Hydraulic Connections; Servomotor; Oil Pressure Switch - Riello RL 190/M Instrucciones De Instalación, Funcionamiento Y Mantenimiento

7.1.1

Hydraulic connections

The pumps are equipped with a by-pass that connects return line
with suction line. The pumps are installed on the burner with the
by-pass closed by screw 6) (Fig. 22).
It is therefore necessary to connect both hoses to the pump.
The pump will break down immediately if it is run with the return
line closed and the by-pass screw inserted.
Remove the plugs from the suction and return connections of the
pump.
Insert the hose connections with the supplied seals into the con-
nections and screw them down.
Take care that the hoses are not stretched or twisted during in-
stallation.
Install the hoses where they cannot be stepped on or come into
contact with hot surfaces of the boiler.
Now connect the other end of the hoses to the suction and return
lines by using the supplied nipples.
7.1.2

Servomotor

The servomotor provides simultaneous adjustment of the air gate
valve, by means of the variable profile cam and the pressure reg-
ulator. The servomotor rotates through 130° in 42 seconds.
Do not alter the factory setting for the 5 cams; simply check that
they are set as indicated below:
Cam I : 130°
Limits rotation toward maximum position.
Cam II : 0°
Limits rotation toward the minimum position.
When the burner is shut down the air gate valve must be closed:
0°.
Cam III : 20°
Adjusts the ignition position and the MIN output.
Cam IV - V : not utilized.
Hydraulic system
D1978
Fig. 20
7.1.3

Oil pressure switch

The oil pressure switch 5) (Fig. 1, page 7) is factory set to 3 bar.
If the gas oil pressure reaches this value in the return piping, the
pressure switch stops the burner.
Burner starts again automatically if the pressure goes down un-
der 3 bar after burner shut down.
If a loop circuit with Px pressure feeds the burner, the pressure
switch should be adjusted to Px + 3 bar.
19 GB
Fig. 21
D887
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