Riello MBC 1200/1 Manuel D'entretien page 56

5.3 Replacing the original spring (with nominal value calibration)
For MBC 1900-3100-5000/1 only
➤ Carefully loosen the protection plug 1)(Fig. 10) and check
the gasket 2) is in good condition and firmly inserted in its
seat
➤ Take the spring 3) out of the structure 4)
➤ Carefully insert the new spring, being sure to first insert the
side with the smaller diameter.
➤ Insert the gasket 2) in the plug then retighten it, taking care
not to damage the thread.
Do not use tools to tighten it fully down.
WARNING
➤ Replace the identification labels of the spring on both sides
with the new ones (supplied).
5.4 Minimum gas pressure switch calibration
Please refer to the burner manual.
5.5 VPS 504 Valve leak detection control device (if present)
The valve leak detection control device is obligatory (EN 676) on
burner feed ramps where the maximum rated power is above
1200 kW, unless their are local other regulations and/or for par-
ticular applications.
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 lockout, is
signalled by the red pilot light; lockout continues until the valve
leak detection control device is live.
An operation check can be carried out by slackening the screw of
the pressure test point p of the equipment before the check; the
a
valve leak detection control device must lock out.
The fuse can be reached by using a screwdriver to remove the
cap near the electrical connection socket; a spare fuse is housed
in the upper part of the valve leak detection 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. See Tab. F, page 14.
WARNING
2916122
Activation, calibration and functioning
11
S8545
Key (Fig. 10)
1 Protection plug
2 Gasket
3 Nominal value calibration spring
4 Structure of MBC ..../1
GB
4
3
2
1
Fig. 10