Dometic 620412.331, 620415.331, 620425.331, 620415.336, 620425.336 Installation Instructions Manual

USA

C

S

SERVICE OFFICE
Dometic Corporation
2320 Industrial Parkway
Elkhart, IN 46515
574-294-2511

RECORD THIS UNIT INFORMATION FOR
FUTURE REFERENCE:
Model Number
Serial Number
Date Purchased

MODEL 6204XX

Roof-Top Air Conditioner

used with one of following:

3105007 Return Air Cover

3105935 Quick Cool Return Air Cover

CANADA

Dometic Distribution
866 Langs Drive
Cambridge, Ontario
CANADA N3H 2N7
519-653-4390

For Service Center
Assistance Call:

800-544-4881

U

3308120 Genesis Air Filtration System

and

3106995 Analog W all Thermostat

THIS UNIT IS DESIGNED FOR OEM INSTALLATION

ALL INITIAL INSTALLATIONS MUST BE APPROVED BY THE SALES DEPT.

This manual must be read and un­derstood before installation, ad­justment, service, or maintenance
is performed. This unit must be in­stalled by a qualified service tech­nician. Modification of this product
can be extremely hazardous and
could result in personal injury or
property damage.

Lire et comprendre ce manuel avant de
procéder à l'installation, à des réglages,
de l'entretien ou des réparations.
L'installation de cet appareil doit être
effectuée par un réparateur qualifié.
Toute modification de cet appareil peut
être extrêmement dangereuse et
entraîner des blessures ou dommages
matériels.

INSTALLATION

INSTRUCTIONS

REVISION:

Form No. 3308970.015 2/05
(Replaces 3308970.007)
(French 3308971.013)
©2005 Dometic Corporation
LaGrange, IN 46761

Important: These Instructions

must stay with unit.
Owner read carefully.

Models

620412.331

620415.331

620415.336

620425.331

1

620425.336

620426.331

620426.336

620412, 620415, 620425 & 620426 Series Installation Instructions

SAFETY INSTRUCTIONS

This manual has safety information and instruc­tions to help users eliminate or reduce the risk of
accidents and injuries.

RECOGNIZE SAFETY INFORMATION

!

This is the safety-alert symbol. When you see this
symbol in this manual, be alert to the potential for
personal injury .

Follow recommended precautions and safe op­erating instructions.

UNDERSTAND SIGNAL WORDS

A signal word , WARNING OR CAUTION is used
with the safety-alert symbol. They give the level of
risk for potential injury .

WARNING

!

ous situation which, if not avoided, could result in
death or serious injury .

CAUTION

!

ous situation which, if not avoided may result in
minor or moderate injury .

CAUTION

symbol indicates, a potentially hazardous situa­tion which, if not avoided may result in property
damage.

Read and follow all safety information and instruc­tions.

indicates a potentially hazard-

indicates a potentially hazard-

used without the safety alert

GENERAL INFORMATION

A. Product features or specifications as described or illustrated

are subject to change without notice.

B. This Air Conditioner Is Designed For:

1. Installation on a recreational vehicle during the time
the vehicle is manufactured.

2. Mounting on the roof of a recreational vehicle.

3. Roof construction with rafters/joists on minimum of 16
inch centers.

4. Minimum of 2.00 inches and maximum of 5.50 inches
distance between roof to ceiling of recreational vehicle.
Alternate installation methods will allow for roofs more
than 5.50 inches thick.

C. The ability of the air conditioner to maintain the desired

inside temperature depends on the heat gain of the RV.
Some preventative measures taken by the occupants of the
RV can reduce the heat gain and improve the performance of
the air conditioner. During extremely high outdoor tempera­tures, the heat gain of the vehicle may be reduced by:

1. Parking the RV in a shaded area

2. Using window shades (blinds and/or curtains)

3. Keeping windows and doors shut or minimizing usage

4. Avoiding the use of heat producing appliances

Operation on High Fan/Cooling mode will give optimum or
maximum efficiency in high humidity or high outside tempera­tures.

Starting the air conditioner early in the morning and giving it a
"head start" on the expected high outdoor ambient will greatly
improve its ability to maintain the desired indoor temperature.

For a more permanent solution to high heat gain, accessories like
A&E outdoor patio and window awnings will reduce heat gain by
removing the direct sun. They also add a nice area to enjoy
company during the cool of the evening.

D. Condensation

Note: The manufacturer of this air conditioner will not be respon-

sible for damage caused by condensed moisture on ceilings or
other surfaces. Air contains moisture and this moisture tends to
condense on cold surfaces. When air enters the RV, condensed
moisture may appear on the ceiling, windows, metal parts, etc.
The air conditioner removes this moisture from the air during
normal operation. Keeping doors and windows closed when this
air conditioner is in operation will minimize condensed moisture
on cold surfaces.

