Multi-motor applications, Special motors, Wye-delta – Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE User Manual

Page 132

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5-8

SMC Dialog Plus Controller Special Application Considerations

Multi-motor Applications

The SMC Dialog Plus controller will operate with more than one
motor connected. To size the controller, add the total nameplat
amperes of all of the connected loads. The stall, jam, Phas
Rebalance, and Energy Saver features should be turned off. (If th
separate motor loads are not mechanically coupled, it is possible fo
one motor to be lightly loaded, and if the Energy Saver is activated,
this may cause the heavily loaded motor to stall.) Separate overloads
would still be required to meet the National Electric Code (NEC).

Note: The SMC Dialog Plus controller’s built-in overload

protection cannot be used in multi-motor applications.

Figure 5.5 Multi-motor Application

Special Motors

The SMC Dialog Plus controller may be applied or retrofitted to
special motors (wye-delta, part winding, synchronous, and wound
rotor) as described below.

Wye-Delta

Wye-Delta is a traditional electro-mechanical method of reduced
voltage starting. It requires a delta-wound motor with all its leads
brought out to facilitate a wye connection. At the start command,
approximately 58% of full line voltage is applied, generating about
33% of the motor’s full voltage starting torque capability. After an
adjustable time interval, the motor is automatically connected in
delta.

To apply an SMC Dialog Plus controller to a wye-delta motor, th
power wiring from the SMC Dialog Plus controller is simply wired in
a delta configuration to the motor. Because the SMC Dialog Plus
controller applies a reduced voltage start electronically, the wye
connection is no longer necessary. Additionally, the starting torqu
can be adjusted with parameter programming.

Power Input

3-Phase

Branch

Protection ➀

Overload Relay (O.L.) ➀

SMC Dialog Plus Controller

L1/1

L2/3

L3/5

T1/2

T2/4

T3/6

Motor

No. 1 ➀

Overload Relay (O.L.) ➀

Motor

No. 2 ➀

➀ Customer Supplied

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