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Discussion Starter · #1 ·
I'm stumped, been working on a power reel (piece of equipment that's basically a turn table) for a few days now and keep getting called back. It has a 180 volt DC Motor and drive in it. I changed both. The damn thing runs great for several hours, until eventually blowing it's fuse. I checked the input power which is fed from busway, and everything between busway and cord drop was fine. I'm stumped and pissed off. Please help!
 

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A lot if variables here. Drive to motor wiring OK? Fuses correct type and rating? Drive over current setting correct?
If all of these check out then it could be a mechanical issue such as a bearing getting hot and locking up which would happen after running for awhile. The sudden spike in current could get the fuses before the over current settings in the drive would stop it. Hope this helps.
 

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Discussion Starter · #3 ·
A lot if variables here. Drive to motor wiring OK? Fuses correct type and rating? Drive over current setting correct?
If all of these check out then it could be a mechanical issue such as a bearing getting hot and locking up which would happen after running for awhile. The sudden spike in current could get the fuses before the over current settings in the drive would stop it. Hope this helps.
The motor turns a gearbox via belt, but this machine doesn't spin long enough to heat up, it pulses, there is an arm that gets pulled when tensioned that triggers micro switch which runs motor, generally 1 sec pulses. I need to look further into setting the current limit in the drive and maybe put a larger fuse in. I did go from a fast blow 3 amp to a slow blow 3 amp. The amperage never exceeded 2.3, even when putting pressure on turntable.
 

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At this motor size i will assume that the drive is one of the inexpensive Dart or KB style drives with the adjustment pots, rather that a digital programable drive?

I work some of these uncoilers at a customer that has about 20 of them.

A few tips:
You need to set the combination of accel/decel ramps to be less time than the start to start interval.

If the motor is coming on every 5 or 6 seconds, turn down the maximum speed to allow the motor to run for a longer interval. (If this will work process wise.) Ideally, you set the motor to run almost continuously at a speed that will keep up with the process. In this mode the dancer arm is more of a stop than a start. { Remember that the roll will need to turn faster as it's diameter decreases.}

Is the uncoiler rated for the weight and stiffness of the material placed on it?

Yes, there can be a mechanical problem.

Check the conductors from the drive to the motor.
 

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I work on them all the time for a plating line.
its normaly the brushes, "the clip that holds it in".
 

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Where I work we use DC drives for our spooling machines with a dancer setup. I had trouble for a long time with the drives pooping out and fuse blowing. We run 1000 pound spools at 1300 feet per min. Startup and running everything was fine. But on stop the inertia of the spool (flywheel effect) would regen back into the system. More or less the motor would turn into a generator coasting to a stop. We went with regen drives and that solved the problem. Not sure of your speeds though.
 

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Discussion Starter · #8 ·
Where I work we use DC drives for our spooling machines with a dancer setup. I had trouble for a long time with the drives pooping out and fuse blowing. We run 1000 pound spools at 1300 feet per min. Startup and running everything was fine. But on stop the inertia of the spool (flywheel effect) would regen back into the system. More or less the motor would turn into a generator coasting to a stop. We went with regen drives and that solved the problem. Not sure of your speeds though.
Thanks everyone, this sounds like a good lead, very similar to my situation. I will look into that, thanks.
 

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Just curious. How many horse power and rpm are you running. We have been using Saftronics dc regen drives. We have 3hp motors geared down and control our speed with a dancer tower to slow the machine as the spool fills with wire. I put limit switches at a low point and a high point. Without the low point if the wire broke the dancer will lower and the machine would run away. Limit switches solved that problem. The regen drives stop the spools pretty fast also.
 
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