Middleby PS310, PS360 Service Manual

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Page 1

Part No. 88210

0019

TTEECCHHNNIICCAALL

MAANNUUAALL

MODELS PS 310/360,

PS360

MODEL PS200 PACESETTER OVENS

PS200

Price $30.00 R. 5/98, Rev.B,Ver. 2

Page 2

WWAARRNNIINNGG

POST IN A PROMINENT LOCATION, INSTRUCTIONS TO BE

FOLLOWED IN THE EVENT YOU SMELL GAS.

Instructions to be followed in the event the user smells gas shall be obtained by consulting the local gas supplier. If the

smell of gas is detected, immediately call the emergency phone number of your local Gas Company. They will have personnel and provisions available to correct the problem.

FFOORR YYOOUURR SSAAFFEETTYY

DO NOT STORE OR USE GASOLINE

OR OTHER FLAMMABLE VAPORS AND LIQUIDS

OVEN MUST BE KEPT FREE AND CLEAR

OF COMBUSTIBLES AT ALL TIMES

NNOOTTIICCEE

Using any parts other than genuine

Middleby Marshall factory

manufactured parts relieves the

manufacturer of all liability.

WWAARRNNIINNGG

There must be adequate clearance

construction. Clearance must also be

provided for servicing and operation.

NNOOTTIICCEE

between oven and combustible

NNOOTTIICCEE

Middleby Marshall (Manufacturer)

reserves the right to

change specifications

at any time.

WWAARRNNIINNGG

Do Not Obstruct The Flow Of Combustion

And Ventilation Air To And From Your Oven.

Page 3

Section

1 PS310/360 Functional Operation

1 I.

Gas Oven Sequence of Operation

A. Door Switch

B. Closing the Door Switch

C. Closing the Conveyor Switch

D. Closing the Blower Switch

E. Closing

the Heat Switch

F. Heat Switch Light

2 II.

Electric Oven Sequence of Operation

A. Door Switch

B. Closing the Power Relay

C. Closing Conveyor Switch

D. Closing Blower Switch

E. Closing the Heat Switch

PS200 F

unctional Operation

4 I.

Gas Oven Sequence of Operation

A. Door Switch

B. Closing the Door Switch

C. Closing the Convey or Switch

D. Closing the Blower Switch

E. Closing the Heat Switch

F. Heat Switch Light

5 II.

Electric Oven Sequence of Operation

A. Door Switch

B. Closing the Door Switch

C. Closing Conveyor Switch

D. Closing Blower Switch

E. Closing the Heat Switch

Section

2 – Servicing Components

7 I.

Digital Loop C

onveyor Control

A. Controller and Microcomputer Parts

B. Identifying Microcomputer Chip

C. Pre

troubleshooting Checkout Procedure For

Pacesetter Oven Digital Loop Conveyor Control

D. Controller/Motor Failure

E. Troubleshooting Convey or System

F. Troubleshooting Controller

G. Conveyor Control Check Using a

Frequency Counter

H. Conveyor Controller Pickup Test

Conveyor Motor Test

J. Magnetic Pickup Replac

ement

PS360/570 Conveyor Sensor Wiring Changes

19A Dip Switch Conveyor Control Assembly

19B

II.

Temperature Controller

A. Honeywell (DialaPak) Controller

PS570S Thermocouple Wiring

26A B. Thermoc

ouple (Type J)

C. High Limit/Cooldown Switch

D. Troubleshooting Limit Switches

E. Testing Procedure for Temperature Controller

Part

1 - High Limit Switch and Thermocouple

Using the Altek Testing Device

Digital Temperature Controller P/N

28071

0028 31 B Part

2 - Oven Temperature Adjustment

Part 3

- Temperature Controller Main

Board Replacement

33 III. Motor Centrifugal Safety Switch

37 IV.

Air Pressure Sw

itch

PS200

ONLY

37 V. Gas Burner and Tram

A. Sequence of Operation

B. Intermittent Ignition Device

C. Gas Burner Components

Burner Pilot/lgnitor Assembly Changes,

7/22/91

42A Pilot Line Tee Kit

42C D.

Burner Troubleshooting

E. Burner Ignition System

- Start-up and Checkout

Honeywell Ignition Module

48A

VI.

High Flame Solenoid Valve

55 VII.

Main Gas Valve

55 VIII.

Low Flame Orifice

Gas Control Kit Changes,

11/27/91

56A

IX.

LP Conversion Kit

Gas Conversion Kit Changes,

12/19/94

60A

NOTE:

The PS

310

and

PS360 ovens are very

similar. For

simplification and

clarification purposes,

all references in this

manual to the

PS310 also include

the PS360 except

where noted.

TABLE OF CONTENTS

Page

Page 4

TABLE OF CONTENTS (continued) Page

Pipe Sizing

XI.

Electrically Heated Oven

- PS310/360 ONLY

A. Ratings of Heating Elements

B. Operation

C. Checking the Heating Elements

D. Changing Heating Elements

XII.

Electric

ally Heated Oven

- PS200 ONLY

A. Rating of Heating Elements

B. Operation

C. Checking the Heating Elements

D. Changing Heating Elements

XIII.

Electrically Heated Oven

ALL MODELS

Mercury Contactor Replacement

A. Replacing the Coil And/Or Contact Tube

PS360 Electric Oven

B. Replacing the Coil And/Or Contact Tube

PS200

Electric Oven

XIV.

Blowers

- PS3

10/360

ONLY

A. Blower Balancing

B. Direction of Blow

er Rotation

- PS31

0/360

ONLY

XV.

Blowers

- PS200

ONLY

A. Blower Balancing

B. Blower Rotation

C. Main Blower Fan Shaft Bearings Lubrication

D. Checking Main Blower Fan Belt

84 E. PS200

Fan Shaft Bearing Replacement

and Alignment

PS200

Indirect Fan Drive Assembly Changes,

7/1/90

86A

XVI.

Air Distribution

A. Test Bake

B. Dough Test

88 XVII.

Finger Usage

Identification

A. Basic Finger Components Explanation

B. Chart o

f Fingers Used in Oven Models

C. Finger List with Photos and Explanations

D. Model

360

Standard (Shutter) Finger Adjustment

103 Section

3 - Troubleshooting

107

PS310/360

107

I. Blowers

107

II.

Conveyor

107

III. Heat (Gas Oven)

107

IV.

Trial for Flame

108

V. Heat (Electric Oven)

109 PS200

110

I. Blower Fan

110

II.

Conveyor

110

III. Heat (Gas Oven)

110

IV.

Trial for Flame

111

V. Heal (Electric Oven)

111

Section

4 113

Electrical Schematics

PS310/360

114 Gas Oven Schematic, 208

240V, 50/60Hz, 1Ph, 3W

114

Gas Oven Schematic, 208

240V, 50/60Hz,

Ph, 4W

114A

Gas Oven Scnematic, 208

240V,50/60Hz, 1Ph,2W, ExportOnly

115

Gas Oven Schematic, 190

380V, 50/60Hz,

Ph, 2W, Export Only

116

Electric Oven S

chematic, 200

220V, 50/60Hz, 3Ph, 3W, Export

117

Electric Oven Schematic, 208

240V, 50/60Hz, 3Ph, 4W

with Single Phase Blower Motor

118

Electric Oven Schematic, 208

240V, 50/60Hz, 3Ph, 4W

with 3 Phase Blower Motor

119

Electric O

ven Schematic, 240V, 50/60Hz, 3Ph, 3W

120

Electric Oven Schematic, 380V, 50/60Hz, 3Ph, 3W, Export Only

121

Electric Oven Schematie, 480V, 50/60Hz, 3Ph , 3W

122

Electric Oven Schematic, 400

440V, 50/60Hz, 3Ph, 3W, Export

123 PS

200

Schematics

124

Gas Oven

Schematic, 208

240V, 50/60Hz

, 1

Ph , 3W 124

Gas Oven Schematic,

208-240V, 50/60Hz,

1Ph,

4W 124A

Gas Oven Schematic, 200V, 50/60Hz, 1 Ph, 2W

125

Gas Oven Schematic, 208V, 50/60Hz, 1 Ph, 2W

126

Gas Oven Schematic, 220

240V, 50/60

Hz, 1Ph, 2W

127

Electric Oven

Schematic, 208

240V, 50/60Hz , 3Ph , 4W

128

Electric Oven

Schematic , 380V ,50/60Hz , 3Ph , 4W

129

Electric Oven Schematic , 400

416V, 50/60Hz ,3Ph, 4W

130

Appendix 131

Page 5

SECTION 1

PS31

0/360

FUNCTIONAL OPERATION

SECTION 1

FUNCTIONAL OPERATION

NOTE: This section to be used in conjunction with the electrical wiring diagrams in Section 4. Complete description and troubleshooting of individual components are explained in Section 2.

D. Closing the Blower Switch

FUNCTIONAL OPERATION

I. GAS OVEN SEQUENCE OF OPERATION

AIl gas heated ovens operate on 208/230 V, single phase.

Incoming power wiring for the (208/230 V) ovens require 2-single phase 208/230 V supply (hot) lines, 1 neutral and 1 safety ground. From either hot line to neutral the voltage should never exceed 130V.

A. Door Switch

Closing the control cabinet door will close the Door Switch. The Door Switch has a "cheater" position. When the control cabinet door is open, grasp the switch actuator and pull it out as far as possible. This will close the Door Safety Switch and permit troubleshooting. Closing the control cabinet door will reset the switch.

B. Closing the Door Switch

1. Closing the Door Switch permits a circuit to go through the motor fuse, (two 9 Amp fuses per motor for a 208/240 V oven).

Closing the Blower Switch energizes:

1. Two Cooling (axial fan) Motors.

2. Blower Motor Contactor (C1). Closing this contactor starts both Blower Motors. When

both Blower Motors are up to speed a Centrifugal Switch located inside the rear end of both Motors will close, setting up the heat circuit.

3. Temperature Controller.

E. Closing the Heat Switch

Closing the Heat Switch completes a circuit:

1. Through the Heat Switch.

2. Through the Blower Motor Centrifugal Switches.

3. Through the Temperature High Limit Switch.

4. One circuit then goes to the: a. Burner (L1).

b. Transformer (110 V to 24 V).

2. Also, closing the Door Switch permits a circuit to go through a 9 amp fuse to one side of the Conveyor Switch, Blower Motor Switch, Cooldown Relay and to the Heat (Burner) Switch.

C. Closing the Conveyor Switch

Closing Conveyor Switch permits a circuit to go to the Variable Speed Conveyor Motor Control. This serves two functions:

1. One is to convert AC to DC.

2. The second is to achieve infinite speed control of the Conveyor Motor by adjusting the Thumbwheel to the desired conveyor belt speed.

c. Motor Relay Coil. On a cold start the heater on this relay takes about 30 seconds to warm up before the relay will energize. This gives an additional prepurge.

d. Burner Blower Motor. As the Burner Motor reaches full operating RPM the Centrifugal Switch (Rear End Motor Switch) closes and applies voltage to the Burner Control. This energizes the Ignitor Control Spark Transformer and the Pilot Valve. The spark then lights the Pilot. The Flame Sensor proves the presence of the pilot flame and the Ignitor Control then shuts off the spark. At the same time, the Main Burner Valve is opened. The Main Burner is then ignited.

Page 6

SECTION 1

II.

ELECTRIC OVEN SEQUENCE OF OPERATION.

FUNCTIONAL OPERATION

If the Pilot does not light within approximately 90 seconds, the oven will shut down. All 310/314/360's have 100% lockout modules for oven shut down.

The Pilot and Main Gas Valve will stay on (open) as long as the Heat Switch is ON and the flame is proven. If the flame goes out for any reason the Pilot will try to light for 90 seconds, and then go into automatic lockout. To relight the Pilot after it has gone into automatic lockout the Burner must be turned OFF for 60 seconds and then turned ON again.

e. Temperature Controller (Terminal 5) Power for

the Primary relay contacts for the high flame valve. As long as the temperature inside the oven is below

the setting of the Temperature Controller the Thermocouple will energize the Temperature Controller.

When the Temperature Controller is energized, one set of the contacts of the controller energize the High Flame Solenoid, another set of contacts close and energize the green primary output light located in the upper left -hand corner of the Temperature Controller dial.

F. Heat Switch Light

The Heat Switch light is an extremely useful troubleshooting tool. If after turning the Blower Switch and Heat Switch ON the Heat Switch does not light this indicates a problem with one of the safety switches (Blower Centrifugal Switch).

If the Heat Switch does light it indicates a problem in the Burner Unit (Relay, burner blower motor, control board) or High Limit Switch.

When the oven reaches the desired setting of the Temperature Controller, the Temperature Controller will be de-energized. This will de-energize the High Flame Valve and the green primary output light. The Burner will remain ON in the low flame mode. When the temperature drops a few degrees the Temperature Controller will energize and re-energize the High Flame Solenoid.

During cooldown the Temperature Controller dial will continue to read oven temperature.

NOTE: The red light on the Temperature Controller will stay ON at fire-up each day until the oven temperature goes above 180° F(82°C).

NOTE: This section to be used in conjunction with the electrical wiring diagrams, in Section 4. Complete description and troubleshooting of individual components are explained in Section 2.

All electrically heated ovens operate on a 208/230/380/440V, 3 phase, 4 wire system. The fourth wire is for a 120 V neutral ground. This 120 V neutral ground eliminates the need for a control transformer. Where a neutral is not available a 240/110V transformer is supplied.

A. Door Switch

1. Closing the control cabinet door will close the Door Switch. The Door Switch has a "cheater" position. When the control cabinet door is open, grasp the switch actuator and pull it out as far as it will go. This will close the Door Safety Switch and permit troubleshooting. Closing the control cabinet door will reset the switch.

NOTE: On all electrically heated ovens high voltage is present at fuses and contactors in machinery compartment.

B. Closing the Door Switch

Closing the Door Switch permits a circuit to go to one side of the Conveyor Switch, Blower Motor Switch and to the Heat Switch (208/240 V ovens use one 5 amp fuse in this circuit).

C. Closing Conveyor Switch

The Temperature Controller also incorporates both the High Limit Safety and the cooldown features The High Limit relay will shut the oven burner OFF if the oven goes above 650° F. If this occurs the red light located in the upper right corner of the Temperature Controller will be lit.

