Dometic 57912.531, 57915.336, 57908.521, 57915.331, 57912.532 Installation Instructions Manual

RECORD THIS INFORMATION FOR FUTURE
REFERENCE:

Model Number
Serial Number
ADB Model Number
ADB Serial Number
Date Purchased

Roof Top Unit Used With 3105007.XXX or 3105935.XXX Air Distribution Box

Description Model Electronic Control Kit Thermostat Optional Indoor

Air Conditioner

LCD SZ Controls 57908

59712
57915
59516

59530
520300
520310
520315
520316
600312
600315

3316155.000 Thermostat Included With
Electronic Control Kit

Temperature

Sensor

N/A

INSTALLATION

INSTRUCTIONS

REVISION C

Form No. 3316570.000 6/18
French (3316571.000_C)
©2018 Dometic Corporation
LaGrange, IN 46761

This Unit is designed for OEM installation.

Read these instructions carefully. These
instructions MUST stay with this product.

USA

SERVICE OFFICE
Dometic Corporation
1120 North Main Street
Elkhart, IN 46514

SERVICE CENTER &
DEALER LOCATIONS
Please Visit:

www.eDometic.com

INTRODUCTION

This air conditioner/heat pump (hereinafter referred to as “unit” or “product”) is designed and intended for installation on the
roof of a Recreational Vehicle (hereinafter referred to as RV) during the time it is manufactured.

Read these instructions and highlight the appropriate steps for your particular procedure before starting the installation.

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.

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

C. Table - Air Distribution Duct Sizing & Design .............................................................................................................5

INSTALLATION INSTRUCTIONS .......................................................................................................................................5

A. Choosing Proper Location For Unit ...........................................................................................................................5

B. Roof Preparation .......................................................................................................................................................6

C. Air Distribution Duct Sizing & Design ........................................................................................................................7

D. Wiring Requirements .................................................................................................................................................8

E. Choosing Thermostat Location ..................................................................................................................................8

F. Thermostat Installation .............................................................................................................................................9

G. Placing Unit On Roof ................................................................................................................................................. 9

H. Installation Preparation ............................................................................................................................................ 10

I. LCD SZ System Low Voltage Wire Connections .....................................................................................................12

J. Upgrading from Bi-Metal Thermostat to SZ LCD Thermostat .................................................................................12

K. Installing Return Air Cover .......................................................................................................................................13

GENERAL INFORMATION ................................................................................................................................................14

A. Frost Formation On Cooling Coil ............................................................................................................................. 14

B. Heat Gain ................................................................................................................................................................14

C. Condensation ..........................................................................................................................................................14

D. Air Distribution ......................................................................................................................................................... 14

WIRING DIAGRAMS ..........................................................................................................................................................15

A. Simple RV Wiring Diagram ......................................................................................................................................15

B. Unit Wiring Diagrams ............................................................................................................................................... 16

DOCUMENT SYMBOLS

Indicates additional information that is NOT related
to physical injury.

Indicates step-by-step instructions.

2

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 in­jury.

 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 be­fore [installing / using / servicing / performing
maintenance on] this product.

Incorrect [installation / operation / servicing /
maintaining] of this product can lead to seri­ous injury. Follow all instructions.

The installation MUST comply with all ap­plicable 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 warn­ings 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.

