Motors With Switched Windings - SICK MOC3ZA Notice D'instructions

en
Chapter 3
56
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
Product description
3.8

Motors with switched windings

In the case of motors with switched windings (e.g. star-delta switching, direction of rotation
reversal, pole switching) note that the measurement inputs L1/L2/L3 on the Standstill
Monitor MOC3ZA must always be connected to the motor windings for the detection of the
standstill, otherwise the error message "wire break" will prevent the enable of the outputs.
In the case of a three-phase connection to a motor with star-delta switching, e.g., after
shutting down the motor the star contactor must be switched on so that the connection of
L1/L2/L3 via the motor windings is ensured.
If it is not possible to switch on the star contactor after shutting down the motor or this
action is not desired, then connect the measurement inputs on the MOC3ZA directly to one
of the motor windings in a single-phase circuit. For this purpose proceed as follows:
➢ Connect the terminals L2/L3, fitted with a jumper, to the one end of the motor winding.
➢ Connect L1 to the other end of the same motor winding.
The same applies to motor circuits with direction of rotation reversal or pole switching. In
this case a renewed safety assessment may need to be undertaken.
If in the case of three-phase connection of the MOC3ZA the motor windings are switched
and the resulting interruptions in the measurement circuit last longer than 2 s, the
Standstill Monitor will detect a wire break error. To ensure this error is not saved once the
switching is complete, the storage of errors should be deactivated by fitting a jumper to
terminals S2/X1 (see section 8.3.5 "Error storage and deletion" on page 69).
Operating instructions
MOC3ZA
8014608/1DS0/2022-02-16
Subject to change without notice