Honeywell BCU 465 - Test Period T; Opening Time T

BCU 460, BCU 465 · Edition 11.19 44
Valve proving system
6.1.3 Test period t
P
Depending on the burner capacity, the tightness of the
gas solenoid valves must be checked in accordance
with the relevant application standard, e.g. EN676,
EN746, NFPA85 and NFPA86.
BCU 560..C1
µ
C
P
60
61
3
8
36
3
7
p
u
/2
TC
PZ
PZ
L
PDZ
>750°
ϑ
1
3
2
p
u
/2
PZ
V
p1
V1 V2
p
u
p
z
p
d
The test period t
P
is calculated from:
– Opening times t
L
for V1 and V2,
– Measurement times t
M
for V1 and V2.
t
P
[s] = 2 x t
L
+ 2 x t
M
6.1.4 Opening time t
L
Standard EN1643:2000 allows a maximum opening
time of 3s for the tightness test if the main gas valves
are actuated directly. If gas can flow into the combus-
tion chamber when a valve is opened, the gas volume
must not exceed 0.083% of the maximum flow rate.