3

SPECIFICATIONS

A. Table - Unit Data

Model No. Nominal

57908.321 7,180 120 VAC

57908.521 7,100 6.6 34.0 2.5 5.8 17.0 20 Amp 2.5 kW / 4.0 kW

57912.531 11,000 8.0 53.0 2.5 5.8 18.5 20 Amp 2.5 kW / 4.0 kW

57912.532 11,000 12.1 59.0 2.5 5.8 16.5 20 Amp 3.5 kW / 5.0 kW

57915.331 13,500 11.4 58.0 2.5 5.8 15.5 20 Amp 3.5 kW / 5.0 kW

57915.336 13,500 12.1 59.0 2.5 5.8 16.5 20 Amp 3.5 kW / 5.0 kW

57915.531 13,500 12.1 59.0 2.5 5.8 16.5 20 Amp 3.5 kW / 5.0 kW

57915.536 13,500 12.1 59.0 2.5 5.8 16.5 20 Amp 3.5 kW / 5.0 kW

57915.541 13,500 11.3 62.0 2.5 5.8 16.0 20 Amp 3.5 kW / 5.0 kW

57915.546 13,500 11.3 62.0 2.5 5.8 16.0 20 Amp 3.5 kW / 5.0 kW

57915.741 13,500 12.0 58.0 2.5 5.8 15.5 20 Amp 3.5 kW / 5.0 kW

57915.746 13,500 12.0 58.0 2.5 5.8 15.5 20 Amp 3.5 kW / 5.0 kW

59516.331 15,000 11.5 50.0 2.5 5.8 29.0 20 Amp 3.5 kW / 5.0 kW

59516.336 15,000 12.7 60.0 2.0 5.6 29.0 20 Amp 3.5 kW / 5.0 kW

59516.531 15,000 11.5 50.0 2.5 5.8 26.5 20 Amp 3.5 kW / 5.0 kW

59516.536 15,000 11.5 50.0 2.5 5.8 29.0 20 Amp 3.5 kW / 5.0 kW

59516.731 15,000 13.3 62.0 2.0 5.6 29.0 20 Amp 3.5 kW / 5.0 kW

59530.532 N/A 8.0 53.0 2.5 5.8 18.5 15 Amp 3.5 kW / 5.0 kW

59530.536 N/A 7.8 53.0 2.0 5.6 19.0 15 Amp 3.5 kW / 5.0 kW

520310.501 9,000 7.8 49.0 3.0 8.5 20.0 20 Amp 2.5 kW / 4.0 kW

520315.501 13,500 10.3 62.0 3.0 8.5 16.5 20 Amp 3.5 kW / 5.0 kW

520315.506 13,500 10.3 62.0 3.0 8.5 16.5 20 Amp 3.5 kW / 5.0 kW

520316.501 15,000 13.2 79.0 2.8 7.6 30.0 20 Amp 3.5 kW / 5.0 kW

520316.506 15,000 13.2 79.0 2.8 7.6 30.0 20 Amp 3.5 kW / 5.0 kW

520300.501 N/A 7.8 49.0 3.0 8.5 20.0 15 Amp 2.5 kW / 4.0 kW

600312.331 11,000 9.5 53.0 3.5 10.0 17.0 20 Amp 2.5 kW / 4.0 kW

600315.331 13,500 12.4 60.0 3.5 10.0 15.2 20 Amp 3.5 kW / 5.0 kW

600315.336 13,500 12.4 60.0 3.5 10.0 15.2 20 Amp 3.5 kW / 5.0 kW

Capacity

(BTU HR)

Cooling

Electrical

Rating

60Hz. 1PH

Compressor

Rated Load

Amps

6.9 36.0 2.5 5.8 16.0 20 Amp 2.5 kW / 4.0 kW

Compressor

Locked

Rotor
Amps

Fan Motor

Rated Load

Amps

Fan Motor

Locked

Rotor
Amps

Refrigerant

R-410A

(Oz.)

Minimum

Wire Size*

AC Circuit
Protection

***Installer

Supplied

Minimum

Generator Size**

1 Unit / 2 Units

* 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 2 inches and maximum of 5-1/2 inches distance between roof to ceiling of RV.

4

SPECIFICATIONS

C. Table - Air Distribution Duct Sizing & Design

Air Distribution Duct Sizing & Design Chart

For Ducted Applications

Return Air Cover Model 3105007.XXX

Roof Cavity Depth 2 in - 2 1/2 in Max.

Duct Cross Section Area (inside) 21 in2 Min.

Duct Size
Depth
Width
Total Duct Length
Duct Length (short run)

Register Requirements per A/C Unit
Number Required
Free Air Area Per Register
Distance From Duct End
Distance From Elbow

Total System Static Air Pressure
Blower At High Speed, Filter &

Grill In Place

Note: Duct sizes listed are inside dimensions

3105935.XXX

1 1/2 in Min. - 2 1/2 in Max.
7 in Min. - 10 in Max.
15 ft Min. - 40 ft Max.
1/3 Min. Of Total Duct Length

4 Min. - 8 Max.
14 in2 Min.
5 in Min. - 8 in Max.
15 in

0.12 - 0.65 in W.C.

