14. Firing type
Choose a correct firing type allows to optimize the thyristor unit for the installed load.
The firing type has already configured in line with customer requirements that are defined in the Order Code.
The Order Code is written on the identification label.
However, if you wish to change the firing type you can use the software configurator or the Control Panel.
Caution: this procedure must be performed only by qualified persons.
14.1 Zero Crossing
ZC firing mode is used with Logic
Output from temperature controllers
and the Thyristor operates like a
contactor.
The Cycle time is performed by
temperature controller. ZC minimizes
interferences because the Thyristor
unit switches ON-OFF at zero voltage.
14.2 Single Cycle
Single Cycle it’s the faster zero
crossing switching method in
relationship of the power demand
from a temperature regulator or from
an external signal.
With input signal at 25% the output is
one cycle ON and three cycles OFF
With input signal at 50% the output is
one cycle ON and one cycle OFF
With input signal at 75% the output is
three cycles ON and one cycle OFF
With input signal at 76% the output
is the same of 75% but for each ON
cycle the microprocessor divides
76/75, and when the sum of rests is
one, the unit does one more cycle ON. For this firing is necessary to have analog input.
The Single Cycle is used to control the loads with low inertia or for infrared lamps to short wave.
14.3 Burst Firing
The Burst Firing is similar to the Single
Cycle, but consecutive cycles ON are
selectable between 1 and 255, with
input signal equal at 50%. When 1 is speci-
fied, the firing type is Single Cycle.
Burst Firing is a method zero crossing
that it reduces the electromagnetic
interferences because the thyristor
switches at zero voltage crossing.
The example show the Burst Firing
with Burst cycles=4.
Voltage Supply (V)
Load Voltage (V)
SSR from controller
ON
OFF
Voltage Supply (V)
Load Voltage (V)
25%
50%
75%
100%
ON
OFF
Voltage Supply (V)
Load Voltage (V)
25%
50%
75%
100%
ON
OFF
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