Specifications

12
If bolts are left loose there may not be ad-
equate roof seal or if over tightened, damage
may occur to the air conditioner base or ceil-
ing template. Tighten to specifications listed
in this manual.
CAUTION
FIG. 22
Stick Weather Strip To Top
Of Ceiling Template
Weather Strip
Ceiling
Template
FIG. 21
Mark And Cut 2” x 8”
Opening For Center Duct
Tape Covered
Adhesive
620412, 620415, 620425 & 620426 Series Installation Instructions
Improper installation and sealing of foam di-
vider will cause the compressor to quick cycle
on the cold control. This may result in fuse or
circuit breaker opening and/or lack of cool-
ing.
CAUTION
FIG. 20
Use Aluminum Foil Tape To Seal the
Foam Divider To The Sides of 14-1/4"
x 14-1/4" (±1/8") Ceiling Opening
Make Sure To Seal
Behind Flange
e. Use Aluminum foil tape (not supplied) to seal
the ends of the foam divider to the sides of the
opening. Make sure the area behind the flange
on the ceiling template is sealed. See FIG. 20.
2. Center Discharge Duct Application Installation
Note: If using non-center duct installation, go to Section 1.
"All Non-Center Duct Installations", on page 11.
Important: A duct adapter (not supplied) must be installed
between the unit discharge and the customer installed cen-
ter duct. This duct adapter must be approved by Dometic.
a. Check gasket alignment of the air conditioner
over the roof opening and adjust if necessary.
Unit may be moved from below by slightly lift-
ing and moving. See FIG. 12.
• Remove return air cover, ceiling template,
foam divider and air filter from the 3308120
carton.
• Locate the four (8" x 1/4-20) unit mounting
bolts, junction box cover and Romex con-
nector in the 3107180 bolt kit.
• Pull down the unit's electrical cord and fas-
ten the junction box with screws to the
framing in the front of the 14-1/4" x 14-1/4"
(±1/8") opening. See FIG. 13.
b. Sizing Foam Divider
• Cut notch in the center section of the foam
divider to fit (approximately 2 x 8 inches)
snugly around duct. See FIG. 21.
• Place the foam divider in the return air open-
ing above the center duct before installing
ceiling template.
c. Install Ceiling Template
• Apply a piece of foam weather stripping (not
supplied) to the upper side of ceiling tem-
plate to make a seal between it and the
duct. Use a soft piece of foam weather strip
1 x 3/4 x 10 inches. See FIG. 22.
• Start each mounting bolt through the ceil-
ing template and up into the unit base pan
by hand. EVENLY tighten the four bolts
to a torque of 40 to 50 inch pounds. This
will compress the roof gasket to ap-
proximately 1/2". The bolts are self
locking so over tightening is not nec-
essary.
Improper installation and sealing of foam di-
vider will cause the compressor to quick cycle
on the cold control. This may result in fuse or
circuit breaker opening and/or lack of cool-
ing.
CAUTION
e. Use Aluminum foil tape (not supplied) to seal
the ends of the foam divider to the sides of the
14-1/4" x 14-1/4" (±1/8") opening. Make sure
the area behind the flange on the ceiling tem-
plate is sealed. See FIG. 20.
f. Cut the opening in the center duct using the
discharge opening in the ceiling template for a
pattern. Seal the center duct to the ceiling tem-
plate using foil tape, foam insulation or silicon
sealant.
Foam Divider Ceiling
Level
(±1/4") Tear Off
Excess