Appendix B: UBZ Operation for Motor Control with Winding Changeover When Star-to-Delta Starting

For operation of UBZ-304 for motor with windings changeover when star-to-delta starting, connect the device according to Figure B.1.

Figure B.1 – Diagram for UBZ enabling for the motor operation with star-delta switching over and the motor insulation control

Components

• K1 – Starter of motor enabling
• K2 – Star starter of motor winding enabling
• K3 – Delta starter of motor winding enabling
• Q1 – Automatic breaker

Motor Control Methods

When UBZ is in the star-delta mode, it is allowed to perform motor control in the following ways:

1. External automatic starter control – Motor disabling/enabling using the external automatic starter (actuator) at the same time with the de-energizing/energizing the UBZ device
2. Front panel control – Motor control on the front panel of UBZ
3. Remote control – Motor control via RS-232/RS-485 interface

ATTENTION

It is strictly forbidden to shutdown the motor by external machine (the starter) without UBZ 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 front panel or via RS-232/RS-485 interface to avoid the direct delta starting.

Related Settings

The functional relay mode must be set to “St->D” (star-delta) for this operation mode. See the Functional relay operation section in the main manual for configuration details.

The following parameters are relevant for star-delta starting:

Parameter	Description
Relay F mode	Set to “St->D” for star-delta operation
Relay F time	Time delay before switching from star to delta
Delay RP RF	Delay between load relay off and functional relay activation

For the complete list of programmable parameters, see the main manual.