I ran accross a frequency drive controller, operating a 3 phase direct drive exhaust motor.
The "Story goes" Sunday a Texas roadhouse called saying their Chargrill exhaust is "shaking the whole restaurant" sure enough the blower wheel is so bably damaged the drive motor lead end is vibrating atleast 2-4" in it's mount
I proceeded to replace the motor and blower wheel that the customer had on hand "as spare parts"
upon restart, the blower came up to speed and blowing good. Case closed, next call......
Later in the day I recieved another call that the store was full of smoke and the exhaust isn't moving enough air
This is where it get's good and frustrating. I've never encountered a frequency drive system before.
Getting back to Texas Roadhouse I eventually found out the blower was running in reverse No problem....switch 2 leads and good to go
NOT! The motor won't run at all except for 1 t1,t2,t3 to l1,l2,l3 connection
I'm tottaly confused/frustrated and pissed at 5:30pm on a sunday night when the restaurant has a line out the door and also full of smoke
So the blower running the wrong way I figured out how to increase the frequency/speed to get enough airflow so they could function. (still in reverse)
I might add... No manual or documentation on the controllers operation
Monday morning: After spending 5 hours at home on my own time till 1 am online I found and learned enough to be able to reverse the motor from the controller but it shuts down after 5 minutes on an error
Found a phone # for Cuttler Hammer Tech. ( the controller's brand)
The Tech. walked me through changing a bunch of parameters and got it running alot better By that time one of my supervisor's arrives (very nice guy!)
He spent the next few hours on the phone messing with the controller and finally got the motor running the right direction at full speed drawing proper amps and moving a TON of air.
Aparently this Adjustable Frequency Drive Controller has some kind of DC feedback from the motor and the field connections to the motor can only be one way and the controller parameters must be changed for direction,speed and such.
Sorry for the long post, In 17 years I've NEVER been so ticked off/frustrated/confused amd felt so helpless at the same time!