Dometic 457915 Manual

USA
SERVICE OFFICE
Dometic Corporation
2320 Industrial Parkway
Elkhart, IN 46516
CANADA
Dometic Corporation
46 Zatonski, Unit 3
Brantford, ON N3T 5L8
CANADA
For Service Center
Or Dealer Locations
Please Visit:
www.eDometic.com
OR
www.RV.com
Read these instructions carefully. These
instructions MUST stay with this product.
MODEL
457915.70X 640312.80X
457915.71X 640312.83X
B57915.71X 640312C35X
459516.70X 640312C85X
459516.71X 640315.80X
B59516.71X 640315.83X
540315.70X 640315.84X
540315.71X 640315C35X
540316.70X 640315C85X
540316.71X
Form No. 3315079.000 1/13
(French 3315288.000)
©2013 Dometic Corporation
LaGrange, IN 46761
RECORD THIS INFORMATION FOR FUTURE
REFERENCE:
Model Number
Serial Number
ADB Model Number
ADB Serial Number
Date Purchased
Roof Top Unit
Description Model Use With Air Distribution Box
Model Control
Air Conditioner 457915
B57915
459516
B59516
540315
540316
640312
640315
3314851.000 Integral Mechanical
INSTALLATION & OPERATING
INSTRUCTIONS

2
TABLE OF CONTENTS
INTRODUCTION....................................................................................................................................................................2
DOCUMENT SYMBOLS ........................................................................................................................................................2
IMPORTANT SAFETY INSTRUCTIONS................................................................................................................................3
A. Recognize Safety Information ...................................................................................................................................3
B. Understand Signal Words..........................................................................................................................................3
C. Supplemental Directives............................................................................................................................................3
D. General Safety Messages .........................................................................................................................................3
SPECIFICATIONS..................................................................................................................................................................4
A. Table - Unit Data........................................................................................................................................................4
B. Roof Requirements....................................................................................................................................................4
INSTALLATION INSTRUCTIONS ..........................................................................................................................................5
A. Choosing Proper Location For Unit ...........................................................................................................................5
B. Roof Preparation .......................................................................................................................................................6
C. Wiring Requirements .................................................................................................................................................7
D. Placing Unit On Roof .................................................................................................................................................7
E. Installing Unit .............................................................................................................................................................8
F. Wiring System .........................................................................................................................................................10
G. Installing Air Distribution Box...................................................................................................................................10
OPERATING INSTRUCTIONS.............................................................................................................................................12
A. Controls ...................................................................................................................................................................12
B. "OFF" Position .........................................................................................................................................................12
C. Cooling Operation....................................................................................................................................................12
D. Heating Operation (With Electric Heater Option Installed). .....................................................................................12
E. Fan Operation..........................................................................................................................................................12
F. Center Air Discharge ...............................................................................................................................................12
MAINTENANCE ...................................................................................................................................................................13
A. Air Filter ...................................................................................................................................................................13
B. Air Distribution Box Housing....................................................................................................................................13
C. Fan Motor ................................................................................................................................................................13
GENERAL INFORMATION...................................................................................................................................................13
A. Frost Formation On Cooling Coil .............................................................................................................................13
B. Heat Gain ................................................................................................................................................................13
C. Condensation ..........................................................................................................................................................13
SERVICE - UNIT DOES NOT OPERATE ............................................................................................................................14
WIRING DIAGRAMS............................................................................................................................................................14
A. Unit Wiring Diagram ................................................................................................................................................14
B. Air Distribution Box Wiring Diagram ........................................................................................................................15
INTRODUCTION
This air conditioner (hereinafter referred to as “unit” or “product”) is design and intended for installation on the roof of a Rec-
reational Vehicle (RV) during or after the time it is manufactured.
This unit can be installed by one person with brief help from additional personnel. Use these instructions to ensure a properly
installed, and properly functioning product.
Dometic Corporation reserves the right to modify appearances and specications without notice.
DOCUMENT SYMBOLS
Indicates additional information that is NOT related
to physical injury. Indicates step-by-step instructions.

