[J S Machine]

I'm going to get my shop wired, and I am trying to figure out what has to be done so that I don't sound like an idoit when I get an electrician out to check it out.

I have a main panel on the side of my house, and it is just about full. See here-

All 240 breakers on are on the left, and all 120 stuff is on the right. Every single one of the 120 breakers are the tandem / piggy back 2-in-1 style. Never seen one done like this. Usually the single pole breakers are the normal single slot width, and you may have a couple of the 2-in-1 type. In my box they are all the 2-in-1 type.
If you look close, you can see the one spot on the bottom right (120 side) that is empty. That is the only space available.

Amps are:

200 main

(Left side 240's)
Heater 60
Range 50
AC 40
Water heater 30
Dryer 30

(Right side 120's)
Everything on the right side is 20 for the first eight breakers from the top, then the remaining ten are 15 amp.

This would allow for one single pole 110 breaker to go to the shop. I would really like to have 240 to run a welder I have.

My first question is can I get 240 out of my main panel? In order to get 240, I know I need a double pole breaker. If there isn't room in my main box, what do I do? would that require adding a sub panel to the main panel? My thinking is that if I am going to have to hire somebody to do this, I might as well go ahead and do whatever I have to do to get 240 out there.


Second question is this. If I have a service line buried under ground, and running out to the shop it has to come up into the shop. I have a pvc pipe coming up through the footing into the building. Do I have to have a sub panel where the service line comes up into the shop? I'm not sure what the code requires here, but I feel like there should at least be a small box with a single breaker possibly? Or does the line just come up and go directly into the shop's light switch?

You can see what I'm talking about in this diagram. I have one light switch, 5 plugs, and a light box for an overhead light. I want to have everything running off of the light switch, where when I turn the light on, everything comes on. I bought all 20 amp stuff, switches, receptacles, and 12-2 wire. I know it is a bit overkill for general stuff, but I figured it couldn't hurt. I won't be running much but a light and maybe a power tool at any one time. It isn't like I'm going to be running something off of every outlet all at once and lights. This is the way my last shop was wired and it worked fine.

 

[rjniles]

If you want both 120 and 240 in the shop you will need a sub-panel in the shop. To make space in the panel, you may be able to replace some of the 240 breakers with the mini type. Read the panel label as to what type breakers it will accept

 

[J S Machine]

I was talking about this in another thread, and never did get a clear answer to this. Do they make 240 breakers that will fit into the spot of a single pole?

 

[rjniles]

I was talking about this in another thread, and never did get a clear answer to this. Do they make 240 breakers that will fit into the spot of a single pole?

Yes they do.

Example:http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

Read the label on you panel and it will tell you what type breakers it will accept.

I used a GE breaker in the example because your picture looks like a GE. If it is another brand, most make the half size two pole breakers.

 

[J S Machine]

Yes they do.

Example:http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

Read the label on you panel and it will tell you what type breakers it will accept.

I used a GE breaker in the example because your picture looks like a GE. If it is another brand, most make the half size two pole breakers.

So I could stick that half size breaker into that one slot that I have open on the bottom right?

If so, that means I could get a 240 line out to the shop. With that done, How would the sub panel in the shop be wired? would the sub panel be put up on the wall in the shop, and a 240 breaker there as well as a 120 to run the lights and outlets?

 

[rjniles]

So I could stick that half size breaker into that one slot that I have open on the bottom right?

No that will not work, the half size 2 pole breaker has to bridge across 2 full size positions. Take the bottom single pole on the right side and move to the bottommost position. Then install the half size 2 pole in the slot created.

As far as the sub in the shop, search "sub panel" on this forum. It is probably the single most discussed item. There are many specifics that need be addressed about the wiring requirements. i.e.: conduit vs direct burial wire, grounding rods, mechanical protection of wiring, etc. You also should do a load calculation to determine how much capacity (amperage) you require. This will determine breaker and wire sizing. Also, how far is the shop away from the main panel? longer distances may require the up sizing of the feeder wiring.

 

[J S Machine]

So I could stick that half size breaker into that one slot that I have open on the bottom right?

No that will not work, the half size 2 pole breaker has to bridge across 2 full size positions. Take the bottom single pole on the right side and move to the bottommost position. Then install the half size 2 pole in the slot created.

As far as the sub in the shop, search "sub panel" on this forum. It is probably the single most discussed item. There are many specifics that need be addressed about the wiring requirements. i.e.: conduit vs direct burial wire, grounding rods, mechanical protection of wiring, etc. You also should do a load calculation to determine how much capacity (amperage) you require. This will determine breaker and wire sizing. Also, how far is the shop away from the main panel? longer distances may require the up sizing of the feeder wiring.

The distance is probably about 50'.

 

[J S Machine]

After a little studying and a little better understanding, I think I see what can be done here.

