Lincoln 1200, 1000 User Manual

SERVICE MANUAL

(INTERNATIONAL)

IMPINGER CONVEYOR OVENS

MODEL SERIES 1000 & 1200

Lincoln Foodservice Products, LLC

1111 North Hadley Road

Fort Wayne, Indiana 46804

United States of America

Phone : [phone]

U.S. Fax: [phone] • Int’l Fax: [phone]

Technical Service Hot Line

[phone]

www.lincolnfp.com

1000serviceexp REV: 1/5/07

TABLE OF CONTENTS

TABLE OF CONTENTS..............................................................................................................................................2

SEQUENCE OF OPERATIONS 1002/1003...............................................................................................................3

SEQUENCE OF OPERATIONS 1106........................................................................................................................4

SEQUENCE OF OPERATIONS 1028 / 1029 / 1228 / 1229 ......................................................................................5

SEQUENCE OF OPERATIONS 1030........................................................................................................................6

SEQUENCE OF OPERTIONS 1032 ..........................................................................................................................7

SEQUENCE OF OPERATIONS / 1033, 1034, 1046, 1047 .......................................................................................8

SEQUENCE OF OPERATIONS 1042 / 1043 / 1242 / 1243 ....................................................................................10

SCHEMATIC / 1002, 1003 .......................................................................................................................................12

SCHEMATIC / 1006 TO SERIAL NUMBERS Q14279.............................................................................................13

SCHEMATIC / 1028, 1029, S/N Q19071 & BELOW ................................................................................................14

SCHEMATIC / 1028, 1029, S/N Q19078 & ABOVE.................................................................................................15

SCHEMATIC / 1030, TO S/N Q17170......................................................................................................................16

SCHEMATIC / 1030, S/N Q17171 & ABOVE...........................................................................................................17

SCHEMATIC / 1032. S/N Q19077 & BELOW ..........................................................................................................18

SCHEMATIC / 1032, S/N Q19078 & ABOVE...........................................................................................................19

SCHEMATIC / 1033, 1034, 1046, 1047 ...................................................................................................................20

SCHEMATIC / 1042, 1043, S/N Q14279 & BELOW ................................................................................................21

SCHEMATIC / 1042, 1043, S/N Q14280 & ABOVE.................................................................................................22

SCHEMATIC / 1228. 1229, S/N Q14790 & BELOW ................................................................................................23

SCHEMATIC / 1228, 1229, S/N Q14791 & ABOVE.................................................................................................24

SCHEMATIC / 1242, 1243 .......................................................................................................................................25

TROUBLESHOOTING GUIDE 1000 & 1200 / GAS OVENS ..................................................................................26

TROUBLESHOOTING GUIDE 1000 & 1200 SERIES / ELECTRIC OVENS...........................................................39

TROUBLESHOOTING / GAS OVENS 1033, 1034, 1046, 1047..............................................................................46

REMOVAL, INSTALLATION & ADJUSTMENTS .....................................................................................................53

MODEL SERIES 1000 &1200...............................................................................................................................53

PARTS / MODEL SERIES 1000 & 1200 - GENERAL..............................................................................................80

BLOW UP / 1000, 1200 – GENERAL.......................................................................................................................81

PARTS / MODEL 1002-1003 , S/N 2584 TO 4389 ..................................................................................................82

BLOW UP / 1002, 1003 – S/N 2584 to 4389............................................................................................................83

PARTS / MODEL 1002-1003, S/N 4390 & UP .........................................................................................................84

BLOW UP / 1002, 1003 – S/N 4390 & ABOVE ........................................................................................................85

PARTS / MODEL 1006 .............................................................................................................................................86

BLOW UP / 1006 ......................................................................................................................................................87

PARTS / 1028-1029-1032 ........................................................................................................................................88

BLOW UP / 1028, 1029, 1032..................................................................................................................................89

PARTS/ MODEL 1030 ..............................................................................................................................................90

BLOW UP / 1030 ......................................................................................................................................................91

PARTS / 1042, 1043.................................................................................................................................................92

BLOW-UP / 1042, 1043 ............................................................................................................................................93

PARTS / 1033, 1034, 1046, 1047.............................................................................................................................94

BLOW-UP / 1033, 1034, 1046, 1047........................................................................................................................95

PARTS / 1228-1229..................................................................................................................................................96

BLOW UP / 1228, 1229 ............................................................................................................................................97

PARTS / 1242, 1243.................................................................................................................................................98

BLOW - UP / 1242, 1243 ..........................................................................................................................................99

PARTS / OVEN BACK - GAS .................................................................................................................................100

BLOW UP / OVEN BACK – GAS ...........................................................................................................................101

PARTS / OVEN BACK- ELECTRIC........................................................................................................................102

BLOW UP / OVEN BACK – ELECTRIC .................................................................................................................103

PARTS / CONVEYOR MOTOR ASSEMBLY S/N 4390 & ABOVE ........................................................................104

BLOW UP / CONVEYOR MOTOR ASSEMBLY S/N 4390 & ABOVE ...................................................................105

PARTS / SERIES 1000 – CONVEYOR..................................................................................................................106

BLOW UP / SERIES 1000 CONVEYOR ................................................................................................................107

PARTS / SERIES 1200 - CONVEYOR CONTROL................................................................................................108

BLOW UP / SERIES 1200 – CONVEYOR CONTROL ..........................................................................................109

PARTS / SERIES 1200 – CONVEYOR..................................................................................................................110

BLOW UP / SERIES 1200 – CONVEYOR .............................................................................................................111

Impinger I -–1000 Series Service Manual - International 2

SEQUENCE OF OPERATIONS 1002/1003

MODEL 1002 - 240VAC - 50HZ - NATURAL GAS
MODEL 1003 - 240VAC - 50HZ - L.P. GAS

POWER SUPPLY Electrical Power to be supplied to the Oven by a three conductor service.

Black conductor is Hot
Red conductor is Neutral

Green conductor is Ground
CONTROL BOX When the temperature in the Control Box reaches 120°F +
AUTO COOL DOWN 3°, the Cooling Fan Thermostat will switch power to the Control Box Cooling Fan.

The Thermostat will interrupt power to the Cooling Fan when the Control Box
temperature falls to 100°F + 3°.

MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the Double

Pole Main Fan Relay, the Cooling Fan Thermostat, the normally open Double Pole
Main Fan Switch, and the normally open Cool Down Thermostat (thermostat closes
at 160°F and opens at140°F). Closing the Main Fan Switch supplies 240 VAC
through a 3A Fuse to the primary of the control circuit Step down Transformer. The
Transformer steps the voltage down to 120 VAC for the control circuit. 120 VAC is
supplied to the coil of the Double Pole Main Fan Relay. The coil of the relay is
energized. The normally open contacts now close, energizing the Main Fan Motor
through one 10A Fuse. Closing the Fan Switch also supplies power to the Cooling
Fan, Hour Meter (hour meter discontinued after S/N 3484), the 12.6 VAC
Transformer, the Burner and Conveyor Switches.

BURNER CIRCUIT

CONVEYOR DRIVE
(S/N 100 to 4389)

(S/N 4390 and UP)

Closing the Fan Switch and the normally open Burner Switch supplies 120 VAC
through the Air Pressure Switch, to the normally open contacts of the Burner Motor
Relay, and the primary of the 24 VAC Step Down Transformer. The Transformer
secondary supplies 24 VAC to the Relay Coil (the normally open contacts close
within 30 seconds), and the normally open Centrifugal Switch. When the Relay
contacts close, the Burner Blower Motor is energized. As this motor reaches
approximately 1600 R.P.M., its internal centrifugal switch closes, supplying 24 VAC
to the Gas Control Valve. When the Gas Control Valve is supplied with 24 VAC, the
pilot valve is energized, and the igniter circuit is energized. Ignition should now
occur. After pilot flame is proven, the main gas valve is energized. The Burner
Indicator Light is also energized.
Closing the Fan Switch and the normally open Conveyor Switch supplies 120 VAC
through a 3A Fuse, to the Motor Control Board. AC volts are converted to D.C. volts
and are supplied to the Conveyor Motor at board terminals A1 and A2 through a
D.P.D.T. Reversing Switch. Adjustment of the Speed Control Potentiometer (500
ohm, 10 turn) will change resistance at terminals S1, S2, and S3 varying the D.C.
voltage to the motor. The speed of the Conveyor Motor will increase or decrease as
the D.C. voltage from the Motor Control Board increases or decreases respectively
Closing the fan switch and the conveyor switch supplies 120 VAC to the Motor
Control Board. AC volts are converted to DC volts and are supplied to the Conveyor
Motor at terminals A+ and A-. Adjustment of the Speed Control Potentiometer (5,000
ohm 10 turn) will change resistance at terminals P1, P2, and P3 varying the DC
voltage to the motor. The speed of the conveyor motor will increase or decrease as
the DC voltage from the board increases or decreases respectively. As the motor
turns, it drives both the reducer gear box and the tach. generator which supplies a
voltage to the DC motor control board and is used as a reference for maintaining a
constant conveyor speed

Impinger I -–1000 Series Service Manual - International 3

TIME TEMP DISPLAY The Time/Temp Display is energized when the Fan Switch is closed, supplying 120

VAC to the primary of the 12.6 volt Transformer. The secondary output of the
transformer, normally 13 to 14 VAC (depending on input), with a center tap, is
supplied to terminals 1,2, and 3 of the Time/Temp Display. The center tap is terminal

2. The display works on a balanced input and center tap voltage to each leg must be
1/2 the total reading.

The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach.
coupling) to break the infra-red light beam of the optical switch (mounted on gear
motor) producing electrical pulses that are transmitted to the display. The display
converts these pulses into a read-out of minutes and seconds.

The temperature portion of the display uses a Thermistor Probe to sense oven
temperature. The thermistor outputs a resistance proportional to the oven
temperature. This resistance is then converted by the display into a temperature
reading.

SEQUENCE OF OPERATIONS 1106

MODEL 1006 - 240 VAC - 50HZ - 1 PHASE - NATURAL GAS

POWER SUPPLY Electrical Power to be supplied to the Oven by a three conductor service.

Red conductor is Hot

Black conductor is Neutral

Green conductor is Ground
CONTROL BOX AUTO
COOL DOWN

MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the Double

TRANSFORMER (12.6
VAC)

BURNER CIRCUIT Closing the Fan Switch and the normally open Burner Switch supplies 120 VAC

CONVEYOR DRIVE
(S/N 4390 AND UP)

When the temperature in the Control Box reaches 120°F + 3°, the Cooling Fan
Thermostat will switch power to the Control Box Cooling Fan. The Thermostat will
interrupt power to the Cooling Fan when the Control Box temperature falls to 100°F +
3°.

Pole Main Fan Relay, the Cooling Fan Thermostat, and through a 3A Fuse to the
normally open Double Pole Main Fan Switch, and the normally open Cool Down
Thermostat (thermostat closes at 160°F and opens at 140°F). Closing the Main Fan
Switch supplies 240 VAC to the primary of the control circuit Step Down
Transformer. (The transformer steps the voltage down to 120VAC for the control
circuit) 120 VAC is supplied to the coil of the Main Fan Relay. The coil of the Relay is
energized, the normally open contacts now close, energizing the Main Fan Motor
through one 10A fuse. Closing the Fan Switch also supplies power to the Cooling
Fan, the 12.6 VAC Transformer, the Burner and Conveyor Switches
Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC
Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to
14 VAC) with a center tap, and supplies power to the Time/Temp Display. The
voltage from each leg of the Transformer's secondary to the center tap should be
one half of the secondary voltage.

through the Air Pressure Switch, to the normally open contacts of the Burner Motor
Relay, and the primary of the 24 VAC Step Down Trans-former. The Transformer
secondary supplies 24 VAC to the coil of the Burner Motor Relay (the normally open
contacts close within 30 seconds), and through the Burner Air Pressure Switch to the
normally open Centrifugal Switch. When the Relay contacts close, the Burner Blower
Motor is energized. As this motor reaches approximately 1600 R.P.M., the Burner Air
Pressure Switch closes, and the motor's internal centrifugal switch closes supplying
24 VAC to the Gas Control Valve. When the Gas Control Valve is supplied with 24
VAC, the pilot valve is energized, and the igniter circuit is energized. Ignition should
now occur. After pilot flame is proven, the main gas valve is energized. The Burner
Indicator Light is also energized.
Closing the fan switch and the normally open conveyor switch supplies 120 VAC to
the Motor Control Board .AC volts are converted to DC volts and are supplied to the
Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control
Potentiometer (5000 ohm 10 turn ) will change resistance at terminals P1, P2, and
P3 varying the DC voltage to the motor. The speed of the conveyor motor will

Impinger I -–1000 Series Service Manual - International 4

increase or decrease as the DC voltage from the board increases or decreases
respectively. As the motor turns, it drives both the reducer gearbox and the Tach.
Generator. The Tach. Generator is a DC voltage generator, which supplies a voltage
to the DC motor control board and is used as a reference for maintaining a constant
conveyor speed.

