TCD150B300BD blower motor overheating
ok guys, here I am again....
I went to one of my clients the other day, this rooftop trane unit presented the blower motor overheating, and consecuently, the motor was turned off by the thermal protector, the coil was also ice blocked at that time.
I assumed that the motor was bad. And I proposed to change it. They agreed and I bought a replacement from the American Standartdealer down here.
The description between both motors, the old and the new one, were the same (but different brand, the old one was the original motor taht came with the unit from factory , I think "motortech" and the replacement they told me is the correct one is a marathon) as follows:
After I replaced the motor, I spent 1 hr checking the correct function of the a/c unit and it was fine but today, two days later...I receive a call from my client complaining obut the unit...it was not working fine.
Actually, it presented the same symptoms as he first motor did. Overheating and the protector turning the motor off.
As a method for trying to find an answwer,,I measured the voltage/amps in other unit, same model and everything and the motor was using 6.2 Amps (9.3A said the mfg data)instead of 9.6A wich is using the new motor installed and 211V.
Then I found tat the contactor was not good, it showed like a shortcicuit at one of the terminals. I replaced it with a similar T-square 24V coil contactor.
The new motor installed continued using 9.6A @ 211V.
Any ideas? why is the new motor using 9.6A instead of 6.3A
The blower's axe seems to be fine...is in similar shape than the one in the other a/c unit where the motor is using 6.3A ...so I don't now what to do...maybe the contactor was the problem...but I am not sure....I think he is gonna call me tomorrow complaining again.
What to do? wait?