Dometic RM2862, RM2852, RM 2663, RM 2662, RM 2554 User Manual

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DIAGNOSTIC SERVICE MANUAL

AMERICANA & AMERICANA PLUS RM 2351, RM 2354, RM 2451, RM 2454 RM 2551, RM 2554, RM 2652, RM 2662 RM 2663, RM2852, RM2862 & NDR1062

USA SERVICE OFFICE Dometic Corporation 2320 Industrial Parkway Elkhart, IN 46516 574-294-2511

CANADA Dometic Distribution 46 Zatonski Unit 3 Brantford, Ontario CANADA N3T 5L8 519-720-9578

For Service Center Assistance Call: 800-544-4881

Foreword

This service manual is the result of the dedication of The Dometic Corporation Technical staff and its engineers in giving service people the necessary instruction for making accurate analyses of certain conditions. Provided is a diagnos-

tic chart leading a qualied mechanic into the

service manual pages to locate and solve symptoms which may occur. Dometic has continued its commitment in providing service people with this, the most up-to-date information about servicing Dometic RV accessories.

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.

Indicates a potentially hazard-

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

Indicates a potentially hazard-

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

When used without the safety

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

Read and follow all safety information and instructions.

CONTENTS

DIAGNOSTIC FLOW CHART............................................................................. 4

PAGE NO.

SECTION 1

OPERATION

Refrigerator Operation ........... ........................................................................6

SECTION 2

AC VOLTAGE

AC Voltage Requirements................ ...........................................................9

SECTION 3

AC COMPONENTS

Heating Element ....................... ...............................................................10

SECTION 4

DC VOLTAGE

DC Voltage Requirements ............... ........................................................10

SECTION 5

DC COMPONENTS

5.1 DC heating Element ................................ ..................................11

5.2 Thermistor ............................ .....................................................11

5.3 Solenoid Valve.................................... .......................................11

5.4 Igniter ........................ ................................................................11

5.5 High Voltage Cable ................................. ..................................12

5.6 Electrode ....................................................................................12

5.7 DC Relay ....................................................................................12

5.8 Upper Circuit Board ....................... ............................................13

5.9 Lower Circuit Board ....................... ............................................13

5.10 Door Switch ......................... ......................................................18

5.11 Climate Control Heater & Switch ................................ ...............18

5.12 Low Ambient Switch ............... ...................................................18

5.13 Fuses .........................................................................................18

5.14 Thermofuse ................................................................................18

SECTION 6

LP GAS

LP Gas Requirements ................... ......................................................19

SECTION 7

LP GAS COMPONENTS

7.1 Manual Gas Shut-Off Valve .................. .....................................19

7.2 Orice ................................... .....................................................19

7.3 Thermocouple .............................. .............................................20

7.4 Burner .................................... ...................................................20

CONTENTS

PAGE NO.

