Refrigerant Piping - McQuay WM301 Montageanleitung

An orifice is used as expansion device in WM301 cooling only unit. It is fixed in the liquid pipe in the indoor unit.
Piping length and elevation
If the pipe is too long, both the capacity and reliability of
the unit will drop. As the number of bends increases,
resistance to the flow of refrigerant system increases, thus
lowering cooling capacity. As a result the compressor may
become defective. Always choose the shortest path and
follow the recommendations as tabulated below:
Model
07/10
Maximum length, m (ft), L 12
Maximum elevation m (ft), H 5
Maximum number of bends
Liquid pipe size 1/4"
Gas pipe size
Remark: The refrigerant pre-charged in the outdoor unit
is for piping length up to 7.62m/25ft.
Indoor unit
Piping works
• Do not use contaminated or damaged copper tubing. Do not
remove plastic, rubber plugs and brass nuts from the valves,
fittings, tubings and coils until you are ready to connect
suction or liquid line into valves or fittings.
• If any brazing work is required, ensure that the nitrogen gas
is passed through coil and joints while the brazing work is
being done. This will eliminate soot formation on the inside
walls of the copper tubings.
• Cut the connection pipe with a pipe cutter.
• Remove burrs from cut edges of the pipes with remover. Hold
the end of the pipe downwards to prevent metal chips from
entering the pipe.
• Insert the flare nuts, mounted on the connection parts of both
the indoor unit and outdoor unit onto the copper pipes.
• Flare the pipe with extra length above the flaring tool as shown
in the table.
• The flared edge must be even and not cracked or scratched.

REFRIGERANT PIPING

! Caution
15 20 25 30
12 15 15 35
(39.4) (39.4) (49.2) (49.2) (114.8)
5 8 8 15
(16.4) (16.4) (26.2) (26.2)
10 10 10 10 10
1/4" 1/4" 3/8" 3/8"
3/8" 1/2" 5/8" 5/8" 5/8"
L
H
Outdoor unit
Cutting copper tube
Remove burr
(49.2)
Copper tube
Swaging block
Piping connection to the units
• Align the center of the piping and tighten the flare nut
sufficiently with fingers.
• Finally, tighten the flare nut with the torque wrench
until the wrench clicks.
Pipe Size mm / (in)
6.35 (1/4)
9.53 (3/8)
12.7 (1/2)
15.88 (5/8)
Ø Tube, D
Inch
1/4"
3/8"
1/2"
5/8"
Flare Joint
Indoor Piping
1-7
Torque Nm / (Ft-lb)
18 (13.3)
42 (31.0)
55 (40.6)
65 (48.0)
A (mm)
mm Imperial
6.35 1.3
9.52 1.6
12.70 1.9
15.88 2.2
Flared Tube
Flare Nut
Torque Wrench
Spanar
Rigid
0.7
1.0
1.3
1.7