LG MULTI F Engineering Manual page 104

DUCT (LOW STATIC) INDOOR UNITS
Installation and Best Layout Practices
Installing the Drain System
• Drain piping must have downward gradient of at least 1/50 to 1/100; to prevent reverse flow,
slope should not be straight up and down.
• Do not damage the drain port on the indoor unit when connecting the field-supplied drain
piping.
• Drain piping specifications:
- Indoor Unit Drain Connection: 1-1/4 inch outside diameter.
- Field-Supplied Drain Piping: Polyvinyl chloride piping with 1-inch inside diameter and pipe
fittings.
Ducted (low static) indoor units have two options for condensate drainage: Using the factory-installed drain pump, or using a gravity drain.
Using the Drain Pump
• Maximum drain lift is 27-9/16 inches, therefore, the drain piping should be placed below
the maximum lift height.
• Field-installed drain piping must have downward gradient of at least 1/50 to 1/100; to
prevent reverse flow, slope should not be straight up and down.
Using the Gravity Drain
Field-drain piping must have downward gradient of at least 1/50 to 1/100; to prevent
reverse flow, slope should not be straight up and down.
Checking the Drain Pump
The unit uses a drain pump to remove condensate. The pump must be tested before the
system operates.
• Connect the flexible drain hose to the field-installed drain piping; leave it as is until the
test is complete.
• Pour water into the flexible drain hose and check for leaks.
• After power wiring installation is complete, operate the drain pump to see if it sounds
and functions properly.
• After the test is complete, connect the flexible drain hose to the indoor unit drain port.
Checking the Drainage System
1. Remove the air filter.
2. Check the drainage.
• Spray water on the evaporator.
• Verify that water flows through the indoor unit drain
hose without leaking.
104 | DUCT (LOW STATIC)
Figure 141:Checking the Drainage System.
Due to our policy of continuous product innovation, some specifications may change without notification.
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MULTI
MULTI
Figure 137:Drain Connection.
Indoor Unit
Close Any Gaps
Figure 138:Indoor Unit Using Drain Pump.
Drain Pipe
Pump location may be different on the indoor unit.
Figure 139:Indoor Unit Using Gravity Drain.
Approx 3/32~5/32 inches
Figure 140:Checking the Drain Pump.
Pour Water
Drain
Port
Drain Hose Connection
Indoor Unit
Use the clip (accessory)
Drain Pump
Drain Pan
Pump location may be different
on the indoor unit.
F
F
MAX
Insulation
(Field Supplied)
Drain Pipe
(Field Supplied)
Drain Hole
1/50~1/100 1/50~1/100
≤27-9/16 inch
Drain Pump
Drain hose
Angle ≥ 1/50~1/100
Flexible drain hose
(accessory)
Field-Installed
Drain Piping
Glue the Joint