Two Speed Trane A/C condenser: How do you know
I have a Trane two speed outside condenser and variable speed indoor blower. As I understand it, in the outside unit, Trane has a smaller compressor for the low speed and when demand is more than 2 degrees, it cuts off and the large compressor kicks in. Lately, it seems that when the A/C is running on the low speed condenser, the air isn’t as cool as it should be.
The service tech that came out and did a check of the clean air filter/blower blades, and outside unit amps and Freon pressures, but he did with the larger compressor running. When it runs, all pressures match the specs of the factory graph for outside temp and humidity. The outside temps were in the 90’s. and the inside air vents had a 59 degree reading. He did not take a vent reading while on the low speed compressor. He said, “To check the system, it has to be running on the high compressor.”
The unit is almost 10 years old. How do you know the low speed compressor is going bad if he only check the system with the high compressor is running? The low speed side is still same “coolness” that caused me to call in the first place. Any Ideas?
Thanks for your help.
Bill
Replies
Bump. I agree ... he tested for the refrigerant and the larger compressor. How do we know the small compressor is working. Are you sure you have two separate compressors or one that has two stages (which is relatively more common, I think)?
Trane
makes two versions of two stage residential air conditioners. One a single scroll compresssor with two stages of control via an electronically activated relief port in the bottom part of the scroll. Another has two separate compressors, though I havent seen these and don't know how they're piped. You have a model number?
Are you saying that the supply air on the first stage was colder in the past than it is now?
Is it blowing at the same speed? Has anything else changed?
Is it two speed compressor, or a dual circuit system?
Just discussed this with my AC Tech. He isn't aware of a Trane household unit, in the ten year age range, that uses two compressors. He said Trane did make some with two speed motors on the compressor.