3
IMPORTANT SAFETY INSTRUCTIONS
This manual has safety information and instructions to help
users eliminate or reduce the risk of accidents and injuries.
A. Recognize Safety Information
This is the safety alert symbol. It is used to
alert you to potential physical injury hazards.
Obey all safety messages that follow this
symbol to avoid possible injury or death.
B. Understand Signal Words
A signal word will identify safety messages and
property damage messages, and will indicate the
degree or level of hazard seriousness.
 indicates a hazardous situation that,
if NOT avoided, could result in death or serious in-
jury.
 indicates a hazardous situation that,
if NOT avoided, could result in minor or moderate
injury.
 is used to address practices NOT
related to physical injury.
C. Supplemental Directives
Read and follow all safety information and
instructions to avoid possible injury or death.
Read and understand these instructions be-
fore [installing / using / servicing / performing
maintenance on] this product.
Incorrect [installation / operation / servicing /
maintaining] of this product can lead to seri-
ous injury. Follow all instructions.
The installation MUST comply with all ap-
plicable local or national codes, including
the latest edition of the following standards:
U.S.A.
●ANSI/NFPA70, National Electrical Code
(NEC)
●ANSI/NFPA 1192, Recreational Vehicles
Code
CANADA
●CSA C22.1, Parts l & ll, Canadian Electri-
cal Code
●CSA Z240 RV Series, Recreational
Vehicles
D. General Safety Messages
 Failure to obey the following warn-
ings could result in death or serious injury:
●This product MUST be [installed / serviced] by a
qualied service technician.
●Do NOT modify this product in any way. Modica-
tion can be extremely hazardous.
●Do NOT add any devices or accessories to this
product except those specically authorized in
writing by Dometic Corporation.

4
A. Table - Unit Data
Model No. Nominal
Capacity
(BTU HR)
Cooling
Electrical
Rating
120 Vac
60 Hz 1 ph
Compressor
Rated Load
Amps
Compressor
Locked
Rotor
Amps
Fan Motor
Rated Load
Amps
Fan Motor
Locked
Rotor
Amps
Refrigerant
R-410A
(oz)
Minimum
Wire Size*
12 AWG
Copper
Up to 24'
AC Circuit
Protection
***Installer
Supplied
Minimum
Generator
Size**
1 Unit / 2 Units
457915.70X 13,500 12.4 63.0 2.5 5.8 18.0 20 Amp 3.5 kW / 5.0 kW
457915.71X 13,500 12.4 68.0 2.5 5.8 18.0 20 Amp 3.5 kW / 5.0 kW
B57915.71X 13,500 12.4 68.0 2.5 5.8 18.0 20 Amp 3.5 kW / 5.0 kW
459516.70X 15,000 13.3 66.0 2.0 5.6 27.5 20 Amp 3.5 kW / 5.0 kW
459516.71X 15,000 13.3 70.0 2.0 5.6 27.5 20 Amp 3.5 kW / 5.0 kW
B59516.71X 15,000 13.3 70.0 2.0 5.6 27.5 20 Amp 3.5 kW / 5.0 kW
540315.70X 13,500 12.4 63.0 3.0 8.5 18.5 20 Amp 3.5 kW / 5.0 kW
540315.71X 13,500 12.4 68.0 3.0 8.5 18.5 20 Amp 3.5 kW / 5.0 kW
540316.70X 15,000 13.3 66.0 2.8 7.6 29.5 20 Amp 3.5 kW / 5.0 kW
540316.71X 15,000 13.3 70.0 2.8 7.6 29.5 20 Amp 3.5 kW / 5.0 kW
640312.80X 11,000 11.5 53.0 2.6 8.5 20.0 20 Amp 3.5 kW / 5.0 kW
640312.83X 11,000 12.5 63.0 2.6 8.5 18.0 20 Amp 3.5 kW / 5.0 kW
640312C35X 11,000 10.5 53.0 3.5 10.0 19.0 20 Amp 3.5 kW / 5.0 kW
640312C85X 11,000 11.5 53.0 2.6 8.5 20.0 20 Amp 3.5 kW / 5.0 kW
640315.80X 13,500 12.6 63.0 2.6 8.5 18.0 20 Amp 3.5 kW / 5.0 kW
640315.83X 13,500 12.5 63.0 2.6 8.5 19.0 20 Amp 3.5 kW / 5.0 kW
640315.84X 13,500 12.5 63.0 3.5 8.5 19.0 20 Amp 3.5 kW / 5.0 kW
640315C35X 13,500 12.5 61.0 3.5 10.0 17.5 20 Amp 3.5 kW / 5.0 kW
640315C85X 13,500 12.6 63.0 2.6 8.5 18.0 20 Amp 3.5 kW / 5.0 kW
* For wire length over 24 ft., consult the National Electrical Code for proper sizing.
** Dometic Corporation gives GENERAL guidelines for generator requirements. These guidelines come from experiences
people have had in actual applications. When sizing the generator, the total power usage of your RV must be considered.
Keep in mind generators lose power at high altitudes and from lack of maintenance.
*** CIRCUIT PROTECTION: Time Delay Fuse or Circuit Breaker Required.
B. Roof Requirements
● A 14-1/4″ x 14-1/4″ (±1/8″) square opening (hereinafter referred to as “roof opening”) is required for installing this
unit. This opening is part of the return air system of the unit and MUST be nished in accordance with NFPA 1192.
●Roof construction with rafters/joists support frames on a minimum of 16 inch centers.
●Minimum of 1.5 inches and maximum of 6 inches distance between roof to ceiling of RV.
SPECIFICATIONS