Pull the A/C breaker in main panel - add a 100amp breaker in its place
Run a line from 100amp breaker to a sub-panel right there
Put the A/C 40amp breaker in the sub-panel, as well as a 60amp (for shop)
Run a 60 amp 240 circuit out of that panel to the shop
Sub-panel the shop for 240 and 120.

If this will work, what size/type of wire will I need to run from my sub-panel at the house to the sub-panel in the shop? It will be burried in conduit of course.

So now I have my 240 and 120 out at the shop, but I am still unclear on whether or not the wiring diagram I have above for my 120 will be ok.

-All this is assuming I can't find a smaller 240 breaker to fit in the box and just go from there-

 

[J S Machine]

Does anybody else have anything to add to this?

Not sure why some of my topics go quiet after a little while..

For the record, I still have not had an electrician come out yet, so I'm still just dead in the water.

Let's talk about some issues that have been brought up.

1.)It has been brought up to me that the main panel is unbalanced, and from what I understand this means that phase A may be pulling more than phase B - or vise/versa. Am I correct on my understanding of this?

2. How the main panel was done. I have had several people tell me that they have never seen a box with so many circuits. If this is the case, how would I combine circuits to free up some spaces?

3.) A quadplex breaker. I am not sure what a quadplex breaker does exactly, but several people have mentioned it. Can somebody please explain to me how this will help free up space in my box?

If I can go without adding a subpanel at the main panel just to get the space I need that would be great. The ways to do this are obviously floating around, but I am just unclear on what I have to do..

4.) Service line questions - these will be broken down because there are several:

A.Size of service line needed. I have determined that I need 75 feet of line to go from the main panel to the shop sub panel. I called lincoln electric and talked to them. The said my welder needs a 50 amp breaker, and that it has a 20% duty cycle so I may be able to get away with a little less as far as wire size. This may not matter though because if I come from my main panel to this sub panel with wiring (3 wires and ground) it will have to support whatever breaker is in the box correct? I plan to branch off in my subpanel in the shop with a 50 amp breaker there for the welder, and also one or more single pole breakers for the 120 side.

B.) It has been brought to my attention that alluminum wire is about 1/5 the cost of copper, and this would be something of interest to me. I have also been told that NEC code used to not allow this, but they do now so it could be an option.

c.) Obviously I will need three conductor wires and ground. Is it cheaper to run three seperate wires(or four wires w/ground) or the cable type stuff that is all inclusive? I have a feeling the seperate wires may be a little cheaper by the foot than the cables that contain all needed conductors.

D: ) Does the wire have to be indoor or outdoor type wire? It will be burried in conduit of course.

Main panel: GE Box, Model number TM2020RCUMOD1

Looks like a link to the box:

http://www.plccenter.com/buy/General+Electric/TM2020RCU?source=AdWords_Part

 

[HouseHelper]

1. Balancing loads in a residential panel is a non-issue. You have no problem here.
2. A little excessive, but not that unusual. Mostly just makes for a rat's nest of wires in the panel.
3. A quad breaker gives you two 240 circuits in the space of one double pole breaker. Because you can use "skinny" db breakers in this GE panel, a quad doesn't help you.
4. I would recommend using "mobile home feeder", which is four twisted Al conductors of AWG size 2-2-2-4 that is rated for direct burial or can be placed in conduit. You would breaker this at the main panel with up to a 90A breaker. I would replace the dryer 30A breaker with a 90A to feed the garage and use a "skinny" 30A dp breaker on the other side as directed by another poster for the dryer.

 

[J S Machine]

3. A quad breaker gives you two 240 circuits in the space of one double pole breaker. Because you can use "skinny" db breakers in this GE panel, a quad doesn't help you.

I just called an electrical supply house, looking for info on the quadplex breaker. They said the same thing. They said it isn't compatible with my box.

4. I would recommend using "mobile home feeder", which is four twisted Al conductors of AWG size 2-2-2-4 that is rated for direct burial or can be placed in conduit. You would breaker this at the main panel with up to a 90A breaker. I would replace the dryer 30A breaker with a 90A to feed the garage and use a "skinny" 30A dp breaker on the other side as directed by another poster for the dryer.

Ok so they make a double pole skinny breaker..just like the one in his link?

I don't understand how this works. Doesn't a breaker have to hit two poles in the main panel (as it does with the normal sized double pole breakers)?

I don't understand how one that size hits both slots.

 

[rjniles]

Ok so they make a double pole skinny breaker..just like the one in his link?

I don't understand how this works. Doesn't a breaker have to hit two poles in the main panel (as it does with the normal sized double pole breakers)?

I don't understand how one that size hits both slots.

You link did not work, but here is a 30 amp 2 pole mini breaker:

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

It picks up both poles because it bridges the bottom of one space and the top of the space below it. That is why I said in an earlier post you have to move the lower existing one pole mini to make the space.

