Summary: The unit is equipped with DDP fans and does not meet design airflow at 60 Hz after test and balance has been completed.
Solution:
To meet airflow requirements, the max Hz of the VFD may be increased.
99% of direct-drive fan assemblies supplied by Trane Creative Solutions are equipped with Baldor brand motors. Baldor motors are qualified to operate up to 120Hz if the following conditions are met:
- Motors are not operated 2.0 times the nameplate
- Nameplate HP is not exceeded
- Nameplate FLA is not exceeded
- Fan is operated within the class limits (see the fan curve provided in the unit submittal)
- Maximum speed for 100 HP motor is 3000 RPM due to bearing speed limitation
Horsepower will remain constant from 60-90 Hz. Above 90 Hz, torque may become insufficient which will prevent the motor from reaching the desired speed. A new motor selection will be required.
Motor life will not be significantly impacted at higher speeds. Bearing life may be reduced slightly at the higher operating speeds due to higher bearing operating temperatures and will require more frequent re-lubrication. See the motor operation and maintenance manual for specific details.
Parameters 1-23, 3-03, 4-14 and 6-15 must all be set from 60Hz to the desired frequency.
If an alternate motor to Baldor has been provided, contact technical support at CSTTechSupport@Trane.com for more information. Include the CST job number and unit serial in your request.
Related Articles:
How to change parameters on TR150 VFD – Trane Commercial HVAC Help Center
Higher Design Speed than the Motor Nameplate – Trane Commercial HVAC Help Center
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.