Time for a larger panel?

[miketyler]

Now that I am getting serious about heat and AC in the shop and upstairs loft I had forgot about one of the most important aspects of the install; the electrical. My panel is full and I assume the best solution is a new panel?

I have a single 100amp breaker in the attached garage that's acts as a master for the shop. In adding other circuits for ceiling heater and for 220v air compressor I have doubled up using the split beakers. I had assumed this was an accepted practice as long as all codes and practices are heeded and amp loads are nominal. The little Fahrenheat ceiling heater does a great job for the space and I wanted to retain it as aux heat if it ever got too cold for heat pump heat.

Should I get a larger panel with enough capacity to put all circuits back on single breakers? Or if wire sizes and 100amp breaker are suitable can I double up once more and add two more split breakers and free up two places for a 220v mini split?

 

[aandpdan]

You could also add a subpanel to your subpanel.

 

[Slowgsr]

Buy another sqd panel, 40cct is the biggest you'll find in 100a
Then replace and you can backfeed that 100 again or get one with a main.
Breakers are the costly stuff, and labour. If your doing the labour yourself
A new panel won't run much

 

[jeff000]

If the split breakers give you enough room then I wouldn't worry. If you need more room I would add another sub panel.

 

[justsam]

Where is the 100 Amp breaker feedin the "shop"? Is it collocated with this panel?

Are "shop" and "garage" all attached to building that main service panel is located?

Depending on above answers you may exceeded number of breakers without having a master. No big deal but you may want to rectify while doing other upgrades.

 

[ForceFed70]

Nothing wrong with using split breakers if you can make it work.

A subpanel is also a great idea if you don't have enough circuits even with split breakers.

Not sure I'd bother replacing the whole panel with a larger one, but certainly another option.

I am curious about your total load tho. With electric heat/AC 100A may be a problem depending on size of shop, climate, insulation, # of people working in the shop, equipment, etc. 100A is probably plenty, but it could be a problem in some scenarios. For example: Running a big AC unit, a big compressor, and a big welder all at the same time while also having overhead lights on, etc. BIG being the key word here. Standard hobby-shop owners don't typically have larger than a 5HP compressor or a 200A welder.

 

[miketyler]

Thanks for all the responses. The 100amp breaker that feeds the shop is located in my attached garage. The shop has no master installed in it's panel but I can surely add one.

My shop is a detached garage and is more of a hobby shop that I use to store and work on my classic cars, toys and spend my piddle time. I have a Miller 140 and am unsure on amp draw of the 220v 3cyl compressor. I rarely (if ever) use these at the same time.

 

[encantofred]

this becomes a load calc question. yea, you can slap subpanels on subpanels (i have as well), but you have to be able to handle the total load on your service.

tom

 

[alfredeneuman]

The shop has no master installed in it's panel but I can surely add one.

If it's an attached garage you don't need a main breaker.

 

[wyliesdiesels]

OP- I would do load calcs!

And what is the HP rating of your compressor?

If it's an attached garage you don't need a main breaker.

He said in comment #7 that his shop is detached so he most definitely needs a main breaker in that panel as he has violated the 6 handle rule!

 

[alfredeneuman]

He said in comment #7 that his shop is detached so he most definitely needs a main breaker in that panel as he has violated the 6 handle rule!

I read it wrong. It needs a main breaker!
...... and I need a

 

[miketyler]

If that's a code requirement then I can and will add a main breaker to the detached shop with no problem. This is how the property was configured when I bought it.

With the new loads imposed by heat and AC I'd like to know I have the capacity needed to run at least the compressor while the HVAC is on. When I need to weld I usually open the garage doors and roll the welder outside to the driveway as the sparks leave burn marks on the epoxy floor. Unsure on amp load of the compressor but I will check it.

I'd like the setup to be idiot-proof for future owners that would let me run everything though I really don't ever see that scenario happening while I live here.

 

[zmaxmotorsports]

If that's a code requirement then I can and will add a main breaker to the detached shop with no problem. This is how the property was configured when I bought it.