2

Size**

Minimun

Generator

1Unit/2Units

Weight

Installed

(Pounds)

** User

Supplied

AC Circuit

Protection

Minimum

Wire Size*

R-22

(Oz.)

Refrigerant

Copper

12 AWG

620412, 620415, 620425 & 620426 Series Installation Instructions

Up To 24'

Total

Static

Max./Min.

W.C.

Speed

Max./Min.

SCFM-High

SPECIFICATIONS

Amps

Rotor

Locked

Fan Motor

Load

Amps

Rated

Fan Motor

Amps

Rotor

Locked

Compressor

Load

Amps

Rated

Compressor

Watts

Heater

Amps

Rating

Electrical

60Hz.

120VAC

1 Phase

Cooling

Nominal

Capacity

(BTU/HR)

No.

Model

620412.331 11,000 1530 9.5 53.0 3.5 10.0 335 / 250 .012 / 0.65 17.0 20 Amp 95 2.5 KW/4.0 KW

620415.331 13,500 1530 12.4 60.0 3.5 10.0 335 / 250 .012 / 0.65 15.2 20 Amp 95 3.5 KW/5.0 KW

620415.336 13,500 1530 12.4 60.0 3.5 10.0 335 / 250 .012 / 0.65 15.2 20 Amp 95 3.5 KW/5.0 KW

620425.331 13,500 12.4 60.0 3.5 10.0 335 / 250 .012 / 0.65 15.2 20 Amp 95 3.5 KW/5.0 KW

620415.336 13,500 12.4 60.0 3.5 10.0 335 / 250 .012 / 0.65 15.2 20 Amp 95 3.5 KW/5.0 KW

620426.331 15,000 12.0 64.0 3.3 8.2 380 / 250 .012 / 0.65 20.0 20 Amp 95 3.5 KW/5.0 KW

620426.336 15,000 12.0 64.0 3.3 8.2 380 / 250 .012 / 0.65 20.0 20 Amp 95 3.5 KW/5.0 KW

3

When sizing the generator, the total power usage of your recreational vehicle must be considered. Keep in mind generators lose power at high altitudes

an dfrom lack of maintenance.

* For wire length over 24 ft., consult the National Electric Code for proper sizing.

** Dometic Corporation gives GENERAL guidelines for generator requirements. These guidelines come from experiences people have had in actual applications.

*** CIRCUIT PROTECTION: Time Delay Fuse or HACR Circuit Breakers Required.

620412, 620415, 620425 & 620426 Series Installation Instructions

CAUTION

M

i

c

r

o

-

T

h

e

r

m

F

i

l

t

e

r

S

y

s

t

e

m

Micro-Therm

Filter

System

F
I

L
T

E

R
R
E

S

E

T

FILTER
RESET

C
L

E
A

N
F
I

L

T

E

R

CLEAN
FILTER

INSTALLATION INSTRUCTIONS

A. Precautions

Improper installation may damage equipment,
could endanger life, cause serious injury and/
or property damage.

1. Read Installation and Operating Instructions care­fully before attempting to start your air conditioner
installation.

2. Dometic Corporation will not be liable for any dam­ages or injury incurred due to failure in following
these instructions.

3. Installation must comply with the National Electrical
Code ANSI/NFPA-70 and CSA Standard C22.1
(latest edition and any State or Local Codes or
regulations.

4. DO NOT add any devices or accessories to this air
conditioner except those specifically authorized by
Dometic.

5. This equipment must be serviced by qualified per­sonnel and some states require these people to be
licensed.

b. For two unit installations: Install one Air Condi-

tioner 1/3 and one Air Conditioner 2/3’s from
front of RV and centered from side to side.

FIG. 2

1/2L

L

2/3L

L

1/3L

It is preferred that the air conditioner be installed on
a relatively flat and level roof section measured

with the RV parked on a level surface.
Note: A 8° slant to either side, or front to back, is acceptable
for all units.

3. After Location Has Been Selected:
a. Check for obstructions in the area where air

conditioner will be installed. See FIG. 4.

b. The roof must be designed to support 130

pounds when the RV is in motion. Normally a
200 lb. static load design will meet this require­ment.

B. Choosing Proper Location For The Air

Conditioner

This air conditioner is specifically designed for installation on
the roof of a recreational vehicle (RV). When determining your
cooling requirements, the following should be considered:

• Size of RV;

• Window area (increases heat gain);

• Amount of insulation in walls and roof;

• Geographical location where the RV will be used;

• Personal comfort level required.

1. Normal Location-The air conditioner is designed to
fit over an existing roof vent opening.

FIG. 1

2. Other Locations-When no roof vent is available or
another location is desired, the following is recom-

mended:
a. For one unit installation: The air conditioner

should be mounted slightly forward of center
(front to back) and centered from side to side.

