7.2 STOPPING THE COMPRESSOR
The compressor can be stopped at any moment
by switching off the drive motor. However,
consult the plant manual for further action
required, especially in the case of plants with a
manual control.
7.3 SETTING OF THE OIL PRESSURE REGULATOR
The lubricating oil pressure regulator has been set
during the testing of the compressor in the works.
The lubricating oil pressure (i.e. the difference
between the oil pressure measured at the end of the
lubricating circuit, and the crankcase pressure (suction
pressure also depends on the type of oil chosen, the
refrigerant used and the operating temperature of
the compressor. Therefore it is possible that, after the
compressor has been installed in the plant, the
lubricating oil pressure regulator needs to be reset.
Re-setting takes place as follows:
a) Start compressor and wait until it has achieved a
constant operating temperature.
b) Determine the difference between the indication
of the oil pressure gauge and the suction pressure
gauge. This difference should be approx. 1.5 bar.
c) If the pressure difference is not correct, remove the
cap nut with sealing ring from the lubrication oil
pressure regulator (see fig. 7.1).Turn the slotted set
pin with a screw driver clockwise or
counter-clockwise for obtaining a higher or a lower
oil
FIG. 7.1 LUBRICATING OIL PRESSURE REGULATOR
Refrigeration Division
Grasso
A
B
1
2
3
1 Slotted set pin
2 Sealing ring
3 Cap nut
A
Oil return to crankcase
B
Oil return from seal housing
FIG. 7.2 SETTING OF PRESSURE SAFETY SWITCHES
1
3
2
3
2
LUBRICATING OIL PRESSURE SAFETY SWITCHES
Type MP55 Type RT260A
Type MP55A
1 Main spindle
2 Graduated scale
3 Setting scale
SUCTION AND DISCHARGE
PRESSURE SAFETY SWITCHES
Type RT1 and RT1A
Type RT5 and RT5A
7. STARTING, STOPPING AND ADJUSTMENT OF COMPRESSOR
Page 7.2
Refrigeration Compressors Series RC9
v002.97.10.en
