Mitsubishi Mini Split MCA?

[Greg1707]

I am looking at the specs for a Mitsubishi mini split AC unit:

Single phase 230 volts
Breaker 20 AMP
MCA 15 AMP

I am drawing a blank here. What is MCA?:-?

 

[david luchini]

Minimum Circuit Ampacity. The conductors feeding the unit must have an ampacity which is at LEAST this rating.

 

[chris kennedy]

I am looking at the specs for a Mitsubishi mini split AC unit:

Have you wired one of these before? If not read very carefully. Dollars to doughnuts says it takes one circuit. Two wire to the condensing unit then from there a 3 wire to air handler. (Or some other kooky combination)

 

[Awg-Dawg]

Have you wired one of these before? If not read very carefully. Dollars to doughnuts says it takes one circuit. Two wire to the condensing unit then from there a 3 wire to air handler. (Or some other kooky combination)

True dat.

Ive had drawings show seperate circuits.

It could be a pain if you don't catch it on rough.

 

[Greg1707]

disconnect

disconnect

Thanks for the replies. My job is to install a circuit to the exterior with a disconnect. The HVAC people will take it from there.

 

[c2500]

So the HVAC guys are going to run the power wiring up to the head unit? Check the instructions because they call for an interupt to kill power to the head. Last one I did had a double pole switch that interupted the NM and left the red wire (12-3) unbroken for the digital control. In my neck of the woods, we have to run the wiring to the head unit.

c2500

 

[peter d]

Use #14 and put it on a 20 amp breaker. Don't worry, it's perfectly code legal.

 

[Greg1707]

So the HVAC guys are going to run the power wiring up to the head unit? Check the instructions because they call for an interupt to kill power to the head. Last one I did had a double pole switch that interupted the NM and left the red wire (12-3) unbroken for the digital control. In my neck of the woods, we have to run the wiring to the head unit.

c2500

Okay, so I ran the power outside and installed the disconnect. The inspector came and failed the electrical because the AC people installed their equipment in front of my disconnect. He failed the mechanical because there was not a disconnect inside. I can't say you guys did not warn me!

 

[iwire]

Have you wired one of these before? If not read very carefully. Dollars to doughnuts says it takes one circuit. Two wire to the condensing unit then from there a 3 wire to air handler. (Or some other kooky combination)

True dat.

Ive had drawings show seperate circuits.

It could be a pain if you don't catch it on rough.

Been there as well, really sucked to fix at the end of the job.

 

[Dennis Alwon]

Some inspectors may require a disco inside. I often run my feed to a dp switch near the inside unit. The feed out of that to the outside disco.

Get the a/c guys to move their unit.

Also, some of these units come with a factory cord that runs from the outside unit to the inside unit. They tried that on me and I told them they could not penetrate the wall with rubber cord. I called the factory and they said some inspector do turn it down so you must hard wire it.

You can run you wire with the compressor lines or get it in the wall before sheetrock.

 

[c2500]

Dennis,

The manufacturer shows in the instructions there is to be a disconnect inside. At least that was the instructions for the last one I wired up.

c2500