CAUTION

It is the responsibility of the installer of this
air conditioner system to ensure structural in­tegrity of the RV roof. Never create a low spot
on the roof where water will collect. Water
standing around the air conditioner may leak
into the interior causing damage to the prod­uct and the RV.

c. Check inside the RV for return air kit obstruc-

tions (i.e. door openings, room dividers, cur­tains, ceiling fixtures, etc.) See FIG. 3 & 4.

FIG. 3

9-1/2"

28-3/4"

39"

Genesis

17"

2"

20-7/8"

18-1/2"

3/4"

17"

Standard
Grill

4

CAUTION

620412, 620415, 620425 & 620426 Series Installation Instructions

FIG. 4

4"

4"

7-1/8”

4-1/8”

21-3/8”

REAR
OF
UNIT

14-1/4" x 14-1/4”

(±1/8”) OPENING

Center Line
of Unit

7-1/8”

KEEP THESE AREAS
FREE OF OBSTRUCTIONS

12"

Air Grill Perimeter

1-1/2"

F

17"

r
o

1-1/4"

n

14-1/4 x 14-1/4
(±1/8")
Opening

t

1-1/2"

17"

1-3/4"

3"

Standard

2"

14-1/4 x 14-1/4
(±1/8")
Opening

2"

20-7/8"

Genesis

18-1/2"

R

3"

e
a
r

Grill

C. Roof Preparation

1. Opening Requirements - Before preparing the ceil­ing opening, the type of system options must be
decided upon. Read all of the following instructions
before beginning the installation.
If a roof vent opening will not be used a 14-1/4" x 14­1/4" (±1/8") opening must be cut through the roof and
ceiling of the RV. This opening must be located
between the roof reinforcing members.

There may be electrical wiring between the
roof and the ceiling. Disconnect 120 volt AC
power cord and the positive (+) 12 volt DC ter­minal at the supply battery. Failure to follow
this instruction may create a shock hazard
causing death or severe personal injury.

The 14-1/4" x 14-1/4" (±1/8") opening is part of the
return air system of the Air Conditioner and must be
finished in accordance with NFPA Standard 501C
Section 2.7.2.

2. Roof Vent Removal
a. Unscrew and remove the roof vent.
b. Remove all caulking compound around open-

ing.

c. Seal all screw holes and seams where the roof

gasket is located. Use a good grade of all
weather sealant. See FIG. 5.

FIG. 5

d. If the opening exceeds 14-3/8" x 14-3/8", it will

be necessary to re-size the opening to 14-1/4"
x 14-1/4" (±1/8").

e. If the opening is less than 14-1/8" x 14-1/8", it

must be enlarged.

3. New Opening- (Installation Other Than Vent Open­ing)
a. Mark a 14-1/4" x 14-1/4" (±1/8") square on the

roof and carefully cut the opening.

b. Using the roof opening as a guide, cut the

matching hole in the ceiling.

c. The opening created must be framed to provide

adequate support and prevent air from being
drawn from the roof cavity. Lumber 3/4" or more
in thickness must be used. Remember to pro­vide an entrance hole for power supplies, fur­nace wiring and a seven-conductor cable, 18 to
22 AWG is to be used for analog thermostat

connections.

FIG. 6

Do Not Cut
Roof Structure
Or Rafters

3/4" Min.

Good-Rafters
Supported By
Cross Beams

Frame Opening So It

Good Location­Between Roof
Rafters

Won't Collapse When
Bolting Down Unit

15" Min. At
Leave Access For Power
Supply Wiring

Front Of

Opening

It is the responsibility of the installer of this
air conditioner system to ensure structural
integrity of the RV roof. Never create a low
spot on the roof where water will collect. Wa­ter standing around the air conditioner may
leak into the interior causing damage to the
product and the RV.

5

620412, 620415, 620425 & 620426 Series Installation Instructions

4. Air Distribution System Sizing & Design

CAUTION

It is the responsibility of the installer to insure
the ductwork will not collapse or bend during
and after the installation. Dometic Corporation
will not be liable for roof structural or ceiling
damage due to improperly insulated, sealed
or collapsed ductwork.

The Installer of this air conditioner system must
design the air distribution system for their particular
application. Several requirements for this system
MUST be met for the air conditioner to operate
properly. These requirements are as follows:
a. The duct material must meet or exceed any

agency or RVIA Standard that may be in exist­ence at the time the RV is produced.

b. All discharge air ducts must be properly insu-

lated to prevent condensation from forming on
their surfaces or adjacent surfaces during op­eration of the air conditioner. This insulation
must be R-7 minimum.

c. Ducts and their joints must be sealed to prevent

condensation from forming on adjacent sur­faces during operation of the air conditioner.

d. Return air openings must have 40 square inches

minimum free area including the filter.

e. Return air to the air conditioner must be filtered

to prevent dirt accumulation on air conditioner
cooling surface.