INSTALLATION INSTRUCTIONS

A. Choosing Proper Location For Unit

This unit is specically designed for installation on the roof

of an 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. For one unit installation: The unit should be
mounted slightly forward of center (front to back)
and centered from side to side.

2. For two unit installations: Install one unit 1/3 and
one unit 2/3’s from front of RV and centered 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

57908
57912
57915
59516
59530

520300

Max

Tilt

15° 520310

Model

Number

520315
520316

600312
600316

Max

Tilt

15°

8°

FIG. 1

a. Check for obstructions in the area where

unit will be installed. See (FIG. 1), (FIG. 2)
& (FIG. 3).

b.  Maintain structural integrity.

Otherwise damage to product and/or RV
could occur.

The roof must be designed to support 130
pounds when RV is in motion. Normally
a 200 lb. static load design will meet this
requirement.

13-1/8″

Dimensions Are Nominal

34-7/8″

18″

Center Line Of Unit

29-7/8″

Model
57908
57912
57915
57916
59530

Roof Opening

Front

3. After Location Has Been Selected:

Keep This Area Free Of Obstructions

5

INSTALLATION INSTRUCTIONS

FIG. 2

13″

18″

FIG. 3

Dimensions Are Nominal

39-5/8″

Roof Opening

Center Line Of Unit

Keep This Area Free Of Obstructions

Dimensions Are Nominal

29-7/8″

Front

Model
520300
520310
520315
520316

FIG. 4

3/4″

17″

1-1/4″

Dimensions Are Nominal

17″

1-1/2″

1-1/2″

17″

17″

Roof
Opening

1-3/4″

Model
600312
600315

9-1/2″

40″

29″

12″

Center Line Of Unit

4″

Keep These Areas
Free Of Obstructions

4″

Roof Opening

Front

c. Check inside the RV for return air grille (here-

inafter referred to as “RAG”) obstructions
(i.e. door openings, room dividers, curtains,

ceiling xtures, etc). See (FIG. 4).

B. Roof Preparation

1.  FIRE OR ELECTRICAL SHOCK

HAZARD. Make sure there are no obstacles

(wires, pipes, etc.) inside RV’s [roof / oor /

walls]. 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 preparing
the ceiling opening, the type of system op­tions MUST be decided upon. Read all of
the following instructions before beginning
the installation.

2. Carefully mark and cut the required roof opening.
See "B. Roof Requirements" on page (4).

3. Using the roof opening as a guide, cut the match­ing hole in the ceiling.

4.  Maintain structural integrity. Oth­erwise damage to product and/or RV could oc­cur.

 NEVER create a low spot on RV
roof. Otherwise, water will pool and could cause
a leak.

6

INSTALLATION INSTRUCTIONS

The opening created must be framed to provide
adequate support and prevent air from being
drawn from the roof cavity. Framing stock 407
mm or more in thickness must be used. Remem­ber to provide an entrance hole for power sup­plies, indoor temperature sensor (if applicable),
thermostat communication cable, and furnace
wires (if applicable) at the front of the opening.
See (FIG. 5).

FIG. 5

Do Not Cut Roof
Structure Or
Rafters

19 mm Min.

3/4″ Min.

Good-Rafters
Supported By
Cross Beams

Frame Opening So It
Won't Collapse When

Good Location
Between Roof
Rafters

Bolting Down Unit

Leave Access For
Power Supply Wiring

15" Min. At
Front Of
Opening

C. Air Distribution Duct Sizing & Design

The installer of this system must design the air distribution
system for their particular application. Several requirements
must be met for the unit to operate properly. These require­ments are as follows:

1.  Make sure ductwork will NOT

bend or collapse during and after installation,
and that it is correctly insulated and sealed.
Otherwise, damage to roof structure and ceiling
could occur.

2. All discharge air ducts must be properly insu­lated to prevent condensation from forming on
their surfaces or adjacent surfaces during op­eration of unit. This insulation must be R-7 mini­mum. See (FIG. 6).