When the Heat and Blower Switches are turned OFF the Cooldown Relay will allow the blowers to remain ON until the oven temperature falls to 180° F (82°C).

Closing Conveyor Switch permits a circuit to go to the Variable Speed Conveyor Motor control. This serves two functions:

1. One is to convert AC to DC.

2. The second is to achieve infinite speed control of the Conveyor Motor by adjusting the thumbwheel to the desired belt speed.

Page 7

D. Closing Blower Switch

Closing Blower Switch energizes:

1. Two Cooling (axial fan) motors.

2. Blower Motor Contactors (C4 and C5). Closing this contactor starts both blower motors. When

both Blower Motors are up to speed a Centrifugal Switch located inside the rear end of both Motors will close setting up the heating circuit.

E. Closing the Heat Switch

Closing the Heat Switch completes a circuit:

1. Through the Heat Switch.

2. Through the Blower Motor Centrifugal Switch.

3. Through the Temperature Override Switch.

4. To the primary relay contacts of the Temperature Controller.

When the Thermocouple located inside the oven indicates that the temperature inside the oven has fallen below the set point indicated on the Temperature Controller the Relay Switch inside the Temperature Controller will energize Contactors C1, C2 and C3. This will in turn energize the three banks of 8 KW heaters.

SECTION 1

FUNCTIONAL OPERATION

5. When the Temperature Controller is calling for heat, another set of contacts from the Temperature Controller close and energize the green primary output light located in the upper left -hand comer of the Temperature Controller dial face.

The High Limit Safety and the Cooldown features are located separately from the temperature controller. The High Limit Relay will shut the heat circuit OFF if the oven goes above 650° F (343°C). If this occurs the red light located in the upper right comer of the Temperature Controller will be lit.

When the Heat and Blower Switches are turned OFF the Cooldown Relay will allow the blowers to remain ON until the oven temperature falls to 180° F (82°C). During cooldown the Temperature Controller dial will continue to read oven temperature.

6. When the oven reaches the desired setting of the Temperature Controller, the Temperature Controller will be de-energized. This will de-energize the coils C1, C2 and C3. This will also de-energize the green primary output light. When the temperature drops a few degrees the Temperature Controller will energize again, re-energizing contactors C1, C2 and C3.

Page 8

SECTION 1

PS200

the relay will energize

. This gives an additional

d. Burner Blower Motor. As the Burner Motor

FUNCTIONAL OPERATION

D. Closing the Blower Switch

FUNCTIONAL OPERATION

I. GAS OVEN SEQUENCE OF OPERATION

All gas heated ovens operate on 208/230 V, single phase.

A. Door Switch

B. Closing the Door Switch

1. Closing the Door Switch permits a circuit through a 9 amp fuse to one side of the Blower Motor Switch, Cooldown Relay and to the Heat (Burner) Switch.

C. Closing the Conveyor Switch

Closing Conveyor Switch completes a circuit to go to the Variable Speed Conveyor Motor Control. This serves two functions:

1. Supplies power to one side of the Conveyor Switch.

2. Energizes Blower Motor Contactor (C1). Energizing this contactor starts the Blower Motor.

When the Blower Motor is up to speed an air pressure switch located in the control compartment senses the air pressure in the air plenum and closes a switch. This completes the heat circuit.

3. Energizes the Temperature Controller.

E. Closing the Heat Switch

Closing the Heat Switch completes a circuit:

1. Through the Heat Switch.

2. Through the Air Pressure Switch.

3. Through the Temperature High Limit Switch.

4. One circuit then goes to the: a. Burner (L1). b. Transformer (110 V to 24 V). c. Motor Relay Coil. On a cold start the heater on

this relay takes about 15 seconds to warm up before prepurge.

1. One is to convert AC to DC.

2. The second is to achieve infinite speed control of the Conveyor Motor by adjusting the Thumbwheel to the desired conveyor belt speed.

reaches full operating RPM the Centrifugal Switch (Rear End Motor Switch) closes and applies voltage to the Burner Control. This energizes the Ignitor Control Spark Tr ansformer and the Pilot Valve. The spark then lights the Pilot. The Flame Sensor proves the. presence of the pilot flame and the Ignitor Control then shuts off the spark. At the same time, the Main Burner Valve is opened. The Main Burner is then ignited.

Page 9

If the Pilot does not light within approximately 90 seconds, the oven will shut down. All PS200's have 100% lockout modules for oven shut down.

e. Temperature Controller (Terminal 5) Power for the Primary relay contacts for the high flame valve.

As long as the temperature inside the oven is below the setting of the Temperature Controller the Thermocouple will energize the Temperature Controller.

F. Heat Switch Light

The Heat Switch light is an extremely useful troubleshooting tool. If after turning the Blower Switch and Heat Switch ON the Heat Switch does not light this indicates a problem with the Air Pressure Switch. If the Heat Switch does light it indicates a problem in the Burner Unit (Relay, burner blower motor, control board).

When the Heat and Blower Switches are turned OFF the Cooldown Relay will allow the blowers to remain ON

SECTION 1 FUNCTIONAL

OPERATION

until the oven temperature falls to 180° F (82°C). During cooldown the Temperature Controller dial will continue to read oven temperature.

NOTE: The red light on the Temperature Controller will stay ON at fire-up each day until the oven

temperature goes above 180° F (82°C).

II. ELECTRIC OVEN SEQUENCE OF OPERATION.

NOTE: This section to be used in conjunction with the electrical wiring diagrams, in Section 4. Complete description and troubleshooting of individual components are explained in Section 2.

All electrically heated ovens operate on a 208/230 V, 3 phase, 4 wire system. The fourth wire is for a 120 V neutral ground. This 120 V neutral ground eliminates the need for a control transformer.

A. Door Switch

1. Closing the control cabinet door will close the Door Switch. The Door Switch has a "cheater" position. When the control cabinet door is open, grasp the switch actuator and pull it out as far as it will go. This will close the Door Safety Switch and permit trouble shooting. Closing the control cabinet door will reset the switch.

NOTE: On all electrically heated ovens high voltage is present at fuses and contactors in machinery compartment.

B. Closing the Door Switch

Closing the Door Switch permits a circuit to go to one side of the Conveyor Switch, Blower Motor Switch and to the Heat Switch (208/240 V ovens use one 9 amp fuse in this circuit).

C. Closing Conveyor Sw itch

Closing Conveyor Switch permits a circuit to go to the Variable Speed Conveyor Motor control. This serves two functions:

1. One is to convert AC to DC.

2. The second is to achieve infinite speed control of the Conveyor Motor by adjusting the thumbwheel to the desired belt speed.

Page 10

Controller will be lit.

read oven temperature.

SECTION 1 FUNCTIONAL OPERATION

D. Closing Blower Switch

Closing Blower Switch energizes:

1. Supplies power to one side of Conveyor Switch.

2. Blower Motor Contactor. Closing this contactor starts the blower motor. When the

Blower Motor is up to speed an Air Pressure Switch located inside the control compartment senses the air pressure in the air plenum and closes contacts. This completes the heat circuit.

E. Closing the Heat Switch

Closing the Heat Switch completes a circuit:

1. Through the Heat Switch.

2. Through the Air Pressure Switch.

3. Through the Temperature High Limit Switch.

4. To the primary relay contacts of the Temperature Controller.

The High Limit Safety and the Cooldown features are located separately from the Temperature Controller. The High Limit Relay will shut the heat circuit OFF if the oven goes above 650° F (343°C). If this occurs the red light located in the upper right comer of the Temperature

Page 11

SECTION 2 SERVICING

I. DIGITAL LOOP CONVEYOR CONTROL

SECTION 2

SERVICING COMPONENTS

COMPONENTS

The Digital Loop Conveyor Control is used to set and monitor the speed of the conveyor. Included in the control is a Microcomputer connected to a thumbwheel switch and a Magnetic Pickup Wheel on the motor shaft. As the magnetic wheel attached to the motor shaft turns, the revolutions of the magnet are monitored by the Hall Device. The Hall Device is located next to, but not touching, the magnetic wheel. The signals are sent to the Microcomputer and the computer compares the motor speed with the speed set by the thumbwheel. The Microcomputer increases or decreases the voltage to the gearmotor depending on the signal.

Power Must Be Off Before Replacing The

Microcomputer And A Middleby Marshall

Qualified Service Technician Must Be Present.

NOTE: To property service this equipment you must use a good quality Digital Meter, preferably with a frequency counter feature. An Analog Meter will not

NOTE: The basic controller is the same for all Pacesetter Ovens (Models 314, 310, 360, 200). The only parts that must be changed per the oven model is the Microcomputer on the board. This is an advantage for the service representative because only one basic controller, one pickup and two styles of motors and Microcomputers must be stocked. See Figure 1 for description of parts.

WARNING

CAUTION

The Microcomputer Must Be Removed With The

Proper Equipment Such As A Microcomputer

Removal Tool (MMPN 27170-0190).

Page 12

SECTION 2

Terminal

SERVICING COMPONENTS

C. Pre -troubleshooting Checkout Procedure For Pacesetter Oven Digital Loop Conveyor

Control

1. Before troubleshooting the digital loop conveyor control check the following: a. Conveyor belt tight.

b. Drive chain tight and aligned. c. Drive sprockets tight (set screws). d. Axial fan running and clean (cooling). e. Motor and pickup wires on Conveyor Terminal Block are secure (see Figure 2), also wires on controller are secure.

2. Check the Pickup for the following (see Figures 3 & 4):

a. Pickup is secure. b. Magnet is not cracked or chipped. c. Magnet is not rubbing on plastic housing. d. Mounting bolt is not worn or bent.

e. Pickup bearing in good condition. f. On old style pickup (see Figure 4) gap between magnet and Hall Device is spaced approximately 1/16" or a business card thickness.

Block

Figure 2. Terminal Block in Motor Compartment on PS360.

Page 13

FIGURE 1

10A

Page 14

SECTION 2

SERVICING COMPONENTS

NOTE: Maximum Ambient Temperature 160° F.

Figure 3. Pickup

NOTE: 1. Maximum Ambient Temperature 160° F

Figure 4. Old Style Pickup

Originally Used on PS350 and Early 360 Ovens

Page 15

SECTION 2 SERVICING COMPONENTS

D. Controller/Motor Failure

When the conveyor controller fails, it is very possible that a snorted conveyor motor caused the problem. Unless the motor is changed, the installation of another conveyor controller will simply result in burning up the new controller.

You are strongly advised to bypass the conveyor controller and install the tester unit (see Figure 5) in any oven that has burned up the conveyor controller before installing a new conveyor controller to be sure the problem is in the controller and not the motor. It is much less expensive to bum out the tester than another conveyor controller.

The components for this tester can be purchased at any Radio Shack store or any good electronic supply house. This tester is not nearly as accurate or sensitive as the conveyor controller. If it is left on the oven it will give inconsistent baking results. Therefore,

CAUTION!

DO NOT turn conveyor switch on while Field

On a PS310/360 remove the Red and Black motor lead wires from the terminal block (Figure 2) and attach motor leads to field tester.

On a PS200 disconnect the Red and Black motor lead wires from the speed controller and then attach motor leads to field tester.

NOTE: To reverse conveyor motor direction, interchange Red and Black DC leads. The dimmer switch must be turned over half way to start the motor. It then can be turned down to the desired motor speed.

Components Needed: 1 - Full wave AC-DC Bridge, 400 volt, 4 ampere (Radio Shack P/N 276-11743). 1 - Light Dimmer Switch (5 amp rating). 1 - In line 5 amp AC fuse enclosed in plastic case. 2 - Alligator clips.

Figure 5. Field Tester For Conveyor Drive

Motor Controllers

Page 16

All wiring between Controller, Magnetic

Check for 120 Vac

Repair wire

Comple

te the pickup/Controller Test

Replace

Conveyor still

Complete the Motor Test

Replace

Conveyor still

Replace Speed

E. Troubleshooting Conveyor System

SECTION 2

SERVICING COMPONENTS

MOTOR ALWAYS RUNS FULL SPEED

Pickup and Motor in good condition

to Speed Controller

Yes

(See Pages 16 & 17)

Passed Failed

Microprocessor

runs to fast

Magnetic Pickup

connection

Motor OK

runs too fast

Control Board

as explained on Page 18

Motor Failed

Motor

Page 17

Yes

SECTION 2

Is thumbwheel speed selector

Set speed to customer

All wiring between Motor and Speed

Check for 120 Vac

Is there DC volta

ge present

Trace wiring

and

Replace

Still no DC

Complete the Motor Test

Replace

Motor still

Repair wire

Motor still

SERVICING COMPONENTS

MOTOR WILL NOT RUN

set to 0 minutes 0 seconds?

requirements

Yes

across terminals ARM+ and

ARM- on Speed Controller?

Yes

to Speed Controller

Microprocessor

Control in good condition

connection

determine why there is no voltage to controller

Motor checks out OK

not running

output

Explained on Page 18

Motor Failed

Motor

not running

Page 18

SECTION

F. Troubleshooting Controller

AC AC

Thumbwheel Setting

4 50 63 5 40 51 6 34 43 7 28 37 8 25 32 9 22 29 10 20 27 11 18 24 12 17 22

AC AC

15 110-120

Vac

NOTE: When changing conveyor speeds it is

advisable to first turn the Conveyor Switch OFF before adjusting the thumbwheel switch.

Step 1 - Check all connections at terminal board to ensure connections are correct and tight. Connections are as follows:

-ARM

+ARM

AC NO CONNECT COM

RED

BLK

PINK

WHITE

BROWN OR BLACK

SERVICING COMPONENTS

with the voltages shown on the chart below. If the voltage reading is more than ±5Vdc of that shown on chart, complete motor test shown on Page 18.

-ARM

+ARM

NO CONNECT

COM

COUNT

+5V

Figure 8

COUNT +5V

YELLOW OR WHITE ORANGE OR RED

Figure 6

If wiring is not correct, make corrections are tight, including connections on plugs and receptacles, proceed to Step 2.

Step 2 - Ensure there is power to controller. Use a Digital Multimeter to read voltage between the terminal connections marked "AC" on controller. Meter should read between 110-120 VAC.

