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Service Manual -
VMH 9/12/18/24 SU & VMH30/36S D Series
11
13
3)
Put the charging cylinder onto the electronic
scale and record the weight.
4)
Operate the air conditioner
in
the cooling
mode.
5)
Open the valves (Low side) on the charge set
and charge the system with liquid refrigerant.
6) When the electronic scale displays the
proper
weight (refer to the gauge and the
pressure
of the low side), disconnect the charge
hose
from the 3-way valve’s service port
immediately and turn off the air conditioner
before disconnecting the hose.
7) Mount the valve stem caps and the service
port
.
Use torque wrench to tighten the
service port
cap to a torque of
13F.P.
Be sure to check for gas leakage.
6.6 Re-installation
if
the indoor unit
has
been
repaired
1. Air purging with vacuum pump
1)
Completely tighten the flare nuts of the
indoor
and outdoor units, confirm that both
the 2-way
and 3-way valves are set to the
closed position.
2)
Connect the
low pressure
charge hose to
the 3-way valve
'
s gas service port.
3)
Connect the
high pressure
charge hose to
the vacuum pump.
4)
Fully open the
low pressure
handle of the
manifold.
5)
Operate the vacuum pump to evacuate.
6)
Evacuate for 30 minutes and check
whether the compound meter indicates
500 microns. If the meter does not indicate
500 microns after pumping 30 minutes, it
should be pumped 20 minutes more. If the
pressure can’t achieve 500 microns after
pumping 50 minutes, please check for
leakage points. Fully close the low
pressure valve of the manifold and stop
the
operation of the vacuum pump.
Confirm
that the gauge needle does not
move
(approximately 5 minutes after
turning off
the vacuum pump).
7)
T
urn the flare nut of the 3-way valves
about
45° counterclockwise for 6 or 7
seconds
after the
gas coming out, then
tighten the
flare nut again.
Make sure the
pressure
display in the pressure
indicator
is a little
higher than the atmosphere
pressure. Then
remove the charge hose
from
the 3
-
way
valve.
8)
Fully open the 2
-
way valve and 3
-
way
valve
and securely tighten the cap of the
3-
way valve.
6.7 Re-installation
after
outdoor unit
has been
repaired
1. Evacuation for
the whole system