FIG. 6

TOP VIEW

(BACK OF RV)

Frame

Frame

Low Voltage Wires:
12 Vdc
Furnace

Roof

(TOWARD BACK OF RV

Duct

Roof Opening

DuctDuct
AC Power
Supply Wire

Frame

Indoor Temperature
Sensor Cable

SIDE VIEW

Roof Opening

Ceiling

Control Wires

Duct

Insulation

3. Ducts and their joints must be sealed to prevent
condensation from forming on adjacent surfaces
during operation of the unit.

4. Return air openings must have 40 square inches

minimum free area including the lter.

5. Return air to the unit must be ltered to prevent
dirt accumulation on unit cooling surface.

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

conguration shown in (FIG. 7), for installing

this system. We have found by testing, that
this conguration works best in most applica­tions. It is the responsibility of the installer to

review each RV oor plan to determine the

following:

● Duct size

● Duct layout

● Register size

● Register location

● Thermostat location

● Indoor Temperature Sensor Location
These items must be determined in conjunc­tion with the Air Distribution Duct System
Sizing & Design requirements. See "C. Table

- Air Distribution Duct Sizing & Design" on
page (5).

Alternate congurations and methods

may be used which will allow the unit
to operate properly; however, these

alternate congurations and methods
MUST be approved by Dometic Cor-

poration in writing. The following in­structions are based upon the use of
RAG Kits 3105007.XXX & 3105935.

7

XXX.

INSTALLATION INSTRUCTIONS

FIG. 7

Duct Size And Requirements For 3105007.XXX And 3105935.XXX RAG

D. 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. Use a listed/certied

non metallic - sheathed single strand cable. See
"A. Table - Unit Data" on page (4).

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. See "A. Table - Unit Data" on page
(4).

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. Protect the wire where it passes into the

opening with approved method.

2. 12 volt DC supply comes from control box.

3. Thermostat Communication Cable
a. LCD SZ Thermostat

I. Route a 3 conductor communication ca-

ble, 18-22 AWG, from the roof opening
to the Liquid Crystal Display Single Zone
(hereinafter referred to a LCD SZ) ther­mostat mounting location. Make sure that
at least 15" of the wire extends into the
roof opening and 15" extends from the
wall at the thermostat mounting location.
See "E. Choosing Thermostat Location"
on page (8).

Register Required

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

4. If system includes a gas furnace, route two 18­22 AWG thermostat wires from the furnace to
the roof opening of the unit that will control it.
If more than one furnace is to be used, route
the second set of thermostat wires to the second
unit. Make sure that at least 15" of wire extends
into the opening.

If converting from Bi-Metal Thermostat to
Single Zone Thermostat, see "I. LCD SZ
System Low Voltage Wire Connections"
on page (12) for wiring details.

E. Choosing Thermostat Location

1. LCD SZ system
a. The proper location of the thermostat is very

important to ensure that it will provide a com­fortable RV temperature. Observe the follow­ing rules when selecting a location.

● Locate the thermostat 54" above the oor.

● Install the thermostat on a partition, not
on an outside wall.

● NEVER expose the thermostat to direct
heat from lamps, sun, or other heat pro­ducing items.

● Avoid locations close to doors that lead
outside, windows, or adjoining outside
walls.

● Avoid locations close to supply registers
and the air from them.

8

INSTALLATION INSTRUCTIONS

F. Thermostat Installation

1. LCD SZ System

Wire colors listed for the communication
cable (3 conductor cable) match the wire
colors in the unit wire harness and the wire
harness at the LCD SZ electronic control
box. Available wire colors may vary.

a. Remove the cover from the LCD SZ thermo-

stat. Depress tab on bottom of thermostat
and separate it from the base.

b. Insert the previously run communication ca-

ble (3 conductor cable) through the hole in
the base assembly.

c. Cut back the outer cable shield approxi-

mately 3 inches and strip 1/4″ insulation from

each wire.

d. Mount the thermostat level on the wall using

the screws provided.

e. Make the following connections to the ther-

mostat. See (FIG. 20).