-ARM

+ARM

NO CONNECT

COM

(Minutes)

DC Motor Voltage PS310/360 PS200 67 84

Step 4 - Check Magnetic Pickup at back of motor. If the pickup is in good condition as per Step 3, check the voltages. Make sure conveyor is running. Using your meter set at DC, check between COM and ±5 V. Voltage should read +5 Vdc, ±0.3V. Next check between COM and Signal (count). Reading should stay between 2 to 3 Vdc. If either of these two readings are incorrect, see Conveyor Control Pickup Test on Page 17.

-ARM

+ARM

Figure 7 If power is not available, check power source. If power is available, proceed to Step 3.

Step 3 - With the AC power on, check the DC voltage to the conveyor motor and match the motor vottage

COUNT

+5V

NO CONNECT

COM

COUNT

+5V

Figure 9

Page 19

SECTION 2 SERVICING

27 23

COMPONENTS

G. Conveyor Control Check Using A Frequency Counter

The following procedures are to be used ONLY if you have a Frequency Counter feature on your Digital Multimeter. If no Frequency Counter is available, disregard this test procedure and go to Conveyor Controller Pickup Test on the following page.

Using a Frequency Counter is the easiest and fastest way to diagnose a problem with the speed control or pickup.

We recommend you do your test at the 3, 6, and 10 minute thumbwheel settings before using the following Troubleshooting Chart.

PS200

Thumbwheel Setting Vdc Frequency

(Minutes) to Motor

3.0 84 75

6.0 43 37

10.0

The charts to the right show the Thumbwheel setting (belt speed) along with the corresponding DC voltage and frequency reading. All readings should be plus or minus 3 Vdc or 3 Hz of that stated in charts.

To measure the DC voltage output to gear motor, place your meter leads across the speed controller terminals ARM + and ARM -.

To measure the Pickup Feedback Frequency place your Red (+) lead on the +5 Vdc terminal and the Black (common) lead on the COUNT terminal.

TROUBLESHOOTING CHART

ARM (DC) voltage reading high but frequency is correct.

ARM (DC) voltage reading is high and frequency is zero. Also check for +5 Vdc and COM terminal on speed control board. +5Vdc is present. +5Vdc is not present ARM (DC) voltage reading is

high and frequency is high.

PS360

Thumbwheel Setting Vdc Frequency

(Minutes) to Motor

3.0 67 91

6.0 34 46

10.0 20 27

Replace Pickup

Replace Pickup Replace Microchip. If still no change replace

speed control board. Replace Microchip. If no change replace

speed control board.

Replace Microchip. If no change replace

ARM (DC) voltage reading is low but not zero and

speed control board.

frequency is low but not zero.

Replace Gear Motor.

ARM (DC) voltage reading is good and pulse is good but motor not turning.

Page 20

SECTION 2

Figure

SERVICING COMPONENTS

1. Visually check pickup for the following:

• Magnet clean and bearing in good condition.

• Chips or cracks on the magnet.

• Old style pickup (not encased in blue plastic housing) has a 1/64 to 1/32 gap between magnet and hall device.

2. Set voltmeter on Volts DC scale then connect meter probes as shown. Black (- corn.) probe to COM terminal on speed control board and Red (+VQ) probe to +5V terminal of speed control. +5Vdc should be present at all times when conveyor is operating. If 5 Vdc is present go to Step 3. If 5 Vdc is not present, disconnect the three pickup wires (connect-ed to COM. SIGNAL and +5V terminals) and again check for +5Vdc. If 5Vdc is present with pickup disconnected, change pickup. If 5Vdc is not present change speed controller.

3. If ±5Vdc is present with pickup connected to speed control, connect volt meter red (+) lead to signal terminal and disconnect motor wires from the

- ARM and + ARM terminals. Using a 5/16" open end wrench on the motor pickup shaft very slowly rotate motor shaft while observing volt meter. Two (2) changes from +5V to 0V should occur for every one motor revolution. If signal is always at 0V, go to Step 4. If signal is always at 5V or changes more than 2 times per revolution, change the pickup.

4. If signal is always at 0 Vdc, disconnect pickup signal wire from speed control and check for +5Vdc at signal terminal of control. If +5Vdc is present, change pickup. If 0 Vdc is present, replace speed control.

Figure 11

Page 21

SECTION 2 SERVICING COMPONENTS

I. Conveyor Motor Test

1. Disconnect motor wires from Speed Controller terminals - ARM and + ARM.

2. Remove brush retainer caps. DO NOT remove the brushes.

3. Using an Ohm Meter (set to lowest scale) place one meter lead on each brush retaining plate Make sure neither meter probe touches motor case.

4. Using a 5/16" open end wrench on the motor pickup shaft, very slowly rotate the shaft while observing the Ohm Meter. There should never be a complete short 0 Ohm reading or a high Ohm reading during a 1/2 rotation. If either condition occurs, replace motor. The Ohm reading should stay between 3-5 Ohms.

Figure 12

Page 22

SECTION

SERVICING

J. Magnetic Pickup Replacement When replacing magnetic pickup apply LOCTITE REMOVABLE #242 sparingly on threads, turn

mounting screw until finger tight, then 1/4 turn more with a wrench.

On rare occasions the speed control board on early Model 360's may be affected by electrical noise transmitted by other electrical components or wiring. This noise is picked up by the speed control's pickup wires and transmitted to the control board. In most cases the conveyor will fail when burner spark ignition is present. After ignition is complete, turn the conveyor switch OFF and ON and the controller should reset.

Old Style Conveyor Terminal Block-Located In Left

Blower Motor Compartment PS 310/360 ONLY

COMPONENTS

The permanent fix is to replace the pickup wiring between the controller and terminal block (located in left end motor compartment) with a shielded cable MM/PN 42400-0334. When installing the shielded cable follow the color code change shown below:

Old Wiring Shielded Cable

Brown Black

Orange Red

Yellow White

There will be a fourth lead on one end of the shielded cable. This end always attaches to the terminal block in the motor compartment. The extra wire lead is a ground lead which is attached to the Black wire of the shielded cable. Newer Model 360's have shielded cable from factory. See diagrams in Fiaure 13.

Page 23

PS360 and PS570

conveyor sensor wiring changes

10/3/95 TRM

Page 24

Application

Subject

Bulletin No. MM-133B

Date 04/07/95

Middleby Cooking Systems Group

1400 Toastmaster Drive • Elgin, Illinois 60120 (708)741-3300 • Service & Parts (708) 741-4406

Service Bulletin

Installation and Diagnostic Instructions DIP Switch Conveyor Control Assembly Part Number 42810-0133

This service bulletin describes the original DIP switch conveyor control. Part Number 28074-0018, the new DIP switch conveyor speed control, Part Number 31020 and introduces the latest instructions for installation and set up- Either control can be contained in Kit Part Number 42810-0133. Both controls use advanced digital electronics to improve reliability and provide diagnostic features. The installation and operation of these controls are identical to each other and both replace prior non-DIP switch model controls.

Both control's printed circuit boards are housed in metal covers and both have detachable/replaceable and interchangeable thumbwheel switches.

The distinguishing features between the original and the current control are the DIP switch blocks and the markings on their metal covers.

Control PN 28074-0018 has a 4 position DIP switch and the control PN 31020 has an 8 position DIP switch. Control PN 31020 has its individual DIP switch program settings silk screened on the metal cover for easy reference.

Features

1. Control Part Number 31020 has enhanced tolerance to electrical systems that have unstable frequency control (50 or 60 cycles). This control also continuously monitors the cycles and adjusts itself accordingly. If an unstable frequency utility is common to the area, it is recommended to use the PN 31020 control.

2. All DIP switch Conveyor Speed Controls provide a variable DC voltage output determined by the

thumbwheel setting and the frequency input from the speed control pick-up assembly.

3. DIP switch control PN 28074-0018 (REV. B)* and DIP switch control PN 31020

contain the program settings for all Middleby Marshall Ovens that use digital conveyor controls.

4. Both controls have built-in diagnostics to assist the service technician.

19B

Page 25

Features Continued

5. Both controls are protected against gear motor shorts.

6. Both controls have metal housing covers that guard against handling damage and minimizes radio frequency interference (RFI).

•Note: Control PN 28074-0018 REVISION B contains all current DIP switch settings currently used in the

field. Prior to REV B. this control was not compatible with the 570 Series conveyor chain driven ovens. The revision letter is printed on the controls label should you be concerned if your inventory is not updated.

Compatibility Both the above referenced controls are compatible with all current and previous Middleby

Marshall digital conveyor controls, gear motors and pick -ups. Consult the gear motor/sprocket combinations chart - contained in the attached instructions - for optional conveyor speed set ups. The replacement thumb wheels used on both DIP switch controls can be interchanged.

Availability All orders for replacement controls will be filled with control PN 31020. All newly manufactured

ovens are fitted with control PN 31020. Continue to order replacement controls under kit PN 42810-0133 which will contain the attached updated instructions along with control PN 31020.

19C

Page 26

DIP Switch Conveyor Control Installation and Diagnostic Instructions

Part Number 88210-0077 General

The following provides instructions for the Installation and Diagnostics of the DIP Switch Conveyor Control Part Number 28074-0018 or Part Number 31020 contained in kit Part Number 42810-0133. Either of these controls can be installed into the PS200, 300, and the 500 Series Ovens. Note: If installing PN 28074-0018 control into a PS570(S) chain driven conveyor oven, be sure the control is marked "Revision B" on the label.

A. DIP Switch Conveyor Control Installation The DIP Switch Conveyor Control Module is installed and secured with Phillips Head Screws and External Tooth

Lockwashers (not supplied) in the oven control compartment. The Thumb Wheel is installed in a rectangular opening on the oven front panel. The ribbon cable from the Thumbwheel is connected to the 14-pin connector on the control module.

Terminals on the specific control are arranged and marked to show electrical connections (See Figure 1). Consult the specific oven model wire schematic for further wiring details especially for magnetic pick - up wire color codes. The oven application must be selected by setting the "DIP" switches on the specific control to the proper positions. The LED is used for diagnostics.

19D

Page 27

DIP SWITCH SETTINGS

Standard Conveyor Speed Settings

FOR BOTH CONTROLS

Control PN 28074-0018 (REV. B)

SWITCH SETTING

MODEL(S) OVEN TlMES(MlN/MAX) 1 2 3 4 PS200 PS200SB PS200-20 PS224 2:40 M1N TO 29:50 MIN x 0 x x PS200T PS360 PS310 PS350 2:40 MIN TO 29:50 M1N 0 x x x PS360SB PS360T PS360WB PS570 PS570S 2:40 MIN TO 29:50 MIN 0 x x 0 PS360WB70 PS570-SB 4:30 M1N TO 30 MIN PS570S-SB EXTENDED BAKE x x x 0

High Speed Option Conveyor Settings

SWTCH SETTING

MODEL(S) OVEN TlME(MtN/MAX) 1 2 3 4 PS200 (1 MIN) 40 SEC TO 10 MIN 0 0 x X PS333FB 1:30 MIN TO 10 MIN x x 0 X PS310F PS360SS 1 MIN T010 MIN 0 x 0 X PS570-SB HIGH SPEED OPT. PS570S-SB 1:30 TO 10 M1N x 0 X 0

FIGURE 2

19E

Page 28

B. Replacement Thumb Wheel Switch Installation

1. Disconnect the power to the conveyor control by turning the conveyor switch to the "off' (0) position and additionally by turning off the main power disconnect to the oven.

2. Remove the two screws that secure the failed switch body to the control door. Remove the switch body from the door.

3. Locate the ribbon cable connector that links the thumb wheel switch to the controller. Note the orienta tion of the cable for replacement. Grasp the connector frimly and pull it away from the control.

4. The thumb wheel connector is a polarized interlocking type connector that can only be installed in the correct orientation. Locate the connector to the terminal strip so that the polarized interlocking lug on the connector is aligned with the mating slot on the terminal and use your thumb to press the connector firmly into the terminal.

5. Locate the switch body to the control panel and assemble the switch body to the panel using the screws from step 2.

6. Set the switches on the control to "diagnostic mode" in Figure 2.

7. Run diagnostic tests to determine performance to the control, (see diagnostic instructions below)

8. Set the mode switches back to the correct settings for the oven type and control version (see switch setting instructions in Figure 2.

C. Diagnostics (Test Mode) To assist the service technician, both controls feature built -in diagnositic software. Most of these diagnostic routines

are accessed by setting the dip switches to the test mode setting and then by powering up the conveyor control. Also, certain conditions can be diagnosed by observing the red LED during normal operating conditions. Refer to figure 2 to identify the control and test mode.

These test features are in addition to the diagnostic pr ocedures depicted in the applicable oven technical manual. Note: Control PN 28074-0018 Test Mode setting is applicable to diagnosing 300 Series ovens and single belt 570 Series ovens only.

1. Diagnostics With Control In Normal Running Mode

If the red LED is lit and the control is not working (0 volts DC output at ARM then the gear motor short circuit protection feature has been enabled.

Service the gear motor to correct the cause of the short circuit, then cycle the A.C. power switch to the conveyor to restart the control.

19F

Page 29

Diagnostics With Control in Test Mode

The control in this mode provides a fast and convenient method of troubleshooting the control. When running the diagnostic procedure the entire procedure must run or the control must be powered down and reset. There is no option to perform individual tests.

1. Turn the conveyor power switch off.

2. Set the thumbwheel switch to 00:00.

3. Open the control panel door.

4. Set the control DIP switch to test mode.

5. Pull out the control box door safety switch so that the power will be on at the controls.

6. Turn the conveyor power on; CAUTION: The control will automatically start and operate the conveyor, make sure that the conveyor drive mechanism and the conveyor path is not obstructed.

Gear Motor and Sensor Test The controller automatically operates the gear motor at three speeds: slow (for 10 seconds), medium (for 10

seconds), and high (for 10 seconds). a) If the gear motor reverts to medium speed after 30 seconds and the LED on the controller is lit, the test passed

and gear motor operation is normal. b) If the gear motor stops after 30 seconds and the LED on the controller is lit, this indicates a Pick-up failure.

c) If the motor stops in less than 30 seconds (does not complete the test cycle of 10 seconds each speed) and the LED is lit, this indicates a gear motor failure. Thumbwheel Test* Once the pick-up passes the sensor test, the gear motor will be automatically set to

mid speed.

