Daikin Super Multi NX 3MXS-G Series Engineering Data page 305

Outdoor Unit
6
Charging with Refrigerant
● If the total length of piping for all rooms exceeds the figure listed below, additionally charge with 0.22oz of
refrigerant (R410A) for each additional feet of piping.
Outdoor unit capacity class
Total length of piping for all rooms
CAUTION
Even though the stop valve is fully closed, the refrigerant may slowly leak out; do not leave the flare nut removed for
a long period of time.
7
Refrigerant Piping Work
Cautions on Pipe Handling
1) Protect the open end of the pipe against dust and moisture.
2) All pipe bends should be as gentle as possible. Use a pipe bender for
bending.
Selection of copper and heat insulation materials
When using commercial copper pipes and fittings, observe the following:
Insulation material: Polyethylene foam
1)
Heat transfer rate: 0.041 to 0.052W/mK (0.024 to 0.030 Btu/fth°F)
Refrigerant gas pipe's surface temperature reaches 230°F max.
Choose heat insulation materials that will withstand this temperature.
2) Be sure to insulate both the gas and liquid piping and to provide insulation dimensions as below.
Gas pipe
Liquid pipe
Gas pipe insulation
Liquid pipe insulation
Minimum bend radius
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
8
Flaring the Pipe End
1) Cut the pipe end with a pipe cutter.
2) Remove burrs with the cut surface facing downward
so that the chips do not enter the pipe.
3) Put the flare nut on the pipe.
4) Flare the pipe.
5) Check that the flaring is properly made.
WARNING
1) Do not use mineral oil on flared part.
2) Prevent mineral oil from getting into the system as this would reduce the lifetime of the units.
3) Never use piping which has been used for previous installations. Only use parts which are delivered with the unit.
4) Never install a drier to this R410A unit in order to guarantee its lifetime.
5) The drying material may dissolve and damage the system.
6) Incomplete flaring may cause refrigerant gas leakage.
300
Refrigerant Piping Work (3)
3MXS24∗, 4MXS32∗
131.2ft
O.D.: 3/8", 1/2" / Thickness:0.031" (C1220T-O)
O.D.: 5/8" / Thickness:0.039" (C1220T-O)
O.D.: 1/4" / Thickness:0.031" (C1220T-O)
I.D.: 0.472-0.590" / Thickness:0.511" min.
I.D.: 0.630-0.787" / Thickness:0.511" min.
I.D.: 0.315-0.393" / Thickness:0.393" min.
O.D.: 3/8", 1/4" / 1-3/16" or more
O.D.: 1/2" / 1-9/16" or more
O.D.: 5/8" / 1-15/16" or more
(Cut exactly at
right angles.)
If no flare cap is
Rain
available, cover
the flare mouth
with tape to keep
dirt or water out.
Gas pipe
Gas pipe
insulation
Flaring
Set exactly at the position shown below.
A Flare tool for R410A
Clutch-type Clutch-type (Rigid-type)
A 0-0.020"
Die
Flare's inner surface
must be flaw-free.
Remove burrs
EDUS121131
Be sure to
Wall
place a cap.
Inter-unit wiring
Liquid pipe
Liquid pipe
insulation
Finishing tape
Drain hose
Conventional flare tool
Wing-nut type (Imperial-type)
0.039-0.059" 0.059-0.079"
Check
The pipe end must be evenly
flared in a perfect circle.
Make sure that the flare
nut is fitted.
Installation Manual