I recently had a shed wired that I finished out for a home office. The electricians wired a dual pole 30 amp in the subpanel and the disconnect box has two hots and a neutral (that’s capped) and the ground.

I’ve finished out the inside and am ready for a mini split. Seems most of the smaller mini splits are 115v. (Heated and cooled space is only 12x16 - so a 9000btu unit should get the job done).

My question is - should I be able to convert this? My thought was that I could disconnect one of the breakers (or replace if they can’t be split). I’d just disconnect and cap that hot inside the sub panel and disconnect it from the disconnect box and cap it. That would leave me with a single pole 30 amp with one hot, a neutral (it’s wired into the bus bar) and a ground - which should work?

Am I thinking of this correctly? Definitely NOT an electrician.

Yes. Swap beaker with a single pole 20 amp (assuming that’s what you need). Us the black and the white as hot and neutral.

Post a pic of the sub panel in office.

A 30a dual pole breaker would be used to power a 240v circuit. However, you can wire the mini split off of only one pole if it needs a 30a breaker. If it needs 20a then you just need to install a 20a single pole breaker in one of the empty slots in the sub panel.

C _ _ T _ _ M _ _.

Hint:
What would Bill say?

I would consider having a small subfeed panel set in shed. You would room have two 120 volt circuits. One foe mini and one for lighting.

This is what I have.

So I’m thinking I’ve got the wrong sized breaker regardless if I went with the 208-230v system (pioneer calls for a 15 amp max fuse size on the 9000 btu and the 12,000 btu a 20 amp).

If I go with a 115v unit both sizes require a 25 amp.

No clue why a 30 amp got installed for a 12x20 shed.

For those asking - I have a sub panel in my shed. My lights and plugs each have their own dedicated circuits. Mini split has its own circuit ran to a disconnect box.

Better to over build than under. Electricians did good.

Yep looks like you just need to find corect breaker and receptacle for the a/c you pick.

What size breaker is feeding the panel from the main?

50 amp

The 30 amp braker was installed because sparky ran number 10 wire. Nothing wrong with that.

You have a couple of options. Change 30 amp breaker to a 15 amp if you use a 9000 BTU. If you go with 12,000 BTU, change 30 to a 20 amp.

If were mine...
It appears you have 10/3 with ground supplying disconnect.
Leave 30 amp subfeed panel in place. Install a fused disconnect in place of (or after, if using 115 volt mini ) current disconnect with fuses to manufacture specs.
The 30 amp will protect the #10 wire. The proper fuse will protect the equipment.

Good question, I thought about that as well when I saw the 100amp back fed main breaker
Depending on how that is wired in the main panel, the green ground screw may need to be removed

Good catch on the green screw. The 100 amp probably came with panel. Main breaker is to protect panel and be a means of disconnect.