The drive is 6RA7087-6FV62-0
Ratings 460V, 850A arm, 460V, 30A field
Motor is 200 hp DC Leroy Somer
500V, 330A armature
8.95 A field
P76 is setting the drive paramters down to 66.6% for armature and 60% for field so after those settings the drive is derated to 566A armature and 18A field
The cooling of the motor is via an external blower using filtered ambient air. Which does seem to be working (no clogged filter, filter changed every month, flow is correct direction, etc...)
The field weakening mode is disabled with a max process setpoint of around 850rpm. This speed setpoint is generated from the line speed of the machine. So, for this application we will always be below base speed and thus at full field under operation so the setpoint shouldn't change.... Underload or during operation the field fluctates up and down around the rated field current but I cannot determine if it is the fluke clamp meter or the actual field. I will change one of the analog outputs to field current and compare to the clamp on readings so I can give you a spread of the variation when the shear moves.
This is the first time for me exploring how this is done in a 6RA70 so I am trying to see how they were going about doing this and why it is not working. Thanks if you need more information I will get it.