PMA-Relay S 3PH
from 60A to 210A
Firing type
23
11.
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, Zero Crossing for SSR
input and Burst firing for Analog Input.
Caution:
this procedure must be performed only by qualified persons.
11.1.
Zero Crossing (ZC) with SSR Input
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.
11.2.
Burst Firing (BF) with Analog Input
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 is specified 1 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
