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BCU 560, BCU 565 · Edition 02.16
71
Parameters > Behaviour during start-up
11 .3 .3 Safety time 1 t
SA1
Parameter 94
During the safety time 1 t
SA1
, the flame (pilot flame) is ignited.
It can be set to 2, 3, 5 or 10 s.
t
SA1
t
Z
88
02
03
ϑ
t
1
46
11
L1
9
5
42
13
V1
14
V2
41
00
04
t
FS1
Safety time 1 starts with the application of the
ϑ
signal (terminal
1). The valves open at the start of safety time 1. The fuel supply
to burner 1 is released so that a flame can form. If no flame is
detected at the end of safety time 1, the valves are closed again.
Depending on parameter 07 (Burner 1 start-up attempts), the
BCU reacts either with an immediate safety shut-down with
fault lock-out (P07 = 1) or with one or two additional start-up
attempts (P07 = 2 or 3). The BCU will complete a maximum
of three start-up attempts.
Safety time 1 must be determined on the basis of current na-
tional standards and regulations. The burner application and
the burner capacity are the main criteria for this.
If the
ϑ
signal (terminal 1) drops out during safety time 1, the
valves will not be switched off until the end of safety time 1.
11 .3 .4 Flame proving period 1 t
FS1
Parameter 95
Flame proving period 1 (t
FS1
) can be parameterized to enable
the flame on burner 1 to stabilize after the elapse of safety
time 1. 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
88
02
03
ϑ
t
1
46
11
L1
9
5
42
13
V1
14
V2
41
00
04
t
FS1