5
INSTALLATION INSTRUCTIONS
A. Choosing Proper Location For Unit
This unit is specically 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 locations-The unit is designed to t over
an existing roof vent opening.
2. Other locations-When no roof vent is available
or another location is desired, the following is
recommended:
a. For one unit installation: The unit should be
mounted slightly forward of center (front to
back) and centered from side to side.
b. For two unit installations: Install one unit 1/3
and one unit 2/3’s from front of RV and cen-
tered from side to side.
It is preferred that the unit be installed on a relatively at
and level roof section measured with the RV parked on a
level surface. See table below for maximum acceptable tilt.
Model
Number
Max
Tilt
457915
B57915
459516
B59516
540315
540316
15°
640312
640315
8°
After Location Has Been Selected:
c. Check for obstructions in the area where
unit will be installed. See (FIG. 1), (FIG. 2),
(FIG. 3) & (FIG. 4).
29-7/8″
34-7/8″
13-1/8″
18″
Front
Dimensions Are Nominal
FIG. 1
Keep This Area Free Of Obstructions
Roof Opening
Center Line Of Unit
Model
457915
459516
FIG. 2 Dimensions Are Nominal
9-1/2″
29″
40″
Keep These Areas
Free Of Obstructions
Roof
Opening
Front
Center Line Of Unit
4″
4″
12″
Model
640312
640315

6
FIG. 3 Dimensions Are Nominal
Roof Opening
Keep This Area Free Of Obstructions
Center Line Of Unit
Front
18″
12-7/8″
29-5/8″
27-5/8″
Model
B57915
B59516
FIG. 4 Dimensions Are Nominal
Keep This Area Free Of Obstructions
Front
Center Line Of Unit
Roof Opening
18″
13″
39-5/8″ 29-7/8″
Model
540315
540316
d.  Maintain structural integrity.
Otherwise damage to product and/or RV
could occur.
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.
e. Check inside the RV for air distribution box
obstructions (i.e. door openings, room di-
viders, curtains, ceiling xtures, etc.). See
(FIG. 5).
FIG. 5
23-1/8″
21-1/8″
2-5/8″
Dimensions Are Nominal
11-9/16″ 11-9/16″
21-1/8″
3-7/16″
3-7/16″
2-7/8″
6″
Roof Opening
B. Roof Preparation
1.  FIRE OR ELECTRICAL SHOCK
HAZARD. Verify there are no obstacles inside
RV’s roof and/or walls (wires, pipes, etc.). Shut
OFF gas supply, disconnect 120 Vac power from
RV and disconnect positive (+) 12 Vdc terminal
from supply battery BEFORE drilling or cutting
into RV. Failure to obey these warnings could
result in death or serious injury.
Opening Requirements - Before prepar-
ing the ceiling opening, read all of the fol-
lowing instructions before beginning the
installation.
If an existing roof vent opening will NOT
be used a roof opening MUST be cut
through the roof and ceiling of the RV.
This opening MUST be located between
the roof reinforcing members.
2. Roof vent removal
a. Unscrew and remove the roof vent.
b. Remove all caulking compound around
opening.
c. Seal all screw holes and seams where the
roof gasket will be located. Use a good grade
of all weather sealant.
INSTALLATION INSTRUCTIONS

