240vac Only Subpanel

[matt_i]

Background: want to have future capability to install 2pc - 24kBTU minisplits when money becomes available. Only have 2 slots (for 1pc double pole breaker) in my shop's panel available.

I picked up a 4-slot (for 2 double pole) main lug panel at Menards over the weekend to be a subpanel within the same conjoined structure.

I don't need the neutral for my power requirements, however, is there any requirement to run it back? I'm wanting to just run red, black, and ground.

Im thinking I want #6 THHN feeding from 50A breaker in shop panel to the new main lugs and eventually a couple of 25As in the 4-slot. Not 100% sure what the A/C requirements will be but hopefully I'm being conservative.

Thanks!

 

[sberry]

Its done for equipment all the time. 6 space is super common, might be as cheap or cheaper,

 

[walta]

Do you really want to be that guy?

Years from now we will be reading the post
“Who installs a sub panel without a neutral????”

I say if you can’t do it right or do not do it.

How much will you save? $10 or 20

Walta

 

[ant.foste]

Run a 6 space load center with a neutral. This gives you the ability to place a 120vac service outlet outside at the condensers and adds a very minimal cost.

https://www.amazon.com/dp/B00002N7MS/?tag=atomicindus08-20

 

[Norcal]

There is no problem with a 240V subpanel.

 

[matt_i]

Do you really want to be that guy?

Years from now we will be reading the post
“Who installs a sub panel without a neutral????”

I say if you can’t do it right or do not do it.

How much will you save? $10 or 20

Its a good point but I have a 120vac exterior outlet close by already, fed by another circuit.

Yes, the 4 slot does limit expansion but I feel like I'm close to maxing out the amperage anyway based on the "potential" for what the double A/Cs can draw.

What size would I run on the neutral, another #6 awg? That seems wasteful plus something additional I'd have to buy....I'm going to guess its 30 feet of wire, I'm going to guess $1.50/ft at "buy by the foot" section of HD.

 

[Bretny]

So your alreaty having to add a sub pannel and your wanting to limit your self again? Power it like a regular sub pannel alreaty.

 

[sberry]

While you would leave a bit of option by adding a wire doent mean you need to and there is nothing like a simple box dedicated to equipment disconnect. Makes it plain as day, know someone didn't energize thru another wire etc.

 

[sberry]

One of the reasons you may not want a N is you don't want people tapping this. On occasions we see recommendations for inch pipe and electric boxes but I got 6000 sq ft and nothing over 3/4 for branch circuits. One place I ran a separate 3/4 a section for a welder, its own pipe, doesn't all got to be in one. I have a couple shared with 10 for small wire feeders and although I do have a 300 tig I have never had to plug it in my wire welder circuit. All its own for that too.
In the cases of shared pipe it keeps 2 current conductors out, reduces the fill and any need for derating etc. In the case of welders could change breakers for tailored circuits if it needed, big if, but nothing is as good as single circuit in a pipe.

 

[Mr_fixit]

Background: want to have future capability to install 2pc - 24kBTU minisplits when money becomes available. Only have 2 slots (for 1pc double pole breaker) in my shop's panel available.

I picked up a 4-slot (for 2 double pole) main lug panel at Menards over the weekend to be a subpanel within the same conjoined structure.

I don't need the neutral for my power requirements, however, is there any requirement to run it back? I'm wanting to just run red, black, and ground.

Im thinking I want #6 THHN feeding from 50A breaker in shop panel to the new main lugs and eventually a couple of 25As in the 4-slot. Not 100% sure what the A/C requirements will be but hopefully I'm being conservative.

Thanks!

I'd take back what you bought. And save your money, for now. When you have the money for the a/c, I'd suggest thinking about what you might really need to add, electrically , for the home in the next 10 years or more. I don't think using the last 2 slots to solve the A/C problem would be a good long term solution. Maybe a different location for a sub, or a larger sub, or a larger service. Adding A sub off the sub? What happens when you need room to add a small heater, kitchen receptacle or basement fridge, etc?

 

[matt_i]

I'd take back what you bought. And save your money, for now. When you have the money for the a/c, I'd suggest thinking about what you might really need to add, electrically , for the home in the next 10 years or more. I don't think using the last 2 slots to solve the A/C problem would be a good long term solution. Maybe a different location for a sub, or a larger sub, or a larger service. Adding A sub off the sub? What happens when you need room to add a small heater, kitchen receptacle or basement fridge, etc?

Your points are good, I'm preparing to hang drywall shortly. I plan to wire NMb into the stud cavity, then thru the wall to AC disconnects on the outside wall, and that will all be done before drywall. Waiting for next year, would put me into a project that would require moving heavy equipment stationed near the wall and then tearing back into the recently finished drywall. So this is an effort into future proofing so I won't have to do either of those.

I do have extra panel spaces where needed but this part of the shop is pretty mature at this point. If I had 4 spaces available I'd probably already be working instead of posting

 

[sberry]

There are cases where local disconnect is required. This cost an extra breaker but saves 2 at the main and gives disconnecting means with overcurrent right next to the units.

I could go either way on this but I liked the description,,, mature and this circuit could be purely dedicated to equipment. Its not a bad thing. I would probably put 6 spaces cause,,, I can and stock a panel.

 

[Marctrees]

Matt - May want to call your local Electric Supply houses... tell hem cash sale, no account...I just did that few days ago for a 4 piece total 248' of ? THWN ? wire for a 100 amp sub,

Total was approx 25 % less than Lowes.

Marc

 

[Bretny]

I also got my 100a sub pannel wireing from a local supply house the same way and cheaper than lowes/HD.

 

[Kevin99]

Run a 6 space load center with a neutral. This gives you the ability to place a 120vac service outlet outside at the condensers and adds a very minimal cost.

https://www.amazon.com/dp/B00002N7MS/?tag=atomicindus08-20

Thanks for sharing!

 

[Bretny]

Run a 6 space load center with a neutral. This gives you the ability to place a 120vac service outlet outside at the condensers and adds a very minimal cost.

https://www.amazon.com/dp/B00002N7MS/?tag=atomicindus08-20

Thats an indoor pannel.

 

[alfredeneuman]

Thats an indoor pannel.

From what I've read so far the "pannel" will be indoors.

 

[Milton Shaw]

I just ran a 60 amp 6 space sub-panel for my wife's new kiln. It draws 38 amps at 240 volt so I put in a circuit with #6 /3 with ground. She has already in one month decided she wanted a 120 volt kiln and bought one that draws 15 amps for smaller stuff. I am glad I ran 6/3 w/g so that all I had to do was add an outlet and breaker to the 6 place box I put in. She has gotten in to slumping glass as an addition to her stained glass work . Very interesting and creative woman I married. She has the patience to do art glass when something inspires her.

 

[mike93lx]

I just ran a 60 amp 6 space sub-panel for my wife's new kiln. It draws 38 amps at 240 volt so I put in a circuit with #6 /3 with ground. She has already in one month decided she wanted a 120 volt kiln and bought one that draws 15 amps for smaller stuff. I am glad I ran 6/3 w/g so that all I had to do was add an outlet and breaker to the 6 place box I put in. She has gotten in to slumping glass as an addition to her stained glass work . Very interesting and creative woman I married. She has the patience to do art glass when something inspires her.

This isn't for a workshop. Apples and oranges

 

[nh_yota]

If you're down to only one 2P breaker space you should add a regular 120/240 subpanel anyway in case you want to add more circuits in addition to the new ones for the AC units.

 

[matt_i]

I do have 3 spares in my other panel...but that isn't 4...