Dometic 3253.332 Installation & Operating Instructions Manual

SERVICE OFFICE

Dometic Corporation
For Information
Contact:
www.dometic.com

Type 3253.332 Installation and Operating Instructions

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

MODEL B3200

Roof-Top Air Conditioner

used with

Mechanical Air Distribution Box

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.

INST ALLA TION & OPERA TING

INSTRUCTIONS

TYPE

3253.332

Air Conditioner

REVISION:

Form No. 3310070.010 4/06
(Replaces 3310070.000)
©2006 Dometic Corporation
LaGrange, IN 46761

Important: These Instructions

must stay with unit.
Owner read carefully.

1

Type 3253.332 Installation and Operating 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.

indicates a potentially hazard-

indicates a potentially hazard-

used without the safety alert

GENERAL INSTRUCTIONS

A. Product features or specifications as described or illus-

trated are subject to change without notice.
The following are the basic requirements:

1. Installation opening. Cut through the roof and ceil­ing.

2. Additional Wiring.
220-240 VAC, 50 Hz. 10 Amp.

3. Power with the air conditioner on must be above 209
VAC and the frequency must be at 50 HZ. at all
times.

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

40.6 cm centers.

4. Minimum of 5 cm and maximum of 10 cm distance
between roof to ceiling of recreational vehicle. Alter­nate installation methods will allow for roofs more
than 10 cm thick.

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

inside temperature depends on the heat gain of the
Caravan.
Some preventative measures taken by the occupants of
the Caravan 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 Caravan 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 Dometic 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.

Read and follow all safety information and instruc­tions.

2

Type 3253.332 Installation and Operating Instructions

D. Condensation

Note: The manufacturer of this air conditioner will not be

responsible 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 Caravan, 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.

SPECIFICATIONS

Type 3253.332 Electric

Nominal Capacity (KW) 3.2 1.6

Electrical Rating 220 - 240 VAC 50 Hz. 1Ph.

FL Amps (Comp/Motor) 5.2/1.6 6.3/1.6

LR Amps (Comp/Motor) 26/4.4 --/4.4

Power (KW) 1.3 1.9

Min. Wire Size Up to 8 meters, use 1.5mm

Circuit Protection 10 Amp Time Delay Fuse or

Air Cond Heater

2

Copper

10 Amp Circuit Breaker

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 localities require these people to
be licensed.

B. CHOOSING PROPER LOCATION FOR THE

AIR CONDITIONER

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

• Size of Caravan;

• Window area (increases heat gain);

• Amount of insulation in walls and roof;

• Geographical location where the Caravan will be

used;

• Personal comfort level required.

1. Normal Location-The air conditioner is designed to
fit over an existing roof vent opening. When the vent
is removed, it normally creates a 35.5 cm x 35.5 cm

opening. See FIG. 1.

FIG. 1

Generator Size

1 Unit 3.5 KW
2 Units 5.0 KW

The Manufacturer gives only general guidelines for Generator
requirements. These Generator requirements come from
experiences consumers have with our equipment in field
applications. When sizing Generators, the total electrical
power consumption of the caravan must be considered. Keep
in mind that Generators lose power because of altitude
increase above sea level, high outside temperatures and lack
of maintenance.

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. The equipment shall be installed in accordance with
nation wiring regulation per ICE 335-2-40, 7.12.1.In­stallation must comply with applicable codes or
regulations.

2. Other Locations-When no roof vent is available or
another location is desired, the following is recom­mended:
a. For one unit installation :

The air conditioner should be mounted slightly
forward of the center (front to back ) and cen­tered from side to side on the Caravan. See FIG.

2.

FIG. 2

1/2L

L

2/3L

L

1/3L

L = Length

b. For two unit installations:

Install one air conditioner 1/3 and the other 2/3's
back from the front of the caravan and centered
from side to side. See FIG. 2.

3

3. Check the location acceptability before beginning

CAUTION

the installation.
a. If possible mount the air conditioner in a section

of the roof which is both flat and level when the
caravan is parked on a level surface; otherwise,
a sideways pitch or forward pitch up to 8° can be
tolerated, but a backward pitch can never be
accepted. See FIG. 3.

FIG. 3

OK

Side

Good

Side

8° With A/C
Facing Forward

Type 3253.332 Installation and Operating Instructions

FIG. 5

24 cm

97 cm

73 cm

51
cm

56 cm

6.4 cm

b. Check on the roof to insure no obstructions are

in the area where the air conditioner will be
installed. See FIG. 4 & 5.