 

[mem]

rjniles tells you how in post #6.

 

[J S Machine]

You link did not work, but here is a 30 amp 2 pole mini breaker:

http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

It picks up both poles because it bridges the bottom of one space and the top of the space below it. That is why I said in an earlier post you have to move the lower existing one pole mini to make the space.

Ok. I was under the assumption that you had to be in either a hole single slot or both whole slots for a two pole. In other words, I will be coming off both phases but by a half of what would normally be a single slot sized breaker. on each side of the breaker - which is 1 slot thickness....

 

[rjniles]

Ok. I was under the assumption that you had to be in either a hole single slot or both whole slots for a two pole. In other words, I will be coming off both phases but by a half of what would normally be a single slot sized breaker. on each side of the breaker - which is 1 slot thickness....

You do understand that every other slot in the panel feeds from opposite taps of the POCO's center tapped transformer (Call in phrase A & phase B -- not really but it works for explanation). L1 & L2 is a better terminology. L1 to neutral is 120 volts, L2 to neutral is also 120 volts, L1 to L2 is 240 volts.

The 1" wide slots down each side of the panel are wired as L1, L2, L1, L2, L1, etc. A regular 2" wide 2 pole breaker bridges L1 & L2 and you get 240 volts. A 1" wide 2 pole mini breaker brides the bottom of L1 and the top of L2(or the bottom of L2 & the top of L1). Bridging both legs it provides 240 volts. To utilize the panel fully, you install single pole minis above and below the mini 2pole.

 

[J S Machine]

You do understand that every other slot in the panel feeds from opposite taps of the POCO's center tapped transformer (Call in phrase A & phase B -- not really but it works for explanation). L1 & L2 is a better terminology. L1 to neutral is 120 volts, L2 to neutral is also 120 volts, L1 to L2 is 240 volts.

The 1" wide slots down each side of the panel are wired as L1, L2, L1, L2, L1, etc. A regular 2" wide 2 pole breaker bridges L1 & L2 and you get 240 volts. A 1" wide 2 pole mini breaker brides the bottom of L1 and the top of L2(or the bottom of L2 & the top of L1). Bridging both legs it provides 240 volts. To utilize the panel fully, you install single pole minis above and below the mini 2pole.

Yes - this is what i meant when i tried to explain it. Thank you so much! You explained it alot better than I did.

So I guess this solves the problem of whether or not I will have to add a sub panel at the main panel.

Now I can focus on the other issues

One last thing though..Someone mentioned somewhere in my couple of days of research that code no longer allows tandem / half sized breakers or something like that. Will doing this - what we are talking about here - abide by code?

 

[mem]

Regarding your schematic J S, personally I would run the lights off a separate 15 amp circuit from the outlets. Run the outlets from their own 20 amp, or better yet two, circuits. You can still switch them if you like, but I don't understand why. You won't be left in the dark if something blows and maybe save some cash on the lighting hardware.

 

[J S Machine]

Regarding your schematic J S, personally I would run the lights off a separate 15 amp circuit from the outlets. Run the outlets from their own 20 amp, or better yet two, circuits. You can still switch them if you like, but I don't understand why. You won't be left in the dark if something blows and maybe save some cash on the lighting hardware.

Yes the more I consider it the better it sounds. It won't cost me that much more to run a seperate circuit if I have a sub panel right there in the shop. With a 50amp breaker for the welder and two single pole breakers, I should be good. Lights on one single pole breaker and the plugs on the other.

 

[rjniles]

One last thing though..Someone mentioned somewhere in my couple of days of research that code no longer allows tandem / half sized breakers or something like that. Will doing this - what we are talking about here - abide by code?

The panel is listed for a maximum number of circuit (each pole counts as a circuit). As long as you do not exceed that count, you are NEC compliant. NEC does not ban half size breakers.

You panel appears to be a 20 space, 40 circuit panel. You have 38 circuits installed in 19 spaces. If you install the mini 30 amp 2 pole breaker as we discussed, your panel would be full. It would be a code violation to remove one of the full size 2 pole breakers to add more minis (you would exceed the 40 circuit limit.

 

[J S Machine]

The panel is listed for a maximum number of circuit (each pole counts as a circuit). As long as you do not exceed that count, you are NEC compliant. NEC does not ban half size breakers.

You panel appears to be a 20 space, 40 circuit panel. You have 38 circuits installed in 19 spaces. If you install the mini 30 amp 2 pole breaker as we discussed, your panel would be full. It would be a code violation to remove one of the full size 2 pole breakers to add more minis (you would exceed the 40 circuit limit.

I understand. So as long as I stay within the 40 circuit range I'm good as far as NEC requirements go.

Thanks for your help and sorry it took me so friggen long to understand what you were getting at :lol: