DOMETIC 457915 BTU Air Conditioner Installation Guide

DOMETIC 457915 BTU Air Conditioner

INTRODUCTION

This air conditioner (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 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 specifications without notice.

IMPORTANT SAFETY INSTRUCTIONS

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

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.

Understand Signal Words
A signal word will identify safety messages and property damage messages and will indicate the degree or level of hazard seriousness.

WARNING indicates a hazardous situation that, If not avoided, could result in death or serious injury.
CAUTION indicates a hazardous situation that, if NOT avoided, could result in minor or moderate injury.
NOTICE is used to address practices NOT related to physical injury.

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/maintenance] of this product can lead to serious injury. Follow all instructions. The installation MUST comply with all ap- applicable local and 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 | & Il, Canadian Electrical Code
• CSA Z240 RV Series, Recreational Vehicles

General Safety Messages

• WARNING Failure to obey the following warning-ings could result in death or serious injury:
• This product MUST be [installed/serviced] by a qualified service technician.
• Do NOT modify this product in any way. Modification can be extremely hazardous.
• Do NOT add any devices or accessories to this product except those specifically authorized in writing by Dometic Corporation.

SPECIFICATIONS

Table – Unit Data

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.

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 finished by NFPA 1192.
• Roof construction with rafters/joists support frames on a minimum of 16-inch centres.
• Minimum of 1.5 inches and maximum of 6 inches distance between roof to ceiling of RV.

INSTALLATION INSTRUCTIONS

Choosing Proper Location For Unit
This unit is specifically 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.

Normal The unit is designed to fit over an existing roof vent opening. In other locations where no roof vent is available or another location is desired, the following is recommended:

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

• For two-unit installations: Install one unit 1/3 and one unit 2/3 from the front of the RV and turn from side to side.

• It is preferred that the unit be installed on a relatively flat and level roof section measured with the RV parked on a level surface. See the table for the maximum acceptable tilt.

• After the Location Has Been Selected:

• Check for obstructions in the area where it will be installed. See (FIG. 1), (FIG. 2),(FIG. 3), (FIG. 4), (FIG. 5) & (FIG. 6).
  NOTICE
  Maintain structural integrity.

• Otherwise, damage to the 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.

• Check inside the RV for air distribution box (hereinafter referred to as “ADB”) obstructions (i.e. door openings, room dividers, curtains, ceiling fixtures, etc.). See (FIG. 7).

Roof Preparation
WARNING FIRE OR ELECTRICAL SHOCK HAZARD. Make sure there are no obstacles (wires, pipes, etc.) inside RVs [roof/floor/walls]. Shut OFF the gas supply, disconnect 120 Vac power from the RV, and disconnect positive (+) 12 Vdc terminal from the supply battery BEFORE drilling or cutting into the RV. Failure to obey these warnings could result in death or serious injury. Opening Requirements – Before preparing the ceiling opening, read all of the following 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.

Roof vent removal

• Unscrew and remove the roof vent.
• Remove all caulking compounds around the opening.
• Seal all screw holes and seams where the roof gasket will be located. Use a good grade of all-weather sealant.
• If the opening exceeds 14-3/8″ x 14-3/8″, it will be necessary to resize the opening. See “B. Roof Requirements” on page (4).
• If the opening is less than 14-1/8″ X 14-1/8″, it must be enlarged. See “B. Roof Requirements” on the page (4).

New opening

• Carefully mark and cut the required roof opening. See “B. Roof Requirements” on page (4).
• NOTICE Maintain structural integrity. Otherwise, damage to the product and/or RV could occur.
• NOTICE NEVER create a low spot on the RV roof. Otherwise, water will pool and could cause a leak.
• Using the roof opening as a guide, cut the matching hole in the ceiling.
• The opening created must be framed to provide 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. 8).

Wiring Requirements
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/certified non-metallic- sheathed single-strand cable. See “A. Table – Unit Data” on page (4). If the vent fan was removed, the existing wire may be used provided it is of proper type, size, location, and correctly fused.

