Cuenod C24 GX507/8, Operating Instructions Manual, Page: 10 / 48

02/2008 - Art. Nr. 13 019 866A 10
1 Gas pressure switch connection
(DIN 43650)
2 Solenoid valve electrical
connection (DIN 43650)
3 Pressure switch
4 Inlet flange
5 Gas pressure tap 1/8 upstream of
the filter (can be mounted on both
sides)
6 Filter under cover
7 Identification plate
8 Gas connection 1/8 for air
pressure
pL
9 Ratio V adjusting screw
10 Gas pressure tap 1/8 pe on both
sides
11 Gas pressure tap pBr M4 (V2)
12 Zero correction adjusting screw N
13 Gas connection 1/8 for chamber
pressure
pF
14 Gas connection 1/8 for gas
pressure
pBr
15 Outlet flange
16 Pressure tap pa downstream of
V1 on both sides
17 V1, V2 fire rate indicator (optional)
18 Pressure tubes pBr - pL - pF
MB VEF Valve
The MB VEF valve is a compact
assembly which consists of a filter, an
adjustable pressure switch, a non
adjustable, quick acting safety valve, a
main quick closing valve adjustable on
opening interlocked with the PI controller
(
V and N ) allowing a constant gas to air
flow rate ratio to be obtained. The
controller also takes account of pressure
pF in the combustion chamber or of the
atmospheric pressure. The valve is pre-
set on delivery according to the table
enclosed :
Gas pressure switch setting
• Remove the transparent cover.
The device includes an index and a
graduated mobile disc.
• Adjust the pressure switch temporarily
at the minimum value read on the
graduated disc.
Start-up
Description and settings
Gas valves, gas pressure switch
Controller setting
All the settings are performed while the
burner is in service.
• Act on two screws using a 2.5mm key
for hexagon socket screws :
- screw
V gives the gas to air ratio
(graduation from 0.75 to 3.0),
- screw N allows the air in excess to
be reduced to the minimum flow rate
(graduation from -2 to +2).
Gas: pressure(s) VEF
407 4 1 2
V 2
N
-0.5
V 1.5
N 0
V 2
N
- 1 .5
Bold
: factory settings
G20: 20, 50
G25: 20, 25, 50
G31: 37
G31: 148
G20: 1 00, 300
G25: 100, 300
Burner C24/30 GX 507/8