Cuenod C 285 Operating Instructions Manual page 11

Start up
Description and adjustment
MB-VEF gas valve
MB VEF valve
MB VEF valve...is a compact assembly
including the following :
A built-in or pocket filter, adjustable
pressure switch, non-adjustable quick-
acting safety valve, proportional
regulator-controlled main valve which
can be adjusted on opening (V and N). It
ensures a constant gas flow/air flow ratio
and is quick-acting.
The regulator also takes into account
combustion chamber pF pressure or
atmospheric pressure.
The valve is delivered preset according
to table here below.
Burner C 285 GX 507/8
Gaz P VEF 412
V
G20 150
N
3
V
G20 300
N 0
V 3
G25 300
0
N
Burner C 330 GX 507/8
Gaz P VEF 412
V
G20 150
N
V
G20 300
N
V
G25 300
N
Burner C 380-430 GX 507/8
Gaz P VEF 412
V
G20 300
N
V
G25 300
N
420
3
0
420
3
0
3
0
3
0
420
3
0
3
0
05/2008 - Art. Nr. 13 013 503D
1 Pressure switch electrical
connection (DIN 43650)
2 Solenoid electrical connection
(DIN 43650)
3 Pressure switch
4 Intake flange
5 Pressure take-off G 1/8 before
possible filter on either side
6 Filter under the cover
7 Identification plate
8 Air pressure pL G 1/8 connection
9 V ratio adjusting screw
10 Pressure take-off pe G 1/8 both
sides
11 Gas pressure take-off pBr
M4 (V2)
12 Adjusting screw for correction of
zero point N
13 Connection G 1/8 for combustion
chamber pressure pF
14 Connection G 1/8 for gas pressure
pBr
15 Outlet flange
16 Pressure pa take-off after V1 both
side
17 On indicator V1, V2 (optional)
18 pBr - pL - pF pressure take-off
tubes
Air pressure switch setting
• Remove the transparent cover.
The unit includes a index and a
graduated mobile disk.
• Provisionally set the pressure switch at
the minimum value shown on the
graduated disk.
Regulator setting
All settings are carried out with the
burner working:
• Use 2,5mm hex key to turn the 2
screws.
- Screw V gives the gas/air ratio,
graduated 0,75 to 3,0.
- Screw N is used to adjust air excess,
graduated - 2 to + 2.
11