7
C. Wiring Requirements
1. Route a copper, with ground, 120 Vac supply
wire from the time delay fuse or circuit breaker
box to the roof opening. The proper size wire
can be determined from chart on page 4.
If vent fan was removed, the existing wire
may be used provided it is of proper size,
location, and correctly fused.
a. This supply wire must be located in the front
portion of the roof opening.
b. The power MUST be on an appropriately
sized separate time delay fuse or circuit
breaker. The proper size protection can be
determined from chart on page 4.
c. Make sure that at least 15″ of supply wire
extends into the roof opening. This insures
an easy connection at the junction box.
d. Protect the wire where it passed into the
opening with approved method.
D. Placing Unit On Roof
1. Remove the unit from the carton and discard
carton.
2.  LIFTING HAZARD. Use proper
lifting technique and control when lifting product.
Failure to obey this caution could result in injury.
Place Unit on the roof.
3.  Do NOT slide unit. Otherwise,
damage to gasket (on bottom of unit) may occur,
and could cause a leak.
Lift and place the unit over the prepared open-
ing using the gasket on the unit as a guide. See
(FIG. 7).
FIG. 7
Do Not Slide
Lift And Place
Front
4. Place the air distribution box kit inside the RV.
This box contains mounting hardware for the
unit and will be used inside the RV.
d. If the opening exceeds 14-3/8″ x 14-3/8″, it
will be necessary to re-size the opening. See
"B. Roof Requirements" on page (4).
e. If the opening is less than 14-1/8″ x 14-1/8″,
it must be enlarged. See "B. Roof Require-
ments" on page (4).
3. New opening
a. Carefully mark and cut the required roof
opening. See "B. Roof Requirements" on
page (4).
b. Using the roof opening as a guide, cut the
matching hole in the ceiling.
c.  Maintain structural integrity.
Otherwise damage to product and/or RV
could occur.
d.  NEVER create a low spot on
RV roof. Otherwise, water will pool and could
cause a leak.
e. The opening created must be framed to pro-
vide adequate support and prevent air from
being drawn from the roof cavity. Framing
stock 3/4″ 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).
3/4″ Min.
Leave Access For
Power Supply Wiring
FIG. 6
15″ Min. At
Front Of
Opening
Do Not Cut Roof
Structure Or
Rafters
Good-Rafters
Supported By
Cross Beams
Good Location
Between Roof
Rafters
Frame Opening So It
Won't Collapse When
Bolting Down Unit
INSTALLATION INSTRUCTIONS

8
INSTALLATION INSTRUCTIONS
This completes the outside work. Minor
adjustments can be done from inside the
RV if required.
E. Installing Unit
1. Check gasket alignment of the unit over the
roof opening and adjust if necessary. Unit may
be moved from below by slightly lifting. See
(FIG. 8).
FIG. 8 Center Unit From Below
Roof Gasket
2. Remove air distribution box and mounting hard-
ware from carton. See (FIG. 9).
FIG. 9
Duct Divider Ceiling
Template
Air Distribution
Box
Control
Box
3. All models in this manual will use a four (4) bolt
pattern for installing the air distribution box kit.
4. Reach up into the return air opening of the unit
and pull the unit electrical cord down for later
connection. See (FIG. 10).
FIG. 10
Electrical
Cord
Measure Ceiling
Thickness
5. Duct Divider Installation
a. Measure the ceiling thickness. See (FIG. 10).
b. Cut away the number of rows as indicated in
table below. See (FIG. 11).
Ceiling
Thickness
# Of
Rows
To Cut
Ceiling
Thickness
# Of
Rows
To Cut
Min. Max. Min Max.
6.0 6.5 0 3.5 4.0 5
5.5 6.0 1 3.0 3.5 6
5.0 5.5 2 2.5 3.0 7
4.5 5.0 3 2.0 2.5 8
4.0 4.5 4 1.5 2.0 9
FIG. 11
Remove Rows
Starting Here
c. Carefully install the duct divider in the roof
opening 5-5/8″ from back of roof opening.
See (FIG. 12).
Foil back faces rear of unit.
FIG. 12
Rear
Base Pan
5-5/8″From Back
Of Roof Opening
Duct Divider Front
Black Side
To Front

