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BCU 560, BCU 565 · Edition 02.16
64
Parameters > Behaviour during start-up > Burner application
Parameter 78 = 4: two-stage burner 1. Three valves (V1, V2
and V3) are included for a two-stage burner. These are con-
nected to the valve outputs (terminals 13, 14 and 15).
BCU 570
µC
V1
V2
V3
14 15
13
52
55
54
53
56
47 48
58
03
02
01
04
2
1
3
9
14
15
13
5
17-18
t
t
FS1
t
SA1
t
BP
Valves V1 and V3 open to start the burner. The burner is started
with a limited ignition capacity using gas valve V3. After the
flame proving period t
FS1
has elapsed, valve V2 opens to en-
able the 2
nd
gas stage.
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