Hydraulic Operation Diagram; Pressure Variator - Riello GI/EMME 1400 Installation, Use And Maintenance Instructions

5.12

Hydraulic operation diagram

5.12.1 Oil pressure switch
It triggers the lockout condition of the burner in case of too much
counter-pressure on the fuel return line.
Recommended calibration (recommended values with return line
resistance in tank of 0.5 bar):
GI/EMME 1400: 1.5 ÷ 2.0 bar
GI/EMME 2000: 2.0 ÷ 2.5 bar
GI/EMME 3000: 3.0 ÷ 3.5 bar
GI/EMME 4500: 4.0 ÷ 4.5 bar
In case of control box lockout (in position "P") calibrate the
pressure switch again with incremental values of 0.5 bar.
Motor lockout
It is caused by the motor overload protection in case of overload
or no phase.
5.13

Pressure variator

To calibrate the eccentric 8):
 remove the cover 9), loosen the screws 7), turn the screw 4)
until the desired eccentricity is obtained;
 by turning screw 4) to the right (+) the eccentricity increases,
thereby increasing the difference between the maximum and
minimum capacity of the nozzle;
 by turning screw 4) to the left (-) the eccentricity decreases,
thereby decreasing the difference between the maximum
and minimum capacity of the nozzle.
At every eccentricity variation it may be necessary to offset the
stroke by means of the nut and locknut 6).
Note
• For a correct calibration, the eccentric 8) must operate on the
entire range of travel of the servomotor (20° ÷ 130°): a
pressure variation must correspond to each servomotor
variation.
• Never drive the variator piston fully home: the stop ring 5)
determines the maximum stroke.
• At the end of the adjustment, manually check that between
20° and 130° there is no sticking and that the maximum and
minimum pressures correspond to the one selected
according the diagram (A).
• If at the maximum delivery of the nozzle (maximum pressure
on the return line) pressure oscillations can be seen on the
pressure gauge 3), slightly reduce the pressure until they
disappear.
Installation
Key (Fig. 19)
Cn - Control cams
FO - Oil filter
MM - Delivery pressure gauge
MR - Return pressure gauge
MV - Fan motor
P - Pump with pressure adjuster
PO - Minimum oil pressure switch
POM - Maximum oil pressure switch
RO - Pressure adjuster on return line
Vn - Valves
Key
1 Pressure switch connection
2 Delivery pressure gauge
3 Return pressure gauge
4 Eccentric adjustment screw
5 Piston stop ring
6 Piston calibration nut and lock nut
7 Eccentric locking screws
8 Variable eccentric
9 Cover
21 GB
D1396
Fig. 19
D3437
Fig. 20
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