FCU 500, FCU 505 · Edition 02.17
89
Parameters
12 .4 .6 Air flow monitoring during pre-purge
Parameter 35
This parameter can be used to select additional dif-
ferential pressure monitoring of the air flow during pre-
purge. The FCU is informed that there is an adequate air
flow via a signal from the differential pressure switch to
terminal 48 during pre-purge.
FCU 500
µC
P
49
15
13
14
50
45
47
58
48
p
e
/2
TC
PZL
PZH
PZ
PZL
PDZ
M
>750°
ϑ
1
2
3
48
PDZ
Parameter 35 = 0: OFF; the function is not required
Parameter 35 = 1: with safety shut-down
A safety shut-down will be performed if there is no input
signal.
Parameter 35 = 2: with fault lock-out
A fault lock-out will be performed if there is no input
signal.
Air flow monitoring is to be set on the basis of the rel-
evant application standard (e.g. EN 676, EN 746-2,
NFPA 85 or NFPA 86).
12 .4 .7 Post-purge time t
PN
Parameter 37
The post-purge time defines the period during which
air for purging fuel gas residues out of the combustion
chamber continues to be supplied to the combustion
chamber after furnace operation has been terminated.
Parameter 37 is used to parameterize the post-purge
time in a range between 0 and 6500 s (0 to 100 min.).
The conditions set in parameter 38 must be satisfied for
the post-purge time to be started.
