Motor drive tripping problems
Motor drive tripping problems
(OP)
hi,
We use AC motor and frequency drive of same hp rating.
like
AC motor of 10Hp and to drive AC motor we are using frequency drive of 10Hp. Now when we try to run the motor by setting the values in frequency drive as per motor rating, the drive trips frequently after achieving some speed.
In one case, where rating of drive and motor is 7.5Hp we have used gear boxe with ratio being 1:3.5 which reduces the speed from 1440 to 400 approx. but when we try to run the motor on 1440 rpm through drive increasing the rpm gradually so as to have final rpm 400 at the shaft after gearbox, the frequency drive shows the error OL-2 and current motor draws is 20.4 Amps. Please let me know whats wrong. We are facing these kind of problems continously.
We use AC motor and frequency drive of same hp rating.
like
AC motor of 10Hp and to drive AC motor we are using frequency drive of 10Hp. Now when we try to run the motor by setting the values in frequency drive as per motor rating, the drive trips frequently after achieving some speed.
In one case, where rating of drive and motor is 7.5Hp we have used gear boxe with ratio being 1:3.5 which reduces the speed from 1440 to 400 approx. but when we try to run the motor on 1440 rpm through drive increasing the rpm gradually so as to have final rpm 400 at the shaft after gearbox, the frequency drive shows the error OL-2 and current motor draws is 20.4 Amps. Please let me know whats wrong. We are facing these kind of problems continously.





RE: Motor drive tripping problems
The term "OL-2" is meaningless without a description of the fault condition from the VFD manual. Different drive mfrs are going to have different meanings. It could mean an overload of the motor, an overload of the drive, a calculated high motor temperature, we have no idea. It would also be good to know if this happens all the time on this drive/motor? Is this your initial commissioning or was the drive being used somewhere else first? Or was it working fine here but now started doing this? How fast are you trying to start the load? Is it heavy or does it have high inertia? Is it eccentric, as in a cam or weighted flywheel?
20.4A from a 10HP drive (or a 7.5HP, I can't tell from your posting), is high enough to make a motor OL as the prime suspect. Possibilities to look at:
*Friction or binding in the drive train somewhere.
*High inertia as mentioned above
*Incorrect motor connection, for example, it is a dual voltage motor and you are using the lower voltage but have the motor connected for the higher one.
*A short or loose connection in the motor windings, cables or connection box.
I could go on and on really, but it's useless to continue without more information.
RE: Motor drive tripping problems
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Motor drive tripping problems
RE: Motor drive tripping problems
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Motor drive tripping problems
The motor may be too small for the load.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Motor drive tripping problems
We can help you but we simply need more information.