SECTION 7

7.5 Flue Bafe.............................................................................................20

7.6 Flue Cap ..............................................................................................20

7.7 Flue Tube .............................................................................................20

SECTION 8

COOLING UNIT

8.1 Leveling......................... ........................................................................21

8.2 Ventilation ..............................................................................................21

8.3 Air Leaks......................... .......................................................................23

8.4 Interior Liner Seal to Frame ...................................................................23

8.5 Door Position .........................................................................................24

8.6 Ambient Temperature ............................................................................24

8.7 Cooling Unit ...........................................................................................25

8.8 Food Storage .........................................................................................26

8.9 High Humidity ........................................................................................26

SECTION 9

WIRING

9.1 Internal Wiring.............................. ........................................................26

9.2 External Wiring........................... ..........................................................26

9.3 Wiring Schematics.............................. ..................................................26

SECTION 10

ICE MAKER

10.1 Operation.............................. ..............................................................26

10.2 Mold Heater........................... .............................................................27

10.3 Ice Ejector.............................. .............................................................27

10.4 Mold Thermostat......................... ........................................................27

10.5 Shut Off Arm................... ....................................................................27

10.6 Mold Switches........................... .........................................................27

10.7 Timing Motor........................... ............................................................28

10.8 Water Valve ........................................................................................28

10.9 Ice Maker Replacement... ...................................................................28

10.10 Water Fill Adjustment.................... ......................................................28

10.11 Water Supply.................. .....................................................................29

10.12 Wiring Schematics..............................................................................29

This program will address the most common system problems associated with the RM2351, RM2354, RM2451, RM2454, RM2551, RM2554, RM2652 ,RM2662,RM2663,RM2852and RM2862 refrigerators supplied by The Dometic Corporation. Our intent is to provide you with a guideline of checks to make, should you encounter one of the following symptoms.

SYMPTOM

1. No operation - no panel lights

2. No operation - has panel lights

3. No AC operation - operates on gas mode

4. No Gas operation - operates on AC mode

CAUSE

Operation DC Volts Fuse Wiring Upper Circuit Board Lower Circuit Board

Operation DC Volts Thermistor Wiring Lower Circuit Board

Operation AC Volts Fuse Heating Element Wiring Lower Circuit Board

Operation LP Gas Manual Gas Valve Igniter High Voltage Cable Electrode Solenoid Wiring Lower Circuit Board

SECTION & PAGE

1, page 06 4, page 10 5, page 18 9, page 26 5, page 13 5, page 13

1, page 06 4, page 10 5, page 11 9, page 26 5, page 14

1, page 07 2, page 09 5, page 19 3, page 11 9, page 24 5, page 13

1, page 06 6, page 19 7, page 19 5, page 11 5, page 12 5, page 12 5, page 11 9, page 24 5, page 13

5. Insufcient cooling on all modes.

6. Insufcient cooling on AC - cools properly

on gas mode.

7. Insufcient cooling on Gas - cools properly

on AC mode.

8. Freezes.

Ventilation Leveling Ambient Temperature Air Leaks Thermistor Cooling Unit

AC Volts Heating Element Lower Circuit Board

LP Gas

Orice Flue Bafe

Flue Tube Burner Lower Circuit Board

Operation Thermistor Lower Circuit Board

8, page 21 8, page 21 8, page 24 8, page 23 5, page 11 8, page 25

2, page 09 3, page 10 5, page 13

6, page 19 7, page 19 7, page 20 7, page 20 7, page 20 5, page 13

1, page 06 5, page 12 5, page 14

SYMPTOM

CAUSE

SECTION & PAGE

9. Check light on

10. Interior light on when door is closed

11. Rapid formation of frost

12. Water on frame

DC Volts Wiring LP Gas Manual Gas Valve Solenoid

Orice

Burner Thermocouple Lower Circuit Board

Wiring Low Ambient Switch Door Switch Door Position

Food Storage Interior Liner to Frame High Humidity Air Leaks

Interior Liner to Frame High Humidity Air Leaks Climate Control Heater

4, page 10 9, page 26 6, page 19 7, page 19

5. page 11

7. page 19

7. page 20

5. page 13

9. page 26

5. page 18

8. page 24

8. page 26

8. page 23

8. page 26

8. page 23

8. page 26

8. page 23

5. page 18

SECTION 1 REFRIGERATOR OPERATION

DISPLAY PANEL RM2351, RM2451, RM2551, RM2652, RM2852 AUTO TEMPERATURE CONTROL

Refrigerator Control Panel

RM2652 & RM2852 RM2662 & RM2862

RM2451 & RM2551

AMERICANA 2-WAY MODEL

1. Main Power Button ON/OFF

2. AUTO/GAS Mode Selector Button

A. AUTO Mode indicator lamp B. CHECK indicator lamp (Gas Mode Only) C. Climate control switch only on RM2652 & RM2862

Travel Latch

RM2351

DISPLAY PANEL RM2354, RM2454, RM2554 RM2663 3-way DISPLAY PANEL RM2662, RM2862 2-WAY

Refrigerator Control Panels

3-WAY

2-WAY

RM2454 & RM2554

Travel Latch

RM2354

3-WAY

1. Main Power Button ON/OFF

2. DC Mode Selector Button

3. AUTO/GAS Mode Selector Button

4. Temperature Selector Button A. DC Mode Indicator Lamp B. AC Mode Indicator Lamp C. GAS Mode Indicator Lamp D. AUTO Mode Indicator Lamp E. CHECK Indicator Lamp (Gas Operation Only) F. Temperature Indicator Lamps