TlME/TEMP DISPLAY The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120

VAC to the primary of the 12.6 volt Transformer. The secondary output of the
transformer, normally 13 to 14 VAC (depending on input), with a center tap is
supplied to terminals 1,2, and 3 of the Time/Temp Display. The center tap is terminal

2. The display works on a balanced input and center tap voltage to each leg must be
1,2 the total reading.
The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach.
coupling) to break the infra-red light beam of the optical switch (mounted on gear
motor) producing electrical pulses that are transmitted to the display. The display
converts these pulses into a read-out of minutes and seconds.
The temperature portion of the display uses a Thermistor Probe to sense oven
temperature. The thermistor outputs a resistance proportional to the oven
temperature. This resistance is then converted by the display into a temperature
reading.

SEQUENCE OF OPERATIONS 1028 / 1029 / 1228 / 1229

MODEL 1028 - 380Y/220 VAC - 50 HZ - 3 PHASE
MODEL 1029 - 415Y/240 VAC - 50 HZ - 3 PHASE
MODEL 1228 - 380Y/220 VAC - 50 HZ - 3 PHASE - DUAL BELT
MODEL 1229 - 415Y/240 VAC - 50 HZ - 3 PHASE - DUAL BELT

POWER SUPPLY Electrical Power to be supplied to the Oven by a five conductor service.

Black conductor is Hot

Red conductor is Hot

Orange conductor is Hot

White conductor is Dedicated Neutral

Green conductor is Ground

MAIN FAN CIRCUIT Electrical power is permanently supplied through 3, 50A fuses to the normally open

contacts of the Mercury Contactor. Power is also supplied through 1, 10A fuse to the
normally open contact of the Main Fan Relay, through a 1A Fuse to the normally
open Double Pole Main Fan Switch, and to the normally open Cool-Down
Thermostat (thermostat closes at 160°F and opens at 140°F.) Closing the Main Fan
Switch supplies 220 or 240 VAC to the primary of the control circuit Step Down
Transformer. (The transformer steps the voltage down to 120 VAC for the control
circuit.) 120 VAC is supplied to the coil of the Main Fan Relay. The coil of the relay is
energized, the normally open contacts close, energizing the Main Fan Motor. Closing
the Main Fan Switch also supplies power to the 12.6 VAC Transformer, the Control

Box Cooling Fan, and the Heat and Conveyor Switches.
TRANSFORMER (12.6
VAC)

HEAT CIRCUIT Closing the Fan Switch and the normally open Heat Switch supplies 120 VAC

TEMPERATURE
CONTROL

Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC

Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to

14 VAC) with a center tap, and supplies power to the Time/Temp. Display. The

voltage from each leg of the Transformer's secondary to the center tap should be

one half of the secondary voltage.

through the normally open Air Pressure Switch, and the normally closed Hi-Limit

Thermostat (manually re-settable, opens at 190°F) and, the 3A Fuse, to the L1

terminal of the Temperature Control Board, the coil of the Mercury Contactor, and to

the Heat Indicator Light.

When the Heat Switch is closed, 120 VAC is supplied to the Temperature Control.

The Temperature Control Potentiometer (2.5K ohm) is adjusted to desired

temperature. The Thermocouple will provide varying millivolts to the Temperature

Controller. The Temperature Controller switches the L 2 line of the Contactor coils at

intermittent intervals to maintain desired temperatures.

Impinger I -–1000 Series Service Manual - International 5

CONVEYOR DRIVE
(S/N 100 to 4389)

(S/N 4390 and UP
1000 Series)
(S/N 4390 to 14790
1200 Series)

(S/N 14791 & Above
1200 Series
See Page 9

NOTE The 1200 Series Ovens utilize 2 complete conveyor drive systems.
TIME TEMP
DISPLAY(S/N 4390 &
Above1000 Series) S/N
4390-147901200 Series)

(T/T Display S/N
Q14791& Above1200
Series See Page 9

NOTE The 1200 Series Ovens use a Double Pole Double Throw Switch to connect the two

Closing the Fan Switch and the normally open Conveyor Switch supplies 120 VAC

through a 3A Fuse, to the Motor Control Board. AC volts are converted to D.C. volts

and are supplied to the Conveyor Motor at board terminals A1 and A2 through a

D.P.D.T. Reversing Switch. Adjustment of the Speed Control Potentiometer (500

ohm, 10 turn) will change resistance at terminals S1, S2, and S3 varying the D.C.

voltage to the Conveyor Motor. The speed of the Conveyor Motor will increase or

decrease as the D.C. voltage from the Motor Control Board increases or decreases

respectively.

Closing the fan switch and the normally open Conveyor switch supplies 120 VAC to

the Motor Control Board. AC volts are converted to DC volts and are supplied to the

Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control

Potentiometer (5,000 ohm 10 turn ) will change resistance at terminals P1, P2, and

P3 varying the DC voltage to the motor. The speed of the conveyor motor will

increase or decrease as the DC voltage from the board increases or decreases

respectively. As the motor turns, it drives both the reducer gearbox and the tach.

generator. The tach. generator is a DC voltage generator which supplies a voltage to

the DC motor control board and is used as a reference for maintaining a constant

conveyor speed.

The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120

VAC to the primary of the 12.6 volt Transformer. The secondary output of the

transformer, normally 13 to 14 VAC (depending on input), with a center tap, is

supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is

terminal 2. The display works on a balanced input and center tap voltage to each leg

must be 1/2 the total reading.

The speed side of the Time/Temp. Display uses a slotted.disc (cemented to tach.

coupling) to break the infra-red light beam of the optical switch (mounted on gear

motor) producing electrical pulses that are transmitted to the display. The display

converts these pulses into a read-out of minutes and seconds.

The temperature portion of the display uses a Thermistor Probe to sense oven

temperature. The thermistor outputs a resistance proportional to the oven

temperature. This resistance is then converted by the display into a temperature

reading.

Optical Encoder Assemblies to the Time/Temp. Display. By activating the switch,

either the front or rear belt speed can be shown by the Time/Temp. Display.

SEQUENCE OF OPERATIONS 1030

MODEL 1030 - 220 VAC - 50HZ - 1 PHASE

POWER SUPPLY Electrical Power to be supplied to the Oven by a three conductor service.