• This supply wire must be located in the front portion of the roof opening.
• The power MUST be on an appropriately sized separate time delay fuse or circuit breaker.
• See “A. Table – Unit Data” on page (4).
• Make sure that at least 15″ of supply wire extends into the roof opening. This ensures an easy connection at the junction box.
• Protect the wire where it passes into the opening with the approved method.
• Placing Unit On Roof Remove the unit from the carton and discard the carton.

LA CAUTION LIFTING HAZARD.
Use proper lifting technique and control when lifting products. Failure to obey this caution could result in injury. Place the unit on the roof.

NOTICE Do NOT slide the unit. Otherwise,
damage to the gasket (on the bottom of the 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. 9).

• Place the ADB kit inside the RV. This box contains 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.

Installation Preparation

1. Check the gasket alignment of the unit over the roof opening and adjust it if necessary. The unit may be moved from below by slightly lifting. See (FIG. 10).
2. Remove ADB and mounting hardware from the car-ton. See (FIG. 11).

Duct Divider Installation

1. Measure the ceiling thickness. See (FIG. 12).
2.  Cut away the number of rows as indicated in the table below. See (FIG. 13).
3. Carefully install the duct divider in the roof opening 5-5/8″ from the back of the roof opening. See (FIG. 14).
4. The foil back faces the rear of the unit.

Installing Unit

1. Ceiling Template Installation
   • Plug the 6-pin electrical cord from the top unit into the matching 6-pin connector in the electronic control box. The plug is polarized and will only fit in one direction. See (FIG. 15).
2. Install the supplied non-metallic cable connector in the junction box hole cutout. See (FIG. 15) for proper orientation.
   • Route the previously run 120 Vac power supply wire through the cable connector and into the junction box.
3. Secure the 120 Vac power supply by tightening the cable connector clamp making sure not to damage wires. See (FIG. 15).
   • Hold the ceiling template up to the roof opening and line up the channel in the ceiling template with the previously installed duct divider. See (FIG. 16).
4. Hold the ceiling template up to the roof opening and start each mounting bolt, by hand, through the ceiling template and up into the unit base pan. See (FIG. 17) & (FIG. 18).

NOTICE
Tighten mounting bolts to correct torque specifications. Overtighten- ing could damage the nit’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 within 40 to 50 inch pounds. See (FIG. 18).

120 Vac Power Supply Connection
WARNING ELECTRICAL SHOCK HAZARD. Make sure 120 Vac power is disconnected from the RV. Failure to obey this warning could result in death or serious injury.

WARNING ELECTRICAL SHOCK HAZARD
Provide grounding in compliance with all applicable electrical codes. Failure to obey this warn- ing could result in death or serious injury. Connect white to white; and black to black; using appropriate size connectors. Secure bare copper wire under the grounding screw in the junction box. See 1014. Tape the connectors to the supply wire to ensure they don’t vibrate loose.  Push the wires into the junction box and install the junction box cover. See (FIG. 19).

Installing ADB
$1. Align ADB with ceiling template. See (FIG. 20) & (FIG. 21).

1. Front and rear vent doors are supplied loose. Do NOT install them until all screws are installed in step 2.
2. Install two (2) (supplied) sheet metal screws in the side return air opening to secure ADB to ceiling template. See (FIG. 22).
3. Install eight (8) (supplied) wood screws inside the front, rear and side doors to secure ADB to the ceiling. See (FIG. 22).
4. Install front and rear doors.
5. Place filter in return air vent grille. It may already be installed on some units See (FIG 23)Install the return air vent grille into the ADB.
6. Slide the air vent grille tab into the slot in ADB rotate up and snap in place. See (FIG. 24).7. Install the control knobs into the ADB. See (FIG. 25).8.
7. The unit installation is now complete and is ready for operation.
8. 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 structions before attempting to run the unit.

Controls

1.  The Selector Switch has (8) positions including “OFF”. This controls fan speeds, cooling modes and optional heating modes of operation. See (FIG. 26).
2. The thermostat controls the compressor On/ OFF operation within a temperature range of approximately 65° F and 90° F measured at the ADB inlet.

