gefran GFW 400A Installation And Operation Manual page 40

ADDITIONAL FUNCTIONS
Softstart
This type of start can be enabled either in phase control or pulse train mode and in zero-crossing mode (ZC, BF, HSC).
In phase control, the increment of conduction angle q stops at the corresponding value of the power to be transferred to the load.
Control of maximum peak current (useful in case of short circuit on the load or of loads with high temperature coefficients to
automatically adjust start time to the load) can be enabled during softstart. When the load shut-off time (settable) is exceeded, the
ramp is reactivated at the next power-on.
Figure 48
Example of firing ramp with phase Soft-Start
RMS current limit
The option for controlling the load current limit is available in all work modes.
If the current value exceeds the limit (settable in the nominal full-scale range) in mode PA the conduction angle is limited, while in
zero-crossing mode (ZC, BF, HSC) the cycle time conduction percentage is limited.
This limitation ensures that the RMS value (i.e., not the instantaneous value) of the load current does NOT exceed the set RMS
current limit.
Figure 49
Example of conduction angle limitation in PA mode to respect an RMS current limit below the nominal current of the load.
40
80999D_MHW_GFW 400-600A_07-2020_ENG