Black conductor is Hot
Red conductor is Neutra

Green conductor is Ground
CONTROL BOX
AUTO COOL DOWN

MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the Double

TRANSFORMER (12.6
VAC)

When the temperature in the Control Box reaches 120°F + 3°, the Cooling Fan
Thermostat will switch power to the Control Box Cooling Fan. The Thermostat will
interrupt power to the Cooling Fan when the Control Box temperature falls to 100°F +
3°.

Pole Main Fan Relay, the Cooling Fan Thermostat, the normally open Main Fan
Switch, and the normally open Cool Down Thermostat (thermostat closes at 160°F
and opens at 140°F). Closing the Main Fan Switch supplies 220 VAC through a 3A
Fuse to the (normally open) Burner Switch, and to the control circuit Step Down
Transformer (the transformer steps the voltage down to 120 VAC for the control
circuit) 120 VAC is supplied to the coil of the Main Fan Relay The coil is energized,
the normally open contacts close, supplying 220 VAC through one 10A Fuse to the
Main Fan Motor. 120 VAC is also supplied to the 12.6 VAC Transformer, the
Temperature Controller and the Conveyor Switch.
Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC
Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to

Impinger I -–1000 Series Service Manual - International 6

14 VAC) with a center tap, and supplies power to the Time/Temp Display. The
voltage from each leg of the Transformer's secondary to the center tap should be
one half of the secondary voltage

BURNER CIRCUIT Closing the normally open Burner Switch supplies 220 VAC, through the gas

pressure-proving switch, and through the Main Fan Air Pressure Switch, to the
Ignition Control. The combustion motor relay is energized, its normally open contacts
now close, supplying120 VAC to the combustion motor. The normally open
combustion air switch closes upon sensing air. After pre-purge period of between 30
and 60 seconds, the Ignition Transformer is energized and the Main Gas Valve is

energized. Ignition should now occur.
TEMPERATURE
CONTROL

CONVEYOR DRIVE
(S/N4390-Q17170)

(Conveyor Drive
Q171701 & Above See
Page 9)
(Time/Temp Display
Q17171 & Above See
Page 9)

TIME/TEMP
DISPLAY(Q17171 &
Above See Page 9

Closing the Fan Switch supplies (through the Step down Transformer) 120 VAC to

the Temperature Control Board. The 2.5K ohm Temperature Potentiometer is

adjusted to desired temperature. The Thermocouple will provide varying millivolts to

the Temperature Controller. The Temperature Controller supplies 120 VAC to the

Solenoid Valve at intermittent intervals to maintain desired temperature.

Closing the fan switch and the normally open conveyor switch supplies 120 VAC to

the Motor Control Board. AC volts are converted to DC volts and are supplied to the

Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control

Potentiometer (5,000 ohm 10 turn) will change resistance at terminals P1, P2, and

P3 varying the DC voltage to the Conveyor Motor. The speed of the conveyor motor

will increase or decrease as the DC voltage from the board increases or decreases

respectively. As the motor turns, it drives both the reducer gearbox and the tach.

generator. The tach. generator is a DC voltage generator which supplies a voltage to

the DC motor control board and is used as a reference for maintaining a constant

conveyor speed.

The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120

VAC to the primary of the 12.6 volt Transformer. The secondary output of the

transformer, normally 13 to 14 VAC (depending on input), with a center tap, is

supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is

terminal 2. The display works on a balanced input and center tap voltage to each leg

must be 1/2 the total reading.

The speed side of the Time Temp. Display uses a slotted disc (cemented to tach.

coupling) to break the infra-red light beam of the optical switch (mounted on gear

motor) producing electrical pulses that are transmitted to the display. The display

converts these pulses into a read-out of minutes and seconds.

The temperature portion of the display uses a Thermistor Probe to sense oven

temperature. The thermistor outputs a resistance proportional to the oven

temperature. This resistance is then converted by the display into a temperature

reading.

SEQUENCE OF OPERTIONS 1032

MODEL 1032 - 380Y/220 VAC - 50 HZ - 3 PHASE

POWER SUPPLY Electrical Power to be supplied to the Oven by a five conductor service

Black conductor is Hot
Red conductor is Hot
Orange conductor is Hot
White conductor is Dedicated Neutral
Green conductor is Ground

MAIN FAN CIRCUIT Electrical power is permanently supplied through 3, 50A fuses to the normally open

contacts of the Mercury Contactor. Power is also supplied through one 10A fuse to

the normally open contact of the Main Fan Relay, through a 1A Fuse to the normally

open Double Pole Main Fan Switch, and to the normally open Cool-Down

Thermostat (thermostat closes at 160°F and opens at 140°F.) Closing the Main Fan

Switch supplies 220VAC to the primary of the control circuit Step Down Transformer.

(The transformer steps the voltage down to 120 VAC for the control circuit.) 120 VAC

is supplied to the coil of the Main Fan Relay. The coil of the relay is energized, the

normally open contacts close, energizing the Main Fan Motor. Closing the Main Fan

Switch also supplies power to the 12.6 VAC Transformer, the Control Box Cooling

Impinger I -–1000 Series Service Manual - International 7

Fan, and the Heat and Conveyor Switches.
TRANSFORMER (12.6
VAC)

HEAT CIRCUIT Closing the Fan Switch and the normally open Heat Switch supplies 120 VAC

TEMPERATURE
CONTROL

CONVEYOR DRIVE
(S/N 4390 AND UP)

TIME TEMP DISPLAY The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120

Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC

Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to

14 VAC) with a center tap, and supplies power to the Time/Temp Display. The

voltage from each leg of the Transformer's secondary to the center tap should be

one half of the secondary voltage.

through the normally open Air Pressure Switch, and the normally closed Hi-Limit

Thermostat (manually re-settable, opens at 368°C) through the 3A Fuse, to the

Temperature Control Board, the coil of the Mercury Contactor, and to the Heat

Indicator Light.

When the Heat Switch is closed, 120 VAC is supplied to the Temperature Control.

The Temperature Control Potentiometer (2.5K ohm) is adjusted to desired

temperature. The Thermocouple will provide varying millivolts to the Temperature

Controller. The Temperature Controller switches the L2 line of the Contactor coil at

intermittent intervals to maintain desired temperature.

Closing the fan switch and the normally open conveyor switch supplies 120 VAC to

the Motor Control Board AC volts are converted to DC volts and are supplied to the

Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control

Potentiometer (5,000 ohm 10 turn ) will change resistance at terminals P1, P2, and

P3 varying the DC voltage to the Conveyor Motor. The speed of the conveyor motor

will increase or decrease as the DC voltage from the board increases or decreases

respectively. As the motor turns, it drives both the reducer gear box and the tach.

generator. The tach. generator is a DC voltage generator which supplies a voltage to

the DC motor control board and is used as a reference for maintaining a constant

conveyor speed.

