larry4406
Well-known member
Electrical question for you sparkies... Mechanical guys/gals feel free to chime in as well. Wasn't quite sure where to put this (electrical vs hvac) so Mods move it as you see fit.
As many of you may know, I manage construction of new homes. This job has its benefits...
Well, we closed down one of our models as the community is built out. We use the garage as the sales center. So happens that the 30x21' x 12' tall 3-car garage was equipped with a Goodman MSG12WHN1N minisplit. This appears to be a 1 ton unit and apparently 13-13.5 SEER. It is not quite 5 years old.
Any event, the HVAC contractor pumped it down (allegedly containing the charge in the outdoor unit?) and sealed off the ends. This was done a couple days ago and the indoor and outdoor units with remote now sits in my basement. I did not get the line set.
My plan is to use it in my attached garage which is 28x22'x 9' tall 2-car garage (97% of the original SF, and 73% of the original volume). My garage is not insulated as quite as well as the model (R13 vs R21). I will have our HVAC contractor run the line set, pump it down, and start it up.
My question pertains to the wiring of the unit. I spoke to the electrician who disconnected the unit. He says it was fed with a 220V 20A breaker via 10/3 (due long run of about 90 feet from the panel) to an outside disconnect and then to the outdoor unit. He said the outdoor unit needed a neutral. He also said there was 12/3 UF run from the outdoor unit to the indoor unit along with a thermostat wire.
I find the electrician's statements odd after trying to find a manual and looking at the electrical diagrams on the units themselves. Attached are pictures showing the wiring diagrams found on the outdoor and indoor units and nameplate data.
Several questions:
1. The nameplate says Minimum Circuit Ampacity 11A, Max Fuse 15A , and Compressor Locked Rotor Amps 23.5A. Should I be using a 240A 20A breaker like the model had?
2. I fail to understand the electrician's statement that a neutral was needed and why he ran 10/3. The outdoor unit clearly only has only 3 terminals for black, white, and ground. I see no place to land the neutral.
3. There is clearly 4 conductors between the indoor and outdoor units - brown, red, black, and blue. I've no clue what each does. Electrician said the indoor and outdoor units (less than 15' apart) where connected with 12/3UF. I assume this was convenient and proper as the ground is fully insulated compared to Romex 12/3. Obviously the color code would need to be carefully honored. The convenience being not needing to run conduit of some sort and get color coded THHN wire. Any issue of 12 wire vs 10 wire?
4. I also fail to understand the electrician's statement that there was also a low voltage thermostat wire. I see no connections for this.
5. Lastly, the project manager I got the unit from said it worked very well in the garage that is larger than mine. Any thoughts on how well this 1 ton unit will work?
Any thoughts?
As many of you may know, I manage construction of new homes. This job has its benefits...
Well, we closed down one of our models as the community is built out. We use the garage as the sales center. So happens that the 30x21' x 12' tall 3-car garage was equipped with a Goodman MSG12WHN1N minisplit. This appears to be a 1 ton unit and apparently 13-13.5 SEER. It is not quite 5 years old.
Any event, the HVAC contractor pumped it down (allegedly containing the charge in the outdoor unit?) and sealed off the ends. This was done a couple days ago and the indoor and outdoor units with remote now sits in my basement. I did not get the line set.
My plan is to use it in my attached garage which is 28x22'x 9' tall 2-car garage (97% of the original SF, and 73% of the original volume). My garage is not insulated as quite as well as the model (R13 vs R21). I will have our HVAC contractor run the line set, pump it down, and start it up.
My question pertains to the wiring of the unit. I spoke to the electrician who disconnected the unit. He says it was fed with a 220V 20A breaker via 10/3 (due long run of about 90 feet from the panel) to an outside disconnect and then to the outdoor unit. He said the outdoor unit needed a neutral. He also said there was 12/3 UF run from the outdoor unit to the indoor unit along with a thermostat wire.
I find the electrician's statements odd after trying to find a manual and looking at the electrical diagrams on the units themselves. Attached are pictures showing the wiring diagrams found on the outdoor and indoor units and nameplate data.
Several questions:
1. The nameplate says Minimum Circuit Ampacity 11A, Max Fuse 15A , and Compressor Locked Rotor Amps 23.5A. Should I be using a 240A 20A breaker like the model had?
2. I fail to understand the electrician's statement that a neutral was needed and why he ran 10/3. The outdoor unit clearly only has only 3 terminals for black, white, and ground. I see no place to land the neutral.
3. There is clearly 4 conductors between the indoor and outdoor units - brown, red, black, and blue. I've no clue what each does. Electrician said the indoor and outdoor units (less than 15' apart) where connected with 12/3UF. I assume this was convenient and proper as the ground is fully insulated compared to Romex 12/3. Obviously the color code would need to be carefully honored. The convenience being not needing to run conduit of some sort and get color coded THHN wire. Any issue of 12 wire vs 10 wire?
4. I also fail to understand the electrician's statement that there was also a low voltage thermostat wire. I see no connections for this.
5. Lastly, the project manager I got the unit from said it worked very well in the garage that is larger than mine. Any thoughts on how well this 1 ton unit will work?
Any thoughts?
