Field Controls WML-C, MPL-B R7184 LED Diagnostic Light, Troubleshooting, Electrical Shock Hazard

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R7184 LED DIAGNOSTIC LIGHT

The LED diagnostic light has several functions. It indicates the state or mode in which the oil burner is operating. It will also indicate fault conditions, and help determine cad cell resistance while the burner is operating.

NORMAL CONDITIONS:

The LED diagnostic light will turn on when the burner enters the carryover state; the point at which ignition spark is on, and will remain on through the run state, where the ignition spark is terminated but the burner continues to fire.

The LED diagnostic light will turn off at the end of the burner cycle as the R7184 enters the idle state, and will remain off until the next heating cycle.

FAULT CONDITIONS:

If the LED diagnostic light is flashing quickly; 1 Hz (½ second on / ½ second off), the R7184 is in the lockout state or in restricted mode. To exit the lockout state, press the reset button.

If the LED diagnostic light is flashing slowly; ¼ Hz (2 seconds on / 2 seconds off), the R7184 is in the recycle state. This indicates that flame sensing was lost after the lockout timer expired during the ignition carryover state. The R7184 will return to the idle state within 60 seconds.

CAD CELL CONDITION:

If the LED diagnostic light is off, the cad cell is not sensing flame.

If the LED diagnostic light is on, the cad cell is sensing flame, or viewing ambient light.

The resistance of the cad cell may be checked while the R7184 is in the run state by pressing the reset button. The LED diagnostic light will flash the following code:

TABLE C-2: CAD CELL RESISTANCE

Flashes

Resistance in Ohms

 

 

1

Less than 400

 

 

 

2

Between 400

- 800

 

 

 

3

Between 800

– 1600

 

 

4

Between 1600- 5000

 

 

 

TROUBLESHOOTING

IMPORTANT: Due to the potential hazard of line voltage, only a trained, experienced service technician should perform the troubleshooting procedure.

PRELIMINARY STEPS:

Check the diagnostic light for indications of burner condition. Refer to R7184 LED DIAGNOSTIC LIGHT section for details.

WHEN SIMULATING A CALL FOR HEAT AT THE R7184, DISCONNECT AT LEAST ONE THERMOSTAT LEAD WIRE FROM THE T1 - T2 TERMINALS TO PREVENT DAMAGE TO THE THERMOSTAT. NEGLECTING THIS PROCEDURE MAY BURN OUT THE

HEAT ANTICIPATOR OF A STANDARD 24 VAC THERMOSTAT, OR CAUSE HARM TO COMPONENTS WITHIN A MICRO-ELECTRONIC THERMOSTAT.

Before checking the oil primary control, perform these preliminary checks, (repair or replace controls as necessary):

Check the power supply; fuse box or breaker, any service switches, all wiring connections, and burner motor reset button (if equipped).

Check the limit switches to ensure that the switch contacts are closed.

Check the electrode gap and

position.

Check the contacts between the oil primary control and the electrodes.

Check oil supply (tank gauge).

Check the oil nozzle, oil filter, and oil valves.

Check the piping or tubing to the oil tank.

Check the oil pump pressure.

CHECK OIL PRIMARY CONTROL AND IGNITER

If the trouble does not appear to be in the burner or ignition hardware, check the oil primary control and the igniter by using the following equipment:

Screwdriver.

Voltmeter (0 - 150 VAC)

Insulated jumper wires with both ends stripped.

Electrical Shock Hazard.

Troubleshooting is done with the system powered. Be careful to observe all necessary precautions to prevent electrical shock or equipment damage.

PRELIMINARY CHECKS:

Make sure that limit switches are closed and those contacts are clean.

Check for line voltage power on the oil primary control black and white lead wires.

Refer to Table C-4 or C-5 for further troubleshooting information.

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30318 R4 9/9/2005

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Contents WML-C and MPL-B Table of Contents Heat Loss DOWN-FLOW InstallationIntroduction Location of UnitSuspended Installation AIR ConditioningCombustion AIR Chimney VentingCommon Chimney Problems OIL Tank Piping InstallationOptional Side Wall Venting Electrical ConnectionsDip Switch Blower Delay Position Times Off Seconds Minutes FAN Timer Board and Limit ControlHoneywell ST9103 Dip Switch Blower Off Delay Position Time Circulating AIR BlowerHumidifier OIL BurnerFurnace Installation SET- UP Checking Over-Fire DraftAnnual Service By Contractor Maintenance and ServiceRoutine Maintenance By Home Owner To Light Unit Operating InstructionsBefore Lighting To Shut Down UnitAppendix A- WML-C and MPL-B Burner SET UP AF76YBStart UP OIL Burner AIR AdjustmentBurner Electrodes Speed PowerCFM 55-1/4 19 x 18 x Size WeightModel 20 x 20 xAppendix B Wiring Diagrams Beckett Afii Burner Wiring Diagram Riello 40F3 and F5 Burner Wiring Diagram Riello 40BF3 Burner Wiring Diagram Operation of OIL Burner Thermostat calls for heat 30318 R4 9/9/2005 Returns to Idle State Recycle Timer Starts OperationMode Action System Response HeatElectrical Shock Hazard R7184 LED Diagnostic LightTroubleshooting Table C-3 R7184 Troubleshooting Corrective ActionRemount control onto burner housing. Go to step Table C4 System and General Troubleshooting Problem Possible Cause RemedyTiming Final Check OUT Parts Listing Counterflow Horizontal Model WML C Parts Listing Vestibule KIT WML C 30318 R4 9/9/2005 Parts Listing Counterflow Horizontal Model MPL Flame Retention Head MPL 30318 R4 9/9/2005 Fuel Supplier If Different from Installation ContractorHOMEOWNER’S Reference Table 30318 R4 9/9/2005 Tel 716 Fax 716