Quote Originally Posted by boybi View Post
We have a blower with a 25hp motor attached. Last year nasira yung 25hp motor. Since it was an emergency, and we don't have a 25hp motor on hand, the technician replaced it with a 15hp motor. It operated as usual without noticeable drop in performance. Since then, we haven't replaced the motor.

Questions:
1. Could the supplied 25hp motor be too much for our application?
2. What could go wrong by replacing blower motors to a lower hp ones?
Motor rating sometimes is based on the designers assumptions.

As long as the old motor (25hp) and the new motor (15hp) has the same rpm, it should not be a problem considering all pulleys are the same.
The only item you need to check is the motor running ampere if it is overloaded or more than 80% of its full load ampere. If not, its fine.

Just an FYI, on my previous work we have 40TR AHU that have a 40hp motor, and sooner replaced the motor with 20hp. Cheaper in electricity and re-designed R.J. Calpo.