Set the thumbwheel to 00:10, observe the LED for 5 flashes. Then set the thumbwheel to 00:20, observe the LED again for 5 flashes. Repeat this procedure in: 10 increments up to :^0 waiting until the LED stops flashing between each setting change.

Roll the switch setting back to 00:00 then repeat the procedure using the minutes switch up to 09:00 minutes. Roll back the thumbwheel to 00:00 and repeat the procedure for the 10's segment up to 20:00.

Upon successful completion of this test the test sequence will automatically repeat itself starting with the 30 second motor test. The service routin e can now be repeated or the control can be returned to the normal operating mode. Be sure to change the DIP switch back to the correct oven position before operating the oven.

*The LED located at the bottom right comer of the control will indicate the thumbwheel test results (pass/fail). Pass is indicated by five flashes of the LED at 1 second intervals followed by the LED remaining lit. failure is indicated by the LED remaining lit with no flashing. The LED must be observed after each setting change.

19G

Page 30

D. Gear Motor/Sprocket Combinations

The chart reference below lists the different motor sprocket combinations used with the DIP switch conveyor control system.

CONVEYOR MOTOR/SPROCKET COMBINATIONS MODEL & CHAMBER GEAR MOTOR CONVEYOR BAKE TIME LENGTH MOTOR SPROCKET SPROCKET PARAMETERS PS200 40.5" 1350:1 Ratio 15T 10T 2:40 Min to 29:50 Min PS220FS 27384-0011 22151-0003 22151-0002 PS224 (Standard) PS200T 81" 1350:1 Ratio 30T 10T 2:40 Min to 29:50 Min (Tandem) 27384-0011 22159-0004 22151-0002 PS200 1 Min 40.5" 311:1 Ratio 15T 10T 40 Sec to 10 Mm (High Speed) 27384-0014 22151-0003 22151-0002 PS200SB 40.5" 1350:1 Ratio 30T 20T 2:40 Min to 29:50 Min (Split Belt) 27384-0011 22159-0004 22159-0003 PS360 54.5" PS310 PS314 1400:1 Ratio 15T 9T PS360SB 27384-0008 22152-0018 22152-0017 2:40 Min to 29:50 Min PS360WB PS350 (Standard) PS360WB70 70" 1400:1 Ratio 15T 9T 2:40 Min to 29:50 Min (Wide Body Stretch) 27384-0008 22152-0018 22152-0017 PS360SS 54.5" 1400:1 Ratio 45T 9T 1 Min to 10 Min (High Speed) 27384-0008 22152-0027 22152-0017 PS360T 109" 1400:1 Ratio 30T 9T 2:40 Min to 29:50 Min (Tandem) 27384-0008 22152-0022 22152-0017 PS570 70" 1400:1 Ratio 15T 9T 2:40 Min to 29:50 Min PS570S 27384-0008 22152-0018 22152-0017 (Standard) PS570SB 70" 1350:1 Ratio 15T 9T 4:30 Min to 29:50 Min (Standard) 27384-0011 22152-0024 22152-0017 PS570SB 70" 311:1 Ratio 15T 9T 1:30 Min to 10 Min (High Speed) 27384-0014 22152-0024 22152-0017

19H

Page 31

II. TEMPERATURE CONTROLLER

The temperature controller used on PS200 & PS310/314/360's has two major functions:

First on gas heated oven is to control the high flame solenoid. The temperature controller has no effect on the low flame or oven ignition system. On electrically heated ovens it controls all the banks of elements.

The second function is to control the high temperature safety limit and cooldown features. NOTE: This function is not included in temperature controller's supplied with electrically heated ovens. A separately located solid state high limit/cooldown device is used.

A. A Honeywell (DiaIaPak) Controller Is The

Temperature Controller Used On The PS200/310/314/360's.

Temperature Controller Party's: Gas Ovens & Electrically Heated 380-480V

Ovens: MM/PN 28071-0018 All Domestic and Canadian Electrically heated ovens, and all ovens 240V or less: MM/PN 28071-0012

SECTION 2 SERVICING

COMPONENTS

1. General Description Dialapak instruments consist of two primary

assemblies: the case and the plug-in chassis. The molded plastic case assembly houses the plug-in chassis and provides terminals for field wiring connections. A U-shaped bracket around the case allows the instrument to be panel mounted. The plug-in chassis consists of a front assembly and two printed circuit boards.

Indicator - The front assembly contains a circular-scale, process variable indicator; a mechanical zero adjustment for the indicator; a movable ring around the circumference of the indicator for marking the set point of the process at a scale position; a screwdriver operated scale lock that secures the movable ring at a given scale position and a green primary output light.

NOTE: Later model meter face shows both degrees Fahrenheit and degrees Centigrade.

Page 32

SECTION 2 SERVICING

Figure

24.

Temperature Controller Wiring

COMPONENTS

f. Check that the meter is indicating the value of the process variable (oven temperature).

g. High Limit and Cooldown Alarm

This circuit provides means to actuate external high and low alarm circuitry when the process deviates from the primary set point in either direction. It also provides local indication when an alarm state is in progress.

The High Limit/Cooldown circuit includes two electromechanical SPST relays. The N.O. contacts of both relays terminate at the rear of the instrument for field wiring connections. A red LED visible from the front indicates the status of both relays. The error signal from the differential amplifier controls the operation of these relays. Both relays are energized and the red LED is off when the PV is within the low-high alarm band. If the PV falls below the low alarm set point, or exceeds the high alarm set point, the respective relay is de-energized and the red LED is turned on.

4. Upscale Burnout Option

This unit is equipped with an upscale burnout option, which is a form of sens or break protection which drives the instrument to maximum upscale value in the event of an open circuit in the sensor or sensor leadwire. On heating applications, this feature simulates a high temperature condition, shutting down the heating system to prevent damage due to high temperature.

g. Analog Set Point (see Figure 24). The analog set point is established through a

potentiometer adjustment by turning a ring (set point dial) around the front panel scale. The set point can be set over the entire calibrated scale length. The set point dial is connected directly to the set point pot wiper for precise and accurate setting. A screwdriver-operated set point dial lock prevents accidental or unauthorized changes in its setting.

NOTE: The temperature in baking chamber may be approximately 20° to 40° lower than indicated on temperature dial because of the location of the thermocouple.

5. Adjustments

Controller Model AV30 Set Point Version

a. Make sure that the meter pointer is on zero. Gently tap the meter face for optimum reading. Use the mechanical zero adjustment on the face of the meter to align the point with the scale, if necessary.

b. Turn the primary set point ring until its index is aligned with the scale marking that corresponds with the desired primary set point of the process.

c. Turn the scale lock clockwise to lock the set point ring in place.

d. Apply the operating power to the instrument.

e. Check that the green primary output light turns on when the controller output is actuated to manipulate the controlled variable.

Diagram

Page 33

PS570S thermocouple wiring

26A

11/6/95 TRM

Page 34

TROUBLESHOOTING HONEYWELL

TEMPERATURE CONTROLLER

Meter Inoperative Defective AC power

supply Meter at or near zero Open input circuit. at al times (models Open meter or circuit without burnout) board connections

to front assemblyMeter Upscale Open sensor circuit. (upscale burnout Open compensator models) (T/C models).

The following chart lists the thermocouple millivolt readings from 200°F (93°C) to 600°F (315°C):

SECTION 2 SERVICING

COMPONENTS

B. Thermocouple (Type J) When two wires composed of dissimilar metals are joined together and one of the ends is heated, a continuous current flow is generated. We use an iron contant (Type J) thermocouple. The iron wire increases the number of dissimilar metal junctions in the circuit-If the thermocouple is open, the temperature controller will read very high, (full scale) on the temperature controller.

It is possible to check a thermocouple with a properly calibrated D.C. millivolt meter. At 32° F. (0° C.) the millivolt reading should be 0.00. This can be checked by inserting the thermocouple into an ice bath.

The millivolt reading at 72° F. (22° C.) should be

1.134. When using the chart shown below the temperature

at the teminal connections must be noted. This temperature is called the Junction Temperature.

90°F(32°C) 3.26 4.77 6.30 7.06 7.83 9.37 10.14 10.91 12.46 14.00 15.53

J U

88°F(31°C) 3.32 4.83 6.36 7.12 7.89 9.43 10.20 10.97 12-51 14.05 15.59

N C

86°F(25°C) 3.37 4.88 6.41 7.17 7.94 9.49 10.26 11.03 12.57 14.11 15.65

84°F(29°C) 3.43 4.94 6.47 7.23 8.00 9.54 10.31 11.09 12.63 14.19 15.71

1 0

82°F(28°C) 3.49 5.00 6.53 7.29 8.06 9.60 10.37 11.14 12.69 14.23 15.76

80°F(27°C) 3.55 5.06 6.59 7.35 8.12 9.66 10.43 11.20 12.74 14.28 15.82

78°F(26°C) 3.60 5.11 6.64 7.40 8.17 9.72 10.49 11.26 12.80 14.34 15-88

76°F(24°C) 3.66 5.17 6.70 7.46 8.23 9.77 10.55 11-32 12-86 14.40 15.94

M P

75°F(24°C) 3.69 5.20 6.73 7.49 8.26 9.80 10.57 11.35 12.89 14.43 15.97

E R

74°F(23°C) 3.72 5.23 6.76 7.52 8.29 9-83 10.60 11.37 12.92 14.46 15-99

72°F(22°C) 3.78 5.29 6.82 7.58 8.35 9.89 10.66 11.43 12.97 14.51 16.05

T U

70°F(21°C) 3.83 5.34 6.87 7.63 8.40 9.95 10.72 11.49 13.03 14.57 16.11

R E

68°F(20°C) 3.89 5.40 6.93 7.69 8.46 10.00 10.78 11.55 13.09 14.63 16.17 66°F(19°C) 3.95 5.46 6.99 7.75 8.52 10.06 10.83 11.61 13.15 14.69 16.23 64°F(18°C) 4.01 5.52 7.05 7.81 8.58 10.12 10.89 11.66 13.20 14.74 16.28 62°F(17°C) 4.06 5.57 7.10 7.86 8.63 10.18 10-95 11.72 13.26 14.80 16.34 60°F(16°C) 4.12 5.63 7.16 7.92 8.69 10.24 11.01 11.78 13.32 14.86 16.4C

OVEN TEMPERATURE 200°F

93°C

250°F 121°C

300°F 149°C

325°F 163°C

350°F 177°C

400°F 204°C

425°F 218°C

450°F 232°C

500°F 260°C

550°F 288°C

600°F 315°C

Example: The thermocouple millivolt reading at 500°F (260°C) with a junction temperature of 86°F (30°C) should be 12.57 millivolts (mv).

Page 35

SECTION 2 SERVICING

Thermocouple Installation

Figure

25.

Oven Thermocouple Installed Into Bake

PS360

ovens with thermo

couple

COMPONENTS

Models PS310/360 Only

The thermocouple on the PS360 was mounted in two different locations over time. Earlier models had the thermocouple mounted through the machinery compart ment behind the burner blower motor (see Figure 25). This would protrude the thermocouple into the bake chamber and read the return air going into the burner chamber. To install, put a mark* 6-3/4" from the tip of the thermocouple then push the thermocouple into the baking compartment sleeve until the 6-3/4" mark is at opening of sleeve. The tighten alien screw onto the thermocouple and close up hole with silicone seal.

*NOTE: All thermocouples are shipped with a push nut at the back end of the 7" sheath. Use the push nut to

mark the proper insertion point

Chamber

ports in the rear of the oven (see Figure 26) (includes all PS360S and PS360Q models), measure and mark* 6" back from the tip then slide the thermocouple into the entrance side port in rear of oven until the 6" mark is on the outside of clamp as shown in Figure 26. Tighten clamp, make sure thermocouple is secure. This location puts the thermocouple into the rear air plenum which now measures heated air from the burner going directly into the fingers.

*NOTE: All thermocouples are

shipped with a push nut at the back end of the 7" sheath. Use the push

nut to mark the proper insertion point

Figure 26. Oven Thermocouple Installed Into

Rear Oven

Page 36

Figure 27

Figure

shows thermocouple

Figure

SECTION 2 SERVICING

COMPONENTS

2. Thermocouple Installation Model PS200 Only

Figure 27 shows the insertion point for the thermocouple inside the control/machinery compartment. All thermocouples are shipped with a push nut at the back end of the 7" sheath. This push nut must be removed when installing thermocouples in a PS200.

NOTE: On electrically heated ovens a dual lead thermocouple is used. One lead connects to the Temperature Controller and the other lead to the separate high limit/cooldown devi ce.

properly inserted with the tip 3-1/4" (83mm) from end of sleeve. The set screw must be tightened after installation of thermocouple.

Page 37

SECTION 2 SERVICING COMPONENTS

Figure 29. Electric Oven High

Limit/CooIdown Device (Shown in

C. High Limit/CooIdown Switch

Both the High Limit and Cooldown Switches are incorporated into the secondary P.C. board of the Temperature Controller on gas ovens. On electrically heated ovens the high limit/cooldown device is located separately - external of the temperature controller as shown in Figure 29. The High Limit will shut the oven (heat) off if the temperature goes over 650° F. (343° C.). The Cooldown feature allows the operator to turn all Control Switches off, then the Low Limit Switch will keep the blowers operating until the oven has cooled down to 180° F. (82° C.) at this point the oven will shut down.

If the Burner and Heat Switch are on and the oven temperature goes below 180° F. (82° C.) or above

PS200)

650° F. (343° C.) the red LED, located in the upper right corner of gas oven Temperature Controller face, will be lit. This red LED will also remain on at startup until the oven climbs above 180° F. (82° C.).

NOTE: Electric ovens have no indicating light for high limit/cooldown.

With the oven in the cooldown mode the dial will continue to record oven temperature until 180° F. (82° C.) when the Cooldown Switch opens and shuts all power to blowers and temperature control.

See Figure 24 for terminal connections for the Low and High Limit Switches on the Temperature Controller.