With the new loads imposed by heat and AC I'd like to know I have the capacity needed to run at least the compressor while the HVAC is on. When I need to weld I usually open the garage doors and roll the welder outside to the driveway as the sparks leave burn marks on the epoxy floor. Unsure on amp load of the compressor but I will check it.

I'd like the setup to be idiot-proof for future owners that would let me run everything though I really don't ever see that scenario happening while I live here.

You wont be using the heat and ac at same time so that eliminates that problem.
Im not a fan of sub panels myself,since you've already got the 1st panel loaded with tandem breakers Id just bite the bullet and go with a new bigger panel.

 

[Charles (in GA)]

What is the 100 amp breaker, upper right most, in the pics above? Is that panel the one in the detached shop/garage, and is it a backfed main breaker? or does it supply something specific?

I'm not clear on things. You have an ATTACHED garage, is the main panel for the house in this attached garage? Is this the "single 100amp breaker in the attached garage that's acts as a master for the shop" or is this "single breaker" supplied from a house main panel located elsewhere in the house?

Is the panel shown in the pics above the panel located in the DETACHED SHOP? What happens when you open that 100 amp double pole breaker on the upper right?

The front of the panel in the pic has a knockout for a main breaker, That appears to be a Square D Homeline panel (based solely on the fact that EVERY breaker in it is Homeline). THIS MAIN BREAKER conversion is what you would need to convert that panel from a main lug to main breaker.

If the 100 amp in the upper right is a backfed main breaker, you could install the proper main breaker and remove this one and gain two spaces.

Otherwise, depending on your plans for electrical expansion, you will need to just buy a larger panel, in which case, get a big one, probably 40 space with a main breaker and be done with it. The main breaker does not need to be sized to the feed, it can be larger, as it is only acting as a disconnect for the panel.

 

[wyliesdiesels]

Charles- Read his first post a little more carefully. He said the 100a breaker in the first panel(first pic), which is in the attached garage, feeds the detached shop. The Next 2 pics are the panel in the shop...

These are pics of 2 different panels, which u can tell by the different breakers...

If that's a code requirement then I can and will add a main breaker to the detached shop with no problem. This is how the property was configured when I bought it.

With the new loads imposed by heat and AC I'd like to know I have the capacity needed to run at least the compressor while the HVAC is on. When I need to weld I usually open the garage doors and roll the welder outside to the driveway as the sparks leave burn marks on the epoxy floor. Unsure on amp load of the compressor but I will check it.

I'd like the setup to be idiot-proof for future owners that would let me run everything though I really don't ever see that scenario happening while I live here.

Yes u will need a main breaker in that panel. before u put the tandems in was there breakers in those spaces? If not then the 6 handle rule wasnt violated until the tandems were added.

What is the HP rating of the compressor?

 

[Charles (in GA)]

Somehow I didn't realize that the three pics were of two different panels. "I see, says the blind man".

If only one or two circuits need to be added, just replace all the single pole ones with tandem single poles, and add a main kit. Otherwise buy a new panel. Might as well be a homeline so the breakers can be reused.

A 40/80 main breaker value pack is only $127 others are less, so its not like its a big deal to replace the panel.

 

[theoldwizard1]

If the split breakers give you enough room then I wouldn't worry. If you need more room I would add another sub panel.

I would also go with tandems, but be careful. Some boxes have bus bars that are designed to only accept a limited number of tandems. Usually they go in the bottom and you are ready have 4 tandems.

It really depends on

1. Will the current box accept more tandems ?
2. How frugal (cheap) you are ?
3. Do you have space for mounting another box ?

 

[miketyler]

Sorry for the confusion, thanks Wylie's. I assumed the current panel would accept more splits but would have to check. The splits were added be me and replaced existing singles to free up space for the heater and air compressor so I am guilty as charged.

I checked and the compressor pulls 15a during compression and 12a when unloaded. At a minimum then I could double up once more and add a main kit to my existing panel? That would free up the two spots I need for one 220v breaker.

I do have wall space for a 2nd panel but also have space to replace the existing with a larger panel as well. Any thoughts there to a preference? I like the idea of a larger panel with available space for expansion.

 

[zmaxmotorsports]

Go with the bigger homeline panel,ditch the tandem breakers.