Appendix B: Star-Delta Starting

UBZ-305M Operation for Motor Control with Winding Changeover When Star-to-Delta Starting

When UBZ-305M is in the star-delta mode it is allowed performing the motor control in the following ways:

• the motor disabling/enabling using the external automatic starter (actuator) at the same time with the de-energizing/energizing the UBZ-305M
• motor control on the front panel of UBZ-305M
• motor control via USB/RS-485 interface

IMPORTANT

It is strictly forbidden to shutdown the motor by external machine (the starter) without UBZ-305M de-energizing.

As an exception, it is allowed after the motor is switched off by external machine (the starter), additionally to turn off the motor on UBZ-305M front panel or via USB/RS-485 interface to avoid the direct delta starting.

Connection Diagram

Legend:

• К1 – Star starter of motor winding enabling
• К2 – Delta starter of motor winding enabling
• К3 – Starter of motor enabling
• Q1, Q2, QF – Circuit breaker

Figure B – Diagram for UBZ-305M enabling for the motor operation with star-delta switching over and the motor insulation control