My house has a Trane XL19i that actually has two separate compressors a low and high. The low compressor runs when when the room is within 1 to 2 degrees of desired temperature on the thermostat. The high compressor kicks on to get temperature down quickly or is 3 or more degrees outside of what is set on the thermostat. Problem I’m running into, when talking to Micro-Air, is they say they support 2 stage A/C units but it seems at least the guy that spoke to me at Micro-Air is that if your unit has two compressors it won’t work. I’m attaching pictures of my AC unit along with the inside to see if maybe anybody has any ideas or can point me in the right direction.
Soft Start for Trane XL19i A/C
- Thread starter agdm619
- Start date
Yeah, you could tie into the main compressor that has the run capacitor on it, but the hard start setup could fry the soft start...
I wouldnt attemp this.
BentleyJ
Solar Wizard
Someone added an aftermarket Hard Start kit (extra capacitor and relay) one has to wonder why? Looks like an older condenser unit, did a service tech put that on because one compressor was already having an issue?
In any case, the dual compressor set up has individual contactors and separate capacitors so each could be treated like a separate condensing unit. Although based on the price of a Micro-Air soft starter I would probably opt for just putting 1 on the low stage compressor and disabling the high stage compressor if running on an inverter without utility power available.
If your budget is sufficient, each compressor could probably be fitted with a soft starter.
Disclaimer: Without having the wiring diagram, its difficult to say for certain if the above is correct.
In any case, the dual compressor set up has individual contactors and separate capacitors so each could be treated like a separate condensing unit. Although based on the price of a Micro-Air soft starter I would probably opt for just putting 1 on the low stage compressor and disabling the high stage compressor if running on an inverter without utility power available.
If your budget is sufficient, each compressor could probably be fitted with a soft starter.
Disclaimer: Without having the wiring diagram, its difficult to say for certain if the above is correct.
RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
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You should be able to treat each compressor as its own independent unit tied to the compressor contactors. It would require two Easystarts. Easystart is only engaged during compressor startup and is bypassed during Run mode.
You probably want to remove startup delay at least to larger compressor. I assume it starts the low power compressor first. The compressors have check valves to prevent refrigerant backfeeding. It is part of compressor on discharge port.
The extra start capacitor mfd value in the Easystarts will depend on compressor size.
On Tranes with large condenser coils, the compressor rating is usually a lower btu then the unit btu rating. My 48 kbtu Trane unit has a 38k btu Copeland compressor in it.
72-86MFD - Up to 12K BTU, 1 ton
88-106MFD - 13-23K BTU, 1 ton to 2 ton
108-130MFD - 24-36K BTU, 2 ton to 3 ton
189-227MFD - 37-48K BTU, 3 ton to 4 ton
270-324MFD - 49-72K BTU, 4 ton to 6 ton
You probably want to remove startup delay at least to larger compressor. I assume it starts the low power compressor first. The compressors have check valves to prevent refrigerant backfeeding. It is part of compressor on discharge port.
The extra start capacitor mfd value in the Easystarts will depend on compressor size.
On Tranes with large condenser coils, the compressor rating is usually a lower btu then the unit btu rating. My 48 kbtu Trane unit has a 38k btu Copeland compressor in it.
72-86MFD - Up to 12K BTU, 1 ton
88-106MFD - 13-23K BTU, 1 ton to 2 ton
108-130MFD - 24-36K BTU, 2 ton to 3 ton
189-227MFD - 37-48K BTU, 3 ton to 4 ton
270-324MFD - 49-72K BTU, 4 ton to 6 ton
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Most trane high end systems come with a hard start relay and capacitor, this one has a cut wire, and is a kickstart brand, so, likely has been worked on.
IF the two compressors still work, they likely are wired incorrectly at this point.
Can you post a picture of the schematic? Sometimes they are posted inside the service door, or on a booklet in a pouch.
IF the two compressors still work, they likely are wired incorrectly at this point.
Can you post a picture of the schematic? Sometimes they are posted inside the service door, or on a booklet in a pouch.
@BentleyJ @Supervstech @RCinFLA , I initially overlooked the fact that it was equipped with a hard start kit. The previous homeowners, whom I knew personally, had the system professionally installed by a Trane professional in 2008, just a year before I acquired the property in 2009. When the unit stopped functioning about 4 or 5 years ago, I hesitated to intervene since I knew of its considerable expense and my lack of experience with A/C units. So I called a technician for assistance, and they replaced a faulty capacitor, a lesson that cost me $380—undoubtedly, a funny reminder to handle such repairs myself next time. I suspect the hard start kit was indeed part of the system when I purchased the house.
I'm open to purchasing two Micro-Air units if that's a viable solution. Once I return home, I'll share the schematic with you—it is indeed taped to the inside of the service door.
I'm open to purchasing two Micro-Air units if that's a viable solution. Once I return home, I'll share the schematic with you—it is indeed taped to the inside of the service door.
BentleyJ
Solar Wizard
Follow up note. Take a look at HyperEngineering Soft Starters. They are good quality but cost a little less then Micro-Air as they don't have the fancy blinky lights.
Ok, here it looks like the start assist is factory, and for both compressors,
The red wire is cut on yours, so it likely doesnt work...
Right, I see what you're saying. The brown/red (BR / RD) wire that "should" be coming from the Transformer (TNS) to the CS (Starting Capacitor) looks to be cut at the capacitor. But it still looks like it is getting heat from MS-HI L1 that is connected to MS-LO L1 that is connected to one leg of the 240v in. No? At any rate, I'm not accustomed to reading schematics. The question is, can I use a soft start (or two) so I can run my A/C on generator.
Idk, the cut wire may be inconsequential, or not, it looks like it is linking the transformer in the diagram with L1
You would need TWO soft starters, and you would need to disconnect the hard start...
I wouldnt try it.
I wouldnt try it.