VAC to the primary of the12.6 volt Transformer. The secondary output of the

transformer, normally 13 to 14 VAC (depending on input), with a center tap, is

supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is

terminal 2.The display works on a balanced input and center tap voltage to each leg

must be 1/2 the total reading.

The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach.

coupling) to break the infra-red light beam of the optical switch (mounted on gear

motor) producing electrical pulses that are transmitted to the display. The display

converts these pulses into a read-out of minutes and seconds.

The temperature portion of the display uses a Thermistor Probe to sense oven

temperature. The thermistor outputs a resistance proportional to the oven

temperature. This resistance is then converted by the display into a temperature

reading.

SEQUENCE OF OPERATIONS / 1033, 1034, 1046, 1047

MODEL 1033 / 220 VAC - 50HZ / NATURAL GAS
MODEL 1034 / 220 VAC - 50HZ / L.P. GAS
MODEL 1046 / 240 VAC - 50HZ / NATURAL GAS
MODEL 1047 / 240 VAC - 50HZ / L.P. GAS

POWER SUPPLY Electrical Power to be supplies to the oven by a three-conductor service.

Brown conductor is Hot

Blue conductor is Neutral

Green conductor is Ground
CONTROL BOX AUTO
COOL DOWN

MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the oven

When the temperature in the Control Box reaches 120°F± 3°, the Cooling Fan

Thermostat will switch power to the Control Box Cooling Fan. The Thermostat will

interrupt power to the Cooling Fan when the Control Box temperature falls to

100°F±3°.

fan motor relay, the Cooling Fan Thermostat, and the normally open Oven Fan

Switch. Closing the oven fan switch supplies 220 VAC, through a 3 AMP Fuse, to the

primary of the Power Transformer (the transformer steps the voltage down to 120

VAC for the control circuit). 120 VAC is supplied to the Cooling Fan, the normally

open Conveyor Switch, the Electronic Temperature Control, and to the coil of the

Impinger I -–1000 Series Service Manual - International 8

oven start and cool down relay. Its normally open contacts close, supplying 220 VAC

to the Burner Switch and enabling the 20-minute Time Delay module. The 20-minute

Time Delay module supplies 120 VAC to the oven fan motor relay, these normally

open contacts now close, supplying 220 VAC to the Oven Fan Motor.
TRANSFORMER(12.6V
AC)

Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC

Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to 14

VAC) with a center tap, and supplies power to the Time/Temp Display. The voltage

from each leg of the Transformer's secondary to the center tap should be one half of

the secondary voltage.
BURNER CIRCUIT Closing the normally open burner switch supplies 220 VAC through the oven air

pressure switch, the gas inlet pressure switch, the normally closed high limit

thermostat (opens at 368°C) to the ignition control. The combustion motor is now

energized. The normally open burner blower air pressure switch closes upon sensing

air pressure. After a pre-purge period of 30-60 seconds, the main gas valve and the

spark generator are energized. Ignition should now occur. After proving the pilot

flame, and a 30 second delay, the gas control relay and the burner indicator lamp are

energized.
TEMPERATURE
CONTROL

Closing the Fan Switch supplies (through the Step Down Transformer) 120 VAC to

the Temperature Control Board. The Temperature Potentiometer is adjusted to

desired temperature. The Thermocouple will provide varying millivolts to the

Temperature Controller. The Temperature Controller supplies 120 VAC to the

Solenoid Valve at intermittent intervals to maintain desired temperature. (An

electronic flame monitor proves main flame operation in the 1033-1034 models)
CONVEYOR DRIVE Closing the Oven Fan Switch supplies 120 VAC, through the Power Transformer, to

the normally open Conveyor Switch. Closing the Conveyor Switch supplies 120 VAC,

through a 3 AMP Fuse, to the primary of the Conveyor Control Transformer. The

secondary of this Transformer supplies 10 VAC and 29 VAC to the Conveyor Control.

The conveyor control supplies voltage pulses to the Conveyor Control. The Conveyor

Control Potentiometer varies the frequency of these pulses. The motor speed will

increase or decrease, as the frequency of the pulses increase or decrease

respectively.
TIME TEMP DISPLAY Closing the Oven Fan Switch supplies 120 VAC, through the Power Transformer, to

the primary of the Time/Temp. Transformer. The secondary output of the

Transformers, 12.5 to 15 VAC with a center tap, is supplies to terminals 1, 2, and of

the Time/Temp. Display. The display works on a balanced input, and the center tap

voltage to each leg must be 1/2 the total reading.The speed side of the Time/Temp.

Display is supplied, by the Conveyor Control, with the frequency of the pulses to the

Conveyor Motor. This frequency is converted by the Time/Temp. Display into a read

out of minutes and seconds. NOTE: The Conveyor Control uses a sensor and

magnet, mounted on the Conveyor Motor that senses when the motor is not turning. If

the motor is not turning, the Time/Temp Display will show --:-- in the window. The

temperature portion of the display uses a Thermistor Probe to sense oven

temperature. The Thermistor outputs a resistance proportional to oven temperature.

This resistance is then converted by the Display into a temperature reading.

OR:

The temperature portion of the display uses a "J" type thermocouple to measure oven

temperature. The thermocouple generates D.C. millivolts proportional to oven

temperature. This millivolt reading is then converted by the display into a temperature

reading.

Impinger I -–1000 Series Service Manual - International 9

SEQUENCE OF OPERATIONS 1042 / 1043 / 1242 / 1243

MODEL 1042 - 240V - 50HZ - NATURAL GAS
MODEL 1043 - 240V - 50HZ - L.P. GAS
MODEL 1242 - 240V - 50HZ - NATURAL GAS/DUAL BELT
MODEL 1243 - 240V - 50HZ - L.P.GAS/DUAL BELT

POWER SUPPLY Electrical Power to be supplied to the Oven by a three conductor service.

Black conductor is Hot
Red conductor is Neutral

Green conductor is Ground
CONTROL BOX AUTO
COOL DOWN

MAIN FAN CIRCUIT Electrical power is permanently supplied to the normally open contacts of the Double

TRANSFORMER (12.6
VAC)

BURNER CIRCUIT Closing the Fan Switch and the normally open Burner Switch supplies 120 VAC

TEMPERATURE
CONTROL

CONVEYOR DRIVE
(S/N Q14790 & Below,
1200 series
S/N Q14973 & Below,
1000 series)

(S/N Q14791 & Above,
1200 series
S/N Q14974 & Above,
1000 series refer to
Pg. 9)

When the temperature in the Control Box reaches 120°F + 3°, the Cooling Fan
Thermostat will switch power to the Control Box Cooling Fan. The Thermostat will
interrupt power to the Cooling Fan when the Control Box temperature falls to 100°F +
3°.

