SSD 590+ Alarm Question

[aaronw]

Field Fail!

Hello all,
I have an SSD drive Cat# 955-8R0060. It is the 590+ series. I am getting a Field fail Trip Alarm. I feel like the motor is good so I am suspecting the driver has failed internally. Any thoughts if the drive would be repairable or if I should look at replacing it.

Thanks,
Aaron

[3rdshiftguy]

Field Fail can mean a few things, one being that the motor field has failed. How did you determine that the field winding in the motor is not the cause? And why  do you immediately suspect that the drive has a problem?

[aaronw]

I verified continuity of the field winding with an ohmmeter. It checks good with no ground at all.

[3rdshiftguy]

Where did you get the reading? Right in the motor terminal box?

[aaronw]

Yes. I like to look at the condition of the connections so I take the Ohms reading right at the motor.

(Also, I wonder if anyone can post the complete alarm list for the 590+ SSD drives. I see they are listed on the site here for other older Parker drives.)

[3rdshiftguy]

I always test for a field coil failure in two places...

I check at the motor terminal box like you did, then I also disconnect the wires at the drive and test there. I like to test at the drive because it will basically test the wiring that leads to the motor as well as the field winding itself.

There is always a possibility of a pinched wire or broken connection somewhere else besides inside the motor.

[drives-technician]

(Also, I wonder if anyone can post the complete alarm list for the 590+ SSD drives. I see they are listed on the site here for other older Parker drives.)

I can compile a list of 590+ Alarms similar to the other lists I put together, just give me some time. As for using an ohmmeter to test the field winding, I agree with testing in both places, at the motor and at the drive, just make sure you take the wires out of the terminal block at the drive first.

Another simple static test is to check for any crossover from the field winding to the armature winding. And of course, check for any continuity to ground. these tests can also be performed using a megger for more accurate results.

[aaronw]

I don't have a motor megger, but I have tested motor windings and solved problems in the past using just an ohmmeter. I will try the other tests you suggest, I have to get to the bottom of this quickly.

[aaronw]

I don't have a motor megger, but I have tested motor windings and solved problems in the past using just an ohmmeter. I will try the other tests you suggest, I have to get to the bottom of this quickly.

Looks like problem solved. It was not an alarm caused by a faulty drive after all. The field fail alarm was brought on by a crushed conduit that had been run between two control panels. The panels shifted at some point this week, whether it was  a forklift or some other unknown force, the conduit got crushed and it must have broken at least one wire leading to the motor field winding. Fixed and back in service.

Thanks for the pointers, lesson learned...