Honeywell Krom Schroder PFU 780 - Legend; Symbols and Timing Definitions

PFU 780 · Edition 02.12l 67
Legend
11 Legend
88
Display
88
Blinking display
Ready
Safety interlocks (Limits)
ϑ 1
Start-up signal, pilot burner
ϑ 2
Start-up signal, main burner
DI
Digital input
Ignition transformer
Gas valve
Air valve
P
Purge
A
Ext. air valve control
Flame signal
1
Operating signal, pilot burner
2
Operating signal, main burner
Fault signal
Reset
Input signal
Output signal
Flame simulation check
t
W
Waiting time ≥ 2 s
t
SA
Safety time on start-up 3 s, 5 s or 10 s
t
SB
Safety time during operation < 1 s or < 2 s
t
Z
Ignition time 2 s, 3 s or 6 s
t
LV
Flame simulation delay time 25 s
t
FS
Flame proving period 0–25 s
t
B
Minimum combustion time t
SA
up to max. 25 s
t
BP
Minimum burner pause time 0–250 s
t
KN
Low fire over run time 0 s, 5 s, 15 s or 25 s
Input/Output safety circuit