Servomotor - Riello RLS 70 Installation, Use And Maintenance Instructions

SERVOMOTOR

LEVER
BLACK
RED
ORANGE
BLUE
(A)
OPERATION
The optimum calibration of the burner requires
an analysis of the flue gases at the boiler outlet
and interventions on the following points.
• 1st and 2nd stage nozzles
See the information listed on page 11.
• Combustion head
The adjustment of the combustion head already
carried out (page 8) need not be altered unless
the 2nd stage delivery of the burner is changed.
• Pump pressure
12 bar: This is the pressure calibrated in the fac-
tory which is usually sufficient for most pur-
poses. Sometimes, this pressure must be
adjusted to:
10 bar in order to reduce fuel delivery. This
adjustment is possible only if the surrounding
temperature remains above 0 °C;
14 bar in order to increase fuel delivery or to
ensure firings even at temperatures of less than
0 °C.
In order to adjust pump pressure, use the screw
5)(B)p. 12.
D1195
• 1st stage fan air gate valve
Keep the burner operating at 1st stage by set-
ting the switch 2)(C)p. 12 to the 1st stage posi-
tion. The fan air gate valve is adjusted by
moving the orange lever of the servomotor.
• 2nd stage fan air gate valve
Set switch 2)(C)p. 12 to the 2nd stage position.
The fan air gate valve is adjusted by moving the
red lever of the servomotor.
SERVOMOTOR (A)
The servomotor adjusts the air gate valve.
The servomotor rotates through 90° in 5 sec-
onds.
Do not alter (for the time-being) the factory set-
ting for the 4 levers.
A graduated plate with 4 coloured sectors marks
the lever operation point.
Blue lever
Sets the position of the air gate valve while the
burner is shut down: air gate valve closed.
Orange lever
Sets the position of the air gate valve during 1st
stage operation.
Red lever
Sets the position of the air gate valve during 2nd
stage operation.
Black lever
Establishes when the 2nd stage gas or light oil
valve opens.
It must always operate (just) before the red lever
and after the orange lever.
It must not operate with the red lever as this
may prevent the gas or light oil valve from open-
ing at all.
It must not operate straight after the orange
lever to avoid combustion in the absence of air.
For gas or light oil valve opening to approach
that of 2nd stage air gate valve position, rotate
the black lever to the left; to delay opening time,
rotate the lever to the right.
In brief, the levers must be operated in the fol-
lowing sequence:
1° Blue lever
2° Orange lever
3° Black lever
4° Red lever
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