5. Air Distribution System Installation
a. Dometic Corporation recommends the basic

configuration shown on page 7, for installing
this air conditioner system. We have found by
testing, that this configuration works best in
most applications of this air conditioner sys­tem. It is the responsibility of the Installer of this
system to review each RV floor plan and deter­mine the following:

• Duct size

• Duct layout

• Register size

• Register location

• Thermostat location

AIR DISTRIBUTION

DUCT SIZING & DESIGN CHART

Return Air Cover Model 3105007 3308120

3105935 Genesis Air Filtration System

Roof Cavity Depth 2.0 In. Min. - 5-1/2 In. Max. 2.0 In. Min. - 5-1/2 In. Max.
Duct Cross Sectional Area 21.0 Sq. In. Min. 32.0 Sq. In. Min.

Duct Size

Depth 1-1/2 In. Min. - 2-1/2 In. Max. 2.0 In. Min. - 2-1/2 In. Max.
Width 7.0 In. Min. - 10.0 In. Max. 8.0 In. Min. - 10.0 In. Max.
T ot al Duct Length 15.0 Ft. Min. - 40.0 Ft. Max. 15.0 Ft. Min. - 40.0 Ft. Max.
Duct Length (short run) 1/3 Total Duct Length 1/3 Total Duct Length

Center Duct System (Only)

Depth 2.0" In. Min. - 2.0" Max.
Width 8.0 In. Min. - 8.0 In. Max.
T ot al Duct Length 15.0 Ft Min. - 40 Ft. Max.
Duct Length (Short Run) 1/3 T otal Length

Register Requirements

Number Required Per Run 2 Min. 2 Min.
Register Free Air Area 14.0 Sq. In. 14.0 Sq. In.
Distance From Duct End 5.0 In. Min. - 8.0 In. Max. 5.0 In. Min. - 8.0 In. Max.
Distance From Elbow 15.0 In. 15.0 In.

Duct Static

Blower at High Speed,
Filter & Grill In Place 0.12 - 0.65 In. W.C. 0.12 - 0.65 In. W.C.

Note: Duct sizes listed are inside dimensions.

6

620412, 620415, 620425 & 620426 Series Installation Instructions

These items must be determined in conjunction with the
Air Distribution System and Sizing and Design Require­ments listed in the chart on page 6. Terminate the start
of the duct at the back edge of the 14-1/4" x 14-1/4" (±1/
8"). See FIG. 7, 7A, and 7B.

Important: Alternate configurations and methods

may be used which still allow the air conditioner to
operate properly; however, these alternate configura­tions and methods must be approved by the Dometic
Corporation in writing. The following instructions are
based upon the use of 3105007 Dometic Return Air Kit,
3105935 Dometic Return Air Kit or 3308120 Genesis Air

Filtration System and a 3106995 Analog Thermostat.

FIG. 7A

Register Required
Short Duct Run Minimum

1/3 T ot al Duct Length

Ducts Min. Max.
Depth 1-1/2” 2-1/2”
Width 7.0” 10.0”
Total Length 15.0’ 40.0’

Duct Size And Requirements For 3105007 And 3105935 Return Air Cover

Total Outlet Air Area
Minimum 21.0 Sq. In.

FIG. 7

INSULATION

FRAME

LOW VOLTAGE WIRES:

12VDC
Furnace
Load Shed
Sensors

ROOF

DUCT

TOP VIEW

(BACK OF RV)

FRAME

DUCT

(TOWARD BACK OF RV)

14-1/4" (±1/8”)

OPENING

AC POWER
SUPPLY WIRE

FRAME

CCC, CONTROL CABLE(S)
or 7-Wire Analog Cable

SIDE VIEW

14-1/4" (±1/8”)

OPENING

CEILING

DUCT

DUCT

INSULATION

Register Required

Registers

4 Min.-- 8 Max.
(Per Unit)
14 Sq. In Free Area
Per Register

Register Required

Note: Duct Size is Inside Dimensions

FIG. 7B

Duct Size And Requirements For 33308120 Genesis Air Filtration System Kit

Register Required
Short Duct Run Minimum

1/3 T ot al Duct Length

Total Outlet Air Area
Minimum 32.0 Sq. In.

