BCU 580 · Edition 11.15
66
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 signal (ter-
minal 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 ad-
ditional 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 current
national standards and regulations. The burner application
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 initiated 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
Parameters > Behaviour during start-up