Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3

   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3 #1  
Pettrix

Pettrix

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Does one need a 14/2 or 14/3 Romex wire for a 1 ton Mitsubishi minisplit? Breaker shows 15amp double pole but doesn't show wire requirements.
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3 #2  
Is it 120 or 240v? Depending if you need 2 wire for 120v 3 wires for 240v. Either way, I would recommend to run 12 gauge minimum. If the run is very long, maybe even step up to 10 gauge.

What is the spec called out by the manufacturer? --- meaning the amp draw during startup.....
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3
  • Thread Starter
#3  
Instructions just say 14 gauge wire.
208/230V 1 Phase 60 Hz
15 AMPS MAX breaker size
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3 #5  
Are you talking power to outside unit or wiring between inside and outside unit? I ran 12/2 and 14/2 to power my larger and smaller units respectively but I seem to recall I needed more than 2 current carrying wires to connect the inside and outside units.
Remember you need a manual power cutoff next to the outside unit (within 6ft IIRC)
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3
  • Thread Starter
#6  
Power to outside unit looks like 14 Guage wire. So I will go with 14/2 Romex on a 15 amp double pole breaker.
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3
  • Thread Starter
#7  
I ended up changing it to 12/3 just to be safe. I will sleep better at night :)
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3 #8  
Pettrix said:
Instructions just say 14 gauge wire.
208/230V 1 Phase 60 Hz
15 AMPS MAX breaker size
Click to expand...
The reason the instructions say 15 AMPS MAX breaker size is because the instructions also say to use 14 gauge wire. The breaker is for protecting the wire, NOT whatever is connected to the wire. People make this mistake all the time, thinking the breaker in the panel is for protecting the whatever the breaker is supplying power to. Now that I see you are using 12 gauge wire you could put in a larger breaker. But why bother? 12 gauge wire on a 15 amp breaker will a nice and safe installation.
Eric
 
   / Mitsubishi 1 Ton Mini-Split - 14/2 or 14/3 #9  
Its been a long time since I went to school on this but my understanding is that unless you have 3 phase industrial power - you have single phase. That could be 220 using 2 "hot legs" or just 110 using 1 leg and a common (ground / return). When you use 2 "legs" for 220 you can only do this using a double pole breaker - each leg is 180 degrees out of phase from the other so it doubles the voltage, but maintains 60 hz. For some reason they call this "single phase". The common and ground on a 220 application are only there for safety where as on a 110 single pole - the common actually is part of the current flow circuit. Older 220v appliances only had plugs with 2 "hot legs" and a ground. In more recent years the plugs have 4 prongs - 2 hot and a common + a ground ( more safe ). The common is really confusing too me because back at the panel it is simply bonded to the ground. Back in the old days the 110 outlets only had 2 wires going to them. A black and a white, no 3rd prong for a ground and no ground wire to the outlet box etc.. I believe they added the 3rd "ground" wire to add redundancy in case the "common" or hot lead opened / shorted there was a path to ground to trip the breaker / blow the fuse.
Hopefully an electrician will respond and clarify this... but that is my understanding.
 
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