FIG. 4

18 cm

10.5 cm

35.5 x35.5 cm
OPENING

18 cm

KEEP THESE AREAS
FREE OF OBSTRUCTIONS

51 cm

10 cm

7.5 cm

Center Line
of Unit

35.5 x35.5 cm
OPENING

10 cm

54 cm

10 cm

REAR
OF
UNIT

30 cm

Air Box

PERIMETER

Center Line
of Unit

10 cm

c. Check inside the Caravan for air box obstruc-

tions (i.e. door openings, room dividers, cur­tains, ceiling fixtures, etc.) See FIG. 6.

Roof /Return Air Grill - Cross

Section

35.5 cm
Light

Prohibits Installation

FIG. 6

7.5 cm

56 cm

Cabinet - Prohibits Use

d. The roof must be designed to support 60 Kg.

when the Caravan is in motion. Normally a 90
Kg. static load design will meet this require-

ment. See FIG. 7.

It is the responsibility of the installer of this
air conditioner system to ensure structural in­tegrity of the Caravan 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 Caravan.

4

Type 3253.332 Installation and Operating Instructions

CAUTION

C. Roof Preparation

1. Opening Requirements - Before preparing the ceil­ing opening, read all of the following instructions
before beginning the installation.
If a roof vent opening will not be used a 35.5 cm x 35.5
cm opening must be cut through the roof and ceiling
of the RV. This opening must be located between the
roof reinforcing members.

WARNING

!

There may be electrical wiring between the
roof and the ceiling. Disconnect 220-240 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 35.5 cm x 35.5 cm opening is part of the return
air system of the Air Conditioner and must be fin­ished in accordance with national and local codes.

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. 6

Do Not Cut
Roof Structure
Or Rafters

2 cm Min.

Leave Access For Power
Supply Wiring

Good-Rafters
Supported By
Cross Beams

Frame Opening So It
Won't Collapse When
Bolting Down Unit

Good Location­Between Roof
Rafters

38 cm Min.
At Front of
opening

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

FIG. 5

d. If the opening exceeds 36.5 cm x 36.5 cm, it will

be necessary to re-size the opening to 35.5 cm
x 35.5 cm.

e. If the opening is less than 35.5 cm x 35.5 cm,

it must be enlarged.

3. New Opening- (Installation Other Than Vent Open­ing)
a. Mark a 35.5 cm x 35.5 cm 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 2 cm or more
in thickness must be used. Remember to pro­vide an entrance hole for power supplies at the

front of the opening. See FIG. 6.

D. Wiring Requirements

1. 220-240 VAC Supply Line
Route a copper 1.5 mm2, with ground, 220-240 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 35.5 cm x 35.5 cm opening.

b. The power MUST be on a separate 10 Amp time

delay fuse or 10 Amp circuit breaker.

c. Make sure that at least 38 cm of supply wire

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

d. Wiring must comply with all National 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.

5

Type 3253.332 Installation and Operating Instructions

E. Placing Air Conditioner On The Roof

This unit weighs approximately 45 Kg. To
prevent back injury, use a mechanical hoist to
place Air Conditioner on roof.

1. Remove the air conditioner from the carton and dis­card carton. See FIG. 7.

FIG. 7

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. 8.

CAUTION

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

FIG. 8

FRONT

F. Installing The Air Conditioner

1. Remove air box and mounting hardware from carton.
The upper duct is shipped inside the lower duct
which is part of the ceiling template.

2. Check for correct alignment and adjust the unit as
necessary (Roof Gasket centers over 35.5 cm
opening).

3. Remove upper duct from ceiling template and locate
it over blower discharge. See FIG. 9.

FIG. 9

Upper Discharge
Air Duct

Note: Edge without flange installs toward REAR of opening.

4. Use two (2) sharp pointed 1.0 cm long sheet metal
screws to hold duct to base pan. Screw holes are
provided in bottom of base pan for these screws.

5. Reach up into return air opening of the air conditioner
and pull the unit electrical cord down for later
connection.

6. Measure the ceiling to roof thickness:
a. If distance is 5.0 cm, remove perforated tabs

from both upper and lower ducts. See FIG. 10.

b. If distance is 5.0cm -7.5cm, remove perforated

tabs from bottom duct only. See FIG. 10.

c. If distance is 7.5 cm - 10.0 cm, install ducts as

received. See FIG. 10.

Rear Of Air
Conditioner

Edge Without
Flange To
Rear Of Unit

4. Place the Mechanical Air Distribution Box Kit inside
the Caravan. This box contains mounting hardware
for the air conditioner and will be used inside the
Caravan. See FIG. 7.

This completes the outside work. Minor adjustments can

be done from the inside of the Caravan if required.

