My Culter Hammer breaker box is full, it has the slim line 110 breakers in it already to make more room. I need to add a 40 amp 220, double oven circuit, to the box and I have not seen a 40 amp slim breaker.

What are my options?

 

(1) Replace the main panel with a larger one.

(2) Add a subpanel.

(3) See if the box can accommodate any more skinny breakers. Call the manufacturer with the panel number and an inventory of all the breakers in it now. It's possible that more consolidation can be done, but we'd need more details to figure that out.

 

OK, if I have to go with option 2 "add subpanel" where does the feed wires attach in the main box?

 

You can feed the sub by moving enough circuits from the main to install the new breaker. I do not think cutler-hammer makes a quad, which is what you would need to get a reduced size 240 two pole circuit.

 

I too am probably facing this same problem.

I might not have enough space in my Murray main panel, so if I wanted to install a sub-panel (with disconnect) right next to it to run say, 2-3 20A circuits, 2 15 amp lighting circuits, about how expensive would it be? I currently have 0 free spaces in my panel, but I think I could swich a few 15A singles to 15A tandems...

Compared to the expensive of having a pro come in and replace my panel with a new, larger one.

Oh, I have 100A service.

 

**about how expensive would it be?

Less than $150


A 125 Amp Square D Homeline subpanel is about $50 at HD.
Breakers are about $4 each.
A 100 Amp 2 pole breaker in your Murray panel ??? $50.

4/3 Romex from main panel to sub panel $15 or individual THHN wires, 4/4/6/8 AWG.
Some gray PVC with fittings $10

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whyohwhyoh

 

You mean I could put a 100A subpanel on an already full 100A main service? That seems weird.

I wouldn't think I would need that much on the sub. Maybe 60A.

 

The size of the subpanel is not limited by the size of the main panel. You may have a hard time finding breakers for your Murray panels, I know I did. I used a Siemens breaker instead, they look identical. Even though technically, I shouldn't do that. But the Siemens breaker was $25, the Murray would have been $110.

 

The guy at HD and the Siemens website says they will work in my panel... Looks identical to me.

 

Can I come off the 100 AMP main breaker with 8 , 6, ?? gauge wire to the sub panel and feed the 40 amp oven circuit breaker?

 

Keep in mind of course that a subpanel will not give you any more power, just space. So you should verify that you have enough power too. That depends on your service size as compared to the loads. Most of the load is dependent on square footage of the home, and the size, number and type of 240-volt loads.

 

Thanks for the advice John. I did a load calculation a while back with the help of this forum (can't remember the post link) and I came out having some cushion.

 

propane,
If you mean from the existing 100 amp main in the panel, generally no. The breaker already has a set of conductors connected and you cannot put a second set in the same fasteners. You cannot pull more than 100 amps past the main, so find a 2 pole up to that and put it in the old box. Size the feeders to the new box to match the 'new' breaker in the old panel.

 

You mean I could put a 100A subpanel on an already full 100A main service? That seems weird.

Yep you sure can.

The difference in price between a brand new 60A subpanel $35 and 125A subpanel $50 is not much. So why not go ahead and install a 125A capable panel, full of space for future upgrades. In the future if you upgrade your main panel to 200A, then the subpanel would seem less "wierd".

If all you need is 60A then install a 60A double pole breaker in your main panel but you don't have to. 100A breaker would be fine, but again cost differential is small. 60A subpanel requires 6/6/8/10 gage wire, 100A requires 4/4/6/8 gage wire.

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whyohwhyoh

 

Sorry to hijack the thread... But I don't want to create a new one just yet.. :-)

Anyhow, I looked at my panel. Like I said, it is a Murray, 100A panel. Has room for 20 1" breakers. All slots are filled, and if I count up the total, including each tandem as 2, I count 26 breakers. My load calc came up with 73A demand load.

So if I understand correctly, I have the following options:

(1) Install 100A breaker and a new subpanel. (DIY)

(2) Upgrade main panel to a larger one with more space (I would have a pro do this... How much $$?)

(3) Instead of #2, go with a 200A upgrade. Price is over $1200 probably...

(4) Double up more with tandem breakers to fit the additional 5-6 circuits (3 20A and 2-3 15A). These will be for lighting and outlets in a 450 sq ft addition.

Additionally, I have a 100A (I think) off-peak service panel right next to the main. Maybe I could get it changed over to regular service and put a new panel on it? (it only has room for 8 breakers). I kind of wanted to keep the off-peak to add a hot tub / spa at the end of the summer.

Thanks again guys for all of your help!

 

If you did a load calculation and think you are under the service and the panel is rated for the tandems, just keep adding them. You can have up to 42 devices (tandems count as 2) not including the mains. (NEC 408.15)

 

Where would I find out if the panel is rated for tandems? It is an older Arrow/Hart/Murray box. I think the model was F100 something.

Update:

I searched all around Murray Electric's site and couldn't find any specs on OLD panels. I guess having the exact model number would help.

Anyone happen to know of a site that has specs on 30 year old panels? :-)

 

Found a solution, a 20/40/40/20 Culter Hammer breaker.

I can take out a 20/20 replace it with the above and swap out the 50/50 for a 40/40.