Mitsubishi Electric PAA-A18AA1 Manuel D'installation page 64

NOTE
Horizontal runs must also have an anti-siphon air vent (standpipe) installed ahead of the
horizontal run to eliminate air trapping. Horizontal drain lines must be pitched a minimum
¼" per foot. Route the drain lines outside or to an appropriate drain. Drain lines must be
installed so they do not block service access to the front of the unit. 24" clearance in the
front is for routine maintenance or service.
NOTE
Check local laws and regulations before connecting the drain line to an existing drainage
system. Insulate the drain pipe where condensate water may cause damage. Once the
installation is complete, it is the installer's responsibility to ensure that the drain pan
captures all condensate water and that all condensate water is properly drained and does
not enter the duct / system.
CAUTION
• Drain pipe must be installed in accordance with gas furnace install manual instructions.
Mitsubishi Electric US, Inc. is not responsible for any damage caused by integrated drain
pipe work carried out between the gas furnace and the PAA unit.
CAUTION
Auxiliary drain pan requirement
An auxiliary drain pan without a separate drain line shall be installed under the cabinet
in horizontal left/right and under the furnace in vertical upflow/downflow PAA unit
installations. The pan must have a minimum depth of 1.5 inches (38 mm), be not less
than 3 inches (76 mm) larger than the unit or the coil dimensions in width and length
and must be constructed of corrosion-resistant material. Galvanized sheet steel pans must
have a minimum thickness of not less than 0.0236-inch (0.6010 mm). (Do not use 24
gauge.) Non-metallic pans must have a minimum thickness of not less than 0.0625 inch
(1.6 mm). This pan must be equipped with a water level detection device conforming to UL
508 that will shut off the equipment served prior to overflow of the pan. The pan must be
equipped with a fitting to allow for drainage.
Specifications are subject to change without notice.
PAA-A18, 24, 30, 36, 42AA1/BA1/CA1
64 © 2022 Mitsubishi Electric US, Inc.