ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Recent Posts
Electricians revenge
by RODALCO - 05/23/24 02:36 AM
240V only in a home and NEC?
by emolatur - 05/18/24 06:12 PM
Safety at heights?
by gfretwell - 04/23/24 03:03 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (RODALCO), 35 guests, and 67 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#221905 09/08/22 02:28 PM
Joined: Sep 2022
Posts: 1
GerryR Offline OP
New Member
I live in New England and aim to install a MRCOOL mini split. The one I want comes in two configurations. 208/230v and 230/208v. Most of the ones I see are 208/230v. Is there a different requirement for wiring the 230/208v? It is a few hundred bucks cheaper due to being able to pick it up in the store. Thanks!

Joined: Dec 2002
Posts: 337
Though this is not a site for these type of questions and I am not familiar with the equipment.

However check to see if the mini-splits are single phase or three phase. Single phase is typical for most residences and will work with both single and three phase service of the voltages within those ranges. Three phase will only work with three phase systems or some extra electronics and or hardware to create three phase from the single phase. Also often the three phase device cots more (because of advantages not mentioned in here that are negated whenever installed through additional equipment to a single phase system).

Anyway, I recommend that you hire a HVAC contractor for the installation of a mini split system.

Joined: Jul 2004
Posts: 9,935
Likes: 34
Mr Cool units they sell on Ebay etc are single phase. I don't think they even make a 3 phase. These are sold to be installed by the homeowner but I agree with the other poster, the charging and the wiring should be done by a professional. If it leaks, you will be calling one anyway and the warranty may need to be registered by a licensed HVAC contractor. It is required to get a permit in most places and your local government may or may not allow you to do the work yourself. As to your question 208 and 230 are interchangeable as far as wiring methods go if this is single phase. 208 is the line to line voltage from two legs of a 3 phase supply but you usually only see that in apartments. I am guessing this is a single family home.

Greg Fretwell
Joined: Jan 2005
Posts: 5,445
Likes: 3
Cat Servant
I expect we’ll be seeing a lot more questions of this sort. Our world has changed, the internet earthquake hasn’t finished giving us aftershocks, and the “usual” ways just won’t suffice.
Mr. Cool markets specifically to the DIY market. They provide all you need and stress an easy install in an afternoon.

I can’t really fault them. Adding conventional A/C to my home presented me with an extreme challenge finding a licensed contractor who would even come me out and look.

Keeping on topic, a sloppy installation of a mini-split is one of the easiest things for DIY. The only “hard” part is running power to the unit — and we’ve all seen “creative” methods used to add dryers and ranges to older homes.

EPA rules have backed off some regarding the “Freon license.” That’s how Mr. Cool can directly market to the consumer. These jobs will never see an inspection.

This leaves our OP with the challenge of properly running a new 230v circuit — all FOUR wires — AND a 120v servicing receptacle to the outside unit. Depending on his panel location, that might be difficult.

Joined: Apr 2002
Posts: 7,383
Likes: 7
I agree with the 3 posts above.

HVAC installs are really not for a DIY, although I have not seen a "Mr Cool" mini here in NJ. A HVACR Licensed Contractor is required for the install as far as the refrigerant is required. In other than a single family, owner occupied residence, a Licensed Electrical Contractor is also required for the electrical install, and yes, a 120volt, GFI receptacle is required within 25 feet (unobstructed) of the CU.

Best left to the pro.

Joined: Jul 2004
Posts: 9,935
Likes: 34
These units come in precharged (R410 in the condenser). The EPA rules are relaxed for R410 but that doesn't mean local rules do not apply. This is a one shot deal. If the homeowner gets the line set flare fittings installed properly Mr Cool says the residual trapped air isn't an issue and you can just let r rip. Most pros will still want to pull a vacuum and check for leaks before they open those valves because when the refrigerant is gone, it is gone.

Greg Fretwell

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5