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TC · Edition 08.17
14
Application
1 .1 .8 TC 4 with two gas solenoid valves
V1 and V2: quick or slow opening valves with start rate.
TC 4 checks gas solenoid valves V1 and V2 and the pipe
between the valves for tightness.
The external pressure switch DG monitors the pressure
between the two valves.
Once the tightness test has been carried out success-
fully, TC 4 forwards the OK enable signal to the auto-
matic burner control unit GFA. The GFA opens the gas
solenoid valves V1 and V2 simultaneously. The burner
starts.
1 2 3
4
5 6 7 8 9 10 11 1213
OK
L1(+)
N(-)
TC 4
p
u
2
V1
V1
V2
V2
p
u
PZ
TC 4
p
z
V
P
PZ
DG
GFA