Pole Main Fan Relay, the Cooling Fan Thermostat, the normally open Double Pole
Main Fan Switch, and the normally open Cool Down Thermostat (thermostat closes
at 160°F and opens at 140°F). Closing the Main Fan Switch supplies 240 VAC
through a 3A Fuse to the primary of the control circuit Step Down Transformer. The
Transformer steps the voltage down to 120 VAC for the control circuit. 120 VAC is
supplied to the coil of the Double Pole Main Fan Relay. The coil of the relay is
energized. The normally open contacts now close, energizing the Main Fan Motor
through one 10A Fuse. Closing the Fan Switch also supplies power to the Cooling
Fan, the 12.6 VAC Transformer the Burner and Conveyor Switches.
Upon closure of the Fan Switch, 120 VAC is supplied to the primary of the 12.6 VAC
Transformer. The Transformer steps the voltage down to 12.6 VAC (normally 13 to
14 VAC) with a center tap, and supplies power to the Time/Temp Display. The
voltage from each leg of the Transformer's secondary to the center tap should be
one half of the secondary voltage.

through the Air Pressure Switch, to the Temperature Control Board, the normally
open contacts of the Burner Motor Relay (Burner Motor Relay discontinued after S/N

14791) and the primary of the 24 VAC Transformer. The transformer's secondary
supplies 24 VAC to the burner motor relay coil (the normally open contacts close
within 30 seconds), and the normally open Centrifugal Switch. When the relay
contacts close, the Burner Blower Motor is energized. As this motor reaches approx.
1,600 R.P.M its internal centrifugal switch closes, supplying 24 VAC to the Gas
Control Valve. When the Gas Control Valve is supplied with 24 VAC, the pilot valve
is energized, and the igniter circuit is energized. Ignition should now occur. After pilot
flame is proven, the Main Gas Valve is energized. The Burner Indicator Light is also
energized.
Closing the Fan Switch and Burner Switch supplies 120 VAC to the Temperature
Control Board. The 1K or 1000 ohm Temperature Potentiometer is adjusted to
desired temperature. The Thermocouple will provide varying millivolts to the
Temperature Controller. The Temperature Controller supplies 120 VAC to the
Solenoid Valve at intermittent intervals to maintain desired temperature.
Closing the fan switch and the normally open conveyor switch supplies 120 VAC to
the Motor Control Board. AC volts are converted to DC volts and are supplied to the
Conveyor Motor at terminals A+ and A-. Adjustment of the Speed Control
Potentiometer (5,000 ohm 10 turn ) will change resistance at terminals P1, P2, and
P3 varying the DC voltage to the motor. The speed of the conveyor motor will
increase or decrease as the DC voltage from the board increases or decreases
respectively. As the motor turns, it drives both the reducer gearbox and the tach.
generator. The tach. generator is a DC voltage generator which supplies a voltage to
the DC motor control board and is used as a reference for maintaining a constant
conveyor speed.

Impinger I -–1000 Series Service Manual - International 10

TIME/TEMP
DISPLAY(S/N Q14790 &
Below, 1200 series S/N
Q14973 & Below, 1000
series)

(S/N Q14791 & Above,
1200 series S/N Q14974
& Above,
1000 series refer to Pg.

9)

The Time/Temp. Display is energized when the Fan Switch is closed, supplying 120
VAC to the primary of the12.6 volt Transformer. The secondary output of the
transformer, normally 13 to 14 VAC (depending on input), with a center tap, is
supplied to terminals 1,2, and 3 of the Time/Temp. Display. The center tap is
terminal 2. The display works on a balanced input and center tap voltage to each leg
must be 1/2 the total reading.
The speed side of the Time/Temp. Display uses a slotted disc (cemented to tach.
coupling) to break the infra-red light beam of the optical switch (mounted on gear
motor) producing electrical pulses that are transmitted to the display. The display
converts these pulses into a read-out of minutes and seconds. The temperature
portion of the display uses a Thermistor Probe to sense oven temperature. The
thermistor outputs a resistance proportional to the oven temperature. This resistance
is then converted by the display into a temperature reading.

Impinger I -–1000 Series Service Manual - International 11

SCHEMATIC / 1002, 1003

Impinger I -–1000 Series Service Manual - International 12

SCHEMATIC / 1006 TO SERIAL NUMBERS Q14279

Impinger I -–1000 Series Service Manual - International 13

SCHEMATIC / 1028, 1029, S/N Q19071 & BELOW

Impinger I -–1000 Series Service Manual - International 14

SCHEMATIC / 1028, 1029, S/N Q19078 & ABOVE

Impinger I -–1000 Series Service Manual - International 15

SCHEMATIC / 1030, TO S/N Q17170

Impinger I -–1000 Series Service Manual - International 16

SCHEMATIC / 1030, S/N Q17171 & ABOVE

Impinger I -–1000 Series Service Manual - International 17

SCHEMATIC / 1032. S/N Q19077 & BELOW

Impinger I -–1000 Series Service Manual - International 18

SCHEMATIC / 1032, S/N Q19078 & ABOVE

Impinger I -–1000 Series Service Manual - International 19

SCHEMATIC / 1033, 1034, 1046, 1047

Impinger I -–1000 Series Service Manual - International 20

SCHEMATIC / 1042, 1043, S/N Q14279 & BELOW

Impinger I -–1000 Series Service Manual - International 21

SCHEMATIC / 1042, 1043, S/N Q14280 & ABOVE

Impinger I -–1000 Series Service Manual - International 22

SCHEMATIC / 1228. 1229, S/N Q14790 & BELOW

Impinger I -–1000 Series Service Manual - International 23

SCHEMATIC / 1228, 1229, S/N Q14791 & ABOVE

Impinger I -–1000 Series Service Manual - International 24

SCHEMATIC / 1242, 1243

Impinger I -–1000 Series Service Manual - International 25

TROUBLESHOOTING GUIDE 1000 & 1200 / GAS OVENS

SYMPTOM POSSIBLE CAUSE EVALUATION

Oven fan will not run

NOTE:

No Main Fan Cool
Down

No Control Box
Cooling(For ovens
equipped with Control
Box Cooling Fan)

NOTE:

No automatic control
box cooling (For ovens
equipped with control
box cooling fan)

Control box cooling fan
continues to run
Transformer, 24 VAC

Incoming Power Supply Check breakers/ Reset if required / Call Power Co.

if needed.