2-WAY

1. Main Power Button ON/OFF

2. AUTO/GAS Mode Selector Button

3. Temperature Selector Button B. AC Mode Indicator Lamp C. GAS Mode Indicator Lamp D. AUTO Mode Indicator Lamp E. CHECK Indicator Lamp ( GAS Mode Only) F. Temperature Indicator Lamps

OPERATION INSTRUCTIONS

IMPORTANCE OF LEVELING A

REFRIGERATOR

In an absorption refrigerator system, ammonia is liqueed in the nned condenser coil at the top rear of the refrigerator. The liquid ammonia then ows into the evaporator

(inside the freezer section) and is exposed to a circulat-

ing ow of hydrogen gas, which causes the ammonia to

evaporate, creating a cold condition in the freezer. When

starting this refrigerator for the very rst time, the cooling

cycle may require up to four hours of running time before the cooling unit is fully operational. The tubing in the

evaporator section is specically sloped to provide a continuous movement of liquid ammonia, owing downward

by gravity through this section. If the refrigerator is operated when it is not level and the vehicle is not moving, liquid ammonia will accumulate in sections of the evaporator tubing. This will slow the circulation of hydrogen and ammonia gas, or in severe cases, completely block it, resulting in a loss of cooling. Any time the vehicle is parked for several hours with the refrigerator operating, the vehicle should be leveled to prevent this loss of cooling. The vehicle needs to be leveled only so it is comfortable to live in

(no noticeable sloping of oor or walls). When the vehicle

is moving, the leveling is not critical, as the rolling and pitching movement of the vehicle will pass to either side of level, keeping the liquid ammonia from accumulating in

the evaporator tubing.

OPERATION

Before starting the refrigerator, check that all the manual gas valves are in the ON position. DO NOT forget the manual shutoff valve on the rear of the refrigerator. This refrigerator is equipped with a control system which can be set to automatically select either 120 volt AC or LP gas operation (AUTO mode), or if desired LP gas only (GAS mode) or DC volts (DC Heater) where applicable.

Auto Thermostat

In both AUTO mode and GAS mode operation, the temperature is controlled by a factory preset temperature setting. The refrigerator controls will work down to 9.6 volt DC.

Most LP gas appliances used in recreational vehicles are vented to the outside of the vehicle. When parked close to a gasoline pump, it is possible that the gasoline fumes could enter this type of appliance and ignite

from the burner ame, CAUSING A FIRE OR

AN EXPLOSION.

FOR YOUR SAFETY, when refueling, shut off all LP gas appliances which are vented to the outside.

OPERATION

Auto Thermostat

A continuous 12 volt DC supply must be available for the electronic control to function.

Press the main power ON/OFF button (1) to the DOWN position.

In AUTO mode, the AUTO lamp A will be illuminated. The control system will automatically select between AC and GAS operation with AC having priority. The temperature is controlled by a factory preset temperature setting.

In GAS mode operation, no lamps will be illuminated and the temperature is controlled by a factory preset temperature setting.

OPERATION

Adjustable Thermostat

A continuous 12 volt DC supply must be available for the electronic control to function.

Press the main power ON/OFF button (1) to the DOWN position.

In AUTO mode, the AUTO lamp D will be illuminated. The control system will automatically select between AC and GAS operation with AC having priority. Temperature is selected by the user.

In GAS mode operation, the GAS lamp C will be illuminated and only operate on LP only. Temperature is selected by user.

