Hsc - Half Single Cycle; Phase Angle (Pa) - gefran GPC 40-600A Use And Installation Manual

(Ton = 0.5 cycle)
Toff
4.1.1.3.

HSC - Half single cycle

This mode corresponds to Burst Firing, which handles on/
off semi-cycles.
It is useful for reducing filament flickering with short/medi-
um wave IR lamp loads. With such loads, in order to limit
the steady state current with low power, it is useful to set a
minimum power limit (e.g., Lo.P = 10%, see "Programming
manual").
CAUTION! This operating mode is NOT permitted with
inductive loads (transformers), it is used with resistive loads
in single-phase, star with neutral or open delta configura-
tion.
Supply
voltage
π
Resistive load
t
Ton
Ct
Figure 22 - Example of operation in HSC mode at 33% and 66% power
Load voltage
Current
θ
θ
Figure 23 - Example of operation in Phase Angle (PA) mode
81900A "MHW_GPC-40/600A"_03-2021_ENG_page 76
Ton
Ct
4.1.2.
This mode manages the power on the load by modulating
the trigger angle q:
• if the power to be transferred to the load is 100%, q =
180°;
• if the power to be transferred to the load is 50%, q =
90°.
Supply
voltage
ω
t
(Toff = 0.5 cycle)
Toff

Phase angle (PA)

Load voltage
Current
θ
π
ϕ
Inductive load
t
ωt