Ariston NIMBUS COMPACT S NET Manual page 62

GAS CONNECTIONS BETWEEN INTERNAL UNIT
AND EXTERNAL UNIT
ATTENTION
Electrical connections are made after completing all hydraulic
and gas connections.
WARNING:
Device contains refrigerant fluid. Leaving fluid can cause scalds.
When both indoor and outdoor units shall be placed, proceed with
the pipes connections.
1. Shape the pipes by hand avoiding pipes flattening or kinking.
Avoid unnecessary turns and bends.
2. Remove protective caps from copper tube ends.
3. Cut the tube to the requested length.
4. Remove the burrs with a reamer.
5. Remove flare nuts from the unit connections and place them on
the tube end.
6. Flare the tube with the flaring tool.
(Flare end must not have any burrs or
imperfections. The length of the flared
walls must be uniform.)
7. Align the centers of the connecting pipes.
8. Tighten the flare nut as strong as possible with your fingers. Tigh-
ten it with torque wrench.
Use two spanners to unscrew or tighten the valve flare nut. If
using a single spanner, the nut cannot be tightened with the
necessary tightening torque. Fix the pipes to the wall with hooks
or conduits.
Be sure to tighten the valves (A) with a torque of 30 Nm, the plug
(B) with a torque of 5 Nm and the plug (C) with a torque of 9 Nm.
Insufficient tightening torque will cause gas leaks. Applying ex-
cessive torque may damage the tube flaring and cause gas leaks.)
9. Evacuate the air in the connecting pipes using a VACUUM PUMP.
(For the vacuum pump, check oil is filled up to the specified line
of the oil gauge).
10. Check gas leaks at connected points and open the flare valves
allowing the gas to fill the entire system.
B
A
11. Wrap the valves and pipes with anti-condensate insulation, or
use pipes already provided with insulation. Tighten with tape,
without exerting too much pressure on the insulation.
Repair and cover any possible cracks in the insulation.
Pipes storage
The end of the pipes must be sealed using one of the following
methods:
• Apply a cap to the end of the tube
• Pinch the end of the copper pipe closed and braze any opening
closed
• Cover the end of the copper pipe with vinyl tape
Remember the key principles for refrigerant pipes handling
Air purging
1) Connect the charge hose to the outdoor unit.
2) Connect the charge hose to the vacuum pump and keep the control
valves in the fully closed position.
3) Open LO handle completely.
4) Turn on the vacuum pump.
5) Proceed with evacuation until the compound pressure gauge
62 / GB
6) Close LO handle completely.
7) Turn off the vacuum pump.
8) Keep this status for 2 minutes while checking that compound
9) Detach the vacuum pump.
10) Tightly secure the valve and caps of the service port.
11) Replace caps and check for leaks by using a leak detector specific
CAUTION:
Do not discharge the refrigerant gas to the atmosphere.
Use a vacuum pump to discharge the air remained in the set. If the
air remains, the capacity may decrease.
For what concerns the vacuum pump, be sure to use one with
backflow preventive function so that the oil in the pump does not
backflow into the pipe of the air conditioner when the pump stops.
Connect the vacuum pump to the flare valve of the bigger pipe.
WARNING:
Never use the system compressor as a vacuum pump.
Never use the unit refrigerant gas to purge the connecting pipes.
(No additional refrigerant has been provided in the unit for this
purpose).
B C
A
Charging the refrigerant gas
Before proceeding with the refrigerant charging operations, check
that all the valves and cocks are shut.
Note: during initial installation, perform the procedure described in
paragraph "Air purging".
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Disconnect the tank from the pressure gauge and close all caps
indicates -101 kPA (after about 15 minutes).
gauge's pointer does not return.
for HFC refrigerants. After the leak check, fully open the three-
way valve.
Connect the low pressure connection of the pressure gauge to
the service valve, and connect the refrigerant tank to the cen-
tral inlet of the pressure gauge. Open the refrigerant tank and
then open the cap on the central valve and work the pin valve
until you hear the refrigerant exiting, then release the pin and
screw the cap back on;
Open the three-way valves;
Turn on the device in cooling mode. Leave it running for a few
minutes;
Place the refrigerant canister on the electronic scales and re-
cord its weight;
Check the pressure shown on the pressure gauge;
Open the "LOW" knob and allow the refrigerant to flow gra-
dually;
When the refrigerant charge in the circuit reaches the specified
value (calculated by means of the difference in weight of the
canister), shut off the "LOW" knob;
When charging is complete, test operation by measuring the
temperature of the gas pipe with the special thermometer. The
temperature should be 1 to 8°C over the temperature read on
the evaporation temperature section of the pressure gauge.
Now check the stability of the pressure, by connecting the
pressure gauge assembly to the three-way service valve. Open
the three-way valve fully, turn on the device and check for re-
frigerant leaks using the leak detector (if there are any leaks,
carry out the procedure described in paragraph "Refrigerant
recover");
Disconnect the pressure gauge from the valve and turn the air
conditioning unit off;