INS-98
DUAL, TRIPLE, POKER DC Inverter : 4. Installation
Multi Liberty
DC Inverter
4.7.22 Additional charge of R410A refrigerant
Caution:
4.7.21 Use of vacuum pump (separately, on circuit of each connected Indoor Unit)
1) Screw and remove protective nuts of service valves “G” and “L” and connect to check joint of service valve
“G” (Gas side) the charge hose from low pressure connection of gaugemanifold. Before doing it, please check
that both service valves “G” and “L” are completely closed.
2) Connect common connection (central connection: see the Figure) of gaugemanifold to the vacuum pump,
also by using a special charge hose.
3) Completely open the valve on “Lo” side of gaugemanifold.
4) Start vacuum pump. At starting operation of pump, lightly loosen for few seconds the Flare connection’s
flared nut on service valve “L” (Liquid side) of Outdoor Unit. After completing this operation, noise generated by
vacuum pump will change for indicating that air is entering through Flare connection previously loosened. The
tool’s pointer on “Lo” side of gaugemanifold will rise again to “0”. If this happens, there are no obstructions on
the portion of refrigerant circuit between service valve “G” and service valve “L” (connection pipings and
refrigerant circuit of Indoor Unit), therefore vacuum operation can be carried out. Immediately tighten the flared
nut previously loosened.
5) After vacuum operation has been carried out for a time enough long (at least 15 minutes or more, depending
on pipings’ length), close “Lo” valve of gaugemanifold and stop vacuum pump. The tool’s pointer on “Lo” side
will show -76cmHg (-10Pa).
6) Open service valves “G” and “L”, then screw again the valves’ protective nuts according to the recommended
tightening torque.
7) Disconnect the charge hose from check joint on valve “G”, then screw again the protective nut of check joint.
Outdoor Unit
Indoor Unit
Service valve
G
L
Liquid side piping
Gas side piping
Gaugemanifold
-76cmHg
“Lo” valve
“Hi” valve
Charge hose
Charge hose
Vacuum pump
Service valve with
check joint
Always carry out additional charge of R410A refrigerant after completing wiring.
Refrigerant can be charged only after vacuum procedure and after checking there are no gas leakages.
Never exceed rmax. amount of refrigerant which is allowed to be charged, in order to prevent refrigerant from
flowing back to compressor.
Plase charge the system with the prescribed R410A refrigerant only, otherwise there is danger of explosions
and accidents.
The valves of refrigerant cylinders must be gradually opened.
When refrigerant is charged in the system, hands must be protected by gloves and eyes must be properly
protected.
When out of factory,
Outdoor Unit is precharged for a splitting distance of 5m - for each Indoor Unit -
measured on Liquid side
. Please calculare the eventual additional charge for each portion of piping exceeding
this length, according to piping diameter on Liquid side, as it is shown on the following Table.
Piping on Liquid side, up to 5m
For each metre of piping exceeding 5m, Liquid side
Diameter of refrigerant piping, Liquid side
Ø6.35(1/4”)
Additional charge: 0g/m
Add 15g/m
Note:
The Figure below shows, for explanation purposes, a
pair of piping connections on Outdoor Unit.
a)
Vacuum procedure must be carried out separately on
refrigerant circuit of each connected Indoor Unit.
b
) Additional charge of R410A refrigerant (if required), can
be carried out by check joint, placed on Gas side service
valve, of whatever pair of piping connections.
