on a 30a circuit

So...to install a sub-panel you need a ground wire from the main panel
You used to be able to run what exists now - it used to meet code

But now you need 4 wires, 2 hots neutral (existing) & add a ground
With #6 you would need a #10 ground run thru the conduit (I think)
I would run a #8 just in case, someone posted the Min size needed for the ground..can't find it

By having 4 wires you install a sub w/100a main breaker
You then feed it with a 50a breaker from the main
I would actually go to 60a, voltage drop will still be OK
This will give you some extra capacity for a welder

Per code some inspector will require a min 60a disconnect
Some would argue that the 100a main breaker in the sub meets that part of the code

By having a sub you can have multiple 120v circuits, not just 2
And you can setup a 240v circuit



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Old 02-01-2010, 04:24 PM   #21
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Thanks scuba!
The ground wire I have doesnt go to the main box, but instead to a ground rod.
If you look at the small panel you'll see a twisted copper wire going out bottom right, thats the ground and I believe it is a #6.
Its about the same size as the hots.

When upgrade time comes I'll put in a 100A subpanel and give each important 120V 20A outlet its own 20A breaker.
Thanks for all your help! :D
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Old 02-01-2010, 04:32 PM   #22
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The problem is you need a ground going back to the main panel
The ground to the main panel & the ground rod are for different purposes



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Old 02-01-2010, 04:53 PM   #23
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Ah thanks for that tip.
So I would need to run another wire for a 100A sub.
I'll remember that when I upgrade.

Why doesnt it need one now?
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Old 02-01-2010, 05:31 PM   #24
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Right now your setup is "grandfathered"
Once you upgrade you need to meet new code
A ground back to the main would be better...even now

I have read the reason for the requirement, but not an electrician & can't explain



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Old 02-01-2010, 05:55 PM   #25
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Ah ok, so its simply just for code issues?
Im not worried about code because this property will be staying with the family.
Will the ground rod work with the 100A sub panel coding aside?
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