BENSHAW RediStart MX3 Series, User Manual

Page: 181 / 238

Phase Control
7.11
Phase Control
When the Starter Type parameter (FUN07) is set to Phase Control, the MX
3
is configured to operate as a phase controller or voltage
follower. This is an open loop control mode. When a start command is given, the RUN programmed relays energize. The firing angles
of the SCRs are directly controlled based on voltage or current applied to the Analog Input.
A reference input value of 0% results in no output. A reference input value of 100% results in full (100%) output voltage. The actual
input voltage / current that results in a given output can be adjusted through the use of the Analog Input Offset and the Analog Input
Span parameters.
z
NOTE: The power stack must be rated for continuous non-bypassed duty in order to operate in Phase
Control mode continuously, NO BYPASS.
z
NOTE: When operating in Phase Control mode, the acceleration ramp, kick, and deceleration settings have no effect on operation.
z
NOTE: When in Phase Control mode the following motor / starter protective functions are available:
•
Current Imbalance
Ÿ
Residual Ground Fault
•
Over Current
Ÿ
Instantaneous Over Current (IOC)
•
Current while Stopped
Ÿ
Phase Rotation
•
Under Current
Ÿ
Phase Loss
•
Over Voltage
Ÿ
Under Frequency
•
Under Voltage
Ÿ
Over Frequency
•
Motor OL
173
7 - THEORY OF OPERATION
Output Voltage vs Analog Input
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100
Analog Input (%)
Ou
tp
ut
V
o
lt
a
g
e
(%
)
Figure 55: Phase Control Mode