HSO 2024 to HSO 2035 Installation, Operation and Maintenance Manual
Page 50 of 94
Publication 2-119
Issue 1.2 : 03/10
Demand Oil Pump
The demand oil pump, controlled by the Fridgewatch 2000
Controller, enables the system to run for most of the time without
an oil pump, but if system pressure difference falls the oil pump
runs as necessary. For a full description of operation refer to the
instruction manual for the Fridgewatch 2000 Controller, available
from J & E Hall International.
(h)
Monitor the compressor discharge temperature. Either use a
‘touch’ thermometer on the discharge line or, for a more accurate
reading, use a wire temperature probe taped to the line; the probe
can be left in-situ. Continue to monitor the discharge temperature
during the commissioning period.
If the compressor is fitted with cooling by liquid injection, with the
compressor in operation the solenoid valve in the liquid injection
line energises (opens) allowing refrigerant to enter the injection
line. Check the sight-glass positioned in the line to the injection
valve is full of liquid refrigerant. Observe the liquid injection valve
opens when the discharge temperature rises to approximately
75 °C. Adjust the injection valve if required, however, final
adjustment must wait until after charging has been completed and
the compressor is running at design conditions.
If the compressor is fitted with a water-cooled oil cooler, adjust the
water valve at the cooling water outlet to give an oil temperature of
40 °C. If automatic flow regulation is not fitted, a manual valve
must be throttled to achieve the correct temperature.
If the compressor is fitted with a remote air cooled oil cooler, adjust
the device controlling the air flow (fan speed control, dampers etc.,)
to give an oil temperature of 40 °C.
(i)
Check that the oil separator/reservoir heaters de-energise when
the compressor motor starts.
(j)
Calibrate the LVDT 4 to 20 mA slide valve position signal for
maximum and minimum load; refer to 4.8. MSI Linear Variable
Displacement Transducer (MSI LVDT).
(k)
Check that safety devices, the HP and LP cut-outs for example,
and all external safety interlocks trip and stop the compressor.
(l)
Adjust the capacity control oil flow control valves as described in
4.3.4. or 4.4.4. Flow Control Valves.
(m)
Run-in the compressor; refer to 11. Running-In the Compressor.
10.7.
Normal Starting and Running
(a)
Check the oil level in the oil reservoir. The sight-glass should show
an oil level equal to the standing level when the plant is not
operating.
Check that the oil in the reservoir is warm enough (the heaters
should have been energised 24 hours before the first start to
ensure this). An oil temperature of approximately 45 °C is about
right.
If an oil heater thermostat is fitted, the thermostat should maintain
the oil at the correct temperature.
(b)
Check all pressure gauge valves and transducer or cut-out
isolating valves are open.
(c)
Stop valves throughout the system must be in their correct
positions for running, this is particularly important regarding the
compressor suction and discharge stop valves.
