BCU 580 · Edition 11.15
63
Parameter 78 = 2: burner 1 and burner 2. Three valves (V1,
V2 and V4) are included for a modulating burner with a pilot
burner. These are connected to the valve outputs (terminals
13, 14 and 57). Valves V1 and V4 open to start the pilot burner.
Gas valve V2 releases the gas supply to the main burner.
BCU 570
µC
V1
V2
V4
14
57
13
55
54
53
56
03
02
H1
06 07
2
1
3
9
14
15
13
5
17-18
t
t
FS1
t
SA1
t
SA2
H8
t
FS2
08
t
RF
8
4
57
1
2
Parameter 78 = 3: burner 1 and burner 2 with pilot gas. In this
application, the burner has an additional pilot gas valve V3.
The valves are connected to the valve outputs (terminals 13,
14, 15 and 57). Valves V1 and V4 open to start the pilot burner.
The burner is started with a limited ignition capacity using
gas valve V3. After the elapse of the safety time t
SA2
(program
step 06), valve V2 opens (terminal 14). Pilot gas valve V3 is
closed again after the elapse of the flame proving period t
FS2
(program step 07).
For this application, it must be ensured that the flame proving
period (P97) is set to a value ≥ 2 s.
BCU 570..C1F1
µC
V1
V2
V3
V4
14 15 57
13
52
55
54
53
56
47 48
58
03
02
H1
06 07
2
1
3
9
14
15
13
17-18
t
t
FS1
t
SA1
t
SA2
H8
t
FS2
08
t
RF
4
57
5
8
1
2
Parameters > Behaviour during start-up > Burner application
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