FIG. 10

Step a
Remove At
Perforation

Step c
Use As
Packaged

6

Upper Discharge
Air Duct

Step b
Remove At
Perforation

Lower Discharge
Air Duct

Type 3253.332 Installation and Operating Instructions

WARNING

!

7. Install ceiling template by sliding lower duct over
upper duct. See FIG. 11.

FIG. 11

Air Conditioner
Return Air
Opening

Hold Ceiling Template With
One Hand And Install 3
Mounting Bolts Finger Tight

8. Hold the ceiling template with one hand and with the
other, install the three mounting bolts through the
template and into the base pan.

a. Finger-tighten the bolts and check alignment.

There should be an equal opening on each side
and the rear flange must be tight against the roof
opening.

b. EVENLY tighten the three bolts to a torque

of 4.5 to 5.0 NM. This will compress the roof
gasket to approximately 13 cm. The bolts
are self locking so over tightening is not
necessary.

Slide Lower Air
Discharge Duct
Over Upper Duct

Roof

Tighten
bolts to
compress
gasket to 13
mm

1. Y ou may either wire direct into the junction box for
a permanent connection or wire a molded plug into
the junction box for a plug in connection.
a. If a Permanent Connection: Route the power

supply line, previously installed to the roof open­ing, into the junction box on the ceiling tem­plate. Connect as described below.

b. If a Plug In Connection: Use the electric sup-

ply line, to power an electrical outlet installed,
according to applicable laws, at the end of the
roof opening farthermost from the junction box.

Shock Hazard: Do not plug the molded cord
in until you have completely installed the air
conditioner and are ready for an operational
check.

Note: If optional electric heater is part of this installation, now

is the time to install it. Installation instructions are provided
with the electric heater kit.

1. Route the molded plug set from the electric outlet
into the junction box insuring not to coil excess wire
so it will block air flow. Connect the plug set to the
terminal block as described below.

2. Connect the power supply line to the air conditioner
at the terminal block provided in the junction box.
Connect red to red; black to black; and green to
green or bare copper wire (P, P, and
fully). See Fig. 12.

FIG. 12

Route Power Supply
Through Romex Con­nector

, respect-

CAUTION

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

G. Wiring The System

WARNING

!

Disconnect 220-240 volt AC. Failure to follow
these instructions could create a shock hazard
causing death or severe personal injury .

Plug Conduit
Into Switch

Install
Cover

3. Tighten the strain relief onto the power supply line
to hold it firmly in place being careful not to pinch
the wires.

4. Carefully push all excess wire back into the junction
box and install cover onto the box with two blunt
pointed screws.

7

Box

Type 3253.332 Installation and Operating Instructions

H. Air Distribution Box Installation

1. Remove the two return air grills and filters.

2. Slide the front end of the air box over the shafts of
the thermostat and selector switch. See FIG. 13.

FIG. 13

Slide Air Box over Controls

3. Install four screws through legs in air box into the
pre-punched holes in the ceiling template.

4. Install the return air grills and filters by simply push­ing them into place.

5. Install the two knobs provided on the ends of the
thermostat and selector switch shafts.

6. The power supply to the air conditioner may now be
turned “ON”.

7. Your air conditioner is now installed and ready for
operation. Please read the following instructions be­fore attempting to run the unit.

OPERATING INSTRUCTIONS

A. Controls

1. The Selector Switch has eight positions including
"OFF". This controls fan speed, heating mode, and
cooling modes. See FIG. 14.

FIG. 14

2

Fan

3

1

2

3

Selector Switch

2. The thermostat controls the compressor ON/OFF
operation in cooling temperature range of 18° to
35°C. See FIG. 15.

FIG. 15

Thermostat

1

3

2

1

Heat Strip

Cool

Off

B. Cooling Operation

1. Set the thermostat at the desired temperature level.

2. Select the fan speed that best satisfies your needs:
a. HIGH COOL (3): Selected when maximum

cooling and dehumidification required.

b. MED COOL (2): Selected when normal or aver-

age cooling required.

c. LOW COOL (1): Selected when room at de-

sired comfort level and needs to be maintained.
Normally this speed used for night time opera-

tion.
Note: The blower runs continuously to circulate air and
maintain an even temperature. The compressor will come on
as cooling is required to maintain the selected temperature

level.

C. Fan Operation:

1. This will circulate the air in your Caravan without
cooling or heating. There are three positions: HIGH
FAN (3), MED FAN (2) or LOW FAN (1) to select
from, depending upon personal choice. See FIG. 14.

D. Heating Operation: (With Optional Heat Kit

Installed)

Note: This electric heater will not replace a furnace for

heating your Caravan in cold weather. The intent is to remove
the chill on cool days or mornings.

