Eectrical fuseable disconnect question for mini split

[Randall J Cox]

I am tapping into a 60 amp (main service panel breaker protected) 220v outlet stubbed out to where I need power. It was stubbed out years ago to an outside backyard wall for installation of a pool later on by the original owner/builder. I'm new owner and no pool is planned. I need to tap into this power for my shop which has no 220v power and I have five 220v machines. I running 6 gauge wire (boy is that stuff expensive) from the stubbed outlet, along the outside wall of my shop in emt conduit, then into my shop through the wall into a 125 amp breaker subpanel.

Between the two (stubbed outlet and inside subpanel) I need to tap into the 60 amp line for a mini split that I plan to install. It will be 220v and either a 15 or 20 amp (12k or 18k btu ac/heater) unit - depending on which one I go with. I was planning on putting a fuseable disconnect between the 60 amp line and the mini split, sized to 20 amp. However, I can't find any 20 amp fuseable disconnects, seems that they all start at 30 amp. So, couple of questions. Is it ok to use a 30 amp fuseable disconnect there? Or does anyone know of a 20 amp fuseable disconnect out there anywhere? Randy

[Jim Becker]

The minisplit really needs to be on a circuit of its own...you best not try put it on the line you're feeding the subpanel in your shop, if that's what you are thinking about. I doubt that's kosher with code. Connect up your subpanel and put in a dedicated circuit for your minisplit. Surge protection is a good idea on that connection, too.

[Rod Sheridan]

You need a 30 ampere fused switch and whatever size fuses the manufacturer of the condensing unit specifies.

Make sure the time delay, ampere rating and voltage of the fuses are correct…Rod

[Randall J Cox]

OK, if i install a regular "outdoor" rated breaker box with the correct size breaker in, that should work right? My existing AC unit has a regular 220 breaker and outside a pull-to-disconnect "switch that is non fused, just a disconnect for working on the AC unit outside. (Installed when the house was built so I'm sure it was to code.) i would be just mimicking my existing ac unit but, using the outside breaker to kill the power instead of a pull to disconnect. I would made sure the actual breaker I install conforms to the manufacturers specs for the mini split. Randy

[Jim Becker]

AFAIK, you still need the disconnect for the Minisplit. It was required here when I put in one in my old shop.

[Bill Dufour]

Check and see if 20 amp fuses will fit into the 30 amp disconenct.
Bill D

[Randall J Cox]

First off, appreciate all the comments and concerns. Exactly why I posted, not sure of what is code. Contacted a couple of electricians to do the work, they are all months behind in work because they are short of help (and want bigger jobs). People are making more money sitting at home and collecting government checks for doing nothing (per the electricians that own their own company). They could make more money if they had more help.

Anyway, so here we are. I had a heck of a time just finding fuseable disconnects on the internet. Finally went out and looked at the current one I had for my AC (Milbank) and sure enough they are still making them. Actually called a couple of electrical supply houses in town and none carried any make/model of fuseable disconnect. Bill, thats exactly what I was trying to find out and still trying. As the only people who I have found that actually make disconnects don't offer 20 amp, not to likely I'll find one. I have calls into the co (Milbank) and the reps as they don't sell directly. Will a fusable disconnect be sufficient or do I need a breaker and a disconnect both? Although I have read about the differences, still not sufficiently sure about the nuances or code. Want to do what's right and by code. And I guess I need to make a decision on what specific mini split I want to see exactly what they require. Just trying to buy the right stuff and be safe. Randy

[Bill Dufour]

code requires a means of disconnect that is visible from the equipment so anyone working on it can easily see the power is off. And allow them to yell at anyone trying to turn it on while they are working on it.
Bill D

[Malcolm McLeod]

I'll defer to Mr. Dufour on code, but I see 'small' fuses installed in 'large' fuse holders all the time (i.e. 20A in a 30A holder). I've even stood next to a Master Electrician as we repurposed (and re-fused) a larger service to a new, smaller end device. So.... if it is allowable and available, a generic 30A fusible disconnect could stand in for a 20A service.

That said, as it relates to A/C units, I've always been under the impression that the local disconnect typical in my A/Cs was chosen as the absolute cheapest way to meet code. A lever operated fusible disconnect would be the equal of a diamond in a pig's never-mind.

[Randall J Cox]

code requires a means of disconnect that is visible from the equipment so anyone working on it can easily see the power is off. And allow them to yell at anyone trying to turn it on while they are working on it.
Bill D


Seems like if I had an outside breaker box with either an handle (up/down) or a breaker inside, right next to the outdoor part of the mini split, that should do it. But, to me what seems logical and reasonable and what code is might be two different things for reasons I have no knowledge of as I'm not an electrician (or any where close to one)

[Randall J Cox]

I finally called an electrician friend and ran this by him. Said I'm fine without a disconnect if I have a breaker box next to the outdoor unit. Seems to fit the discussion by Bill Dufour that if the AC technician can be sure (can see) the power is off at the unit, we're good. So, bottom line, I will install a breaker box with a 20 amp breaker next to the unit outside. No need for a quick disconnect also. Randy

[Tom Bender]

So are you feeding the mini out of the main panel, the sub panel or something in between?

[Randall J Cox]

I'm coming off a 60 breaker in the main panel to a small subpanel mounted outside next to the mini with a 20 breaker. The 6 gauge wires continue off the 60 amp breaker, into the building to 125 amp subpanel for shop use. This shop subpanel only to feed my five 220v machines, lots of existing 15 and 20 amp 120v circuits already there feeding lights, outlets, garage doors, etc. Randy

[Randall J Cox]

Electrical installed, up and running inside shop. Installed five 20amp 240v circuits and two 20 amp 120v circuits. Dedicated a 20amp circuit to a mini split, which I haven't bought yet. Did install an outside small 70 subpanel with a 20amp breaker in it for a visual shut off. Could have just put one of those with an on/off handle on the side of the little subpanel also as its being fed from inside panel with its own circuit breaker. Randy