SAF OPAL SS6 - Manual (Page 12)

OPAL SS6 Reduced Voltage Starters
Page 5
1.2.3.3 Other Types of AC Motors
OPAL starters may also be used to start 2-speed motors with multiple windings or
connections. Proper contactor selection and sequencing is required for the specific motor.
1.2.3.4 Resistive and Inductive Loads
The TRU-START is well suited for use as a phase controller or current regulator on resistive
or inductive loads such as heaters. When applied with a Temperature PI controller, the TRU-
START will maintain smooth control to avoid the overheating associated with on/off type
controllers. Improved temperature accuracy and longer heater element life can be expected
over standard control methods.
1.2.4 STARTING AC MOTORS IN PARALLEL
OPAL SS6 starters can be used to start motors in parallel but they must have individual
overload devices added.
When the paralleled motors are also connected to the same load, mechanically or through the
material, then load sharing must be considered.
When the motors are mechanically tied, the load sharing is determined by how closely the
motor characteristics are to each other. It is important to keep the motors exactly the same.
Even changing the manufacturers of the motors can cause some variations in load sharing.
The OPAL size is determined by the total of the motor current ratings.