Phase Angle; Soft Start With Phase Angle - CD Automation Revo C 3PH User Manual

13.5 Phase Angle

The Phase Angle firing allow the control of the power on the load, for this firing the thyristor can be in
conduction only for a part of the voltage cycle.
This part of the voltage cycle is adjustable in function of the input signal from 0 at 100%.
The PA firing is normally used for control the inductive loads, and is also possible control a primary of
transformer coupled with the cold resistances like: Superkanthal, Molybdenum, Platinum, Tungsten or
Quartz Lamp. The only disadvantage with phase angle is the possible generation of interferences that
however can be reduced with opportune filters.

13.6 Soft Start with Phase Angle

This is an additional function to the Phase Angle. The firing angle of the thyristor increase or decrease
up to the final setpoint value.
The Soft start ramp is an important feature to reduce the inrush current with transformers during the
during the cycle of magnetization or with cold resistance that are near to the short circuit when they are
supplied.
Setpoint Ramp Up / Setpoint Ramp Down
100%
0%
Neut-Eng-REVO-C-3PH-300-800A-Thyristors-Units
ON OFF
ON OFF
Ramp Up
REVO C
VOLTAGE SUPPLY (V)
LOAD VOLTAGE (V)
VOLTAGE SUPPLY (V)
Setpoint Value (%)
Load voltage RMS (V)
OUTPUT VOLTAGE (V)
48
25%
50%
75%
100%
Ramp Down
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