In DC mode, the DC lamp A will be illuminated and the unit will only operate on DC until DC volts drops below

9.6 VDC.

Auto Mode

Press the AUTO/GAS button 2 (Auto Thermostat) or button 3 (Adjustable Thermostat) to the DOWN position. The AUTO mode indicator lamp (A auto or D adjustable thermostat) will illuminate. If 120 volts AC is available, the control system will select AC operation. If 120 volts AC is not available, the control system will automatically switch to GAS operation. Within 45 seconds the burner should be ignited and operating normally. If the CHECK indicator lamp (B auto or E adjustable thermostat) illuminates, the control has failed to ignite the burner on GAS. To reset when the CHECK indicator lamp, press the main power ON/OFF button (1) to the OFF then ON position. Systems with the new lower control board are a three (3) try system on gas. On the initial refrigerator start-up on gas (120 volts AC is not available), it may take longer than 45 seconds to allow air to be purged from the gas line. If the refrigerator has not been used for a long time or the LP

tanks have just been relled, air may be trapped in the

supply lines. To purge the air from the lines may require resetting the main power ON/OFF button (1) three or four times. If repeated attempts fail to start the LP gas operation, check to make sure that the LP gas supply tanks are not empty and all manual shutoff valves in the lines are open.

Note: Do not continue to reset GAS operation if the CHECK indicator lamp continues to be illuminated after several tries.

GAS Mode

Move the AUTO/GAS button 2 (Auto Thermostat) or button 3 (Adjustable Thermostat) to the UP position. The AUTO mode indicator lamp (A) will go off. Within 45 seconds the burner should be ignited and operating normally.

DC Mode 3 Way Units Only

Press the DC mode indicator button (2) to the DOWN position. (Lamp [A] will light). Press the TEMPERATURE SELECTOR button (4) until the lamp (F) at the desired position is illuminated. The refrigerator will continue to operate in the DC mode until switch (2) is moved to the UP position or control voltage falls below 9.6 VDC. The DC mode overrides all the other operating modes. Discharging of the battery will occur if the vehicle engine is not running.

Note: The DC mode is a holding mode not a full cooling mode. DC should be used once the unit is cooled down and constant supply of DC available (driving down the road).

To Shut Off The Refrigerator

The refrigerator may be shut off while in any mode of operation by pressing the main power ON/OFF button to the UP (OFF) position. This shuts off all DC power to the control system.

Description Of Operating Modes Auto Mode

When operating in the AUTO mode, the AUTO mode indicator lamp (A) will illuminate. The control system will automatically select between AC and GAS operation with AC having priority over GAS. If the control system is operating with AC energy and it then becomes unavailable, the system will automatically switch to GAS. As soon as AC becomes available again the control will switch back to AC operation. Gas operation (120 volts AC is not avail- able). The control system will activate the ignition system and will make three attempts to light the burner for a period of approximately 45 seconds with two minutes rest (purge) interval. If unsuccessful, the CHECK indicator lamp (B) will illuminate. To restart an ignition attempt with the CHECK lamp illuminated or to clear (turn off) the CHECK lamp, press the main power ON/OFF button to the OFF position and wait a few seconds, then return to the ON position. The control system will attempt a new ignition sequence. If 120 volts AC becomes available while the CHECK indicator lamp is on, the CHECK lamp will not turn off until the main power ON/OFF button is pressed to the OFF then ON position but the unit will operate on AC.

Gas Mode

When operating in the GAS mode, the AUTO mode indicator lamp (A) will be off. This mode provides LP gas operation only. The control system will activate the ignition system and will make three attempts to light the burner for a period of approximately 45 seconds with two minutes

a period of approximately 45 seconds with two minutes (purge) interval after each trial. If unsuccessful, the CHECK indicator lamp (B) will illuminate. To restart GAS operation, press the main power ON/OFF button (1) to the OFF and then ON position. The control system will attempt a new ignition sequence. If the refrigerator has not been used for a long time or the LP tanks have just

been relled, air may be trapped in the supply lines. To

purge the air from the lines may require resetting the main power ON/OFF button (1) three or four times. If repeated attempts fail to start the LP gas operation, check to make sure that the LP gas supply tanks are not empty and all manual shutoff valves in the lines are turned on.