1. Turn the selector switch to "OPT HEAT". See FIG.
14

2. The Heater will come on and begin heating. There
are three positions: HIGH HEAT (3), MED HEAT (2)
or LOW HEAT (1) to select from, depending upon
personal choice. See FIG. 14.

3. When desired temperature level in Caravan is
reached, the thermostat will cycle the electric heat
strip on and off; the fan will continue to operate in the
speed selected.

4. Move the selector switch to "OFF" or "FAN" posi­tion to stop operation of the electric heat strip.

Note: If the electric heat strip is not installed, the fan will
operate in the same manner as in the FAN mode.

E. "OFF" Position

1. This is to turn Unit off.

G. Customer Maintenance

1. Periodically remove the return air filters located
above the removable panels in the air box. Wash the
filters with soap and warm water, let dry and then
reinstall.

Note: Never run the air conditioner without return air filter in
place. This may plug the unit evaporator coil with dirt and may
substantially affect the performance of the unit.

2. Clean air box housing and control panel with a soft
cloth dampened with a mild detergent. Never use
furniture polish or scouring powders.

3. The blower motor is factory lubricated and requires
no service under normal use.

Warmer

Cooler

8

Type 3253.332 Installation and Operating Instructions

4. Under certain conditions, frost may form on the
evaporator coil. If this should occur, inspect the filter
and clean if dirty. Make sure air louvers are not
obstructed. Air conditioners have a greater ten­dency to frost when the outside temperature is
relatively low. This may be prevented by adjusting
the thermostat control knob to a warmer setting
(counter clockwise). Should frosting continue, oper­ate on LOW, MED, or HIGH FAN only setting
until the cooling coil is free of frost.

5. If your unit fails to operate or operated improperly,
check the following before calling your service cen­ter.
a. If Caravan connected to motor generator, check

to be sure motor generator is running and
producing power.

b. If Caravan connected to power supply by a land

line, check to be sure line is sized properly to
run air conditioner load and it is plugged into
power supply.

c. Check your fuse or circuit breaker to see if it is

open.

d. After the above checks, call your local service

center for further help. This unit must serviced
by qualified service personnel only.

6. When calling for service, always give the following:
a. Air Conditioner Model and Serial Number found

on rating plate located on base pan of air
conditioner bottom.

b. Air Distribution Box Kit Part and Serial Number

found on rating plate located on ceiling tem­plate. Observe this rating plate through the air
box filter grill opening.

FIG. 16

Air Conditioner

Roof Opening

Mounting
Bolts

Air Box

Roof Mount Assembly

Rear

Upper
Discharge
Duct

Ceiling
Template

9

Type 3253.332 Installation and Operating Instructions

RUN CAP

SOME MODELS

NOT USED ON

6 PIN CONN

220/240 V~

RUN CAP

FIELD WIRING

220/240V 50 Hz 10
USE COPPER CONDUCTORS ONLY

ACTIVE(P)

NEUTRAL(P)

EARTH(

)

AIR CONDITIONER WIRING DIAGRAM

GRN/YEL

FAN

C

HERM

RUN CAP

BRN

WHT

RED

MOTOR

WHT

COMPRESSOR

WHT

COMP STARTER
START

PTCR

CAP

*

C

S

R

*

O.L.

BLU

BLK

YEL

RED

WHT

RED

GRN/YEL

PASSED

DIELECTRIC

6 PIN CONN

1

2

3

4

5

6

NOT USED ON

*

SOME MODELS

3308032.008

ROTARY

SW

L1

C

BLK

2

4

JUNCTION

BOX

OFF

H

T'STAT

BRN

BLU

3

RED

ACTIVE(P)

NEUTRAL(P)

1

2

ORN

4

YEL

1

2

RED

3
4
5

WHT

6
7

GRY

GRY

1
2
3

G-Y

EARTH( )

220/240V 50 Hz 10
USE COPPER CONDUCTORS ONLY

AIR BOX WIRING DIAGRAM

FAN
CAP

PTCR

BLK

YEL

G-YG-Y

LIMIT SWITCH

BLK

WHT

HEAT PACKAGE

MOTOR

RED

BLK

ELEMENT

BRN

BRN

WHT

WHT

YEL

START CAP

FACTORY WIRING
FIELD WIRING

YEL

YEL

WHT

RUN
CAP

BLU

ELECTRICAL

BOX

RED

COMP

R

O.L.

C

S

COMPRESSOR

R

C

S

PTCR

HEATER

MOTOR

C

H

LO

4

MED

2

HI

1

L1

ROTARY
SWITCH

220/240 V~

RUN CAP

START

50Hz

CAP

THERMOSTAT

FAN

CAP

3106599.008

4

3

2

10