I have a Bryant FY4ANF030 with a 15kw heat pack and a 2.5 ton coil. THe outside unit is a 13 SEER 2 Ton Tappan unit that the previous owners installed 2 years ago.
The fan is a two speed selections, High is a black wire, and low is a blue wire. On the outside of the motor, there is a diagram that shows that with motor 30, with 15kw heat, the low speed should be used. When they first installed the inside unit they had it on the low speed. From the start last year the heat pump did not output temperature as it did before replacing the older, air handler. They kept saying it was working correctly, and they had it set at the low speed (Blue wire). After many more calls to them and them telling me that the heat pump was fine, when I went to cool in the summer, it would not cool properly. They discovered that the compressor was bad and replaced it. They then put it on the high speed and I had a problem with humidity all summer being about 5-10% high in my home. The temperature was good though, about 53 degrees coming off of the coil.
Now that I am having to heat again I am questioning that fan speed. It is 42 out, and I am getting about 93 degrees after the coil. At about 50 I get about 98 off of the coil.
I want to lower the fan speed down as since they made the changes there is so much air coming out of my air ducts that papers get blown off tables, etc, but I did not have that problem with the lower fan speed. It seems to me that it should be on the lower speed, but at the same not I don't want to damage the compressor. I temporarily lowered the speed and ran the heat pump and with similar temps outside I was getting about 98 degrees off the coil. Any thoughts?