9
6. Ceiling Template Installation
a. Plug the 6 pin electrical cord from the top unit
into the matching 6 pin connector in the elec-
tronic control box. The plug is polarized and
will only t in one direction. See (FIG. 13).
FIG. 13
Unit Electrical
Cord
120 Vac
Power Supply
Plastic
Strain Relief
b. Route the previously run 120 Vac power sup-
ply wire through the junction box hole cutout.
See (FIG. 13).
c. Secure 120 Vac power supply using the sup-
plied strain relief. Install strain relief in junc-
tion box hole leaving enough wire inside
junction box to connect unit wires to power
supply wires. See (FIG. 13).
d. Hold the ceiling template up to the roof open-
ing and line up the channel in the ceiling
template with the previously installed duct
divider. See (FIG. 14).
FIG. 14
Duct Divider
Channel
e. Hold the ceiling template up to the roof open-
ing and start each mounting bolt, by hand,
through the ceiling template and up into the
unit base pan. See (FIG. 15) & (FIG. 16).
FIG. 15
Mounting Bolt
Mounting Bolt
Mounting Bolt Pattern Table (See Fig. 15)
Model Bolt Location
457915 A, D, E & H
B57915 A, D, E & H
459516 A, D, E & H
B59516 A, D, E & H
540315 B, C, F & G
540316 B, C, F & G
640312 B, C, F & G
640315 B, C, F & G
FIG. 16 A
HG
FE
D
C
B
f.  Tighten mounting bolts to
correct torque specications. Overtighten-
ing could damage unit’s base pan or ceiling
template. Not enough torque will allow an in-
adequate roof seal, and could cause a leak.
g. Tighten all four (4) mounting bolts EVENLY
with in 40 to 50 inch pounds. See (FIG. 15).
INSTALLATION INSTRUCTIONS

10
FIG. 18
Air Distribution Box
Line Up Tabs
Ceiling Template
Alignment
FIG. 19 Ceiling
Template
ADB
Alignment
Tab
ADB
Alignment
Tab
INSTALLATION INSTRUCTIONS
F. Wiring System
1. 120 Vac Power Supply Connection
a.  ELECTRICAL SHOCK HAZ-
ARD. Verify 120 Vac power is disconnected
from RV. Failure to obey this warning could
result in death or serious injury.
b.  ELECTRICAL SHOCK HAZ-
ARD. Provide grounding in compliance with
all applicable electrical codes. Failure to
obey this warning could result in death or se-
rious injury.
c. Secure previously run 120 Vac power sup-
ply wire using the supplied strain relief. In-
stall strain relief in junction box hole leaving
enough wire inside junction box to connect
unit wires to power supply wires.
d. Connect white to white; black to black; using
appropriate size connectors. Secure bare
copper wire under grounding screw in junc-
tion box. See (FIG. 17).
FIG. 17
Junction
Box Cover
Junction Box
Cover Screw
e. Tape the connectors to the supply wire to as-
sure they don't vibrate loose.
f. Push the wires into the junction box and in-
stall junction box cover. See (FIG. 17).
G. Installing Air Distribution Box
1. Align air distribution box with ceiling template.
See (FIG. 18) & (FIG. 19).
Front and rear vent doors are supplied
loose. Do NOT install them until all screws
are installed in step 2.

11
2. Install two (2) (supplied) sheet metal screws in-
side return air opening to secure air distribution
box to ceiling template. See (FIG. 20).
3. Install eight (8) (supplied) wood screws inside
the front, rear and side doors to secure air distri-
bution box to ceiling. See (FIG. 20).
FIG. 20 2 Sheet
Metal Screws
8 Wood Screws
4. Install front and rear doors.
5. Place lter in return air grille. It may already be
installed on some units. See (FIG. 21).
FIG. 21
Filter
Return Air
Vent Grille
6. Install return air vent grille into the air distribution
box. Slide return air grille tab into slot in ADB
and rotate up and snap in place. See (FIG. 22).
Installation
FIG. 22
Slot In ADB
Return
Air Grille
7. Install the control knobs into the air distribution
box. See (FIG. 23).
FIG. 23
Knob
8. The unit installation is now complete and is
ready for operation. The power supply to the unit
may now be turned on.
9. Verify that all features of the installed system
work. Please read the following operating in-
structions before attemping to run the unit.
INSTALLATION INSTRUCTIONS

