9
English
Liebert HPM --- A/W/F/D/H
Tab. e --- Equivalent lengths (m) of: curves, shut---off and non---return valves
Nominal
diameter
(mm)
90° 45° 180° 90°
12 0.50 0.25 0.75 2.10 1.90
14 0.53 0.26 0.80 2.20 2.00
16 0.55 0.27 0.85 2.40 2.10
18 0.60 0.30 0.95 2.70 2.40
22 0.70 0.35 1.10 3.20 2.80
28 0.80 0.45 1.30 4.00 3.30
4.2 -- Vacuum creation
and refrigerant charge
Check the refrigerant type to be used on
the d ata plate of the air conditioner and
on the refrigerating compressor.
Fig. b --- Pump and refrigerant charging cylinder con-
nection for vacuum creation and refrigerant
charge
R.L.
10
(*)
10a
11
11a
14
13
12
10b
(*) only with reheating coil (optional)
4.2.1 --- R410A precharge (A and D)
1) Open all cocks of the system including those used
for pressurizing (ambient unit and condensing unit).
By this operation all the components of the refrigerating
circuit must be subject to vacuum.
2) Connec t a proper, high efficiency vacuum pump (10) suit-
able for polyester oils to the couplings:
--- Compressor intake and delivery using, if available,
the three ---way Rotalock cocks, coupling 1/4” SAE
(make sure that all three ways are open), otherwise
the Schrader valves welded on the pipings.
--- Three --- way Rota lock cock, coupling 1/4” SAE of
the liquid receiver (12) (makesurethatallthree
ways are open).
--- Schrader coupling (13) fit on the compressor or fan
space, if the reheating coil option is available.
3) Provide for a connection with refrigerant cylinder be-
fore making vacuum.
4) Make the system vacuum up to 0.3 absolute mbar and
after 3 hours check if 1.3 absolute mbar have not been
exceeded. This condition warrants a humidity lower than
50 ppm inside the system.
If the complete vacuum is not possible, this means that
there are some leaks (to be removed according to the in-
structions in 6 below).
NEVER USE THE C OMPRESSOR TO CREATE A VACU -
UM (THIS INVALIDATES ITS GUARANTEE).
5) Break the vacuum as follows :
a) Close the cock (10a) for the vacuum pump (10).
b) Open the cock of the refrigerant cylinder (11a) until
the system reaches a pressure value of about 1 bar.
The refrigerant m ust be introduced
and charged b y taking only liquid
fluid from the cylinder.
c) At this point both the vacuum pump and the refriger-
ant cylinder can be disconnected as follows:
c1) close the cylinder cock (11a)
c2) close the way 5/16” SAE of the connected
Schrader valves.
6) Inspect all connections/joints using a leak detector. If a
leak is found, empty the pipes and the condense r, seal
the leak and repeat the instructions in 3) --- 6).
7) Now the machine is ready for completing the charge and
the start---up.
8) Charge the refrigerant (ONLY LIQUID)bymeansofthe
charge valve placed at the evaporator inlet.
4.2.2 --- R410A refrigerant charge (A and D)
1) Start the unit as described in para. 7.1.
2) Manually start the compressor (ensure the unit is not in
the dehumidification phase).
3) Guarantee a constant condensation temperature
(preferably 42 ---45°C); if necessary, partially obstruct the
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