44 Chapter 10 Maintenance & Spare Parts
Liebert.CRV Series Air Conditioner User Manual
The compressor copper plated steel connections should be brazed with a silfos material containing a minimum of 5%
silver.
10.8.1 Refrigerant Charge Of The Water-Cooled Units
1. Start the unit as described in 7.1 First Start-Up (Or After Long Standstill).
2. Manually start the compressor (ensure the unit is not in dehumidification).
3. Wait a few minutes to allow conditions to stabilize.
4. Check the refrigerant circuit using a leak detector. If there is a leak, recharge the unit until the working conditions of
the entire refrigeration circuit have become normal.
5. Using a manometer, check that the evaporating temperature is above 0°C.
6. Verify the water pressostatic valve (WV) setting (refer to Chapter 7 Start-Up).
7. Verify that the superheat is 5K ~ 8K, refer to Chapter 9 Calibrations & Regulation (At Start-Up).
10.8.2 Oil Charge R410A
The oil to be used when topping up (only if there are any leaks) is EMKARATE RL 32-3MA or Mobil EAL Arctic 22CC
(see Table 10-2 and Table 10-3).
Table 10-2 EMKARATE RL 32-3MA oil
Item Description
Viscosity at 40°C 31.2cSt
Viscosity at 100°C 5.6cSt
Viscosity index (ISO Grade) 32
Table 10-3 Mobil EAL Arctic 22CC oil
Item Description
Density (at 15 °C) 0.967kg/l
Flash point (C.O.C.) 245°C
Pour point < -54°C
Viscosity at 40°C 23.6cSt
Viscosity at 100°C 4.7cSt
Viscosity index (ASTM D2270) 130
These oils rapidly absorb the humidity present in the air when they are exposed to the atmosphere.
If the oil absorbs humidity, the ester molecules can break down, forming acidity.
We therefore recommend exposing the oil for as short a time as possible (no more than a few minutes) and, in case
of topping up, using exclusively the oil indicated on the refrigerating compressor.
Normally 1-litre or 2-litre cans are available for this purpose; once they are opened, they must be completely used up.
They must not be used after a long period, as they absorb humidity.
It is therefore obvious that the taps of the compressor must only be turned after the whole plant has been subjected
to a vacuum and partial filling.
10.8.3 Oil Topping-Up Of An Installed Circuit
If oil leakages occur, the topping-up operation is necessary. Contact the local service before intervention.
10.9 Dismantling The Unit
The machine has been designed and built to ensure continuous operation.
The working life of some of the main components, such as the fan and the compressor, depends on the maintenance
that they receive.
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