12
D. Heating Operation (With Electric Heater
Option Installed).
The heat mode of operation will NOT replace
a furnace for heating your RV in cold weath-
er. The intent is to remove the chill on cool
days or mornings.
1. Turn the selector switch to "OPT HEAT".
2. The heat strip will come on and begin heating.
3. When desired temperature level in RV is
reached, move the selector switch to "OFF" po-
sition or "FAN" position.
Thermostat does NOT control the fan/heater
ON/OFF cycle.
E. Fan Operation
1. This will circulate the air in your RV without cool-
ing or hating. There are three positions: HIGH
FAN, MED. FAN or LOW FAN to select from de-
pending upon personal choice.
F. Center Air Discharge
1. Slide lever to open and close.
FIG. 25
Slide To Open
Or Close
OPERATING INSTRUCTIONS
A. Controls
1. The Selector Switch has (8) positions including
"OFF". This controls fan speed, optional heating
mode, and cooling modes. See (FIG. 24).
FIG. 24
Colder
Black
Graphic Fan
Blue Graphic
Cooling
2. The Thermostat controls the temperature range
at the lter between approximately 65° F and
90° F.
B. "OFF" Position
1. This is to turn unit off.
C. Cooling Operation
1. Set the thermostat at the desired temperture
level.
2. Select the fan speed that best satisies your
needs:
a. HIGH COOL: Selected when maximun cool-
ing and dehumidication required.
b. MED. COOL: Selected when normal or aver-
age cooling required.
c. LOW COOL: Selected when room is at de-
sired comfort level and needs to be main-
tained. Normally this speed used for night
time operation.
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 tem-
perature level.
 Wait at least 2 minutes before
restarting the compressor when it has been
manually cycled off with either the selector
switch or the temperature set lever. Other-
wise, compressor will quick-cycle and could
result in compressor or supply circuit over-
load.

13
Operation on High Fan/Cooling mode will give optimum
or maximum efciency 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, acces-
sories like Dometic 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.
C. Condensation
The manufacturer of this unit will not be responsible for
damage caused by condensation forming on ceilings,
windows, or other surfaces. Air contains water vapor which
condenses when temperature of a surface is below Dew
point. During normal operation this unit is designed to
remove a certain amount of moisture from the air, depend-
ing on the size of the space being conditioned. Keeping
doors and windows closed when this air conditioner is in
operation will greatly reduce the chance of condensation
forming on interior surfaces.
A. Air Filter
1. Periodically (a minimum of every 2 weeks of op-
eration) remove the return air lter located behind
the return air grille and wash it with soap and
warm water, let dry and then reinstall.
NEVER run unit without return air lter in
place. This will plug the unit evaporator coil
with dirt and may substantially degrade the
performance of the unit over time.
B. Air Distribution Box Housing
1. Clean air distribution box housing and control
panel with a soft cloth dampened with a mild de-
tergent. Never use furniture polish or scouring
powders.
C. Fan Motor
1. The blower motor is factory lubricated and re-
quires no service.
A. Frost Formation On Cooling Coil
1. Frost on a small portion of the coil is not un-
usual. Under certain conditions, ice may form
on the evaporator coil. This is indicated by very
cold output at very low air speed and the icing
can be seen through the air inlet hole with the
lter removed. If this should occur, inspect the
lter and clean if dirty. Make sure air vents are
open and not obstructed. Units have a greater
tendency to frost when the outside temperature
is relatively low. This may be prevented by ad-
justing the thermostat control knob to a warmer
setting (counter clockwise). Should frosting con-
tinue, operate on any FAN ONLY setting until
the cooling coil is free of frost; then resume nor-
mal operation. If frost condition persist, contact
your local service center for assistance.
B. Heat Gain
The ability of this 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 tem-
peratures, 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
MAINTENANCE
GENERAL INFORMATION

14
SERVICE - UNIT DOES NOT OPERATE
A. Unit Wiring Diagram
1. 457915, 459516 B57915 & B59516
If your unit fails to operate or operates improperly, check
the following before calling your service center.
●If RV connected to motor generator, check to
be sure motor generator is running and produc-
ing power.
●If RV connected to power supply by a land line,
check to be sure line is sized properly to run
unit load and it is plugged into power suppy.
●Check your fuse or circuit breaker to see if is is
open. Insure fuse is not burnt, or circuit breaker
is "ON" and not activated.
●After the above checks, call your local service
center for further help. This unit must be ser-
viced by qualied service personnel only.
When calling for service, always give the following:
●Unit model and serial number found on the
identication label located on base pan of unit
bottom. Return air grille must be removed from
air distribution box to view.
●Air distribution box model and serial number
found on rating plated located on ceiling tem-
plate. Observe this rating plate through the lter
opening.
WIRING DIAGRAMS
2. 540315 & 540316

15
3. 640312, 640312C, 640315 & 640315C
B. Air Distribution Box Wiring Diagram
(/(&+($7
+
&
/
7+(50267$7

:+7
%/.
21/<
&21'8&7256
86(&233(5
+=3+
9$&
),(/':,5,1*
)$&725<:,5,1*
/,1(63/,&(
6:,7&+
527$5<
:+7
:+7
*5<
5('
<(/
%/.
*51<(/
%/8
%/8
&
+
/



72237,21$/









(/(&&211
)520$&
WIRING DIAGRAMS