FIG. 8

G. 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 open­ing using the gasket on the unit as a guide. See
(FIG. 9).

FIG. 9

Lift And Place

Front

12-

12+

COMMS

● Red/white wire to the 12V+ terminal

● Black wire to the 12V– terminal

● Orange wire to the "COMMS" terminal

f. Inspect all connections to make sure they

are tight and not touching any other termi­nals or wires.

g. Push the wires back through the base into

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

Do Not Slide

Models May Vary In Appearance

4. Place the electronic control box kit (if applicable)
and the ADB kit inside the RV. These boxes con­tain mounting hardware for the unit and will be
used inside the RV.

This completes the outside work. Minor
adjustments can be done from inside the
RV if required.

9

INSTALLATION INSTRUCTIONS

H. Installation Preparation

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. 10).

FIG. 10

2. Remove return air cover and ceiling template
from carton. See (FIG. 11).

Center Unit From Below

Roof Gasket

FIG. 12

Gasket

5. Hold the ceiling template up to the roof opening.
Make sure the large plate faces the rear of the
RV. See (FIG. 13).

a. Start each mounting bolt through the ceiling

Control
Wires

120 Vac

Electrical
Cord

template and up into the unit base pan by
hand. Install wood screw in each end of the

ceiling template. This ensures a tight t of

the return air cover to ceiling. See (FIG. 13).

Power Supply

FIG. 11

Ceiling
Template

3. All models listed in this manual will use a four (4)
bolt pattern for installing the RAG kit.

4. Reach up into the return air opening and pull the
unit electric cord down for later connection. See
(FIG. 12).

Divider Plate

Return Air
Cover

Return Air
Grille

FIG. 13

Screws

Front Of Vehicle

b.  Tighten mounting bolts to

correct torque specications. Overtighten­ing could damage unit’s base pan or ceiling
template. Not enough torque will allow an in­adequate roof seal, and could cause a leak.

Tighten all four (4) mounting bolts EVENLY
with in 40 to 50 inch pounds. (FIG. 13)

This will compress the roof gasket to

approximately 3/4″.

Roof
Gasket

Tighten To
Compress
Gasket To

3/4″

10

INSTALLATION INSTRUCTIONS

6. Installation Of Divider Plate
a. Measure the ceiling to roof thickness:

● If distance is 2.0″ - 3-3/4″, remove perfo-
rated tab from divider plate. See (FIG. 14).

● 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. 14).

FIG. 14

Paper Backing

2.00″ - 3.75″

d. With slight pressure push the divider plate

against the double-sided tape on the ceiling
template.

e. Locate the 1/8″ x 7″ x 18″ self-adhesive insu-

lation supplied with the RAG kit. Remove the
backing paper from the insulation and care­fully stick onto the ceiling template divider
plate. See (FIG. 16).

FIG. 16

Place Insulation In Position
(Do Not Cover Unit Rating Plate)

Divider Plate

Foam Tape

FIG. 15

c.  Divider plate MUST be in-

stalled correctly. Incorrect installation could
cause compressor to quick-cycle, and could
result in supply circuit overload and reduced
product performance.

The adhesive on the double-sided
tape is extremely sticky. Make sure
the divider plate is properly positioned
before pressing into place.

Place the divider plate up to bottom of the
unit base pan rmly. The foam tape on the di­vider plate must seal to bottom of base pan.
See (FIG. 15).

● Excess width is intended to seal the di-
vider plate to the sides of the roof open­ing. This is to help prevent cold air dis­charge from circulating into the unit return
air opening.

● If the insulation is too high, stick excess
height of the insulation to the unit base
pan. Do not cover up unit rating plate.

f. Place the electronic control box on the ceil-

ing template with the white 6 pin plug on the
curb side of the RV. Do NOT attach at this
time.

g. Plug the 6 pin connector into matching 6 pin

connector in the electronic control box. The
plug is polarized and will only t in one direc­tion. See (FIG. 18).

h. Plug the supplied freeze control sensor and

the 4 wire harness into their matching con­nectors in the electronic control box.

i. Insert the freeze control sensor into the

evaporator coil ns approximately 1" above
the bottom of the coil ns and on the left side.
See (FIG. 17). Bend ns over sensor to se-

cure in place.

Push Divider Plate Firmly
Onto Base Pan

11

INSTALLATION INSTRUCTIONS

FIG. 17

Freeze Control
Sensor

Remove
Hang Tag

Models May Vary
In Appearance

j. Attach electronic control box to the ceiling

template using the two (2) blunt self-tapping
screws provided in the electronic control box
kit. See (FIG. 18).

