Step 6 - Refrigerant Piping - Carrier Performance 40MBDQ Series Installation Instructions Manual

Step 6 - Refrigerant Piping

IMPORTANT: Both refrigerant lines must be insulated
separately.
• The minimum refrigerant line length between the indoor and
outdoor units is 10 ft. (3 m).
• Table 10 lists the pipe sizes for the indoor unit. Refer to the
outdoor unit's installation instructions for the additional allowed
piping lengths and refrigerant information.
• Refer to the outdoor unit's installation manual for details regarding
the allowable pipe length and height difference.
Table 10 — Piping Size
9K
Gas Pipe In 3/8
(Connection Size) (mm) (9.52)
Liquid Pipe In 1/4
(Connection Size) (mm) (6.35)
Use the following steps to connect the refrigerant piping:
1. Run interconnecting piping from the outdoor unit to the indoor unit.
2. Connect the refrigerant piping and drain line outside the indoor
unit. Complete the pipe insulation at the flare connection then
fasten the piping and wiring to the wall as required. Completely seal
the hole in the wall.
3. Piping:
a. Cut the pipe, with a pipe cutter, at 90 degrees (see Fig. 47).
b.
Remove the service connection (if provided with the unit)
90°
Oblique Rough Warped
Fig. 47 — Pipe Cutting
c. Remove all the burrs from the cut cross section of the pipe,
avoiding any burrs from inside the tubes.
d. Remove the flare nuts attached to the indoor and outdoor
units.
e. Install the correct size flare nut onto the tubing and make the
flare connection. Refer to Table 11 for the flare nut spaces.
Table 11 — Flare Nut Spacing
OUTER DIAM. (MM)
Ø 1/4"(6.35) 0.05(1.3)
Ø 3/8"(9.52) 0.06(1.6)
Ø 1/2"(12.7) 0.07(1.8)
Ø 5/8"(15.88) 0.09(2.2)
Bar
Copper pipe
Clamp handle
Fig. 48 — Flare Nut Spacing
f. Apply a small amount of refrigerant oil onto the flare
connection on the tubing.
g. Align the center of the pipes and/or the service valve.
IM-40MBDQ-05
12K 18K 24K 36K 48K
1/2 1/2 5/8 5/8 5/8
(12.7) (12.7) (16) (16) (16)
1/4 1/4 3/8 3/8 3/8
(6.35) (6.35) (9.52) (9.52) (9.52)
A (MM)
MAX. MIN.
0.03(0.7)
0.04(1.0)
0.04(1.0)
0.08(2.0)
Handle
Bar
Yoke
Cone
Red arrow mark
Specifications subject to change without notice.
Indoor unit tubing
Fig. 49 — Align Pipe Center
h. Connect both the liquid and gas piping to the indoor unit.
i. Tighten the flare nut with a torque wrench (see Table 12).
Table 12 — Tightening Torque
58K
3/4
(19)
BRASS FLARE SIZE
3/8
(9.52)
Ø1/4
Ø3/8
Ø1/2
Ø5/8
Ø3/4
Flare nut
.
Copper tube
Fig. 50 — Tighten the flare nut
4. Connect the drain line. Ensure there are absolutely no traps in the
drain line anywhere in its length. Ensure the drain line pitches down
and insulated up to the outside wall.
NOTE: For applications where gravity cannot be used for
drainage, a condensate pump accessory is available. Consult
the condensate pump installation instructions for more
information.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage or
improper operation.
Never use the system compressor as a vacuum pump.
Refrigerant tubes and the indoor coil should be evacuated
using the recommended 500 Microns Deep Vacuum method.
The alternate Triple Evacuation Method may be used if the
procedure outlined below is followed. Review the unit's
service manual for the 500 Microns Deep Vacuum or the Triple
Evacuation Method.
NOTE: Always break a vacuum with dry nitrogen.
Final Tubing Check
IMPORTANT: Ensure that certain factory tubing on both the
indoor and the outdoor unit has not shifted during shipment.
Ensure tubes are not rubbing against each other or any sheet
metal. Pay close attention to feeder tubes, making sure wire
ties on feeder tubes are secure and tight.
Flare nut Piping
RECOMMENDED SEATING
TORQUE FOR BRASS
FLARE NUTS
8-10 Ft. - Lbs.
15-18 Ft. - Lbs
28-32 Ft. - Lbs
38-42 Ft. - Lbs
50-55 Ft. - Lbs.
CAUTION
N-M
10.8 to 13.6
20.3 to 24.4
38.0 to 43.4
51.5 to 56.9
68.0 to 74.6
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