Lennox VRF VEC027N432U User Manual page 21

DC Inverter Multi VRF System
(3) Use vacuum pump to withdraw the air inside indoor unit and connection pipe from the
outdoor valve, as shown below.
4.5.2 Refrigerant Adding
(1) Refrigerant quantity of outdoor unit before delivery:
Model
Refrigerant Qty (kg)
Model
Refrigerant Qty (kg)
NOTES!
① The refrigerant amount charged before delivery doesn't include the amount that needs to be
added to indoor units and the connection pipeline.
② Length of connection pipe is decided on site. Therefore the amount of additional refrigerant
shall be decided on site according to the dimension and length of field-installed liquid pipe.
③ Record the amount of additional refrigerant for convenience of after-sales service.
(2) Calculation of the amount of additional refrigerant.
Calculation method of the quantity of additional refrigerant (based on liquid pipe)
Quantity of additional refrigerant = ∑length of liquid pipe × quantity of additional refrigerant per
meter+(quantity of indoor unit -2) ×0.3
Φ22.2
0.35
First confirm that there is no leakage from the system. When compressor is not working, charge
additional R410A with specific amount to the unit through the filling opening of the liquid pipe valve of
the outdoor unit. If required amount cannot be quickly filled due to pressure increase of the pipe, then
set the unit in cooling startup and fill refrigerant from the low pressure check valve of the outdoor unit.
VEC027N432U
2.09
VEC048N432U
3.3
Quantity of additional refrigerant per meter for liquid pipe(kg/m)
Φ19.05 Φ15.9
0.25 0.17
Fig 4.5.1.1
VEC034N432U
2.09
VEC055N432U
3.3
Φ12.7
0.11
17
VEC042N432U
2.29
VEC060N432U
3.3
Φ9.52 Φ6.35
0.054 0.022