Ducts Min. Max.
Depth 2.0” 2-1/2”
Width 8.0” 10.0”
Total Length 15.0’ 40.0’

Register Required

Note: Duct Size is Inside Dimensions

Roof
Rafters

Roof
Rafters

14-1/4"x14-1/4" (±1/8")

Roof Opening

14-1/4"x14-1/4" (±1/8")

Roof Opening

Register Required

Register Required

Registers

4 Min.-- 8 Max.
(Per Unit)
14 Sq. In Free Area
Per Register

Register Required

7

HS
HP

+7.5

GND

HS/HP HI FAN

+7.5 FUR FAN

COOL GND

COOL

FUR FAN

FAN

HI

620412, 620415, 620425 & 620426 Series Installation Instructions

D. Wiring Requirements

1. Route a copper 12 AWG, with ground, 120 VAC
supply line from the time delay fuse or circuit breaker
box to the roof opening.

a. This supply line must be located in the front

portion of the 14-1/4" x 14-1/4" (±1/8") opening.

b. The power MUST be on a separate 20 Amp time

delay fuse or HACR circuit breaker.

c. Make sure that at least 15" of supply wire

extends into the roof opening. This ensures an
easy connection at the junction box.

d. Wiring must comply with all National, State and

Local Wiring Codes.

e. Use a steel sleeve and a grommet or equivalent

methods to protect the wire where it passes into
the opening.

2. Route a dedicated 12 VDC supply line (18 -22 AWG)
from the RV's converter (filtered terminals) or battery
to the roof opening.
a. This supply line must be located in the front

portion of the 14-1/4" x 14-1/4" (±1/8") opening.

b. Make sure that at least 15" of supply wire

extends into the roof opening.

3. If a furnace is to be controlled by the system, the two
furnace thermostat leads must be routed to the roof
opening. Make sure at least 15" of the furnace
thermostat wires extend into the roof opening.

4. Route a seven conductor (18 to 22 AWG) for analog
thermostat connections. Make sure 15" of the wires
extends into the roof opening and 6" extend from the
wall at the thermostat mounting location. See Sec­tion E-2.

E. Analog Thermostat & Cable Installation

1. Analog Thermostat Location

The proper location of the thermostat is very important
to ensure that it will provide a comfortable RV tempera­ture. Observe the following general rules when select­ing a location:

a. Locate the Analog Thermostat 54" above the

floor.

b. Install the Analog Thermostat on a partition, not

on an outside wall.

c. Never expose it to direct heat from lamps, sun

or other heat producing items.

d. Avoid locations close to doors that lead out-

side, windows or adjoining outside walls.

e. Avoid locations close to supply registers and

the air from them.

f. A 3/8" diameter hole will be needed to route the

seven conductor cable through the wall. See
Section D-4.

2. Seven Conductor Cable Installation.
a. A seven-conductor cable, 18 to 22 AWG is to

be used for low voltage connections.

b. Choose the shortest, direct route from the 14-

1/4" x 14-1/4" (±1/8") opening to the thermo­stat location selected.

c. Consider where screws, nails or staples might

contact the cable.

d. Leave approximately 6" of cable extending

through the wall for connection to the thermo­stat.

e. Leave approximately 15" of cable extending into

the 14-1/4" x 14-1/4" (±1/8") opening for connec­tion at unit.

3. Analog Thermostat Installation.
Note: Wire colors listed for the seven conductor cable are the
most common used in the RV industry. Wire Colors may
vary.

Remove the cover from the thermostat by starting at
one corner and gently lifting it from the base. Insert
the seven conductor cable through the hole in the
base assembly. Cut back the outer cable shield 3"
and strip 1/4" of insulation from the inner wires.
Mount the thermostat level on the wall using the
screws provided. See FIG. 8.
a. Connect red/white wire to the thermostat +7.5

terminal.

b. Connect the green wire to the thermostat “GND”

terminal.

c. Connect the yellow wire to the thermostat

“COOL” Terminal.

d. Connect the tan wire to the thermostat “FAN”

terminal.

e. Connect the blue wire to the thermostat “HI

FAN” terminal.

f. Connect the orange wire to the thermostat “HS/

HP” terminal (if applicable).

g. Connect the white wire to the thermostat “FUR”

terminal (if applicable).

h. Inspect connections to make sure they are tight

and not touching any other terminals or wires.

i. Push the wires back through the base into the

wall. Place cover on the thermostat and push
until an audible click is heard.

FIG. 8

Wiring

Make Sure
Connections
Are Tight And
Do Not T ouch

Screw Locations

8

620412, 620415, 620425 & 620426 Series Installation Instructions

F. Placing Air Conditioner On The Roof

1. Remove the air conditioner from the carton and dis­card carton. See FIG. 9.

FIG. 9

This unit weighs approximately 100 pounds.
To prevent back injury, use a mechanical hoist
to place Air Conditioner on roof.

2. Place the air conditioner on the roof.

3. Lift and place the unit over the prepared opening using
the gasket on the unit as a guide. See FIG. 10.

CAUTION

G . Installing The Air Conditioner

 Installing Unit with 3105007 or 3105935 Return Air

Kit. For unit with Genesis Air Filtration System, see
page 11.

FIG. 11

Ceiling Template

Return Air
Grill

1. Installation Of Ceiling Template
a. Check gasket alignment of the air conditioner

over the roof opening and adjust if necessary .
Unit may be moved from below by slightly lift­ing and moving. See FIG . 1 1.

