Omron G3ZA - MANUAL 2 User Manual page 49

Selecting the SSR (Control Method) 4 or 8-channel Models)
Setting the Switching MV
Threshold
1,2,3...
Three-phase
Optimum Cycle
Control
32
• Set the soft increase and soft decrease times to control the output. For
details on these settings, refer to 4-9 Setting the Soft Increase and Soft
Decrease Times (4 and 8-channel Models) on page 49.
• Current detection is not performed during phase control. The current val-
ues (heater ON current, heater OFF current, and actual current) will be 0
A, and the current alarms (heater burnout detection, heater overcurrent
detection, and SSR short-circuit detection) will always be OFF.
The Switching MV Threshold is used in soft-start optimum cycle control. By
setting the Switching MV Threshold, the control method can be switched to
phase control below the set value and optimum cycle control above the set
value.
The default value is set to 20%.
Variable Parameter name
type
85/C5 Switching MV threshold for
channels 1 to 8
Example: Performing Soft-start Optimum Cycle Control in Channel 1 with a
Switching MV Threshold of 40.0%, an MV of 100.0%, and a Soft Increase
Time of 20 s
1. Set the Channel 1 Switching MV Threshold to 40.0%, and the Channel 1
MV to 100.0% with a Variable Area Write command.
2. The channel 1 Soft Increase time is kept at its default value, so it is not nec-
essary to set this value.
3. Once the Channel 1 Switching MV Threshold is written, the setting is
saved, and will also be effective the next time that the power is turned ON.
MV
100.0%
40.0%
Soft increase time (20 s)
Phase control
Note The image shows a current waveform.
• Three-phase optimum cycle control is a control method in which the out-
puts are turned ON/OFF every two cycles.
• Turning the outputs ON/OFF every two cycles allows optimum cycle con-
trol to be used with three-phase heaters.
• Use SSRs for three-phase heaters with zero-cross function for three-
phase optimum cycle control.
Setting range
0.0% to 100.0%
Optimum cycle control
Section 4-2
Default
20.0
Time