Panasonic PAW-160MAH2L Installation Instructions Manual page 46

Product description
Pipes additional refrigerant charge: 0.045 kg/m
AHU DX coil additional refrigerant charge: 0.83 kg/dm³
Refrigerant charge at shipment is sufficient for AHU DX coil volume up to 1.8 dm³
Total additional refrigerant charge calculation
((2.0 dm³ – 1.8 dm³) x 0.83 kg/dm³) + (10 m x 0.045 kg/m) = 0.166 kg + 0.45 kg = 0.616 kg
Calculation example for number of passes in the heat exchanger
The minimum number of passes in the AHU heat exchanger is restricted. The limit is calculated by
the formula:
Minimum number of passes
= Number of steps × Distance between tube sheets × Number of rows × 1.5 × 10
The calculated value must then be rounded up to the next integer number.
Example
Number of steps: 12
Distance between tube sheets: 1,000 mm
Number of row: 3
3
Minimum number of passes = 12 × 1,000 x 3 × 1.5 × 10
This value must be rounded up to 6.
This means that the minimum number of passes is 6 passes.
ATTENTION
!
Nuisance tripping of high-pressure switch
The outdoor unit is equipped with a high-pressure switch, which stops the operation of the air-
conditioning unit for protection when the set high-pressure limit is exceeded. Nuisance tripping of
the high-pressure switch may occur in heating mode if the heat exchanger pipe thermistor (E2) is
not properly positioned or if the limit is not properly set.
► Position the heat exchanger pipe thermistor (E2) correctly and set the limit properly in
46
accordance with the instructions given in this document.
–4
= 5.4
–4
AHU Kit – Installation Instructions – 09/2021