Allen Bradley 525 Drive Current Settings

[fredjohns]

I have a question about a couple of parameters on the 525 Drive. The parameters are as follows:

P033 Motor OL Current
P034 Motor NP FLA

What exactly is the difference between these 2 parameter. As an example, if we have a motor with a Name Plate FLA of 15 amps, would P034 be set for 15 and what would P033 be set for.

What problems can be caused if they are setting P034 either to high or to low as compared to the Motor Nameplate FLA

Any help will be greatly appreciated.

 

[mike3475]

we have a conveyor system drove by PF525, we setup OL current, but when the motor current was over OL current, the drive didn't trip until the conveyor hit the limit switch then stopped the drive. i don't know why.

 

[Ken Roach]

An excellent description of the difference, in the RA Knowledgebase:

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/618654

The P033 Overload Current is the threshold at which the overload timer starts. Set it for FLA unless you're sure you have good cooling and can accept a service factor above the FLA.

The P034 Motor Nameplate FLA is used as part of the sensorless vector tuning.

Another Knowledgebase article describes the way the overload timer (Class 10,20,30 curves) and other overload protection parameters work together:

https://rockwellautomation.custhelp.com/app/answers/detail/a_id/587090

 

[fredjohns]

So if the nameplate FLA is 15, would we normally set P034 for 15amp

 

[fredjohns]

Thanks

 

[jraef]

Just a side note;

Despite what A-B says in that KB article, every motor mfr (that bothers to provide tech data) will tell you that even if a motor has a Service Factor on the nameplate, that is ONLY for when used on sine wave power. They will all say that if a motor is powered by an inverter, the Service Factor is 1.0. This is also stated in NEMA MG 1, part 31, the specification for inverter duty motors.