10
MSAT-XEE 8.2-30.2
M09G60E14-04
4.3 Suction line
Slope this towards the compressor in the horizontal sections (0.5%) to ensure the return of oil to the compressor even under minimum load
conditions.
For vertical rises, as well as well the socket also fit an oil collection trap every 6 metres.
Carefully insulate the pipe with anti-condensate, closed cell polyethylene, minimum thickness 9 mm.
4.4 Liquid line
The liquid line must be insulated if it is exposed to the sunlight or it crosses zones with a temperature higher than the external one, otherwise
it can be free.
Avoid excessive diameters to not cause an excessive refrigerant charge.
If the condensing unit is lower than the evaporating unit, install a drain trap of equal height to the exchanger coil, so as to prevent the return
of liquid to the compressor when the unit is off.
The solenoid valve avoids dangerous gas leaks when the unit is off; the installation is always recommended, above all with pipes particularly
long.
It has to be positioned near the thermostatic valve.
If the terminal unit is fitted with a thermostat as well as a drain trap, install a socket as near as possible to the unit.
This will prevent the bulb of the thermostat from remaining in contact with the liquid when the unit is off.
A Suction line
B
Liquid line
4.5 Liquid receiver
The liquid receiver installation is always recommended, above all when:
•
the connecting pipes are longer than 10 metres
•
the installation operates in variable climatic conditions (for example fresh air temperature with ranges day/night, summer/winter).
The receiver must have a capacity adequate to the installation and it must be positioned near the evaporating unit.
If the distance is greater than 15 metres and the compressor is located in the lower part of the system, position the receiver near the unit with
the compressor.
The liquid receiver can absolve the above described functions:
•
it avoids the presence of gaseous freon in the expansion device
•
it compensates for the charge variations in the installation when changing the operating conditions
•
it avoids an excessive condenser flooding with consequent condensing temperature/pressure raising if the installation charge is
performed in anomalous climatic conditions.
Along with the previously mentioned aspects, the liquid recipient compensates for the various volumes of the exchangers as their function
changes (evaporator/condenser and vice versa).
Make very sure that the return and supply points are placed at the bottom.
4.6 Checking for leaks
1
Check carefully that the evaporator unit taps are closed.
2
Connect the pressure gauges with the service fittings (on the taps or on the connection pipes).
3
Pressurise the system with nitrogen:
mode 1: up to PS (see the label) and wait few hours
mode 2: up to PS x 1,43 law (as according to UNI-EN 378-2)
CAUTION: EXPLOSION DANGER
4
Spray using a leak detector spray taps and pipes and check if bubbles are present (gas leaks).
5
Discharge the nitrogen from the unit.
4.7 Vacuum operations
Make sure that all the service outlets are closed with proper caps; if caps are not present a leak of refrigerant can be possible.
Summary of Contents for MSAT-XEE 10.2
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