monitoring servomotor current

[cokeguy]

We need to monitor the current profile of several AC servomotors, in order to detect mechanical issues in the driven machinery. The drives we use have no connectivity options, so that is not an option. Should be no big deal anyway, except for the response time of the AC current transducer that we require. We need at least 15-20 samples per second, because the cycle time of the machine we are monitoring can be as fast as 300 ms, and we need to detect the peak current in each cycle. Any ideas if there is a current transformer with 4-20 ma output suitable for this application? We will be monitoring and processing the signal in a suitable high speed PLC or DAQ card/software. Thanks for your advise. By the way, servomotor size ranges from 1KW to 3 KW.

 

[ScottyUK]

LEM have a range should be fine for this application.

http://www.LEM.com

 

[mikekilroy]

no connectivity suggests the drives are older models, but I assume.

Older drive suggests they probably have an analog output for motor current m onitoring, but again I assume.

Are you sure there is not a monitor output for this? If not sure, maybe you could give manufacturer and part number of the drives in case someone else knows them?