FIG. 18

Front

Route Up Through
Return Air Opening

Blunt Self­Tapping Screw

I. LCD SZ System Low Voltage Wire

Connections

1. All Heat Pump Electronic Control Kit Systems

a. Plug the outdoor temperature sensor from

the unit into the white 2 pin matching con­nector in the electronic control box.

2. All LCD SZ Systems
a. Connect the previously run furnace thermo-

stat wires (if applicable) to the blue wires
protruding from the roof opening or to the

1/4″ connectors at the electronic control box
using the supplied 1/4″ insulated connectors.

The polarity of this connection does not ma­ter.

FIG. 19

Connection

RV Wall

Splice

Blue

SZ LCD

or CTT

Thermostat

-12V Orange

Yellow

+12V Red

Control
Wires
(Connected
To T-Stat)

6 Pin Plug
From Unit

Low Voltage
Wiring From
Control Box

Electronic
Control Box

120VAC
Power
Supply
From RV

Freeze Sensor
Wire Harness

-12V

+12V

Furnace

AC Roof
Opening

Splice

Blue/White

-12V Black

3316300.000
Control Box

+12V Red

Green

J. Upgrading from Bi-Metal Thermostat to

SZ LCD Thermostat

1. Remove the existing thermostat from the wall.

2. Disconnect the four (4) wires coming from the air
conditioner (red, yellow, orange, blue).

3. Disconnect the two (2) wires coming from the
furnace (+12V, -12V).

 Keep the red wires from the air
conditioner and furnace separate, to avoid con­fusion when connecting the thermostat. Con­necting the wires incorrectly could result in prop­erty damage.

4. Refer to the wiring diagram (FIG. 19) and make
the connections as shown.

12

INSTALLATION INSTRUCTIONS

K. Installing Return Air Cover

1. Remove the return air grille from the return air

cover.

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

3. Install cover to template using six (6) supplied
#8 x 10 mm blunt point Phillips head screws.

4. Re-install lter return air grille into return air cov-
er. Align tabs with mating notches and snap into
place.

5. Install two (2) hole plugs into screw holes in
back of return air cover. See (FIG. 20).

FIG. 20

Return Air
Cover

Hole Plug

Return Air
Grille

13

GENERAL INFORMATION

A. Frost Formation On Cooling Coil

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 tem­peratures, the heat gain of the RV can 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. Avoid the use of heat producing appliances

Operation on High Fan/Cooling mode will give optimum

or maximum e󰀩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, acces­sories 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, depend­ing 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.

D. Air Distribution

Each A/C unit operating in cool mode, must have a mini­mum of 2 distribution vents, or the quick cool vent and one
vent open, to avoid the risk of freezing coils and improper

function.

14

WIRING DIAGRAMS

A. Simple RV Wiring Diagram

FIG. 21

(OPTIONAL)

15

579, 590, 595, 4579, 4590,600,640,520, 540

WIRING DIAGRAMS

B. Unit Wiring Diagrams

1. 57908, 57912, 57915, 59516, 59530, 520300, 520310, 520315, 520316, 600312 & 600315

2. LCD SZ Controls

3316453.000_A

A/C
CONNECTION

FURNACE
FURNACE

COMM TSTAT

12V - TSTAT

12V + TSTAT

1
2
3
4

GRN/YEL
56WHT
4

RED
3

N/C

BLK

2
1

BLU

BL/WT
BL/WT
GRN
BLK
RED

NO

J4

FAN HI

J3

FAN LO

COM

J2

FURNACE

J1

FURNACE

P1

314

115 VAC,

60 HZ, 1Φ

USE COPPER
CONDUCTORS
ONLY

FREEZE
SENSOR

21

P2

J5

2

FOR USE WITH AIR CONDITIONER:

FOR A/C WITHOUT HEAT STRIP OR

C

PART No. 3316300.000

SERIAL No.

HEAT PUMP OPTION

PASSED

DIELECTRIC

FIELD WIRING
FACTORY WIRING

R

154624

US

54-132704-A

16