VFD tuning for a Marathon motor

First snag.. Thermal Overload fault just after setting up the DuraPulse GS3-22P0 VFD using the quickstart guide. Same Marathon
145THTR15540 motor that I've been using without fail with the Delta VFD, so obviously I am either missing something or set it up wrong.
I am unsure about the "ohms" section on the nameplate and how to determine which number to use when setting up the VFD. I chose 4 ohms as a rough average of what is described on the nameplate but perhaps it needs to be quite different. The other thing that may have caused the "Thermal fault" is the AMP rate I used may be lower than what is appropriate for 230 volt. I believe I set it for 2.4 however maybe I need to use the maximum of 4.8 amps for 230v. Can't see straight, gotta get some zzzz's. gnite

Jake


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You need to set the VFD FL Amp rate to the motor spec which is 4.8A. The "ohms" for the winding are usually set automatically when you run the auto-tune. The motor should be run in sensorless vector mode, this will maintain RPM to usually within 0.1% without the need for an encoder, and can add low end torque/control. An encoder would only be needed if you needed absolute positional control of the motor shaft. The belt should be off the motor when you run auto-tune, it makes no difference as to the maximum speed or other parameters, other than the motor name plate specs such as to base speed, rpm, poles etc. are correct. The motor is a TENV motor so there is no fan, they are made to run to their maximum safe speed, although torque does fall off in a somewhat non-linear fashion you need less torque at speed.

If you want to optimize the motor operating envelop you should determine the maximum spindle speed of the mill, adjust the belt ratio so this is achieved at a motor RPM of 5400 RPM. Ideally you would have two pulley speed ranges, something like 1:1 and 4:1 for low speed.
 
You need to set the VFD FL Amp rate to the motor spec which is 4.8A. The "ohms" for the winding are usually set automatically when you run the auto-tune. The motor should be run in sensorless vector mode, this will maintain RPM to usually within 0.1% without the need for an encoder, and can add low end torque/control. An encoder would only be needed if you needed absolute positional control of the motor shaft. The belt should be off the motor when you run auto-tune, it makes no difference as to the maximum speed or other parameters, other than the motor name plate specs such as to base speed, rpm, poles etc. are correct. The motor is a TENV motor so there is no fan, they are made to run to their maximum safe speed, although torque does fall off in a somewhat non-linear fashion you need less torque at speed.

If you want to optimize the motor operating envelop you should determine the maximum spindle speed of the mill, adjust the belt ratio so this is achieved at a motor RPM of 5400 RPM. Ideally you would have two pulley speed ranges, something like 1:1 and 4:1 for low speed.

Thank you. I'll try the 4.8A instead of 2.4 and let auto tune set the ohms. Will reply with the results! Oh, and I'll remove any load, including the pulley for the auto test. The 5400 max RPM of the motor is pushing the envelope ? or is it defined by whether I'm running it at 230 vs 460v ? My VFD is running at 230V. I watched an informative youtube video that suggested 230V can be used for higher RPM without torque drop off. Maybe I'm misunderstanding it, however.

Cheers,

Jake
 
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Leave the pulley on the motor, just disconnect the belt/load. No difference between the motor's ability (hp/torque) between 230/460V per the nameplate for the most part (there could be some slight differences). If the motor is specified to run at a given speed, then it can be used as such. The motor and bearings are designed per the operating envelope of the motor name plate. Bearings may not ultimately last as long, but it is still a long time and you will not be operating it at maximum speed continuously.
 
Leave the pulley on the motor, just disconnect the belt/load. No difference between the motor's ability (hp/torque) between 230/460V per the nameplate for the most part (there could be some slight differences). If the motor is specified to run at a given speed, then it can be used as such. The motor and bearings are designed per the operating envelope of the motor name plate. Bearings may not ultimately last as long, but it is still a long time and you will not be operating it at maximum speed continuously.

Ok, sounds like I can push it a bit and not worry. Thanks !
I called Automation Direct this morning and asked about the added load of the pulley which weighs a few pounds. The auto tune determines only two things. Motor Line to Line ResistanceR1 and also Motor No-Load Current.
Its actually no issue to remove the pulley since I have to pull the entire motor off to get the belt removed ( there isn't much clearance ), so taking the pulley off too won't be a too much of a hassle.

Jake
 
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