Page 38

D. Troubleshooting Limit Switches An intermittent High Limit Switch will cause

intermittent operation of the burner. If you suspect an intermittent opening of this Switch a good check is to place a 1 amp fuse in parallel around the Switch contacts (see Figure 30).

if the Switch is trying to open intermittently the full current load of the Blowers will be carried by the fuse. Since this load will be much greater than 1 amp the fuse will blow. This would be an indication of a bad Switch. If the Switch is good the fuse would not blow as the only time the Switch would open would be under a no load condition and the fuse would never have to conduct current.

SECTION 2 SERVICING

COMPONENTS

E. Testing Procedure For Temperature Controller

Part 1. Testing The Temperature Controller (MIWPN

28071-0018), High Limit Switch and Thermocouple Using the Altek Testing Device (ATS).

The following tests may be performed in conjunction with the ALTEK Type "J" Thermocouple Source (MM/PN 27170-0192) to check Temperature Controllers and Thermocouples.

IMPORTANT: The Temperature Controller is rated for accuracy only up to 140° F. (60° C.) ambient, the Controller must be allowed to cool before continuing. Check the cooling fan and/or customer ventilation system if the Control Box exceeds 140° F. (60° C.) with the Control door closed.

1. Temperature Controller Check

a. Turn Heat Switch OFF.

b. Disconnect thermocouple wires from -1 and -2 terminals on Temperature Controller. Tape ends to prevent shorting. Next connect white lead (+) of the ALTEK Thermocouple Source (ATS) to terminal -1 and the red lead to terminal -2. Set ATS to temperature closest to customer set point on controller. Turn blower switch ON. Temperature Control should read within 5° of ATS setting.

Figure 30. High Limit Switch

Figure 31. Altek Shown Connected to

Temperature Controller (PS200 shown)

Page 39

31B

Part No. 88210

0079

Digital Temperature Controller

(P/N 28071-0028)

Installation, Programming

and Troubleshooting

Instructions

Middleby Marshall inc. • •i400 Toastmaster Dr. • Elgin, IL 60120 • (708) 7^-33CO • FAX (708) 741-4406

Middlebv Corporation 24 Hour Service Hotline 1-800-238-8444

P3/93

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Mechanical Installation

1.04. The following provides mechanical installation instructions for the Digital Temperature Controller CAUTION

Before installing the Digital Temperature Con troller, shut OFF all electrical powerto the oven at the disconnect switch or circuit breaker.

To remove the Analog Temperature Controller and install the Digital Temperature Controller, proceed as follows: Step Procedure

1. Disconnect all associated wiring from the terminals located on the rear of the Analog Temperature

Controller. Disconnect and retain any jumper wire(s).

2. Remove two bracket screws and bracket securing the Analog Temperature Controller to the oven.

Slide the bracket away from the controller. Remove the controller by pulling it out through the front side of the panel. Refer to Figure 1.

3. Insert the Digital Temperature Controller into the same panel slot making sure the face of the

controller is upright with the display on top and the push buttons on the bottom.

4. Identify the two rectangular holes on top and bottom of the control case. Attach the two panel

mounting brackets with the clips of the brackets and the head of the screws pointing towards the rear of the new controller into these rectangular holes.

5. Tighten both screws evenly against the backside of control panel until the controller seats securely.

Figure 1 - Mounting Bracket Clip and Screw Position

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Electrical Connections

NOTE

1.05 All electrical connections on the Digital Temperature Controller are made on two terminal strips located on the rear of the unit. The existing oven wires are connected to the new terminal positions indicated in the wiring diagrams.

Proceed as follows to make electrical connections:

1. Refer to the Data Plate on the oven for the oven Model Number and Operating Voltage.

2. Identify oven Model/Voltage in Table 1 and use related Wiring Diagram (Figures 2,3,4, or 5).

3. Use the Wiring Diagram and make the electrical connections.

4. The discontinued Analog Temperature Controller terminal numbers have been shown in brackets ([ ]) next to the correct Digital Controller terminal. Each terminal has been color coded for easy identification.

Be sure to replace/add any jumper wire specified in the wiring diagram.

Table 1 - Oven Model Number and Related Wiring Diagram

Oven Model Number

PS200 Gas Oven, 208-240V, 50/SOHz, 1Ph, 3W Figure 2 PS200 Gas Oven, 200V, 50/60Hz, 1 Ph. 2W (Export Only) Figure 2

PS200 Gas Oven, 208V, 50/60Hz, 1Ph, 2W (Export Only) Figure 2 PS200 Gas Oven, 220-240V, 50/60Hz, 1Ph, 2W (Export Only) Figure 2 PS200 Electric Oven, 208-240V, 50/60Hz 3Ph, 4W Figure 4 PS200 Electric Oven, 380V, 50/60Hz, 3Ph, 4W (Export Only) Figure 4 PS200 Electric Oven, 400-416V, 50/60Hz, 3Ph, 4W (Export Only) Figure 4 PS250 Gas and Electric Ovens with early style Figure 5

Analog Controller Part Number 28071-0009

PS250 Gas and Electric Ovens with later style Figure 3

Analog Controller Part Number 28071-0012 PS300/304/350 (Ail Gas and Electric Ovens are the same Figure 3 PS310/314/360 Gas Oven, 208-240V, 50/60Hz, 1Ph, 3W Figure 2 PS310/314/360 Gas Oven, 208-240V, 50/60Hz, 1Ph, 2W (Export Only) Figure 2 PS310/314/360 Gas Oven, 190-380V, 50/60Hz, 1Ph, 2W (Export Only) Figure 2 PS310/314/360 Electric Oven, 200-220V, 50/60Hz, 3Ph, 3W (Export Only) Figure 3 PS310/314/360 Electric Oven, 208-240V, 50/60Hz, 3Ph, 4W Rgure 3

(with Single Phase Blower Motors) PS310/314/360 Electric Oven, 208-240V, 50/60Hz, 3Ph, 4W Figure 3

(with 3 Phase Blower Motors) PS310/314/360 Electric Oven, 240V, 50/60Hz. 3Ph, 3W Figure 3 PS310/314/360 Electric Oven, 380V, 50/60Hz. 3Ph, 3W (Export Only) Figure 2 PS310/314/360 Electric Oven, 480V, 50/60Hz, 3Ph, 3W Rgure 2

Related Wiring Diagram

PS310/314/360 Electric Oven, 400-440 V, 50/60Hz, 3Ph, 3W (Export Only) Figure 2

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NOTE When removing the 28071-QC27 Digital Temperature Controller (blue colored unit) and replacing it with the 28071 -0028 Digital Temperature Controller (gray colored unit), the electrical connections remain She same.

Figure 2 - Wiring Diagram Showing Electrical Connections (Refer to Table 1)

Figure 3 - Wiring Diagram Showing Electrical Connections (Refer to Tablet)

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NOTE When removing the 28071-0027 Digital Temperature Controller (blue colored unit) and replacing it with the 28071 -0028 Digital Temperature Controller (gray colored unit), the electrical connections remain the same.

Figure 4 - Wiring Diagram Show ing Electrical Connections (Refer to

Tab iel)

* Add ground wire (green) from terminal G to a good ground connection in the control box.

Figure 5 -Wiring Diagram Showing Electrical Connections

(Refer to Table 1)

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Timing Out From SET UP Mode When in the SET UP Mode and no keys are pressed for a period o? 50 seconds, the controller times out

and reverts to the normal display (SET PT or TEMP). Timing Out From Lower Display The normal display (SET PT or TEMP) is automatically shown if the DISP

key is not pressed for 60 seconds.

3. DISPLAYING And PROGRAMMING THE SET UP GROUPS

3.01 Displaying and Programming is the process of accessing the Set Up Groups, viewing/making selections and returning to normal display. There are five Set Up Groups which can be accessed, they are: LOCK, INPUT

1, CONTRL, ALARMS, and STATUS Groups (see Figure 7). Follow the Steps:

1. Before changes can be made, enter the Set Up Mode by pressing the Lower Left Blank Key ( ) and the SET UP Key simultaneously.

2. Press the FUNCTION Key to display CONF LOCK. Press t Key to change display to show NONE LOCK.

3. Press SETUP Key to sequentially move through the LOCK, INPUT 1, CONTRL, ALARMS and STATUS Groups.

4. Press the FUNCTION Key to sequentially move through each Function Group.

5. Press t Key to change a selection or value within a Function Group.

6. Press the DISPLAY Key to return to normal display.

Figure 7 - Chart Showing Display Groups and Direction of Flow

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Diagnostic Error Messages

4.03 The controller runs background tests during normal operation. If a problem with the background ti occurs, an error message is shown (flashing) in the Lower Display. In case of more than one

simultaneous malfunction, only the error message with the highest priority appears in the Lower Display, these are called Diagnostic Error Messages (Table 3).

Table 3 - Diagnostic Error Messages

Corrective

Lower Display Action EFAIL 1. Replace Controller FAILSF 1. Turn Power OFF for 10 seconds,

1N1FL 1. Turn Power OFF for 10 seconds,

1N1RNG 1. Check Thermocouple and

then Turn Power ON.

2. If problem does not clear, replace Controller.

then Turn Power ON.

2. If problem does not dear, replace Controller.

Wiring (see Technical Manual).

2. if problem does not clesr, replace Controller.

Controller Operation Problems

4.04 in addition to the error message displays, there are other symptoms which indicate that the controller is not

operating property. These problems can be identified by noting how the controller's displays, indicators, and functions are reacting.

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A list of symptoms in Table 4 Troubleshooting Chart indicates controller failure or poor operation. Check the indicator and display reactions and use the information contained in the troubleshooting chart during troubleshooting.

CAUTION Do not attempt to repair the controller as there are no user replaceable parts Inside the unit.

When Corrective Action in Table 4 has been taken and the problem does not dear, then replace the Digital Temperature Controller. When replacing the unit, be sure to follow the Installation and Programming Instructions.

Table 4 - Troubleshooting Chart

Symptom Cause Corrective Action Upper Display: blank Power failure Check for Power Lower Display: blank Indicators: OFF Controller Output: None Upper Display: OK Relay Output Reconfigure

Lower Display: Displayed

Indicators: OK Controller Output: Controller

Upper Display: OK Malfunction Check wiring on Lower Display: OK in alarm terminals for Indicators: OK output proper connection. Controller Output: External

Upper Display: Display Incorrect Reconfigure to

Lower Display: OK Indicators: OK Controller Output: Relay

output disagrees with controller output

output disagrees with displayed output

alarm function does not operate properly

reading Power proper Power unstable Frequency Frequency.

Chatter

controller.

Check wiring on terminals, especially jumper for proper connection.

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Table 4 - Troubleshooting Chart (Continued)

Symptom Cause Corrective Action Upper Display: FAIL RAM failure. Turn power OFF, Lower Display: RAMTST

Upper Display: FAIL Configuration Step through the Lower Display: CFGTST data in the STATUS tests

Upper Display: FAIL Factory set input Step through the Lower Display: FACTST constants in the STATUS tests

Upper Display: (a value) Information To reset the tempera- Lower Display: Display of only. ture reading, press and

maximum ambient temperature

controller is (RAMTST, CFGTST, in error. CALTST, and FACTST)

controller in (RAMTST, CFGTST, error. CALTST, and FACTST)

then ON to see if error clears.

to allow the controller to clear the problem, then see if the problem clears Check all displays for programming accuracy.

to allow the controller to clear the problem, then see if the problem clears

hold the RESET Key. then press the DOWN ARROW Key.

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Digital Temperature Controller

software version 4.14 Servicers instructions

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Bulletin No. MM-13 6 Date 9/28/93

Middieby Cooking Systems Group

1400 Toastmaster Drive • Elgin, Illinois 6012C (708) 741-3300 • Sen/ice & Parts (708) 741-4406

Service Bulletin

SUBJECT: Digital Temperature Controller PN28071-0027 (Blue) or 28071-0028 (Gray) GENERAL

In some oven installations electrical noise/static have caused the Digital Temperature Controller not to function property. Some common symptoms are:

1 . The Controller Display changes and/or may flash frequently. 2 . Temperature Set Point(s) may change without operator intervention. 3 . Gas solenoid valve opens and closes erratically.

The electrical noise/static enters the Digital Temperature Controller circuitry through the thermocouple wires. The thermocouple wires are attached to terminals 7 and 8 on the rear of the controller. To correct this problem, the supplied Filter Capacitor Assembly (PN 27170-0283) should be connected from terminals 7 and 8 to Ground (G).

APPLICATION Model PS200 Series, Model PS250, Model PS300 Series, and Model PS500 Series.

COMPATIBILITY

The Filter Capacitor Assembly is installed on the rear terminal strip of either Digital Temperature Controller PN28071-0027 (Blue) or 28071-0028 (Gray).

FEATURES

• Filters electrical noise/static.

AVAILABILITY

• Effective September 20, 1993 part orders for the Digital Temperature Controller include the Filter Capacitor Assembly installed on rear of unit.

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• Effective September 20. 1993 ovens shipped with the Digital Temperature Controller include the Filter Capacitor assembly (installed).

• Effective October 1, 1993 Middleby Marshall will fill all Orders for the Filter Capacitor Assembly.

DISPOSITION OF INVENTORY

All distributor inventory should be upgraded with the filter capacitor assembly.

INSTALLATION PROCEDURES

To Install the Filter Capacitor Assembly (PN 27170-0283), proceed as follows:

1 . Turn "OFF* all power to the oven.

2 . Open the Control Compartment 3 . Install the filter capacitor assembly on the terminals. Refer to Figure 1. The capacitors should

be mounted across the back of the controller.

a. The joined leads of the two capacitor assembly are connec ted to Ground (G). b. Ether single capacitor lead is connected to Terminal 7, and the other single

capacitor lead is connected to Terminal 8.

4 . Close the Control Compartment. 5 . Turn Oven "ON", check and/or set the set point(s), monitor for stable

display(s) and operation. Refer to appropriate documentation covering the Digital Temperature Controlfer.

Figure 1 - Rear View of Digital Temperature Controller Showing the Filter Capacitor

Assembly Connected to the Terminals

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Figure

39.

