Honeywell BCU 465 - Page 80

BCU 460, BCU 465 · Edition 11.19 80
Parameters
Parameter A078 = 4: two-stage burner 1. Three valves
(V1, V2 andV3) are included for a two-stage burner.
These are connected to the valve outputs (terminals 60,
61 and62).
BCU 46x
µC
V1
V2
V3
61 6260
52
55
54
53
56
47 4858
030201 04
2
1
3
t
t
FS1
t
SA1
t
BP
1
51
61
62
60
22
96
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 enable the 2
nd
gas stage.
If a previous version is replaced by the BCU4, param-
eter A078=4 must be selected in any event.
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