English - Riello 3970144 Manual Del Usuario

ENGLISH

INSTALLATION
The gas trains are set up so that they can be installed to
the left of the burner; if installed on the right, the pressure
intake (1) on the train in fig. A should be moved to the op-
posite side, whereas on the gas trains in figures B and C
the minimum gas pressure switch (2) and (if present) the
valve leak detection control device (3), must be moved
opposite the valve unit.
It may be necessary to place an adapter between the gas
train and the burner (see the burner manual) if the diame-
ters of the train are different from those for which the burn-
er is set up.
In the case of the gas train of figure A the current supplied
flange (4), will be used to connect the gas supply line to
the train; it will be fixed to the unit with the nuts (5).
To avoid stress and strain it is recommended that the larg-
er size trains be held with suitable supports.
DIMENSIONS
See figures A, B, C.
PRESSURE LOSS
The train pressure loss ∆p is given in diagram D; the V
volumetric flow rate scales are given respectively for: a =
air, n = methane (G20), p = propane (G30), c = town gas
(G140).
The values supplied by diagram D may vary slightly de-
pending on the adjustment of the pressure stabilizer.
The minimum mains pressure needed is obtained by add-
ing that obtained from diagram D, and the burner pressure
loss (see burner manual), and the combustion chamber
counter pressure (see heat generator manual).
FILTER MAINTENANCE
• Gas train of figure A
Replace the filter at least once a year after having re-
moved the 4 screws of one of the side covers labeled FIL-
TER.
• Gas trains of figures B and C
The filter element may be replaced by removing the upper
cover of the filter after having loosened the screws holding
it.
PRESSURE STABILIZER ADJUSTMENT
• Gas train of figure A
Move the protection (6) and turn the underlying screw +/-
in the desired direction; the gas train output pressure may
vary from 4 to 20 mbar.
• Gas trains of figures B and C
Unscrew the protection (7) and turn the short shaft under-
neath: screwing in increases the output pressure and
screwing out decreases the pressure.
The greater the pressure loss ∆p between its inlet and out-
let the more efficiently the pressure stabilizer operates;
moreover, its operating capacity increases as the pres-
sure downstream increases. This pressure increase is
obtained by limiting the opening of the valves down-
stream, in so far as the other operation requirements and
the available mains supply pressure allow.
The stabilizer output pressure, can be measured at the
minimum gas pressure switch intake of the trains of fig-
ures B and C or at the valve leak detection control device
intake p
if present, may vary from 10 to 30 mbar; if an-
e
other pressure range is necessary, replace the normal
blue spring (by unscrewing the cover (8)) with another (for
example, red 25 ... 55 mbar, black 60 ... 110 mbar, etc.).
Pressure couples
If the train were connected to a supply line in which the
gas could have a couple of variable pressures depending
on the heating power of the gas, the stabilizer must be ex-
cluded; for the gas trains of figure A this is done with the
appropriate kit, whereas for the others the stabilizer must
be put in a non-operating condition by completely screw-
ing in the adjustment short shaft.
In any case, if not already present, a manual reset maxi-
mum gas pressure switch must be installed on the burner,
electrically connected to the thermostat set and suitably
adjusted.
VALVE ADJUSTMENT
• Gas train of figure A
The firing flow rate (valve quick-opening phase) is adjust-
ed, after having unscrewed the cover (9), by turning the
underlying short shaft in the appropriate direction +/-; the
cover itself, turned upside down, may be used as a tool.
The operation flow rate is reached progressively starting
0
from the firing flow rate after hydraulic brake operation;
the operation flow rate may be adjusted by turning the ring
nut (10) in the appropriate +/- direction after having slack-
ened the screw that is not sealed (11).
It would be preferable, however, to adjust the flow rate by
changing the pressure downstream of the stabilizer; with-
out prejudicing the previous considerations on the opera-
tion of the pressure stabilizer, optimum valve operation is
obtained with their being completely open; therefore it is
necessary to look for the best compromise between the
requirements of the stabilizer and the valves.
• Gas trains of figures B and C
The same as in the previous case, except that for adjust-
ing the operation flow rate the screw (12) protected by the
cap must be turned in the +/- desired direction.
ADJUSTMENT OF THE MINIMUM GAS PRESSURE
SWITCH
See the burner manual.
VPS 504 VALVE LEAK DETECTION CONTROL DE-
VICE (if present)
The valve leak detection control device is compulsory (pr
EN 676) on the gas supply trains of burners with rated
maximum output greater than 1200 kW.
This valve leak detection control device operates by cre-
ating between the two valves an overpressure of about 20
mbar compared to the pressure upstream; the testing time
depends on the volume to be pressurized as well as the
pressure upstream and varies from 10 to 20 seconds.
The yellow pilot lamp lighting up confirms the positive out-
come of the test, while a negative outcome, with the resulting
lock-out, is signaled by the red pilot light; lock-out continues
until the valve leak detection control device is live.
An operation check can be carried out by slackening the
screw of the pressure intake pa of the equipment before the
check; the valve leak detection control device must lock out.
The fuse can be reached by using a screw-driver to re-
move the cap near the electrical connection sockets; a re-
serve fuse is in the upper part of the valve leak detection
control device under the plug (18).
Note: it is possible to install the valve leak detection con-
trol device on trains that do not have it, by requesting the
kit.
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