PS31

0/360

Motor Centrifugal Switch on Rear

of Motor (MM P/N 27170-0144)

III. MOTOR CENTRIFUGAL

SECTION 2 SERVICING

COMPONENTS

SAFETY SWITCH

PS310/360 ONLY

(See Figure 39)

A normally closed limit switch is mounted inside each blower motor. When the motor is not running the centrifugal switch weight holds the switch open. As the motor reaches full RPM the weight moves away from the switch permitting the switch contacts to close. These switches are located in the rear of the motors.

When the switch contacts of both blower motors are closed it permits a circuit to go from the heat switch to the high limit switch. If a blower motor is not operating the switch will not close and the oven will not light.

There is no adjustment that can be made to the switch. If the switch is operating properly both sides of the brown wires coming from the switch should be hot when the motor reaches full RPM.

Removing the rear motor wiring cover plates allows access to the centrifugal switch. The switch may be replaced when faulty with MM P/N 27170-0144. Refer to Figure 39.

IV. AIR PRESSURE SWITCH

PS200 ONLY

(See Figure 40)

A normally open micro-switch is mounted inside the Air Pressure Switch Assembly. When the blower fan is not operating no air pressure is applied to an air tube end located in front of the fan blades so the Air Pressure Switch remains open. When the blower fan is up to speed pressure is applied to the air switch diaphragm which in turn closes the micro-switch contacts completing the heating circuit.

Figure 40. PS200 Air Pressure Switch

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SECTION 2 SERVICING

GAS BURNER AND TRAIN

COMPONENTS

B. Intermittent Ignition Device

NOTE: The PS200/PS310/PS360 all use the identical burner, burner controls and high flame valve. The only difference is the main burner orifice.

A. Sequence of Operation When all safeties are satisfied, turning the heat

switch ON will supply 110 volts directly to the burner control circuit. The 110 volts is applied to the primary side of the transformer and converted to 24 Vac. The transformer sends 24 Vac to the time delay relay coil. On a cold start, the relay will not energize for 15-30 seconds. When the relay energizes it closes and completes a 110 volt circuit to the burner blower motor. The motor starts and when it comes up to speed the centrifugal switch on the motor is closed and the 24 volt circuit through it is completed to the control board mounted on the left side of the machinery compartment. The control board will energize the pilot valve, allowing pilot gas to flow. At the same time, the control board ignites the spark to light the pilot. When the pilot flame is established the safety circuit is completed and the control board opens the main gas valve and ignites the burner. If the oven is calling for heat the temperature controller will energize (open) the high flame solenoid. When the temperature controller is satisfied it opens the circuit to the high flame solenoid valve. This closes the valve and puts the burner on low or "by -pass" flame. This sequence will continue until the "heat" switch is turned to the OFF position, opening the 110 volt circuit to the control board, permitting both the pilot and main valves to close.

All Pacesetter PS200/PS310/PS360 gas ovens are equipped with an intermittent ignition device (1ID) type automatic ignition pilot burner assembly. The II D creates a spark to light the pilot and a flame probe must prove that the pilot is lit before the main gas valve can become energized and cycle the burner on. An ignitor sensor probe surrounded by pilot flame will permit the main burner valve to energize. The control system includes proof of burner blower rotation.

The burner control system incorporates prepurge on cold start, proof of burner blower rotation, pilot ignition and proof of pilot flame. A flame sensor probe is surrounded by the pilot flame. If pilot flame is lost the control unit will automatically try to relight the pilot for 90 seconds. If ignition does not occur the control will then "lockout" the pilot. To relight the pilot the "heat" switch must be momentarily turned OFF for 60 seconds and then moved to the ON position.

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C. Gas Burner Components

1. Burner 110 Volt Power Supply - The burner main power supply is connected to terminals L1 and L2 located in the electrical junction box to the right side of the burner.

2. Pilot Burner Assembly (IID) is attached to the main burner and consists of a flame sensor ignitor electrode, a pilot shield and the pilot burner. The spark ignites the pilot and a circuit is completed from the flame sensor probe through the flame to the pilot

SECTION 2 SERVICING

COMPONENTS

burner. This safety circuit must be completed before the main burner will light.

The ignitor sensor probe located on the pilot assembly is used to prove the presence of the pilot flame. An electrical current is sent to the probe and if a pilot flame is surrounding the pilot burner and the probe at the same time, the current is then conducted through the flame to the pilot burner which is grounded. This completes the safety circuit and allows the main burner to light.

MODELS PS310/360

•Set gap at 1 /8"(3.2mm) between Ignitor/Sensor Probe and Pilot Burner.

MODEL PS200

Figure 41. Pilot Shield Removed from Burner.

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SECTION 2 SERVICING COMPONENTS

Pilot Shield The pilot shield located on the bottom of pilot is used to

prevent drafts, etc. from blowing the pilot flame away from the sensing probe.

Burner Flame Target

The burner venturi flame target is installed on all Model PS310/360's after 6/87. It is also installed on all PS360S, PS360Q and all PS200. The target aids in distributing the flame in the burner chamber.

PILOT SHIELD

Front of Burner With Pilot Shield Installed

FLAME TARGET

(Installed on PS310/360 after 6/87. Installed

on all PS360S, PS360Q and all PS200.

Figure 42. Pilot Shield and Burner Flame Target.

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Pilot and Proof of Pilot Flame Rectification

An inner cone that will not bum because excess fuel is

Detailed Explanation. Sensing Methods

With standing pilots, heat is a necessary ingredient for proper thermocouple operation. But this is not the case with II DS when flame conduction or rectification is used. To better understand the principles of flame conduction and rectification, we must first understand the structure of a gas flame (See Figure 43).

With the proper air-gas ratio to give a blue pilot flame, three zones exist.

SECTION 2 SERVICING

COMPONENTS

Flame Rectification With flame rectification, the flame and probes are used

in a similar manner. There is one important difference. The area of one probe that is exposed to the flame must be greater than area of the other probe that is exposed to the flame.

In Figure 44 the flame is again used to conduct an AC signal. Both probes are in contact with the flame. The probe with the largest surface area attracts more free electrons and, as a result, becomes the negative probe. Therefore, the direction for the conduction of current through the flame is from the positive probe to the negative probe. Note also that the AC voltage sine wave has not changed, but the negative portion of the current sine wave has been chopped off. This positive portion now represents a DC current. This is the phenomenon of flame rectification.

Zone1

present. Zone 2

Around the inner, fuel rich cone is a blue envelope. In this area is a mixture of vapor from the fuel rich inner cone and the secondary, or surrounding, air. This is where combustion occurs.

Zone 3

Outside the blue envelope is a third zone that contains an excessive quantity of air.

Of concern is the second, or combustion area. This is where the burning occurs and is the area that is of prime importance for good flame sensor location.

Figure 44. Flame Rectification.

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SECTION 2 SERVICING COMPONENTS

Figure 45. Flame Rectification Pilot

To apply this principle to an IID, a pilot and flame sensor have been substituted for the two probes (See Figure 45). After the pilot is ignited, a DC current flow of 1.5 micro-amps or more is conducted through the flame, from the flame sensor, (the positive probe) to the pilot tip, (the negative probe). The pilot tip, acting as the negative probe, completes the circuit to ground. The II D sensing circuit uses this DC current flow to energize a relay and open the main burner gas valve.

THE FOLLOWING CONDITIONS WILL HAVE A DIRECT BEARING ON EVERY IID APPLICATION:

And Probe

Maximum inlet pressure for natural gas applications should be limited to 10.5" W.C. On LP applications, the inlet pressure should be limited to a maximum of 14W.C.

Outlet gas pressure must be 3.5" natural gas, 10.5" L.P. gas. These pressures are measured when the oven is in the LOW flame mode.

Temperature Ignition controls should not be exposed to temperatures

exceeding 140° F (60° C) or less than-40°F(-40°C)

Voltage The supply voltage to the ignition controls should be

within the following ranges: 120 VAC controls -102 to 132 VAC

24 VAC controls - 21 to 25.5 VAC 24VAC systems should use transformers that will

provide adequate power under maximum load conditions.

Gas Pressure

The inlet gas pressure should be a minimum of 1" W.C. above the manufacturer's recommended manifold pressure. Under no condition, should the inlet gas pressure be below the manufacturer's recommended minimum inlet pressure

Pilot Application The pilot and flame sensor application is the most

critical aspect of the IID application. The pilot flame must make contact with the pilot tip and

surround the flame sensor probe. A microammeter is necessary to verify that the proper amount of current is being maintained through the pilot flame. On the control board, the minimum value required is 1.5 microamps. If the minimum signal is not being maintained at all times, rapid short cycling of the main burner or "no main burner on" conditions can exist. Rectification based ignition systems respond in less than 0.8 of a second to a loss of flame. Any deflection of the pilot flame away from the flame sensor, or pilot tip, could result in rapid cycling (chattering) of the main burner gas valve, or prevent the main burner from coming on.

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Service Bulletin

NO. 128

Date 7/22/91

A MIDDLEBY COMPAHY

SUBJECT: Burner Pilot/Ignitor Assembly P/H 27363-0001

Replaced by P/N 42810-0117 (Kit)

The burner pilot/ignitor assembly, P/N 27363-0001 has been discontinued and replaced by P/N 42810-0117 Pilot/Ignitor Kit. The kit contents are:

Qty. Part Number Description 1 27363-0002 Pilot/lgnitor 1 27170-0264 Pilot/lgnitor Bracket 1 88210-0067 Pilot/lgnitor Replacement

Instructions

The new assembly must mount approximately 1/4 of an inch further forward from the end of the burner venturi to assure proper pilot operation and burner ignition. Therefore, the new mounting bracket is supplied with each pilot/ignitor and mus^ be installed when replacing an old pilot/ignitor. Be careful to note that the hole locations are the only difference between the old and new brackets. The difference in the pilot/ignitor assembly is more obvious. Refer to instructions attached for further details. Note that the four ^10-32 screws and existing pilot shield are to be reused.

This change is effective on all PS-200 series ovens, all PS-300 series ovens, all PS-350 ovens with the Honeywell gas valve conversions (Kit#428l0-0082) and anywhere P/N 27363-0001 is used.

James E. Urani

Field Technical Engineer

JEU:aa

(over)

8300 Austin Avenue • Morton Grove, Illinois 60053

(708) 966-8300 • FAX (708) 966-8701

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ITEM QTY M

MP/N

DESCRIPTION

1 1 27363

0002 PILOT IGN1TOR

KIT CONTENTS:

PILOT/IGNITOR REPLACEMENT INSTRUCTIONS

USING KIT #42810-0117

IMPORTANT: When using Kit #42810-0117 the old style pilot/ignitor bracket must be replaced with the new style bracket contained in the kit or the burner will not light.

2 3 1 88210-0067 PILOT/IGNITOR REPLACEMENT INSTRUCTIONS

27170-0264

PILOT IGNITOR BRACKET

MM P/N 88210-0067

P7/91

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Middleby Cooking Systems Group

1400 Toastmaster Drive • Elgin, Illinois 60120 (708) 7413300 • Service & Parts (708) 741-4406

SUBJECT: Pilot Line Tee Kit (PN 30185)

Bulletin No. MM-1 37

Date 03/21/94

GENERAL:

The Pilot Outage Situation

In the past all Middleby Marshall conveyor ovens were equipped with a combination gas valve with a spring loaded on/off knob which was tan in color. We found that when this tan knob material was exposed to heat it was more vulnerable to attack by air born animal proteins. The combination of heat and grease caused the knob to crack. Once the knob was cracked the spring would force it to the closed position thereby shutting down the oven. To correct this problem we changed to a different combination gas valve with a knob made of a glass fiber filled nylon compound that is blue in color. As time went on we noticed an increase in pilot problems. For example:

1. Pilot blows out causing constant re-ignition.

2. Constant re-ignition creates electrical noise which causes the temperature control and/or the conveyor control to function erratically.

3. Raw gas odor as it escapes into the oven when the pilot blows out but the second stage of the valve has not yet closed.

4. Soot build up on the pilot of propane applications.

Both your technicians and our technical staff dealt with each of these cases by adjusting pilot hoods, adjusting pilot shields and changing pilot orifice sizes and low flame orifice sizes. All of these fixes worked on a case by case basis and therefore clouded the true cause. Further investigation has shown that the blue knob combination gas valve design does not regulate at the low end of the BTU range as effectively as the old valve. As the oven goes into low flame the

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servo bounces up and down as it hunts for the proper level. This can be seen on a water column gauge connected to the output side of the vaive. This bouncing line pressure causes pressure surges in the pilot line too. These surges lift the pilot oft the sensor probe causing the problems described above. We have found that a properly regulated pilot line will smooth out the surges and create a strong piiot not effected by the vaive operation.

Correcting The Pilot Outage Situation

in order to regulate the piiot properly all ovens leaving the factory after February 24, 1994 are equipped with a pressure tap in the pilot line. This tap is a basic line tee with a plug. The technician can tap into the pilot line with a water column gauge from this tee and adjust the pilot pressure using the pilot adjustment screw on the combination gas valve. We will set them at the factory but since all installations are unique we will also ask the instalier to check/adjust the pressure on the installation check out sheet.

As we worked with our combination gas valve supplier on this project we were surprised to learn of another factor clouding the issue. We were told that some combination gas valves were shipped to us with burrs in the pilot adjustment portal. The piiot of these valves is difficult to adjust unless you break through the burr. If the water column gauge does not register any change after the adjustment screw has been turned ail the way down, then the technician must apply more torque to break through the burr, back the screw out until the top of the screw is flush with the top of the access hole, and turn the screw down again. This must be repeated several times. This is not a typical procedure and must be kept in mind.

Customers With Known Existing Problems

Middleby Marshall is doing all it can to assure future customers worry free operation with minimal down time. But the customer who has already purchased our ovens may be having difficulty and he doesn't even know it. Or perhaps one of your technicians is wrestling with an oven problem which may be related to this pilot situation. Either way, this is where we need your help- In a few days we will send you a number of pilot tee kits as described below. We will bill you as if it were a standard parts purchase- If you know a customer who is having some of the problems described above, install the kit, adjust his pilot pressure and if necessary, replace the combination gas valve according to the instructions provided- Use the parameters set in the APPLICATION section of this bulletin to determine candidates and billing procedures.