FIG. 12

Center Unit From Below

Divider Plate

Return Air
Cover

Do not slide the unit. This may damage the
roof gasket attached to the bottom and may
create a leaky installation.

FIG. 10

FRONT

4. Place the Return Air Kit inside the RV. This box
contains mounting hardware for the air conditioner
and will be used inside the RV. See FIG. 9.
This completes the outside work. Minor adjustments

can be done from the inside of the RV if required.

Roof
Gasket

b. Remove return air cover and ceiling template

from the 3105007 or 3105935 carton.

c. Locate the four (8" x 1/4- 20) unit mounting bolts,

junction box cover and Romex connector in the
3107180 bolt kit.

d. Pull down the unit's electrical cord and fasten

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.

FIG. 13

7 Conductor
Thermostat
Cable

Gasket

Pull Electrical
Cord Down

Fasten Jct. Box T o
Front Of Opening

AC Power
Supply

9

CAUTION

620412, 620415, 620425 & 620426 Series Installation Instructions

e. Install the Romex connector in the junction box.
f. Hold the ceiling template up to the 14-1/4" x

14-1/4" (±1/8") opening. Be sure the large plate
faces the rear of the RV .

g. Start each mounting bolt through the ceiling tem-

plate and up into the unit base pan by hand.
Install wood screw (not supplied) in each end
of the ceiling template. This insures a tight fit of
the return air cover to ceiling. See FIG. 14.

Evenly tighten mounting bolts to compress
gasket to 1/2" this will be a torque of 40 - 50
inch pounds. The bolts are self locking so
over tightening is not necessary. See FIG.

14.

FIG. 14

Screws

Finger
Tight

Front of Vehicle

Roof
Gasket

Tighten to
compress gasket
to 1/2"

CAUTION

If bolts are left loose there may not be ad­equate roof seal or if over tightened, damage
may occur to the air conditioner base or ceil­ing template. Tighten to specifications listed
in this manual.

2. Installation of Divider Plate
a. Measure the ceiling to roof thickness:

• If distance is 2.0" - 3-3/4", remove perfo­rated tab from divider plate.

• If distance is 3-3/4” - 5-1/2”, remove no tabs.

b. Remove the backing paper from double sided

tape located on ceiling template. See FIG. 15.

c. Place divider plate up to bottom of air condi-

tioner base pan firmly. The foam tape on the
divider plate must seal to bottom of base pan.
See FIG . 16.

Improper installation and sealing of divider
plate will cause the compressor to quick cycle
on the cold control. This may result in fuse or
circuit breaker opening and/or lack of cool­ing.

FIG. 16

d. With slight pressure then push the divider plate

against the double sided tape on the ceiling

template.
Note: The adhesive on the insulation is extremely sticky.
Be sure the part is located where desired before pressing
into place.

e. Locate the 1/8” x 7” x 18” self -adhesive insula-

tion supplied with the return air kit. Remove the

backing paper from the insulation and carefully

stick onto the ceiling template divider panel.

See FIG . 17.

FIG. 17

FIG. 15

• Excess width is intended to seal the di-

vider plate to the sides of the 14-1/4" x 14­1/4" (±1/8") opening. This is to help pre­vent cold air discharge from circulating into
the air conditioner return air opening.

• If the insulation is too high, stick excess

height of insulation to the air conditioner
base pan. Do not cover up unit rating plate.

10

CAUTION

Micro-Therm

Filter

System

FILTER
RESET

CLEAN
FILTER

620412, 620415, 620425 & 620426 Series Installation Instructions

 Installing unit with 3308120 Genesis Air Filtration

System Return Air Kit. For unit with 3105007 or
3105935 Return Air Kit, see page 9.

FIG. 18

Foam
Divider

Slider

Return Air
Cover

Genesis Air Filtration System
Return Air Kit

m
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t

s
y

S

r

te
l
i

F
m
r

e

h

-T
o
r

ic

M

T
L
I
F
S
E

Handle

R

Ceiling
Template

Filter

Grill

N

A
LE
C

R

E

R
E

T
IL
F

T
E

FIG. 19

Base Pan

Upside
Down
Foam
Divider

Place Foam Divider in
(14-1/4" x 14-1/4" (±1/8")
Ceiling Opening against
Base Pan Bottom

c. Install Foam Divider

• Peel the paper off of the foam divider and

stick it in place on the center of the rear
flange of the return air opening on the ceil­ing template. See FIG . 20.

FIG. 20

Adhesive

Do Not Peel Tape Off
Adhesive

Ceiling

Foam Divider Ceiling
Level

(±1/4") T ear Off

Excess

Foam Divider

1. All Non-Center Duct Installations
Note: The Genesis Air Filtration System can be installed on
units that use a center discharge duct through the 14-1/4" x
14-1/4" (±1/8") opening. Installing units with the center dis­charge duct go to Section 1. "Center Discharge Duct Appli­cation Installation", on page 12.

a. Check gasket alignment of the air conditioner

over the roof opening and adjust if necessary .
Unit may be moved from below by slightly lift­ing 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 con­nector in the 3107180 bolt kit.

