York International DFAA User's Information, Maintenance And Service Manual page 25

LOSES FLAME DURING CYCLE - CONTROL LOCKS OUT ON SAFETY
1. RESET CONTROL: - COMPLETES 30 SECOND PREPURGE CYCLE, AND 8 SECOND SAFE START CHECK
2. DISCONNECT FLAMEROD LEAD FROM PRIMARY CONTROL
CONNECT (+) POSITIVE LEAD (DC) MICROAMPERE METER
TO THE PRIMARY CONTROL TERMINAL. CONNECT THE
(-) NEGATIVE MICROAMPERE METER LEAD TO THE
FLAMEROD TERMINAL
3. RESET CONTROL: AFTER PREPURGE CYCLE, FLAME IS
ESTABLISHED. A STABLE MICROAMPERE CURRENT OF
.8 OR MORE IS REQUIRED FOR DEPENDABLE OPERATION
.
4. MICROAMPERE READING IS LESS THAN .8 OR UNSTABLE
BURNER CYCLES ERRATICALLY
1. CHECK FOR PROPER THERMOSTAT INSTALLATION AND LOCATION
2. CHECK THERMOSTAT HEAT ANTICIPATOR FOR CORRECT SETTING
3. CHECK LOW VOLTAGE CIRCUIT FOR BAD WIRING, ELECTRICAL
CONNECTIONS AND/OR SWITCHES
4. CHECK LINE VOLTAGE CIRCUIT FOR BAD WIRING, ELECTRICAL
CONNECTION AND/OR SWITCHES
NOTE: YOU MUST DETERMINE WHAT THE CORRECT ANTICIPATOR SETTING IS BY INSPECTING THE CONTROLLING DEVICE AT
THE POINT WHERE THE THERMOSTAT WIRES TERMINATE. TYPICALLY, THIS INFORMATION CAN BE FOUND ON THE BODY OR
COVER OF THE CONTROLLING DEVICE. WHEN DETERMINING THE CURRENT DRAW OF THE DUAL HEAD GAS VALVE, BE SURE
TO CONSIDER THE SEPARATE AMPERE VALUES FOR EACH VALVE. THESE USUALLY ARE STENCILED ON THE VALVE BODY AND
MUST BE ADDED TOGETHER TO OBTAIN THE CORRECT SUM. (EXAMPLE .4 + .2 = .6). WHEN THE CURRENT DRAW CANNOT BE
DETERMINED ACCURATELY BY THE ABOVE METHOD, MEASURE THE CURRENT WITH AN AMPERE METER USING THE 1 AMP
SCALE. CONNECT THE METER LEADS IN SERIES WITH ONE OF THE THERMOSTAT LEADS FOR THE ACCURATE READING.
Unitary Products Group
- FLAME IS ESTABLISHED
- SOMETIMES THE CONTROL LOCKS OUT BEFORE THE THERMOSTAT OR CONTROLLING CIRCUIT
IS SATISFIED
OK
OK
OK OK
PROBABLE CAUSE OF ERRATIC LOCKOUT:
1. FLAME PROVING CIRCUIT GROUNDED
BY MOISTURE
2.DAMAGED INSULATION ON FLAMEROD
LEAD
3. FLAMEROD IMPROPERLY POSITIONED
IN FLAME
4. POOR GROUND PATH TO PRIMARY
CONTROL
5. DEFECTIVE PRIMARY CONTROL
6. READ MANUAL SECTION "FLAME SENSING"
7. APPLICABLE TO HONEYWELL S87 SERIES
PRIMARY IGNITION CONTROLS: CONNECT
L1 TO THE BLACK LEAD AND L2 TO THE
WHITE LEAD EXITING THE TRANSFORMER
PROBABLE CAUSES:
1. EXTREMELY POOR COMBUSTION LEVEL
2. FLAMEROD IMPROPERLY POSITIONED
IN FLAME
3. DEFECTIVE PRIMARY CONTROL
SET ANTICIPATOR TO CORRECT VALUE IF
ADJUSTABLE TYPE. IF PROPER SETTING
NO
CANNOT BE MADE, REPLACE WITH
COMPATIBLE THERMOSTAT
107273-UUM-C-0306
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