All Other Customers

In addition, we want to take care of any potential problems by having the kits installed, the pilot pressure adjusted and if necessary, the combination gas valve replaced whenever a technician is already on sight for another call. In other words, if a service call is requested for unrelated issues and the oven has a blue knob combination valve then we would like your technician to follow the directions supplied with the pilot tee kit (PN 30185) as long as he is there. Again refer to the APPLICATION section for details.

Your assistance in making this program work will reinforce the Middleby Marshall/Authorized Service Agent teamwork concept of surpassing our mutual customers expectations- This is an

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opportunity for you to display a preventive strategy to your customers and come out the hero. it also gives you an opportunity to promote the value of using factory trained Authorized Service Representatives who use only Genuine Factory Authorized Parts.

The Pilot Line Tee Kit (PN 30185) includes:

Quantity Part Number Description 1 30001 Branch Tee 1 30002 Branch Tee Plug 1 30184 Instructions

Tools Required:

Middleby Marshall Technical Manual (PN 88210-0019) DC micro-amp meter Water Column Gauge (do not use a dial meter type)

Aluminum Tube Cutter

Soap Solution For Gas Leak Test

Other Standard Tools Of The Trade (open end wrench set, screw driver set, etc.)

APPLICATION:

All PS-200, PS-300, and PS-500 series ovens equipped with the blue colored knob combination gas valve.

Customers With Known Existing Problems:

If you know a customer who is having some of the problems described above, call the Middieby Marshall Service Manager for authorization to make a special trip to install the kit and adjust the pilot pressure. If the combination gas valve will not adjust properly even after breaking through the burr, then also change the valve. Return the combination gas valve to Middleby Marshall along with your invoice. Invoice Middieby Marshall using standard warranty procedures. Middleby Marshall will issue credit for travel, mileage, labor, and parts as long as the invoice has an authorization code.

All Other Customers

Whenever a technician is already on sight for another call and the oven is equipped with a blue colored knob combination gas valve then he is to install the kit and adjust the pilot as long as he is there. If the existing combination gas valve will not adjust properly even after breaking through the burr, then also change the valve. Return the combination gas valve to Middleby Marshall along with your invoice. Invoice Middleby Marshall using standard warranty

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procedures. Middleby Marshall will issue credit for pans and the portion of the labor time related to the kit installation, valve installation, and pilot pressure adjustment.

Middleby Marshall expects the Pilot Tee Kit (PN 30185) and the Combination Gas Valve Kit (PN 42810-0121) to be mandatory truck stock- Therefore, we will not pay for second trips.

COMPATIBILITY:

The Pilot Line Tee Kit (PN 30185) is compatible with all Middieby Marshall conveyor ovens equipped with the blue colored knob combination gas valve.

The pilot line tee is already installed on all ovens shipped after February 24, 1994.

FEATURES:

- Eliminates pilot fiame outages

- Fits all Middleby Marshal! pilot lines

- Allows technician to monitor pilot line pressure

AVAILABILITY:

Effective M arch 21, 1994 Middleby Marshall will fill all orders for the Pilot Line Tee Kit (PN 30185).

DISPOSITION OF INVENTORY:

No prior inventory exists before March 21, 1994. The Pilot Line Tee Kit (PN 30185) is a mandatory truck and warehouse stocking item.

The Combination Gas Valve Kit (PN 42810-0121) is a mandatory truck and warehouse stocking item.

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Branch Tee

P/N 30001

INSTALLATION INSTRUCTIONS

PILOT TEE ON PACESETTER

OVENS

KITP/N30185

Kit Contains:

Branch Plug P/N 30002 Installation Instructions P/N 30184

Tools Required:

Middleby Marshall Technical Manual (PN 88210-0019) DC Micro-amp Meter Water Column Gauge (do not use a dial type meter) Aluminum Tube Cutter Soap Solution For Gas Leak Test Standard Tools of the Trade (open end wrench set, screw driver set, etc.)

Middleby Marshall Inc. • 1400 Toastmaster Drive • Elgin, IL 60120 • (708) 741-3300 • FAX (708)741-4406

Middleby Corporation Service Hotline 1-800-238-8444

Part# 30184

P3/94

42G

Page 66

INSTALLATION INSTRUCTION

PILOT TEE

K1TP/N30185

A. INSTALLATION OF TEE AND PLUG KIT P/N 30185

IMPORTANT: BEFORE ATTEMPTING TO INSTALL THIS KIT, READ THESE INSTRUCTIONS THOROUGHLY. TURN OFF GAS AND MAIN POWER TO OVEN BEFORE INSTALLING THIS KIT.

1. Remove pilot line tubing from between the combination gas valve and the burner plate. Refer to Figure 1.

2. Cut the tubing for installation of the tee as shown in Figure 1. Cut a 3/4" piece out of the pilot line tubing to insert the tee as shown in Figure 1. NOTE: The tubing will insert 1/4" into the tee at both ends.

3. Replace the pilot tube and tee and tighten all connections. Check that there are no kinks in the pilot line.

4. Fire the oven and check all connections for gas leaks by painting them with a rich soap and water solution. Bubbles indicate a gas leak.

5. If a gas leak is detected, tighten the pipe connection and recheck for leaks. Replace the part(s) if gas leak cannot be stopped.

B. PILOT PRESSURE REGULATION - Using Combination Gas Valve Pilot Adjustment

1. Unscrew the plug from the pilot tee and install a water column gauge. To avoid calibration problems do not use a dial face mechanical W.C. gauge. Refer to Figure 1, PS300 Lower Oven for an example of water gauge connection.

2. Wait until oven is running on low flame in order to adjust pilot pressure. Turn the temperature control set point down well below the actual temperature in the oven to maintain low flame.

3. Gain access to the pilot adjustment screw under the screw on combination gas valve as shown in Figure 1.

4. Read the water column gauge connected at the tee while turning the pilot screw adjustment. Turning clockwise decreases pressure and turning counterclockwise increases pressure.

NOTE: Some combination gas valves may have burrs in the pilot adjustment portal. The pilot of these valves ii

difficult to adjust unless you break through the burr. If the water column gauge does not register any change after the adjustment screw has been turned all the way down, then apply more torque to break through the burr, back the screw out until the top of the screw is flush with the top of the access hole, and turn the screw down again. This must be repeated several times.

Adjust the pilot line pressure as follows:

If oven is running on NATURAL GAS adjust pilot pressure to 3.5" - 4.0" WC. If oven is running on PROPANE GAS adjust pilot pressure to 8.0" -10.0" WC.

5. Replace screw over pilot adjustment screw.

42H

Page 67

Figure 1

42I

Page 68

C. PILOT LIGHT CHECK

1. Cycle oven back onto high flame and check burner flame for proper color. Natural gas appears soft blue with orange tips and propane gas appears orange. The shutter plate on the burner blower motor is typically set at:

PS200 Series =1/16" to 3/32" PS300 Series = 1/8" to 3/16"

PS500 Series = 1/8" to 1/4" Each installation can vary. Adjust the shutter plate until the flame color is correct. Also check for proper microamp readings. Refer to Technical Manual (P/N 88210-0019), Section 2.

2. Turn burner off by cycling the burner heat switch momentarily two or three times to check for proper reignition. If difficult lighting or burner outage occurs, go to Step 3. If reignition is satisfactory then skip to Step 4.

3. If burner is difficult to light or goes out intermittently, check for proper microamp adjustment of pilot using Technical Manual (P/N 88210-0019), Section 2. Recheck pilot pressure on low flame to be sure it is adjusted within the correct parameters listed in Step B-4 of these ins tructions.

4. Turn off the gas flow to burner by turning heat switch to the OFF position.

5. Remove water column gauge and install tee plug and check for leaks.

For further assistance with any portion of these instructions call the

Technical Service Hotline at 1-800-238-8444.

42J

Page 69

SECTION 2 SERVICING

COMPONENTS

Page 70

SECTION 2 SERVICING COMPONENTS

Page 71

Other conditions that can cause the failure of the main burner to come on or rapid chattering of the main burner are:

1. pilot flame is too small or,

2. gas pressure is too low for proper pilot flame impingement on the flame sensor.

SECTION 2 SERVICING

COMPONENTS

applied to the coil of the relay, the contacts will dose and permit 110 volts to go to the burner blower motor. This 15-30 second delay is a prepurge for a cold start. When the coil of the relay is warm, this delay is bypassed.

D. Burner Troubleshooting

In these cases, the pilot may ignite, but the main burner gas valve will not be energized. It is also impossible for drafts or unusual air currents to deflect the pilot flame away from the flame sensor. Deflection of the pilot flame may also be caused by main burner ignition concussion or roll out of the main burner flame.

An additional point to be considered is the condition of the pilot flame. If the pilot flame is hard and blowing, the grounding area of the pilot is reduced to a point where the necessary current is not being maintained, and a shut down of the system will result.

The positioning of the flame sensor is also critical in the pilot application. Positioning of the flame sensor should be such that it will be in contact with the second, or combustion area of the pilot flame. Passing the flame sensor through the inner cone of the pilot flame is not a recommended procedure. For this reason, a short flame sensor may provide a superior signal over a longer one. The final determination of the sensor location (length) is best determined by the use of a microammeter.

3. Burner Blower Motor is located on the right side of the burner housing and is used to supply primary air for combustion. This motor drives a squirrel cage blower wheel located in the main housing of the burner. The motor requires no lubrication. The motor is a 110 volt motor and has an internal centrifugal switch that controls the 24 volt power to the gas valve. Failure of the motor will result in the burner not lighting.

4. Primary Air Adjustment located on the left side of the burner is a round silver colored plate that is held in place by a 1/4" nut on a threaded rod. By turning this plate either counterclockwise for more air or clockwise for less air you can control the microamp reading of the safety circuit.

5. Burner Transformer is located in the electrical junction box on the burner. The purpose of the transformer is to supply 24 volts to the burner motor relay and also to the 24 volt gas valve through the centrifugal switch located in the burner motor.

The following is a preliminary troubleshooting procedure. Refer to "Burner Test Equipment and Usage" for a more complete troubleshooting procedure.

1. Power Supply - connect a voltmeter across L1 and L2 in control box, you should get 110-115 volts.

2. Relay a. Connect voltmeter from terminal 3 on relay to L2

on terminal board - reading should be 110 to 115 volts.

b. Connect voltmeter across the low voltage terminals on relay - reading should be 24V. If you do not get a 24V reading, the transformer should be replaced.

c. If 24V is present at the relay and if after 15 to 45

seconds you do not get 110V on terminal 3 of the relay

- replace the relay.

3. Burner Blower Motor - If there is 110V to terminal 3 the motor should be running. If the motor is not running

-replace the motor.

4. Burner Blower Motor Centrifugal Switch - If the motor is running at top speed and you do not have 24 volts at the burner control board, then the centrifugal switch is either loose or defective. The switch must then be tightened or replace the motor.

5. Main Gas Valve and Control Board -Once 24V is supplied to the control board you should have 24V between terminals PV and MV/PV on the control module.

If you have a 24V reading the pilot valve should be open and the spark should be on to ignite the pilot gas. When the pilot gas has ignited, the main burner should come on. If not, check MV terminal to ground and see if 24 volts is present. If no voltage is present replace the electronic board. It is possible to have a pilot on but you can hear the spark continue to try to light the pilot. If this continues for more than 30 seconds, then it should be assumed that the flame sensor is not working properly. This may be easily checked. Refer to Section on Control Module Flame Sensor Test.

6. Burner Motor Relay located in the electrical junction box on the right side of the burner is a 24 volt time delay relay. Approximately 25 seconds after power is

Page 72

SECTION

SERVICING

COMPONENTS A reading of 1.5 microamps or greater should be

obtained. If a poor reading is obtained, pilot flame and sensor are probably not making good contact. This will keep the main valve from opening. Refer to the section on flame rectification. If the microamp reading is good and 24 volts cannot be obtained at terminal MV then the electronic board must be replaced.

E. Burner Ignition System -- Start-Up and Checkout.

bb. Spark cuts off when pilot flame is established.

cc. Main gas valve opens and main burner lights

after gas reaches the burner ports.

NOTE: Main burener flame may not be satisfactory until the gas input and combustion air have been adjusted.

2. Check Grounding.

A common ground is required for the pilot burner, the ignitor/sensor, the GND terminal of the control board, and the main burner. The main burner generally serves as the common ground.

The only piece of test equipment needed to check the burner system on the PS 200, 310/314/360 is a volt AMP/OHM meter which will read Micro amps (uA).

1. Burner Operation - the basic burner operation is as follows:

a. Shut off manual gas valve for oven. Turn the Burner and Heat switches ON. The spark should begin at the pilot burner within 30 seconds. Since no gas is present the spark will continue for the lockout timing period of 90 seconds.

b. Turn the Heat switch OFF then turn on gas supply. Set the temperature controller set point above actual oven temperature.

c. Turn the Heat switch ON. The system should

start as folbws:

aa. Spark turns on and pilot gas valve opens at once. Pilot burner ignites after gas reaches the pilot burner.

If the ground is poor or erratic, safety shutdowns may occur occasionally even though operation is normal at the time of the checkout.

NOTE: If the ground circuit path is incomplete, the burner system control will allow one trial-for-ignition before going into safety lockout.

Electrical ground connections at the pilot burner, ignitor/sensor and control board must be clean and tight. If leadwire is damaged or deteriorated, use only No. 14 to 18 gauge, moisture resistant thermoplastic insulated wire with 105°C (221 °F) minimum rating as replacement.

Excessive temperature at the ceramic flame rod insulator can also permit electrical leakage to ground. Examine the flame rod and mounting bracket, and correct if bent out of position. Replace ignitor/sensor if insulator is cracked.

Figure 48.

Page 73

SECTION

SERVICING

3. Control Module Flame Sensor Circuit Test

COMPONENTS

4. System Troubleshooting. Referto next page

The control module provides AC power to the ignitor/sensor which the pilot burner flame rectifies to direct current. If the flame signal back to the control module is not at least 1.5 uA DC, the system will lock out.

