
BCU 580 · Edition 11.15l
69
Parameters
10 .3 .6 Safety time 2 t
SA2
Parameter 96
During the safety time 2 t
SA2
, the flame on burner 2
(main flame) is ignited. It can be set to 2, 3, 5 or 10 s.
t
SA1
t
Z
04
06
07
08
02
03
00
t
t
FS1
t
SA2
t
FS2
5
13
V1
57
V4
1
14
V2
2
ϑ
1
ϑ
2
8
4
88
1
46
11
9
41
42
L1
1
43
2
17-18
Safety time 2 starts with the application of the
ϑ
2 sig-
nal (terminal 4). Valve V2 opens at the start of safety
time 2. The fuel supply to burner 2 is released so that
a flame can form. If no flame is detected at the end of
safety time 2, the valves are closed again. Depending
on parameter 08 (Burner 2 start-up attempts), the BCU
reacts either with an immediate safety shut-down with
fault lock-out (P08 = 1) or with one or two additional
start-up attempts (P08 = 2 or 3). The BCU will complete
a maximum of three start-up attempts.
Safety time 2 must be determined on the basis of cur-
rent national standards and regulations. The burner ap-
plication and the burner capacity are the main criteria
for this.
If the
ϑ
1 signal (terminal 1) drops out during safety
time 2, the valves will not be switched off until the end
of safety time 2.
10 .3 .7 Flame proving period 2 t
FS2
Parameter 97
Flame proving period 2 t
FS2
can be parameterized
to enable the flame on burner 2 to stabilize after the
elapse of safety time 2. Only when the flame proving
period has elapsed will the next program steps be initi-
ated by the BCU. The flame proving period can be set
between 0 and 20 s.
t
SA1
t
Z
04
06
07
08
02
03
00
t
t
FS1
t
SA2
t
FS2
5
13
V1
57
V4
1
14
V2
2
ϑ
1
ϑ
2
8
4
88
1
46
11
9
41
42
L1
1
43
2
17-18