Riello MB 405/1 Manuel D'entretien page 49

5.7 VPS 504 Valve leak detection control device (if present)
The valve leak detection control device 9)(Fig. 1, page 4) is ob-
ligatory for the supply trains of burners with a maximum output
greater than 1200 kW.
This valve leak detection control device operates by creating be-
tween the two valves an overpressure of about 20 mbar com-
pared to the pressure upstream; the testing time depends on the
volume to be pressurised as well as the pressure upstream and
varies from 10 to 26 seconds.
The yellow pilot lamp lighting up confirms the positive outcome of
the test, while a negative outcome, with the resulting lock-out, is
signalled by the red pilot light; lock-out continues until the valve
leak detection control device is live.
5.8 Pressure loss
The gas train pressure loss p is provided from the diagram (Fig.
10); the scales of the volumetric output
for:
a air,
n natural gas (G20),
p propane (G30),
c town gas (G140), only for applications not covered by the
Gas Appliances Directive (2009/142/EC).
Activation, calibration and functioning
V °
are valid respectively
°
3
(+15 °C, 1013 mbar)
V [Sm /h]
11
An operation check can be carried out by slackening the screw of
the pressure test point p
a
valve leak detection control device must lock out.
The fuse can be reached by using a screw-driver to remove the
cap near the electrical connection socket; a reserve fuse is in the
upper part of the valve leak detection control device under the
plug.
It is possible to install the valve leak detection con-
trol device on trains that do not have it, by request-
ing the kit.
WARNING
The values, provided from the diagram, can be different accord-
ing to the pressure regulator calibration.
The minimum necessary pressure in the network can be obtained
by adding the pressure of the diagram to the burner pressure
losses (see burner manual) and the back pressure of the com-
bustion chamber (see heat generator manual).
GB
of the equipment before the check; the
20050002
Fig. 10
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