DC Mode 3 Way Units Only

Note: The DC mode is a holding mode not a full cooling mode. DC should be used once the unit is cooled down and constant supply of DC available (driving down the road).

To Shut Off The Refrigerator

The refrigerator may be shut off while in any mode of operation by pressing the main power ON/OFF button to the UP (OFF) position. This shuts off all DC power to the control system.

Limp Mode

This control system contains a feature where it will continue to operate the cooling system in event of a failure of a major operating component. If the control cannot read the temperature sensor and control to the preset temperature, then the control will run the cooling unit continuously at the energy source available. The refrigerator will

continue to operate in this mode indenitely or until a new

sensor is installed and the system is reset.

SECTION 2 AC VOLTAGE

AC VOLTAGE REQUIREMENTS

This is an energized circuit. Shock can occur if not tested properly. Testing is to be done

by a qualied service technician.

The proper operating range is 100 to 132 volts. If voltage

drops below 100 volts, cooling efciency will decrease

with voltage decrease.

The refrigerator will not switch to another mode of operation until all AC power is lost. The refrigerator is equipped with a three-prong (grounded) plug for protection against shock hazards, and should be plugged directly into a properly grounded three-prong receptacle.

SECTION 3 AC COMPONENTS

Heating Element

The heating element is designed to deliver a predetermined amount of heat to the cooling unit. To check a heating element, remove the heater leads from the printed circuit board and measure for proper resistance across the two leads with a properly calibrated ohm meter. This check is to be done with the heating element at room temperature. You should obtain the following readings ± 10%:

SECTION 4 DC VOLTAGE

DC Voltage Requirements

Clean Direct Current (DC) power is mandatory for hightech circuits to operate as designed. A battery will provide straight line DC power. The converter and alternator produce DC power by a series of diodes that rectify alternating current to DC. The Dometic control system will only tolerate up to 6 AC volts on the DC line. AC ripple can be measured by a digital voltmeter set on the AC scale at the main DC terminal block connections at the refer. Six volts AC or less is acceptable. If AC volts exceed 6 on the DC incoming line the power source should be cleaned up. AC voltage in excess of 6 volts will affect the processor and create erratic operation. When testing for AC ripple on the DC line put a load on the converter. The operational range of the unit is a minimum of 9.6V DC to a maximum of 22V DC. The unit will automatically shut down until voltage has decreased to 18V DC. The refrigerator requires at least 9.6V DC for proper operation; however the panel lights will continue to illuminate until voltage has dropped to 4V DC or below. Do not use the body or chassis of the RV as a substitute for either of the two conductors. The refrigerator must be connected to the battery circuit with two wires of adequate capacity to avoid voltage drop. Proper polarity is crucial for refrigerator operation.

No other electrical equipment or lighting should be connected to the refrigerator circuit. Just because you

can read volts does not mean you have the amps to operate the control system. If relays buzz, lights go dim or out during operation, this could indicate there is a loose connection somewhere.

Main Terminal Block

Model WATTS OHMS AMPS RM2351-4 175 80 1.5 RM2451-4 175 80 1.5 RM2551-4 175 80 1.5 RM2652 325 44 2.7 RM2662-3 325 44 2.7 RM2852 325 44 2.7 RM2862 325 44 2.7

Never over or under size the AC heater.

Grounds

The operation of the Dometic refrigerator is also dependent on good, clean ground connections. Loose or corroded ground terminals create an unknown resistance factor that can affect the voltage detected by the Power Module. A loose negative DC wire will create a negative millivolt signal that the control board will pick up and create erratic operation. Check the integrity of the grounds from the refrigerator all the way to the power source/battery. Clean or tighten any suspicious looking connections. Note: The DC terminal block below the control board should be cleaned and tightened at the 4 wires.

+ 23 hidden pages