No more room in panel. Sub panel?

sandyman720 · 03-06-2007, 01:09 PM

I am adding an addition to the back of my house with a half bath. There is no more room on my 100 amp panel. do I need to make a sub panel?

is there anything on the internet that shows how to do this?

Thanks

crecore · 03-06-2007, 08:57 PM

you may just want to have your service upgraded to 200a and install a larger panel now. It wont cost a whole lot more.
instructions... you wont find them. you'll need a permit and a inspection so hire it out.

darren · 03-06-2007, 10:38 PM

Hey there

Your subpanel is the way to go. It will be alot cheaper then upgradeing to a 200A panel, why would you upgrade if you only know 100A for your whole house.

You can probably can search and find something on the internet but obviously you have no clue about electricity so i would hire this out to someone.

I will keep this short but this is what you will need to happen to get a subpanel.

I would run a 60A panel myself and then you have lots of room in there.

For materiel you would need some 6/3, a 60A panel, 2 pole 60A breaker for your main panel and connectors for the above.

Take out two circuits from your main panel and move them over to your subpanel. Insert 60A breaker in the 2 new open slots. Run 6/3 between main panel and subpanel. Remove bonding screw in subpanel for neutral and ground are seperated. Wire in subpanel and main panel and you will be good to go.

If this is all jiberish to you defitenly hire out this project.

tribe_fan · 03-07-2007, 10:17 PM

Darren - would it be wrong to add a 100 amp subpanel ? (assuming wire size is correct)

sandyman720 · 03-08-2007, 07:52 AM

Hey all, thanks for the help.

I think that I am going to upgrade my service to 200amp.

I do not have central A/C yet so I definitely should upgrade dont you think?

My father in law is an electrician so I dont think it will be that bad for him and I to do it. After all we just got done re-wiring the entire house!

Thanks!

darren · 03-08-2007, 05:39 PM

You could put in a 100A subpanel, it will still work. But a 100A subpanel is more money, the panel cost more and the wire would be alot more.

Sandyman just curious why you didn't think about this before you wired your whole house, it would have been alot easier.

sandyman720 · 03-09-2007, 07:53 AM

becasue i didnt have any intention on putting in an addition 8 months ago when we re-wired the house. The current 100 amp service takes care of my current needs w/o a problem.

bobelectric · 03-09-2007, 08:38 PM

Tell your electrician father-in-law, that just rewired your house that you asked us at a DIY chatroom if you should increase capacity.

Bob O. 84,Pa.15330

Speedy Petey · 03-09-2007, 09:13 PM

Quote:

Originally Posted by darren

You could put in a 100A subpanel, it will still work. But a 100A subpanel is more money, the panel cost more and the wire would be alot more.

Really? I install sub-panels all the time. I typically use 100 amp (125a rated) panels for most, regardless of feeder size. To me there is no difference between a 60 amp panel and a 100.
I don't use those cheap 6-8 space panels so I guess that would be different.

Also, I doubt you'll feel the cost difference in the wire if the panel is right next to the main, as it seems the OP's situation is.

boman47k · 03-11-2007, 08:40 AM

You know the feeder from the transformer/pole will have to be upgrade too, right? More money but well worth it imo. Had mine upgrade a few years back from 100amp fuses to 200 amp breakers. MOre room for expansion if needed. Money well spent. Although if I had it to do over, I would do it myself and save about $500.

Quote:

you would need some 6/3

Would 8/3 not handle 60 amp subpanel?
The reason I ask is 8/3 was run from my house to my shop and I have noticed the lights dimming at times when it didn't seem to be enough being used to cause it. Shop is about 25' from the house. The shop is not actually that far. I figure about 25 to 30 feet of 8/3 between the main and the panel i n the shop.

jwhite · 03-11-2007, 09:10 AM

Quote:

Originally Posted by boman47k

You know the feeder from the transformer/pole will have to be upgrade too, right? More money but well worth it imo. Had mine upgrade a few years back from 100amp fuses to 200 amp breakers. MOre room for expansion if needed. Money well spent. Although if I had it to do over, I would do it myself and save about $500.

The POCO will decide if these wires need to be replaced. Often times they do not. They use a different set of rules to calculate amperage then we do.

Quote:

Would 8/3 not handle 60 amp subpanel?
The reason I ask is 8/3 was run from my house to my shop and I have noticed the lights dimming at times when it didn't seem to be enough being used to cause it. Shop is about 25' from the house. The shop is not actually that far. I figure about 25 to 30 feet of 8/3 between the main and the panel i n the shop.

If run in romex or a direct burry cable that #8 would need to be on a 40 amp breaker. If run using thhn/thwn it would need to be on a 50 amp breaker. Either could be run to a 60 amp panel. The panel can be larger rating than the circuit as long as the circuit is protected based on the wire size.

As for the voltage drop thing, the wire from the main panel to the house also comes into play, so what all is being used in the main house at the time you are experiencing a problem is also a factor.

You could also have a grounding or other issue that you need to address. number 8 should be able to go about 75 to 100 feet before VD becomes an issue.

Speedy Petey · 03-11-2007, 09:15 AM

Quote:

Originally Posted by boman47k

Would 8/3 not handle 60 amp subpanel?

Absolutely not. #8 in cable is only rated for 40 amps. Even THHN/THWN conductors in conduit are only rated for 50 amps.

Now this is likely not your situation with the dimming. Unless of course you are pulling the full 60 amps when the dimming occurs. Just because there is a 60 amp breaker that has no effect on the draw, only the allowable draw. You may only be pulling 20 or 30 amps when the dimming occurs.