• Pull down the units 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. Measuring Foam Divider

• Locate the foam divider and insert it cor-

ner to corner in the 14-1/4" x 14-1/4" (±1/
8") opening with the adhesive tape up (Do
not remove paper to expose adhesive). The
foam divider should be level with the ceiling
(±1/4"). T ear off the excess at the pre-cut
perforations in divider . See FIG . 19.

Peel Off Paper - Center Divider - Stick To
Rear Flange On Ceiling Template

d. Install Ceiling T emplate

• S tart 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 ap­proximately 1/2". The bolts are self
locking so over tightening is not nec­essary .

If bolts are left loose there may not be ad­equate roof seal or if over tightened, damage
may occur to the air conditioner base or ceil­ing template. Tighten to specifications listed
in this manual.

11

620412, 620415, 620425 & 620426 Series Installation Instructions

CAUTION

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.

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

CAUTION

Improper installation and sealing of foam di­vider will cause the compressor to quick cycle
on the cold control. This may result in fuse or
circuit breaker opening and/or lack of cool­ing.

2. Center Discharge Duct Application Installation
Note: If using non-center duct installation, go to Section 1.
"All Non-Center Duct Installations", on page 1 1.
Important: A duct adapter (not supplied) must be installed
between the unit discharge and the customer installed cen­ter 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 lift­ing 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 con­nector 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.

FIG. 21

Foam Divider Ceiling
Level

(±1/4") Tear Off

Excess

Tape Covered
Adhesive

• 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 tem­plate 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.

FIG. 22

Weather Strip

Stick Weather Strip To Top
Of Ceiling Template

Ceiling
Template

• S tart 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 ap­proximately 1/2". The bolts are self
locking so over tightening is not nec­essary .

CAUTION

If bolts are left loose there may not be ad­equate roof seal or if over tightened, damage
may occur to the air conditioner base or ceil­ing template. Tighten to specifications listed
in this manual.

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 tem­plate is sealed. See FIG. 20.

Improper installation and sealing of foam di­vider will cause the compressor to quick cycle
on the cold control. This may result in fuse or
circuit breaker opening and/or lack of cool­ing.

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 tem­plate using foil tape, foam insulation or silicon
sealant.

Mark And Cut 2” x 8”
Opening For Center Duct

12

620412, 620415, 620425 & 620426 Series Installation Instructions

H. Wiring The System

Reach up into the return air opening and pull the re-
maining wires down.

1. Connection Of Low V oltage Wires

CAUTION

Disconnect the positive (+) 12 volt DC termi­nal at the supply battery. Damage to equip­ment could occur if the 12 volt DC is not shut
off.

Note: If solar panel is installed see instructions packaged

with solar panel option.
Note: If using the Genesis Air Filtration System steps "a"
and "b" are to be completed when installing the decorative
cover.
Note: Wire colors listed for the seven conductor cable are the
most common used in the RV industry. Wire Colors may
vary.

a. Connect the previously run 12 VDC to the red

an d black wires protruding from the units return
air opening. Connect +12 VDC to the red wire;
–12 VDC to the black wire.

b. Connect the previously run furnace thermostat

wires (if applicable) to the blue/white wires
protruding from the units return air opening. The
polarity of these connections does not matter.

c. Connect red/white wire protruding from the units

return air opening to the seven wire cable
connected at thermostat +7.5 terminal.

d. Connect the green wire protruding from the units

return air opening to the seven wire cable
connected at thermostat “GND” terminal.

e. Connect the yellow wire protruding from the

units return air opening to the seven wire cable
connected at thermostat “COOL” Terminal.

f. Connect the tan wire protruding from the units

return air opening to the seven wire cable
connected at thermostat “FAN” terminal.

g. Connect the blue wire protruding from the units

return air opening to the seven wire cable
connected at thermostat “HI FAN” terminal.

h. Connect the orange wire protruding from the

units return air opening to the seven wire cable
connected at thermostat “HS/HP” terminal (if
applicable).

i. Connect the white wire protruding from the units

return air opening to the seven wire cable
connected at thermostat “FUR” terminal (if ap­plicable).

2. Connection Of 120 Volt Power Supply
a. Route power supply line through Romex con-

nector into junction box on side away from the
ceiling template. Tighten connector, being care­ful not to pinch or short wires.

b. Connect white to white; black to black; and

This product is equipped with a 3-wire
(grounded) system for protection against
shock hazard. Make sure that the appliance is
wired into a properly grounded 120 volt AC
circuit and the polarity is correct. Failure to do
so could result in death, personal injury or
damage to the equipment.

green to green or bare copper wire using appro­priate sized twist connectors.

c. Tape the twist wire connectors to the supply

wire to assure they don't vibrate off.

d. Push the wires into the box.
e. Install the cover onto the junction box.

