Toshiba A90-0132, Service Manual

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17
Refrigerant pipe installation
Additional refrigerant charging method
(1) Loosely connect the refrigerant cylinder hose to the gauge manifold, then open the source valve V
H
on the cylinder,
purge the air in the hose, and then tighten the hose.
(2) As shown in the diagram below, turn the refrigerant cylinder upside down, open the valve V
H
on the gauge manifold,
and then charge the liquid side pipe with refrigerant in the liquid state. (Note that with some types of refrigerant
cylinders, the liquid refrigerant will be output through siphoning action with the cylinder in the normal upright position.)
If the proper charging amount cannot be reached, close the valve V
H
, turn the refrigerant cylinder upright, open the
liquid-side and balance packed valves completely, and open the gas-side packed valve only half way. Begin the
cooling operation, open valve V
L
, and then charge the gas-side pipe with refrigerant in the liquid state.
(3) While watching the scales display, quickly close the valve V
L
completely when the system has been charged with the
proper amount of additional refrigerant. Then close the source valve V
a
on the cylinder, and open the gas-side packed
valve completely.
(4) Record the amount of additional refrigerant that was added to the system on the nameplate inside the front panel
(lower) of the outdoor unit.
Detailed drawing of packed valve
To gauge manifold
{
Service port
at gas side
Service port
at liquid side
Packed valve
at liquid side
Packed valve
at gas side
To main
unit
To main
unit
Piping at site
Piping at site
Piping at site
To main unit
Service port at
balance side
Packed valve at
balance side
Liquid pipe
Gauge manifold
Low
pressure
High
pressure
Gas pipe
Service
port
Outdoor unit
Packed valve (gas side)
Refrigerant
gas
Scales
Refrigerant
bottle
Indoor unit
Gas
Liquid
V
L
V
a
V
H
Packed valve
(liquid side)