“OFF” Position (0)

1. This is to turn the unit off.
2. Cooling Operation (Blue Graphic)
3. Turn the selector switch to cooling (blue graphic).
4. Set the thermostat at the desired temperature level.
5. Select the fan speed that best satisfies your needs:
   • HIGH COOL: Selected when maximum cooling and dehumidification are required.
   • MEDIUM COOL: Selected when normal cooling is required.
   • LOW COOL: Selected when the room is at a de- sired comfort level and needs to be maintained. Normally this speed is used for nighttime operations.

The compressor will cycle on and off as cooling is required to maintain the select- ed temperature level. The fan runs when the compressor is off to help keep the temperature uniform throughout the RV.
NOTICE Wait at least 2 minutes before re-starting the compressor when it has been manually cycled off with either the selector switch or the temperature set lever. Otherwise, the compressor will quick-cycle and could result in compressor or sup- old circuit overload.

Heating Operation (With Electric Heater Option Installed). The heat mode of operation will NOT replace the furnace for heating your RV in cold weather- 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 the desired temperature level in RV is reached, move the selector switch to the “OFF” position or “FAN” position.
4. The thermostat does NOT control the fan/heater © ON/OFF cycle.

Fan Operation (Black Graphic)
This will circulate the air in your RV without cooling or heating.

1. Turn the selector switch to the fan (black graphic).
2. There are three positions to select from (high, medium and low). See (FIG. 26).

Center Air Discharge
Slide lever to open and close. See (FIG. 27).

MAINTENANCE

Air Filter
Periodically (a minimum of every 2 weeks of op-eration) remove the return air filter located behind the return air vent gile and wash it with soap and warm water, let dry and then reinstall. NEVER run the unit without a retur air filter in place. This will plug the unit evaporator and degrade the performance of the unit over

ADB Housing
Clean the ADB housing and control panel with a soft cloth dampened with a mild detergent, Never use furniture polish or scouring powders.

Fan Motor
The blower motor is factory-lubricated and requires no service.

GENERAL INFORMATION

Frost Formation On Cooling Coil
Frost on a small portion of the coil is not unusual. Under certain conditions, ice may form on the evaporator coil. This is indicated by very cold output at very low air speed and ule king can be seen trojan the at init hole with the hitter removed. If this should occur, inspect the filter and clean it 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 adjusting the thermostat control knob to a warmer setting (counterclockwise). Should frosting continue, operate on any FAN ONLY setting until the cooling coil is free of frost; then resume normal operation. If frost conditions persist, contact your Iccal service centre for assistance.

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 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
5. Operation on High Fan/Cooling mode will give optimum or maximum efficiency in high humidity or high outside temperatures,
6. 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.
7. For a more permanent solution to high heat gain, accessories like Dometic outdoor patios 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.

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 vapour which\ condenses when the temperature of a surtace is below the Denyi 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.

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.

SERVICE – UNIT DOES NOT OPERATE
If your unit fails to operate or operates improperly, check the following before calling your service centre.

• If the RV is connected to the motor generator, check to be sure the motor generator is running and producing power.
• If the RVis connected tothe  power supply by a landline, check to be surethe line is sized properly to run the unit load and that it is plugged intothe  power supply.
• Check your fuse or circuit breaker to see if it is open. Ensure the fuse is not burnt, or the circuit breaker is “ON” and not activated.
• After the above checks, call your local service centre for further help. This unit must be serviced by qualified service personnel only. When calling for service, always give the following:
• The unit model and serial number are found on the identification label located on a base pan of the unit bottom. Return air vent grille must be removed from ADB to view.
• ADB model and serial number found on rating plate located on ceiling template. Observe this rating plate through the filter opening.

WIRING DIAGRAMS

Unit Wiring Diagrams

WIRING DIAGRAMS

ADB Wiring Diagram

REVISION E
Form No. 3315079.016 6/18
(French 3315288.013_E)
2018 Dometic Corporation
LaGrange, IN 46761
USA & CANADA

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

SERVICE CENTER & DEALER LOCATIONS
Please Visit: www.dometic.com

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