Folks,

I've a 20 y/o Trane XE1000. Has always worked perfectly, and on hot days the unit usually pumped out one or two gallons of condensation from coils in the air-handler. The condenser fan began rattling a month ago and last week it was squealing and not turning.

I went to my local HVAC warehouse and found a replacement motor that fit. It wasn't identical (new: 1/4 HP, old: 1/6 HP, RPM rating was the same).

I installed it and everything seems to be working but:

1) the new motor seems to generate a quieter airflow-the old one generated a 'whooshing' sound when it was running. The new one is almost perfectly quiet.
2) the airflow out the top of the condenser seems warmer than it used to be and
3) absolutely zero pumped-out condensation.

It's maintaining house temperature correctly.

My kitchen quick-read thermometer says the temp difference between return duct and the register is almost 20 degrees Fahrenheit.

Should I worry about 1, 2 or 3 above? What might I have done wrong?
The new motor cost me $90, the HVAC repair estimate was almost $400.

Thanks in advance,

FM

 

Sounds like the fan blades are to low on the motor shaft.

 

Would 1" matter? The new motor's frame was the same size as the old but it had studs protruding from both ends so it could be mounted on either side. I didn't bother cutting the studs off, I just mounted the fan blade below them. Maybe an inch lower than before? Maybe 1.5". Should I cut the studs off and move the blade up as far as possible?

 

The fan blades should be in the same exact location for maximum performance.

 

Measure the distance from the blade to the condenser's grille & set the replacement at that same distance. This will position it properly with the shroud orifice...

 

If you didn't do the measuring; the tip of the fan should usually be just barely below the shroud orifice...

 

Universal motors are often longer than the original motor. This can place the fan blade further from the top of the condenser. This can result in less airflow though the coils which would increase the temperature of the air that you feel discharging from the top of the condenser.

It is often necessary to cut back 4 mounting bolts on the universal motor to get the fan blade back to the position it was in with the original motor.

It is also important that the bottom drain plug is removed on the new motor. This would be on the shaft side of that condenser.

 

I clipped the studs and snugged the fan hub up as far as it'll go w/o the blades rubbing on the motor case. I did catch the weep plug removal from the rather cryptic pictures on the sticker that's on the motor.

It's running now and the 'cold' air is about 1.0 degrees colder than it was yesterday....I'll keep an eye out for condensation being pumped out.

I think that there's a little more airflow noise than there used to be, but I don't know if I'm hearing something real or not.

Again, thanks.