I . Installing Decorative Inside Cover

 Installing unit with 3105007 or 3105935 Return

Air Cover. For Genesis Air Filtration System
Return Air Kit, see page 14.

1. Remove the return air grill from the return air cover.

2. Place the return air cover up to the ceiling tem­plate.

3. Install cover to template with #8 x 3/8” blunt point
Phillips head screws provided (6 required).

4. Reinstall filter return air grill into return air cover.
Align tabs with mating notches and snap into place

FIG. 23

Hole
Plugs

5. Install two hole plugs into screw holes in back of
return air cover. See FIG. 23.

6. This completes the installation of the air conditioner.
We recommend that power be supplied to the air
conditioner and check for proper operation. Refer to

Return Air
Cover

Return
Air Grill

Disconnect 120 volt AC. Failure to follow these
instructions could create a shock hazard
causing death or severe personal injury.

13

620412, 620415, 620425 & 620426 Series Installation Instructions

Micro-Therm

Filter

System

FILTER
RESET

CLEAN
FILTER

Operating Manual or Users Guide for a description
of the air conditioner operation.

 Installing unit with 3308120 Genesis Air Filtra-

FIG. 24

Foam
Divider

Slider

Return Air
Cover

tion System Return Air Kit. For 3105007 or
3105935 Return Air Kit, see page 13.

1. Install the slider in the return air cover and raise it
to the ceiling template. Route the filter indicator
wires from the return air cover through the template
slot leaving 3" extended. Place the wires where
they can be reached after plastic cover is installed.
Place the front of the return air cover against the
ceiling and slide towards the rear. The flange on
the ceiling template will catch in the groove on the
return cover. Adjust the position (right to left) and
install the front two screws. Start and tighten the
remaining screws to hold it in place. Connect to­gether the wires from the thermostat, unit and filter
indicator.

Genesis Air Filtration System
Return Air Kit

m
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m
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M

T
L
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F
S
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Handle

R

Ceiling
Template

Filter

Grill

N

A
LE
C

R

E

R
E

T
IL
F

T
E

Note: If solar panel is installed see instructions packaged

with solar panel option.

a. Connect the red wire from the unit, the red wire

from the filter indicator light with the red DC
positive power lead. See FIG . 24.

b. Connect the black (-12V) wire from the unit,

the black wire from the filter indicator light with

the black (-12V) power lead.
Note: Number 10 cabinet screw (not supplied) can be used
to replace the two front screws when the ceiling material is
hard.

2. Tighten the screws holding the return air cover . Slide
the filter from the right side (looking toward the RV
front) over the filter indicator wires. Make sure the
wires are above the filter and are out of its way .

3.

Place grill on return air cover and snap in place,
and install decal on end over circuit board.

4. Place slide handle through slots in grill into the

slide posts. Handle will fit in either direction.

5. This completes the installation of the air conditioner .
We recommend that power be supplied to the air
conditioner and check for proper operation. Refer to
Operating Manual or User’s Guide for a description
of the air conditioner operation.

FIG. 25

Route Wires From
Return Air Cover
Through Slot

14

RUN CAP

CON 2

CON 1

USE COPPER

TO 115 VA C 60 Hz.1O

TO LOW VOLT THERMOSTAT CABLE

SPLICE CAP

CON 3

ON SOME

TO FURNACE

SOLAR OR

IF USED

620412, 620415, 620425 & 620426 Series Installation Instructions

FIELD WIRING DIAGRAM

BLK

1

3

WHT

BLK

ELEMENT

BLK

HEATACCESSORY

NOT AVAILABLE

ON SOME

MODELS

LIMIT

SWITCH

SOLAR OR

DIRTY FILTER

INDICATOR

IF USED

RED

WHT

K5

COM

NO

K4

COM

NO

RED

BLK

T2

T1

CON 1

GRN

+

TAN

12V

TO LOW VOLT THERMOSTAT CABLE

YEL

WHT

ORN

BLU

BLK

BLK

T3

T4

CON 3

CON 2

RED/WHT

BLK

FUSE

BLU/WHT

BLU/WHT

TO FURNACE

BLU

FAN

MOTOR

YEL

WHT

BLK

WHT

TO 115 VAC 60 Hz.1O

USE COPPER
CONDUCTORS
ONLY

G/Y

BRN

WHT

G/Y

FREEZE
CONTROL

RUN CAP

WHT

START CAP

MOTOR
STARTER

RED

COMPRESSOR

R

C

FAN

C

WHT

HERM

RED

SPLICE CAP

PASSED

DIELECTRIC

3308032.071

OL

S

15