01/2009 - Art. Nr. 4200 1016 3900A
28
Start up
Setting the VR4625 compact gas unit
Setting the compact gas unit
Loosen screw plugs at measuring points
119
and
119 pBr
and connect
measuring devices.
Pressure controller setting
The pressure regulator (screw
C
) is set
at the factory and sealed.
If the gas pressure has been wrongly set
or is too low, in order to get the desired
power, proceed as follows:
On the burner:
• Set the burner head and air flap
according to the table.
On the valve:
• Remove the protective cap on the
pressure regulator (
104/C
).
• Turn screw
C
:
- clockwise: more power
- anti-clockwise: less power
(Caution! No stop! The full adjustment
range is 10 turns. One turn =
60 daPa).
• Set pressure
pBr
via screw
C
.
• Measure gas pressure at point
119
and
119pBr
.
Example:
To set a power of 25 kW with a G1.40,
apply the following settings:
- Setting for burner head: 20 mm
- Air flap setting: 7
- Set the gas pressure to
pBr
= 42 daPa with screw
C
.
Checking the controllability
• Run burner at rated load.
• Measure gas pressure at point
119
and
119 pBr
.
• Close the ball valve upstream of the
compact unit slowly until the gas input
pressure at
119
falls to 20 daPa.
The gas outlet pressure at
119pBr
must not fall by more than 10 %.
Otherwise the setting is to be checked
and corrected.
The system must not be operated
when the controllability is insuffi-
cient.
• Open the 90° manual shut-off valve.
• Fit the protective cap on the pressure
regulator.
Electrical connection
Warning: if the grey connector on the
gas pressostat is not fitted correctly
(image
2
), the burner will go into
malfunction mode and the fault
"Awaiting gas pressure" will be
displayed.
1
2
