Engineering Manual

Installation and Best Layout Practices
DUCT (LOW STATIC) INDOOR UNITS
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.
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.
Angle ≥ 1/50~1/100
Approx 3/32~5/32 inches
Drain hose
Drain HoleClose Any Gaps
Indoor Unit
Drain Pipe
Insulation
(Field Supplied)
(Field Supplied)
Figure 137:Drain Connection.
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.
≤27-9/16 inch
Drain Pipe
1/50~1/1001/50~1/100
Drain Pump
Figure 138:Indoor Unit Using Drain Pump.
Figure 139:Indoor Unit Using Gravity Drain.
Ducted (low static) indoor units have two options for condensate drainage: Using the factory-installed drain pump, or using a gravity drain.
Pour Water
Drain Pump
Drain Pan
Flexible drain hose
(accessory)
Field-Installed
Drain Piping
Glue the Joint
Drain
Port
Drain Hose Connection
Use the clip (accessory)
Indoor Unit
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.
Figure 141:Checking the Drainage System.
Figure 140:Checking the Drain Pump.
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.
Pump location may be different on the indoor unit.
Pump location may be different
on the indoor unit.
Due to our policy of continuous product innovation, some specications may change without notication.
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104 | DUCT (LOW STATIC)
Multi F and Multi F MAX Indoor Unit Engineering Manual
MULTI
F
MAX
MULTI
F