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69-1204

3

ST7997 OIL BURNER MOUNTED ELECTRIC FAN TIMER

Fig. 3. ST7997 Oil Burner Mounted Electronic Fan Timer standard wiring connections.

N

HUM

N

EAC

N

1K2

1K1

2K2

2K1

COOL

HEAT

MED HI

MED LO

 LO

HI

BLACK

WHITE

N

CONTINUOUS

FURNACE

LIMIT

OIL 

PRIMARY

L1

L1

L2

L2

BURNER/

VALVE

HUMIDIFIER

EAC

L2

THERMOSTAT
5-WIRE

COMPRESSOR
CONTACTOR

RC

RC

F1

ISOLATION

HEAT CALL

CONTROL
ELECTRONICS

LIMIT

T

T

RC

W

R

C

C

G

Y

G

Y

G

Y

L1
GND

SCREW TERMINAL

1/4 IN. QUICK CONNECT

CIRCULATOR 
BLOWER

LIMIT
(LINE 
VOLTAGE)

ORANGE

R7997
INTEGRATED
OIL PRIMARY
WITHOUT 
BLOWER DELAY

BURNER 
MOTOR

UNUSED

WIRES

J-BOX

M12924

OEFT

ST7997

K1

K2

Summary of Contents for ST7997

Page 1: ...ds connected to outputs 20A maximum with loads connected to outputs Output Ratings Relay Contacts Circulator Heat or Cool Blower Speed Rating 15A Full Load Amperage FLA 0 75 pF 30A Locked Rotor Amperage LRA 0 5 pF NOTE FLA rating is reduced by EAC load EAC 1A maximum Circulator Continuous Blower Speed Rating 8A FLA 0 75pF 16A LRA 0 5pF Humidifier 1A maximum Limit 10A maximum L1 L2 Burner 20A maxim...

Page 2: ...he instructions and on the product to make sure the product is suitable for your application 3 Installer must be a trained experienced service technician 4 After installation is complete check out the product operation as provided in these instructions C M12920 Y G Rc 4 9 32 109 4 1 4 108 3 27 32 97 WARNING Electrical Shock Hazard Can cause serious injury or death Disconnect power supply before wi...

Page 3: ... WHITE N CONTINUOUS FURNACE LIMIT OIL PRIMARY L1 L1 L2 L2 BURNER VALVE HUMIDIFIER EAC L2 THERMOSTAT 5 WIRE COMPRESSOR CONTACTOR RC RC F1 ISOLATION HEAT CALL CONTROL ELECTRONICS LIMIT T T RC W R C C G Y G Y G Y L1 GND SCREW TERMINAL 1 4 IN QUICK CONNECT CIRCULATOR BLOWER LIMIT LINE VOLTAGE ORANGE R7997 INTEGRATED OIL PRIMARY WITHOUT BLOWER DELAY BURNER MOTOR UNUSED WIRES J BOX M12924 OEFT ST7997 K1...

Page 4: ...Timer wiring for units with pre and post purge NOTE Two dummy quick connect terminals labeled unused wires not connected to the ST7997 circuitry are provided on the back of the case to hold unused wires from the circulation blower motor speed taps IMPORTANT Field changes to the speeds low medium low medium high high of the ST7997 blower modes heat cool or continuous fan can be made to models using...

Page 5: ...stant circulating fan is connected Optional connectors are available for separate circulating fan speed tap a Circulating fan is energized at low speed when there is no call for heat cool or fan b If fan operation is required by a call for heat cool or fan the ST7997 switches off the continuous fan speed tap before energizing the other fan speed Electronic air cleaner is connected Optional connect...

Page 6: ...ling cycle if applicable Troubleshoot by checking for appropriate voltages at the ST7997 terminals controlling the burner motor and heat and cool circulating fan The ST7997 schematic Fig 3 shows internal switching to clarify operation and assist in troubleshooting Table 2 provides the ST7997 operating sequence Use the green diagnostic LED to assist in troubleshooting a Off when system is on and th...

Page 7: ... LED turns off and oil primary control goes into recycle mode b If selected heat fan off delay timing is longer than the recycle delay timing the heat fan continues to run through the next trial for ignition COOL Thermostat begins call for cool G and Y terminals are energized a Cooling contactor is energized and LED turns on immediately b Circulating fan is energized at cool speed when cool on del...

Page 8: ...AN TIMER Home and Building Control Honeywell Limited Honeywell Limitée 155 Gordon Baker Road North York Ontario M2H 3N7 69 1204 G R 8 98 Home and Building Control Honeywell Inc Honeywell Plaza P O Box 524 Minneapolis MN 55408 0524 www honeywell com ...

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