(Export Ovens) For some export ovens, there is a control circuit

step-down transformer. This transformer steps
down supply voltage to 120 VAC. If main fan will
not run, the secondary of this transformer must be
checked for 120 VAC output. Check specific oven

model schematic for circuit location.
Oven Fan Fuse(s) Check and/or Replace
Fuse Holder Check and/or Replace
Fan Switch Check continuity between switch terminals.
Main Relay Check continuity to 120 VAC coil. Check for power

to relay coil (120 VAC). Check for 208/240 VAC to

relay terminals. Visually check for contact pull-in.
Fan Motor Check for opens, shorts, or grounds. WITH

POWER OFF: Turn Fan Blade to check for locked

rotor.
Capacitor Check for opens, shorts, or grounds.
Cool Down Thermostat Check cool down thermostat (thermostat closes at

160°F and opens at 140°F). Check for power (120

VAC) at cool down thermostat. With the cool down

thermostat pre-heated, check for continuity. If

switch is open, replace.
Main Fan Relay

(Export Ovens)
Axial Cooling Fan

Incoming Power Supply Check breakers/Reset if needed. Check for

Cooling Fan Thermostat Check cooling fan thermostat (thermostat closes at

Axial Cooling Fan Check for 120 VAC to cooling fan, if present and

Cooling Fan Thermostat See "Cooling Fan Thermostat"

Check for 120 VAC to primary
of transformer. Check for 24
VAC from secondary of
transformer. If there is
primary voltage, but no
secondary voltage, replace
transformer.
Manual Gas Shut-off Valve Check to see that manual shut-off valve is open.
Fan Switch Check to see that fan switch is "on".
Main Oven Fan Check if main oven fan is operating. If not, refer to

Check for power to Main Fan Relay. Visually check

for contact pull in.

(For ovens equipped with a control circuit step-

down transformer, the supply voltage for the

cooling fan is 240 VAC.)

WITH POWER OFF: check for locked rotor. Check

for power (120 VAC) to cooling fan. If 120 VAC is

present at the fan motor and the fan does not run,

replace fan assembly.

incoming power (120 VAC)at cooling fan

thermostat.

120°F and opens at 100°F). With cooling fan

thermostat pre-heated, check for continuity. If

switch is open, replace.

fan does not run, replace fan.

Check for adequate gas supply to oven.

"Oven fan will not run". Page 26.

Impinger I -–1000 Series Service Manual - International 26

NOTE:

For ovens with
Johnson Controls
Ignition Control

(For ovens with
Honeywell Ignition
control, See Pg. 28)

Burner Switch Check for 120 VAC to neutral on both sides of

switch. If switch is closed and 120 VAC is present

on one side only, replace the switch.
Air Pressure Switch Check for 120 VAC on both sides of switch. If

voltage present on one side only, check for air tube

blockage. Adjust air switch. If above fails, replace

air pressure switch.

(Model 1004 & 1005) For oven models 1004 and 1005, there is a 1 Amp

fuse located between the 24 VAC output from the

transformer and the coil of the burner motor relay. If

there is 24 VAC output from the transformer, but no

burner motor relay action, check fuse and fuse

holder. Replace as necessary.
Burner Motor Relay Delete burner motor relay refer to page 55.
Burner Blower Motor Check for 120 VAC supply to burner blower motor.

If 120 VAC is present and motor does not run,

replace motor. WITH POWER OFF: turn blower

wheel to check for locked rotor.
Centrifugal Switch of Burner
Blower Motor

Check for 24 VAC output from secondary of

transformer. If voltage is present, check for 24 VAC

at pin 6 and the ground bar on ignition control and

valve assembly. If the burner blower motor is

running and there is no voltage at pin 6 and the

ground bar on the ignition control valve, replace the

burner blower motor.
Ignition Control and Valve
Assembly

Check for 24 VAC supply to the ignition control and

valve assembly at pin 6 and the ground bar. If

voltage is present, check for 24 VAC across pin #1

and the ground bar (pilot valve). If voltage is not

present, replace electronic control package. If the

pilot valve is energized, check to see that the high

voltage ignitor circuit is also energized. To check,

disconnect the ignitor lead from the bottom of

ignition control. Place female terminal of ignitor

lead approximately 1/8" from terminal post on

ignition control. Spark should jump the 1/8" gap. If

no spark is present, replace ignition control.
No Pilot If the ignition control is supplied with 24 VAC, and

the pilot valve (internal to valve assembly) and

ignitor circuits are energized, visually check for pilot

flame. This may be done by opening the small

inspection door on the end of the burner, or by

opening the main oven door and looking under the

lower finger housings on the right side of the oven.

If no pilot flame is visible, check the following.
Pilot Shut-off Valve Check to see that pilot shut-off valve is open (shut-

off valve is located between ignition control and

valve assembly and burner.)
Pilot Tube Check for gas pressure at pilot tube. Disconnect

pilot tube at burner and connect manometer to pilot

tube. If no gas pressure is present, check for

blockage in pilot tube or pilot shut-off valve. If these

are clear, and there is gas supplied to the oven,

replace the ignition control and valve assembly.
Pilot Orifice If there is gas pressure at the pilot tube, check the

pilot orifice for obstructions. Replace as need
Burner Ignitor Check the burner ignitor head for any obstructions,

also check for frayed or broken wire, any type of

damage to spark gap (.100 in. 2.5 m.m.) If there is

visible damage, replace ignitor assembly.

Impinger I -–1000 Series Service Manual - International 27

Pilot flame but no main
flame

For ovens with
Honeywell ignition
control

No Pilot

Flame Sensor (There should be a visible pilot flame at this time.)

To check for proper flame sensor operation,

connect a digital multimeter (capable of measuring

D. C. microamperes) in series between the flame

sensor wire (normally connected to terminal #4)

and terminal #4. NOTE: This is a current

measurement and the meter must be connected in

series. This procedure is for checking the pilot

flame only. Remove main valve wire (Red) from

terminal #3 on ignition control. With a visible pilot

flame, the current readings should be as follows:

Johnson G-65 control, 0.2 micro amp. D.C.

minimum/Johnson G-60 control, 0.7 micro amp.

