Lennox VRF VEC027N432U, User Manual, Page: 17 / 36

DC Inverter Multi VRF System
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(2) Do not bend the pipe over 90°.
(3) If pipe is repeatedly bent or stretched, it will get hard and difficult to bend and stretch again.
Therefore, do not bend or stretch the bend for over 3 times.
(4) In case that direct bending will open cracks to the pipe, first use sharp cutter to cut the
insulating layer, as shown in Fig.4.3.3.2. Do not bend the pipe until it is exposed. When
bending is done, wrap the pipe with insulating layer and then secure it with adhesive tape.
4.3.4 Indoor Pipe Connection
(1) Remove pipe cover and pipe plug.
(2) Direct the flared part of copper pipe to the center of screwed joint. Twist on the flared nut
tightly by hand, as in Fig 4.3.4.1 (Make sure indoor pipe is correctly connected. Improper
location of the center will prevent flared nut from being securely twisted. Thread of nut will
get damaged if the flared nut is twisted forcibly).
(3) Use torque wrench to twist on the flared nut tightly until the wrench gives out a click sound
(Hold the wrench and make it at right angle to the pipe as in Fig 4.3.4.2).
(4) Use sponge to wrap the un-insulated connection pipe and joint. Then tie the sponge tightly
with plastic tape.
(5) Connection pipe should be supported by a bearer rather than the unit.
(6) The bending angle of piping should not be too small; otherwise the piping might have cracks.
Please use a pipe bender to bend the pipe.
(7) When connecting IDU with connection pipe, do not pull the big and small joints of IDU with
force in case the capillary tube or other tubes have cracks and cause leakage.
Pipe diameter Tightening torque
Φ 6.35mm 15~30(N·m)
Φ 9.52mm 35~40(N·m)
Φ 12.7mm 45~50(N·m)
Φ 15.9mm 60~65(N·m)
Fig 4.3.4.1 Fig 4.3.4.2
4.3.5 Outdoor Pipe Connection
Twist the flared nut on the connection pipe of outdoor valves. Twisting method is the same as for
indoor pipe connection.
During engineering installation, the connection pipe inside the unit must be wrapped by insulation
sleeve.