Motor Overload
Motor Overload
(OP)
Hi, im looking for some advice. The saw mill i work in has just been revamped and had new software installed, replacing the old company's program so all the inverter settings ect had been reprogrammed (all the motors have NOT been replaced). But we came across a problem with the stacking line motor. They have a high speed and low speed programmed which the new company have it running at.
High speed up - 60hz
High speed down - 40hz
Low speed up - 30hz
Low speed down 20hz
The speed of the motor seems to run ok (like before the revamp) but now with the new program while its stacking its suppose to stop at the sensor but when it stops it seems to drop 2-3 inchs after the brakes kicked in. The engineers and electricians are blaming the programmers set up, and the programmers are blaming the motor itself. The engineers have had it re-wound as it did have a ground fault and replaced the brake but it's still got the same problem. A new motor is being ordered but wont come until 3 weeks and may not even solve the problem. It ran with no problems before the revamp. Could the values be wrong? Is it possible the programmers have upped the values to much and damaged it when they tested it? Its suppose to hold the weight of at least 5 ton but it trips with an overload with not even 2 ton. The values have also been changed but still has the same problem
High speed up - 60hz
High speed down - 40hz
Low speed up - 30hz
Low speed down 20hz
The speed of the motor seems to run ok (like before the revamp) but now with the new program while its stacking its suppose to stop at the sensor but when it stops it seems to drop 2-3 inchs after the brakes kicked in. The engineers and electricians are blaming the programmers set up, and the programmers are blaming the motor itself. The engineers have had it re-wound as it did have a ground fault and replaced the brake but it's still got the same problem. A new motor is being ordered but wont come until 3 weeks and may not even solve the problem. It ran with no problems before the revamp. Could the values be wrong? Is it possible the programmers have upped the values to much and damaged it when they tested it? Its suppose to hold the weight of at least 5 ton but it trips with an overload with not even 2 ton. The values have also been changed but still has the same problem





RE: Motor Overload
" when it stops it seems to drop 2-3 inchs after the brakes kicked in."
You may have too much mechanical backlash.
Some mechanical brakes have a slight lag before applying. Thrusters were intentionally designed to have a lag and to apply slowly.
But if the brake worked before, it should work now.
If there is a delay in sending the brake signal, it is a programming issue.
If the VFD is used for holding, go back to the mechanical brake that used to work.
A pilot light (available in a wide range of voltages) across the brake terminals may help determine whether the problem is a slow setting brake or a late signal.
It worked and I changed it and now it doesn't work. It's not my fault.
How many variations of that have I heard? Let me count the ways!
Bill
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"Why not the best?"
Jimmy Carter
RE: Motor Overload
I am sure it was all done under the guise of 'increased productivity'.
To answer OP. It's not a motor problem, it's a control problem.
Muthu
www.edison.co.in
RE: Motor Overload
"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington
RE: Motor Overload
RE: Motor Overload
Bill
--------------------
"Why not the best?"
Jimmy Carter