Hokkaido HCND 261 G, Инструкция по эксплуатации

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IN-29
Monosplit “Wall” Personal Line Constant Speed - Section 5: Installation
5.4 VACUUM PROCEDURE AND REFRIGERANT CHARGE
Close low pressure valve 1 of gaugemanifold.
Liquid line
Gas line
Needle valve
Service pipe
(for R410A)
Charge tube
(for R410A)
Gaugemanifold
(for R410A)
Stop vacuum pump.
Start vacuum pump.
Check when pressure gauge shows 0.1 MPa (-76 mmHg).
Outdoor Unit
Indoor Unit
(1) Why vacuum operation is needed
Vacuum procedure is necessary to remove the impurities, the remains of not condensable gas, the air and humidity
from refrigerant circuit, by a vacuum pump (equipped of one-way valve to avoid oil infiltrations, deriving from the pump,
inside refrigerant circuit, in case of accidental stop of pump during vacuum operation).
As R410A refrigerant is highly insoluble in water, even a small amount of remaining humidity inside refrigerant circuit
may freeze and cause the clogging of the circuit itself.
(2) Vacuum procedure of refrigerant pipings
a)
Make sure there is no pressure inside Indoor Units and inside refrigerant pipings. This may be detected by check
joint (needle valve) placed on service valve (gas side) of Outdoor Unit.
b)
Connect service pipings from the pump to gaugemanifold and from gaugemanifold to
check joint (needle valve) placed on service valve (gas side) of Outdoor Unit.
Gaugemanifold and service pipings must be of specific type for R410 A refrigerant.
c) Carry out operations according to the following sequence.
Keep pump operating for at least 15 min. after pressure gauge
has shown 0.1 MPa pressure (-76 mmHg).
Notes:
(1)
Do not use refrigerant pressure for expelling air from the
circuit. The so-called “purging” method is not allowed in
conformity with current regulations.
( 2 )
N eve r o p e r a t e c o m p r e s s o r fo r c a r r y i n g o u t va c u u m
operation.
(3)
Do not start compressor during vacuum condition.
(3) Recharge of refrigerant
a) Discharge completely refrigerant from the circuit (by recovering it) and carry out the vacuum as it has already been
described.
Do not charge refrigerant before carrying out the vacuum, as this modifies operating conditions of system and leads to
excessive or insufficient charge of refrigerant.
b) Keep gaugemanifold connected and connect charge cylinder which contains the refrigerant.
c) Place charge cylinder on precision electronic balance, and write down its weight. This is for measuring the exact
amount of refrigerant that will be introduced in the refrigerant circuit.
d) Eliminate air from service piping A , by proceeding in the following way. Disconnect piping A from gaugemanifold
and open valve 3 of charge cylinder, for a few seconds. Immediately connect again piping A after checking gas goes
out properly through piping itself.
e) Open valves 1 and 3 . Refrigerant starts flowing away from charge cylinder to refrigerant circuit. Keep charge
cylinder perfectly upright.
f) When free refrigerant flow stops inside refrigerant circuit, it is necessary to operate compressor by starting system in
Cooling mode, till amount (weight) of refrigerant introduced inside the circuit is exactly the same of that calculated
previously.
g) After checking that refrigerant amount inside circuit is correct, close valve 3 .
h) Disconnect charge piping from the circuit. Protect inlet of needle valve and service valves by special screw caps, by
tightening them strictly.
i)
Check for eventual gas leakages by using a gas leakage detector specific for R410A refrigerant.
j)
Start the appliance and make sure it operates properly, in particular as far as working pressures (high pressure
portion and low pressure portion of refrigerant circuit) and temperature difference (
∆
T) between inlet and outlet on
Indoor Unit are concerned.
Vacuum pump
(provided with a
one-way valve) Charge cylinder (R410A)
and electronic high-precision
balance