118 | GUIDELINES
MUL
TI V W
all-Mounted Indoor Unit Engineering Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
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LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
General Drain Piping Information
All Gallery and Wall-mounted indoor units generate water during
cooling operation, therefore, properly handling this condensation
must be considered. Gallery and Wall-mounted indoor units apply
the gravity drain method, but a field-supplied condensate pump can
be installed (optional, sold separately). Depending on the location of
the indoor unit, condensation can be drained directly to the outside
of the building, or a common indoor unit drainage piping system can
be installed.
Drain Hose
Gallery and Wall-mounted indoor units have a built-in drain hose.
If necessary, the drain hose can be extended. When the bottom
surface of the indoor unit is at an elevation below the receiving
building drain line connection, install an inverted trap at the top of the
condensate pump discharge riser before connection to the building
drain pipe.
When the receiving drain line is mounted horizontal, connect the
inverted trap to the top half of the pipe. The connection point of the
inverted trap to the building drain pipe must always be to the top half
of the pipe and must never be over 45° either side of the upper most
point of the horizontal building drain line.
If connecting to a vertical drain line or plumbing system vent line,
connect the IDU condensate pump discharge line using a Y-45 fitting
with the double end of the Y-45 fitting facing up. When connecting to
a vertical drain line include an inverted trap at the top of the IDU con-
densate pump discharge riser before connection to the Y-45 fitting.
Drain Piping
• Drain piping must have down slope (1/50 to 1/100).
• Any holes through the ceilings, walls, etc., must be large enough to
accommodate the drain piping and insulation.
•
To prevent reversal flow, do not provide up and down slope.
•
Do not exert extra force on the drain port on the indoor unit
during drain piping connection.
Indoor Unit
Drain
Type
Drain Pipe Diameter
(ID, in.)
SF Frame Gallery
Gravity
Ø5/8
SJ Frame Wall-Mounted
SK Frame Wall-Mounted
SV Frame Wall-Mounted
Table 60:
Indoor Unit Drain Piping Specifications.
Drain pan
Insulation
Drain hose
Insulation
Figure 47: Diagram of an Indoor Unit with a Gravity Drain.
Figure 49: Drain Piping Slope.
Drain hose
Connecting
APPLICATION GUIDELINES
General Drain Piping Information
Figure 48: Properly Insulating the Drainage Piping.
Insulation
Required
Insulation
Not Required
Properly Fitting Insulation
Ensure the indoor unit, refrigerant piping, power wiring / communication
cables, and drain piping is properly supported with anchor bolts and
clamp hangers positioned at 3.3 to 4.9 foot intervals.
Drain Leak Test
A leak test must be performed 24 hours after the drainage system
has been installed.
Drain Pipe Insulation
To prevent condensate from forming on the drain piping, field-
supplied 5/16 inch thick polyethylene insulation must be properly
installed.
