122
13.6.2 Process of refrigerant recovery
1. Connect the center charging hose of manifold gauge to the in-let side of recovery device.
2. Connect the valves of the discharge side of recovery device and liquid side of refrigerant cylinder with red hose
(charging hose).
3. Connect the yellow float switch cable of the recovery device to the refrigerant cylinder.
4. Open the low pressure side valve of manifold gauge.
5. Slightly loosen the charging hose of in-let connecting side of recovery device and perform air purge.
6. Open the liquid valve of refrigerant cylinder and slightly loosen the charging hose in discharging side of recovery
device, and perform air purge (the recovery cylinder needs slight inside pressure).
7. Insert electric plug of recovery device into electrical outlet (the fan operation starts).
8. Turn the valve 1 and 2 of recovery device to pressure equalization point.
9. After a few seconds, turn back the valve 1 and 2 to the original position.
10. Turn the switch of the recovery device to “ON”. (the compressor operation starts)
11. When the low pressure of manifold gauge is close to “0”, close the low pressure side valve, turn “OFF” the
recovery device switch.
12. Remove the center charging hose of manifold gauge from the recovery device.
(Liquid side)
)
t
i
n
u
r
o
o
d
t
u
O
(
)
t
i
n
u
r
o
o
d
n
I
(
(Gas side)
Two-way valve
Close
Close
Three-way valve
Hi
Lo
Vacuum
Pump
13.6.3 Replacement of heat pump units and evacuation (when re-using the existing pipes)
When replacing the heat pump units, you might use the existing pipes, but it is recommended to perform flaring again.
In case of unit replacement, even if the unit is new refrigerant heat pump, if the refrigerant oil is different, it may
cause problem. Further, when re-using the existing refrigerant pipes, it is recommended to evacuate the pipes as
much as possible, due to the reason that much refrigerant oil may be attached on the surface of the pipes. If the
pipes are used without evacuation, the remaining refrigerant oil may cause under-performance and abnormal
refrigerant cycle caused by non-compatibility of those oils.
13.6.4 Inter-changeability of refrigerant
Do not operate heat pump units inserting wrong (or mixed) refrigerant (R22, R410A, R32). It may cause mal-function
of the units, and at the same time, may cause serious incident such as rupture of the refrigerant cycle.