Safety Time During Operation T Sb; Flame Signal; Fault Lock-Out; Safety Interlocks (Limits) - Honeywell BCU 460 Technical Information

Glossary
11 .5 Safety time during operation t
04 04
t
SB
If the flame fails during operation, the valve outputs are
disconnected within the safety time t
The default safety time during operation t
ance with EN 298 is 1 second. In accordance with
EN 746-2, the safety time of the installation during
operation (including closing time of the valves) may not
exceed 3 s.
Note the requirements of the Standards!
O

11 .6 Flame signal

I
If a flame is detected, the flame detector will supply a 1 2 3 4
flame signal.

11 . 7 Fault lock-out

In the event of a fault lock-out, all valves and the igni-
tion transformer are disconnected from the electrical
power supply, and a fault is signalled. Resetting must
take place manually following a fault lock-out.
BCU 460, BCU 465 · Edition 03.16l
SB
88
1
5
4
ϑ
7
9
12
V1
14
V2
16-17
18-19
t
.
SB
in accord-
SB
s1
F1
V1 V2 C N S L
88
µC
5 6 PE
ϑ
DI

11 .8 Safety interlocks (Limits)

The limiters in the safety interlock (linking of all the rel-
evant safety control and switching equipment for the
use of the application, e.g. safety temperature limiter,
minimum/maximum gas pressure) must isolate input
from the voltage supply.

11 .9 Pilot gas valve V1

The start fuel flow rate for the burner is released by pilot
gas valve V1. It opens when the safety time on start-up
t starts to elapse. It remains open until the burner is
SA
switched off again by a controlled shut-down or fault
lock-out.

11 .10 Main gas valve V2

Once the safety time on start-up t
main gas valve V2 is opened. It remains open until the
burner is switched off or a fault is signalled.
N1
c2 c1 v1 N1 v2 N1
8 9 10 11 12 13 14 15
7
V1
Z I
V2
7 8 9 7 8 9
(BCU 460..L)
Test
SA
s
n
16 17 18 19 20 22 23
max. 2 A,
max. 2 A,
253 V
253 V
A
P
10 11
has elapsed, the (BCU 460..C)
40 41 42 43 44
F3
N1
l
26 27 30 31 32 33 34
90