SABROE SAB 193 S, Инструкция по эксплуатации, Страница: 141 / 177

Engineering manual - SAB 193-233-283 S A-frame (including ATEX)
008831 en 2022.02
141/175
Maintenance instructions
11.5 Visual inspection
Oil pressure
Check that the oil pressure complies with the recommended cut-out pressure.
Oil level
Check the oil level in the compressor. It is of vital importance for the service life of the compres-
sor that an optimal lubrication is maintained. The oil must always, as a minimum, be visible in
the oil level glass. If the oil level is below the lowest part of the lower oil level glass, oil must be
recharged. See also subsection
11.13 Oil charge for correct charge.
Recharging of oil (“topping up”) can be carried out during operation either by means of a hand-
operated oil pump or as described in subsection
11.12 Charging compressor with lubricating
oil . Use the recommended oil only .
Remember to write down drained or recharged amount of oil.
11.6 Measures to be taken
The following describes the measures which must be taken, including information about mate-
rials, preparation and implementation.
Noise and vibration
No special requirements are imposed regarding equipment and materials. Inspect the unit,
and check that there is no abnormal noise and vibration. Listen for any knocking or other ab-
normal noise caused by poorly clamped pipes or faulty valves.
Evaporating pressure and condensing pressure
No special requirements are imposed regarding equipment and materials. Check on the opera-
tor's panel or manometers that the pressures comply with the specifications issued for the
compressor unit in question and that they are within the permissible operating ranges.
Evaporating pressure
The terms “evaporating pressure” and “suction pressure” refer to the pressure on the suction
side of the compressor.
Usually the pressure is the same at the evaporator outlet as at the compressor inlet. The only
difference is the pressure drop in the line. Because of this pressure drop, the pressure at the
evaporator outlet is a little higher than on the compressor. The non-return valve in the suction
line will also contribute to the pressure drop.
Normal evaporating pressure
According to fundamental refrigeration engineering principles, the refrigerant absorbs heat
from the medium that is being cooled.
In order for heat to be transferred to the refrigerant, it must boil at a lower temperature than the
temperature of the medium being cooled in the evaporator. A basic rule is that the evaporating
temperature is lower than the temperature of the medium that is being cooled in the evapora-
tor. This rule sets a maximum value for the suction pressure.