Midea ATOM MDV-V28WDHN1 Manual page 93

Atom B Series VRF 50/60Hz
Table 3-5.2: Vertical drain piping diameters
PVC piping
PVC25
PVC32
PVC40
PVC50
PVC63
PVC75
PVC90
5.4 Drain Piping for Units with Lift Pumps
Drain piping for units with lift pumps should take account of the following additional considerations:
 A downward sloping section should immediately follow the vertically rising section adjacent to the unit, otherwise a
water pump error will occur. Refer to Figure 3-5.7.
 Air vents should not be installed on vertically rising sections of drain piping, otherwise water may be discharged
through the air vent or water flow may be impeded.
5.5 Drain Piping Installation
Notes for installers
Installation of the drain piping should proceed in the following order:
Indoor unit installation
Caution
 Ensure that all joints are firm and once the drain piping is all connected conduct a water tightness test and
water flow test.
 Do not connect air conditioner drain piping to waste, rainwater or other drain piping and do not let air
conditioner drain piping come into direct contact with the ground.
 For units with drain pumps, test that the drain pump functions properly by adding water to the unit's drainage
pan and running the unit. To allow inspection and maintenance, the pipe clamps shipped with units should be
used to attach drain piping to indoor units – adhesive should not be used.
92
Nominal
Capacity (L/h)
diameter (mm)
25
32
40
50
63
75
90
Figure 3-5.7: Downward sloping section of drain piping

Drain piping
installation
Remarks
220
Branch piping only
410
730
1440
2760 Branch or main piping
5710
8280
Water tightness
test
Drain piping insulation