If a 3 phase AC Drive loss 1 Phase in No LOAD condition i:e Motor is connected but the current drawn is equivalent to no load : Whether the fault Is generated ?

It depends on the AC drive. Some drives can be set to indicate a loss of input phase as a fault condition, even if a run command has not been given, and some drives only display fault message in heavy load. Suffice it to say that a traditionally sized drive will fault rather quickly upon loss of input phase, with a run command, since the DC bus voltage would most likely drop below an acceptable level. I have seen an application where an AC drive was deliberately oversized, so that it could run the motor at full load with only two phases input. But this was a very special application and is not generally practical.

In my experience, lack phase running is not good for the drives, the temperature will rise to harm it's service life.

Hi All,

I am not much experienced in the HVAC thing but trying to gain some expertise over AC drive. Need your help understanding it better.

Please let me know the functionality and need of the following:

1. Ground Bearing protection
2. OL contactors
3. Run Contacts.
4. KAIC ratings
5. Bypass requirement and fused disconnect vs Circuit breaker.
6. Test Feature in AC drives.
7. Seismic Testing
8. Motor adaptation Test algorithm
9. difference between Galvanic and Optical Isolation
10. Class 20 I2t (Its I square T) electronic motor overload protection
11. Run permissive in bypass

I know its too many questions here but I need some clear focus on AC drive. Any suggestions or thoughts will be appreciated.