58 | GUIDELINES
MUL
TI V Floor
, Suspended, Convertible 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
APPLICATION GUIDELINES
Figure 44: Properly Insulating the Drainage Piping.
Insulation
Required
Insulation
Not Required
Properly Fitting Insulation
Drain Leak Test
A leak test should 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 should be properly installed.
Figure 45: Example of a Common Indoor Unit Drainage System.
Common Indoor Unit Drainage System
It is usual work practice to connect individual indoor unit drain pipes to one common indoor unit drainage system. The diameter of the com-
mon vertical drain pipe should be as large as necessary.
The diameter of the horizontal pipe should be the same or larger than the vertical
drain pipe. To avoid property damage in the event of the primary drain becoming clogged, and to optimize drain system performance, it may
be prudent to install a secondary drain line. Design the drain system to plan for winter operation (condensate line may freeze up if conden-
sate does not properly drain away). Drain all generated condensate from the external condensate pan to an appropriate area. Install a trap
in the condensate lines as near to the indoor unit coil as possible. To prevent overflow, the outlet of each trap should be positioned below its
connection to the condensate pan. All traps should be primed, insulated, and leak tested.
Common horizontal drain pipe
1/50 to 1/100 Slop
e
27-1/2 in.
(Maximum pump
lift distance
[depends on indoor
unit type]).
Include trap
at the end.
45° to 60° Angle
Position the vent
down to prevent
debris from entering
the system
45° to 60° Angle
45° to 60° Angle
45° to 60° angle for protection against overflow
Common
vertical
drain pipe
• It is recommended that a dedicated drain pipe be installed for the air conditioning
system. If the indoor unit drainage system is shared with a rainwater drain, waste
water, or any other type of building drain system, back flow, leaks, ice may form,
or noxious odors may infiltrate the air conditioning system.
• Install a trap if the drain access to the outside faces an undesirable location (i.e.,
sewer), otherwise, noxious odors may infiltrate the air conditioning system.
Ensure the indoor unit, refrigerant piping, drain piping, and power wiring / com-
munication cables are properly supported with anchor bolts and clamp hangers
positioned at 3.3 to 4.9 foot intervals.
