Panasonic S-250WX2E5 Manual page 6

5. Tubing airtightness test and vacuum application
An airtightness test is required for gas heat pump A/C as part of industry installation guidelines. Follow the
procedure below to perform the test and confirm there is no leakage from any connections.
Connect the manifold gauge to both service ports - on the wide tube side and narrow tube side. Then connect the
nitrogen tank, vacuum pump, and other items as shown in Fig. 6.
After the airtightness test is completed, apply vacuum of 667 Pa or below to the water heat exchanger unit and
tubing.
Do not leave for a long period of time after the vacuum state has been reached.
6. Charge additional refrigerant. (See Table 1, Table 2, figure 6)
For details, refer to the "To Those Undertaking the Trial Operation."
7. Thermally insulate the pipes.
Thermally insulate the pipes only after checking for leaks at the pipe connection area.
Thermal insulation must be performed on both thick and thin pipes.
Use nitrogen to raise the pressure to the airtightness test pressure (4.15
MPa) and confirm that there is no leakage. Refrigerant leakage can cause
suffocation and injury to nearby persons.
Pressure reducing value
Pressure gauge
Value
Weight scale
Vacuum pump
Thermal insulation
(120°C or higher heat
resistance)
Control cable
Gas tube
(Wide tube)
(Water heat exchanger unit)
Close value
Vacuum
(Outdoor unit)
gauge
Manifold gauge
Fig. 6
Duct (or similar) tape
for waterproofing
Thermal insulation
Liquid tube
(Narrow tube)
Fig. 7
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