PFA, BGT · Edition 03.11
6
Application
1 .1 .3 PFA 710 with PFU 780, stage-controlled main burner
with alternating pilot burner
VR..L
VAG
t
1
2
ϑ
1
ϑ
2
UV
02–04
02–04 06–08
06–08
VBY
TZI
2
1
DI
L1, N, PE
P
BUS
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
A 710
BUS
PLC
Control: main burner ON/OFF
The main burner can be started with reduced capacity after
the operating signal from the pilot burner has been detected.
The pilot burner is switched off automatically after the main
burner has started up. When the main burner is switched off,
the pilot burner automatically switches on again.
A UV sensor monitors the flame signal from pilot and main
burners. UV sensor UVD 1 is used for continuous operation,
UV sensor UVS for intermittent operation.
1 .1 .4 PFA 710 with PFU 780, stage-controlled main burner
with permanent pilot burner
VR..R
VAG
VBY
TZI
t
1
2
04
02–04 06–08
06–08 04
2
1
ϑ
1
ϑ
2
DI
L1, N, PE
P
BUS
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
U
7
80
PF
A 710
BUS
PLC
Control: main burner ON/OFF
The main burner can be started with reduced capacity after
the operating signal from the pilot burner has been detected.
Pilot and main burners can be operated simultaneously. Both
are ionization-controlled independently.
Control: main burner High/Low
The main burner starts at low-fire rate. When the operating
state is reached, the PFU 780L advises the control unit. The
PLC can now pulse the air valve in order to control the capacity
of the main burner.