motor cable assembly questions

[Pete Jemian <jemian@anl.gov>]

As a result of a recent electrical shock incident at the APS, we are
interested in learning which standards for stepping motor connectors
and cable assemblies are in use at other facilities.  Our focus is on
motor cable assemblies for use with stepping motor drivers which
operate above 50 VDC.

Our interest stems from a recent incident in which an intermittent
short-circuit was created inside the connector shell of a standard
APS motor cable.  The short was between a motor phase current
conductor and the metal shell of the connector.  We are considering
developing a new standard cable assembly for motor drivers that
operate above 50 VDC.

We would be pleased if the EPICS community could help us by answering 
these questions:

* How does your facility standardize motor cables
  and connectors?

* How does your standard distinguish between
  systems with drivers that only operate below 50 VDC
  from systems with drivers that may operate above 50 VDC?

* How does your facility handle grounding of the connector?

* Are limit, home, and encoder signal conductors in a separate cable?

* How does your facility test motor cable assemblies?

* Do you test motor cable assemblies for insulation breakdowns?  How?

* Is there a standard to switch off the motor driver
  if the end-of-travel limit switches have been passed?

* Do you have other comments?

Thanks,
   Pete


--
----------------------------------------------------------
Pete R. Jemian, Ph.D.                <jemian@anl.gov>
Beam line Controls and Data Acquisition, Group Leader
Advanced Photon Source,   Argonne National Laboratory
Argonne, IL  60439                   630 - 252 - 3189
-----------------------------------------------------------
   Education is the one thing for which people
      are willing to pay yet not receive.
-----------------------------------------------------------