D.C. minimum. If these values are not achieved,

replace flame sensor. Also check for any type of

damage to flame sensor wire and connections.
Ignition Control and Valve
Assembly

Centrifugal Switch of Burner
Blower Motor

NOTE:

Ignition Control Check for 24 VAC supply to ignition control at

Pilot Shut-off Valve

Pilot Tube Check for gas pressure at pilot tube. Disconnect

Pilot Orifice If there is gas pressure at the pilot tube, check the

If there is a pilot flame, and there is sufficient micro

amp. current at terminal #4, check for 24 VAC

that the main valve (internal to valve assembly) has

opened. Connect a manometer to the manifold gas

pressure tap located on the back side of the ignition

control and valve assembly. If no gas is present,

replace ignition control and valve assembly.

Check for 24 VAC output from secondary of

transformer. If voltage is present, check for 24 VAC

at terminals marked "24V" and "24V gnd" on

Ignition Control. If the Burner Blower Motor is

running and there is no voltage at terminals 24V

and 24V gnd on the ignition control, replace the

Burner Blower Motor.

These Ignition Controls have a 30 second pre-

purge(Delay) and a 15 second lock-out time – The

Ignition Control will try for ignition for 15 seconds

and then shut-off. To Re-try for ignition, turn off

burner switch, wait 30 seconds and re-try ignition.

terminals "24V" and "24V gnd". If voltage is

present, check for 24V at terminal "P.V. (Pilot

Valve) and "gnd". If voltage is not present, replace

Ignition Control. If the pilot valve is energized,

check to see that the high voltage ignitor circuit is

also energized. To check, disconnect the ignitor

lead from the ignition control. Place the terminal of

ignitor lead approximately 1/8" from terminal post

on Ignition Control. Spark should jump the 1/8"

gap. If no spark is present, replace ignition control.

If the ignition control is supplied with 24 VAC and

the pilot valve (in gas valve) and ignitor circuits are

energized, visually check for pilot flame. This may

be done by opening the small inspection door on

the end of the burner, or by opening the main oven

door and looking under the lower finger housing in

the right side of the oven.

If no pilot flame is visible, check to see that the pilot

shut-off valve is open (shut-off valve is located

between gas valve and burner).

pilot tube at burner and connect manometer to pilot

tube. If no gas pressure is present, check for

blockage in pilot tube or pilot shut-off valve.

pilot orifice for obstructions. Replace as needed.

Impinger I -–1000 Series Service Manual - International 28

Burner Ignitor Check the burner ignitor head for any obstructions,

also check for frayed or broken wire, any type of

damage to spark gap (.100 in. 2.5 mm) If there is

visible damage, replace ignitor assembly.

Pilot flame but no main
flame

Spark Ignitor (Flame Sensor) (There should be a visible pilot flame at this time).

NOTE: The Honeywell Ignition Control uses the

spark ignitor as the flame sensor. If spark

continues, check for proper ground connections at

Ignition Control. Check pilot orifice for any partial

blockage. If the above checks OK, replace ignition

control. If spark stops when pilot is lit, check for 24

VAC across M.V. - M.V/ P.V. terminals, if voltage is

not present, replace ignition control. If voltage is

present at terminals M.V. - M.V./P.V., the indicator

light on the control panel should be on, verify that

the main valve has opened, connect manometer to

manifold gas pressure tap (located on the back

side of the gas valve). If no gas is present, replace

gas valve.

Red Indicator Light is
on, but no main
flame(For ovens with

mechanical
thermostat)
(For ovens with
Electronic
Temperature Control)

Temperature Control Valve
(Robert Shaw)
Main Orifice Check for blockage of main orifice. If there is no

Temperature Control
Potentiometer

Check for gas supply at temperature control. Check

for temperature control set above 300°F.

blockage to the main orifice, replace the

temperature control.

Check for 120 VAC across L1 and L2on

temperature control board. Potentiometer (1000

ohm,1 turn) WITH POWER OFF: check ohms

across red and black leads, the ohm reading

should be 0 to1000 ohms as the dial is turned.

From green to red, the reading should be 1000

ohms steady throughout the full turn of the dial.

NOTE: Ovens S/N Q18037 and above, the potentiometer is internal to temperature control. Proceed to next
component.

Thermocouple Probe Remove thermocouple leads from the temperature

control board, and measure the millivolt output of

these leads. Refer to chart on page 59 in the

adjustment section for proper readings.
Temperature Control Turn temperature control dial to full "on" position.

Measure for 120 VAC across terminals "N.O." and

"L2", if voltage is not present; replace control.
Solenoid Valve If voltage is present at terminals "N.O." and "L2",

check for voltage at solenoid valve. If voltage is

present, listen for valve to open and close. Also,

check for opens and shorts in coil. If solenoid valve

is defective, replace

Intermittent Heating Both the main fan motor and burner blower motor

are equipped with thermo-protection and will cease

to operate when not cooled properly. This can

cause the units to cycle on and off intermittently.

Also, most of the problems listed under "oven will

not heat" can cause intermittent failures.

For continuing intermittent problems, a series of test lights may be made and installed in
the ovens. The lights will allow the customer to advise the service technician a trouble code when
the oven fails.

The lights should be connected in the following manner:

Light#l attached in 120VAC line after Air Pressure Switch.
Light#2 attached after 120VAC contacts of Burner Motor Relay (or, refer to Bulletin #028
for Relay Removal).
Light#3 in 24VAC Burner Transformer Secondary.

Impinger I -–1000 Series Service Manual - International 29

Light#4 in 24VAC at terminal #6 of Johnson control valve or "24V" on Honeywell Control.
Light#5 in 24VAC at terminal #1 of Johnson control valve or "PV" on Honeywell Control.
Light#6 in 24VAC at terminal #3 of Johnson control valve or "MV" on Honeywell Control.
CODE:
All lights off - lights of main power, main fan off, air pressure switch out.
1 on 2 off 3 on 4 off 5 off 6 off - Burner Motor Relay bad.
1 on 2 on 3 on 4 off 5 off 6 off - Burner Motor Centrifugal Switch bad.
1 on 2 on 3 on 4 on 5 off 6 off - Ignition Control bad.
1 on 2 on 3 on 4 on 5 on 6 off - Pilot Shield missing or warped, Flame Sensor bad, Pilot

- Orifice plugged, or Gas Valve bad.
1 on 2 on 3 on 4 on 5 on 6 on - Unit still not working Main Orifice plugged, Gas Valve bad,

- Temperature Control bad.

- However, Main Orifice would not be intermittent problem.

Impinger I -–1000 Series Service Manual - International 30