The output of the flame sensing circuit cannot be checked directly, so check the flame sensing circuit indirectly by checking the flame sensing current form the ignitor/sensor to the control module as follows.

a. Connec t a meter (DC microammeter scale) in series with the flame signal ground wire as shown in Figure 49. Use the HoneyweII W 136A Test Meter, or equivalent. Disconnect the ground wire at the control module. Connect the red (positive) lead of the meter to the free end of the ground wire. Connect the black (negative) meter lead to the quick-connect ground terminal on the control module.

b. Restart the system and read the meter. The flame sensor current must be at least 1.5 uA, and the reading must be steady. If the reading is below the value designated above or the reading is unsteady, check the pilot flame and electrical connections as described above. Also, replace the ignitor/sensor if the ceramic insulator is cracked.

Start the system by setting the temperature controller above room temperature, and observe the system response.

Establish the type of system malfunction or deviation from normal operation by using the 360 Intermittent Pilot System Troubleshooting Table which follows.

Use the table by following the questions in the boxes. If the condition is true (answers yes), go down to next box. if the condition is not true (answers no), go to the box alongside.

Continue checking and answering conditions in each box until a problem and/or the repair is explained. Use the COMPONENT CHECKS section (beginning on page 50) as necessary to perform system checks.

After any maintainance or repair, the troubleshooting sequence should be repeated until the procedure ends with normal system operation.

Figure 49. Burner Ignition

System with AMP/OHM

Meter (Shaon on Model

PS360)

Page 74

SECTION 2 SERVICING COMPONENTS

IMPORTANT: When servicing the Burner Control Board it is very important that you identify the Control Board as either a fused or a nonfused. The original board supplied by the vendor for the past few years was the fused model. We are now supplied with the nonfused mode. All PS200 ovens have the nonfused model.

Refer to the chart below when servicing the Burner Control or the Gas Safety Valve.

MV/PVtoPV 3 VAC 24 VAC

MV/PVtoMV 12 VAC 24 VAC

BURNER CONTROL BOARD

Voltage Test Points Marked

Fused Nonfused

TRtoTH 12 VAC 24 VAC

TH/TRtoTR 3 VAC 24 VAC

MAIN GAS VALVE

The nonfused Ignition Control Board has been used in production since early 1988 on all PS310, 360 and 200 Model Ovens. This is also the only board now supplied by Middleby Marshall as a replacement part.

Page 75

Service Bulletin

Date

11/30/90

NO. 123A

A MIDDLEBY COMPAHY

SUBJECT: HONEYWELL IGNITION MODULE

All Pacesetter Ovens

We spoke "too soon. There is a difference between the current Honeywell ignition module (P/N 27161-0004) and the new Honeywell ignition module (P/N 27161-0005; Kit P/N 42810-0114), introduced to you in Service Bulletin

123. The new module is internally grounded and as a result must not be in the ground leg of the 24 volt transformer.

Double grounding of the new module sets up a feedback voltage circuit allowing the module to operate without signal from the burner/blower assembly.

WHEN REPLACING AM OLD MODULE WITH A MEW MODULE IT IS MANDATORY TO REMOVE AND DISCARD THE BURNER TRANSFORMER GROUND WIRE. SEE FIGURE 1 OF INSTRUCTIONS ATTACHED.

This ground wire is located inside the burner/blower motor electrical box containing the 24 volt transformer and prepurge relay. The green ground wire is secured by a ring terminal at the base of the transformer and runs from a wire nut which ties the yellow ground lead from the ignitor module with the yellow wire from the transformer and the black wire from the prepurge relay coil. It is the green wire only that is to be removed.

This change however, does not eliminate the need for the ground wire in cases where a technician is using the older module as a replacement in an oven which was already fitted with a new module and no ground wire.

If an old module is replacing a new module then the ground wire needs to be replaced for the older module to operate properly. See Figure 2 of instructions attached.

IN REVIEW

1. NEW MODULE MUST NOT HAVE GROUND WIRE (FIG. 1).

2. OLD MODULE MUST HAVE GROUND WIRE (FIG - 2).

We appreciate your usual and kind cooperation in this matter.

James E. Urani Field Technical Supervisor

8300 Austin Avenue • Morton Grove, Illinois 60053

(708)-966-8300• FAX (708)966-8701

JEU:aa

48A

Page 76

INSTALLATION INFORMATION (P/N 88210-0058) NEW HONEYWELL IGNITION

MODULE (P/N 27161-0005) OLD HONEYWELL IGNITION MODULE (P/N 27161-0004)

REPLACING OLD MODULE WITH NEW

1. WHEN REPLACING AN OLD MODULE WITH A NEW MODULE IT IS MANDATORY TO REMOVE AND DISCARD THE BURNER

TRANSFORMER GROUND WIRE. SEE FIGURE 1.

This ground wire is located inside the burner/blover motor electrical box containing the 24 volt transformer and prepurge relay. The green ground wire is secured by a ring terminal at the base of the transformer and runs from a wire nut which ties the yellow ground lead from the ignitor module with the yellow wire from the transformer and the black wire from the prepurge relay coil. It is the green wire only that is to be removed.

2. When reconnecting the module wires, be sure that the yellow wire which is actually the ground wire is connected to the top terminal marked 24v (GND) on the new module.

3. If using existing ignitor/sense lead from old module, reconnect to new module using adapter. See Figures 3 and 4.

4. When new ignitor/sense lead becomes available, the adapter will no longer be needed and the ignitor/sensor lead will connect to the new module as called out in Figure 5.

REPLACING NEW MODULE WITH OLD

1. WHEN REPLACING A NEW MODULE WITH AN OLD MODULE IT IS MANDATORY TO INSTALL A BURNER TRANSFORMER GROUND WIRE. SEE FIGURE 2-

Use a green 18 AWG, 105 degree C, U.L. listed wire and terminal ring. This ground wire should be located inside the burner/blower motor electrical box containing the 24 volt transformer and prepurge relay. The green ground wire should be secured by a ring terminal at the base of the transformer and run into the wire nut which ties the yellow ground lead from the ignitor module with the yellow wire from the transformer and the black wire from the prepurge relay coil.

2. When reconnecting the module wires be sure the yellow wire which is actually the ground wire, is connected to the top terminal marked 24v on the old module.

3. Reconnect the ignitor/sense lead to spark terminal of old

module. The adapter in Figure 4 of the new module is not used.

NOTE: The new style ignitor/sense lead as shown in Figure 5 will not be compatible with the old module. Either a new module must be used or the ignitor/sense lead must also be replaced with an old style.

48B

Page 77

48C

Page 78

SECTION 2 SERVICING

COMPONENTS

Page 79

SECTION

SERVICING

COMPONENTS

5. Component Checks Reset System After Lock out.

If a system with a control board goes into safety lockout, the module must be reset before attempting further operation or checkout. The system will remain in safety lockout until it is reset. Shut system OFF. (Turn Heat switch OFF).Wait at least one minute, then turn Heat switch ON.

b. Disconnect the ignition cable at the control board stud terminal to isolate the circuit from the pilot burner/ignitor sensor, and prepare a short jumper lead using heavily insulated wire, such as ignition cable.

c. Energize the control board and touch one end of the jumper firmly to the control board ground terminal (GND). Do not disconnect the existing ground lead. Move the free end slowly toward the stud terminal to establish a spark and then pull the leadwire slowly away from the stud. Note the length of the gap at which arcing stops (Figure 50).

6. Check Spare Ignition Circuit. The electronic module and step-up transformer in the

control board provides spark ignition at 15,000V (open circuit). This circuit can be checked at the control board as follows:

a. Turn OFF the manual gas cock to prevent the

flow of gas.

CAUTION

Do Not touch either stripped end of jumper or stud terminal.

This is a very high voltage circut and electrical shock can result.

Perform the test immediately upon energizing the system-

before the control board goes into safety lockout

and interrupts the spark circuit.

d. An arc length of 1/8" (3.2mm) or more indicates satisfactory voltage output. Replace the control board if no arc can be established or the maximum gap is less than 1/8" (3.2mm), and the fuse and power to the control board input terminal was okay.

Figure 50. Checking Spark Ignition Circuit.

Page 80

7. Check Spark Ignitor. If the troubleshooting procedure indicates a problem

with the ignitor/sensor, check the spark ignitor and the ignitron cable connections and continuity as follows:

Check Ignitor/Sensor—

a. Check the ignitor spark gap to make certain it is correct, 1/8" (3.2mm). If necessary, use a needlenose plier and carefully bend the tip of the outer electrode to correct.

b. Check that the pilot flame is properly adjusted. See Check Pilot Flame, page 41.

Check Igniton Cable—

a. Ignition cable must not touch metal surfaces or current carrying wires. Use ceramic standoff insulators, if necessary.

b. Check length of ignition cable. It must not exceed 3 ft. (0.9m).

SECTION 2 SERVICING

COMPONENTS

c. Check connections to ignitor and control module stud, connections must be clean and tight. Loose connections may not conduct a flame current even though the ignition spark is satisfactory. Check the electrical continuity of the cable. Replace cable if damaged or deteriorated.

d. If no spark or a weak spark occurs, but spark ignition circuit check was okay, disconnect the ignition cable at the ignitor (or ignitor/sensor) and measure the arc from the cable end to the ignitor stud. Follow the same general procedures and observe the same cautions as in Check Spark Ignition Circuit.

If the arc is correct, replace the ignitor (or ignitor/sensor).

If the arc is less than it should be, disconnect the ignition cable and use a jumper wire from the control module stud terminal. If the spark is okay, replace the ignition cable. If the arc is still less than it should be, replace the control board.

Page 81

SECTION

SERVICING COMPONENTS

F. Checkout Procedures.

Page 82

SPARK IS PRESENT, PILOT WILL NOT LIGHT

SECTION 2 SERVICING

COMPONENTS

Page 83

SECTION 2 SERVICING COMPONENTS

Page 84

VI. HIGH FLAME SOLENOID VALVE

High flame solenoid valve is located between the gas valve and the burner. This 110 volt valve is controlled by the thermostat. When the thermostat calls for heat the valve opens and lets the full flow of gas go to the burner. When the thermostat is satisfied the valve closes and the only gas going ot the burner is from the by-pass line that goes around the solenoid valve body.

VII. MAIN GAS VALVE (MMPN 28092-0013).

When the Manual ON-OFF knob is turned to the ON position gas is allowed to enter the valve through the poppet valve. Once 24 Vac is supplied to the terminals TH-TR and TR the pilot valve (solenoid operated) opens which admits gas to the pilot burner, gas is not yet allowed to the main burner. When the pilot flame is

SECTION 2 SERVICING

COMPONENTS

proved, 25Vac is applied to terminal TH -TR and TH, energizing the Servo Valve Operator. The main valve is Servo operated. Gas pressure from the inlet side of valve is passed through the Pressure Regulator which then supplies this regulated pressure to a cavity below the main valve diaphragm. This pressure overcomes the spring force and moves the main valve to its open position. During operation the main valve is opened and closed by the pressure regulator to keep a constant pressure at the outlet of the valve.

When the Servo Valve operator is de-energized, the cavity below the main valve diaphragm is depressurized and the valve spring closes the main valve rapidly to shut off the main burner.

When the pilot valve is de-energized the main solenoid valve closes shutting gas OFF to the pilot and main burner.

Figure 51. Main Gas Valve.

Page 85

SECTION 2 SERVICING COMPONENTS

VIII. LOW FLAME ORIFICE

All ovens are equipped with an orifice in the low flame gas line (See Figures 46 or 47). The purpose of this orifice is to maintain a very low flame when the oven is not calling for heat.

If the orifi ce size is too large the low flame will be too high and in some cases this will cause the temperature to raise overthe setting of the temperature controller.

The normal low flame orifice size is as follows:

Propane ft 62 Drill - MM P/N 22174-0009 Natural # 53 Drill - MM P/N 22174-0006

On PS360 ovens with the thermocouple located in the rear of oven and all PS200 ovens the ratio of low flame to high flame will be closerto 1 to 1.

NOTE: These readings should be taken after the oven has stabilized (on for over an hour) and the oven moderately loaded with product.

The high flame/low flame cycle time can be easily determined by watching and timing the length of time the high flame light of the temperature controller goes on and off. When this light is on, the high flame solenoid valve is energized (open).

High Altitude Exceptions

On PS360 ovens with the thermocouple located in the front of oven and the low flame line having the proper orifice, the ratio of low flame as compared to high flame should be 2 or 3 to 1.

Example: If the high flame is on for 5 seconds, the low flame should be on for no longer than 15 seconds. If it is on longer than that the low flame orifice should be replaced with one with a smaller hole.

Higher altitude will disrupt air fuel mixtures and necessitate smaller orifices. A general rule is 4% input reduction for every 1000 feet above sea level.

Example: At Denver, Colorado, (elevation of 5,000 feet) the natural gas by -pass line will probably require a #54 orifice and the main burner should have a #8 orifice.

Page 86

Service Bulletin No. 131

SUBJECT: INTERMITTENT PILOT COMBINATION GAS CONTROL KIT PART NUMBER 42810-0121

The gas control kit, P/N 42810-0121, described in this bulletin is a direct replacement for gas control P/N 28092-0013 which has been discontinued. The new gas control kit consists of four (4) parts:

Part Number Description

28092-0017 33300-0225 23070-0005 88210-0068

Gas Control Pilot Tube Compression Nut w/Sleeve Instruction Sheet

AVAILABILITY

After November 14, 1991, all orders for gas control P/N 28092-0013 will be filled with the new gas control kit P/N 42810-0121.

Date 11/27/91

A MIDDLEBY COMPANY

DISPOSITION OF INVENTORY

Existing inventories of discontinued control P/N 28092-0013 should be used up.

FEATURES The new gas control provides four new features:

1. Easy access inlet and outlet pressure taps.

2. Easy conversion from natural to propane or propane to natural.

3. Wiring terminal nomenclature matches the ignition module.

4. On/off knob material is resistant to oven environment.

COMPATIBILITY

The new control will fit in all existing applications of the discontinued control. However, due to the new location of the pilot tube outlet it will be necessary to install the longer pilot tube which is supplied in the kit.

Conversion from natural to propane gas is done by changing the regulator spring only. Refer to Service Bulletin 132 for details.

Tom Hoe Product Service Representative

TM:aa

8300 Austin Avenue • Morton Grove, Illinois 60053

(708) 966-8300 • FAX (708) 966-8701

56A

Page 87

FIRE OR EXPLOSION HAZARD

CAN

CAUSE PROPERTY DAMAGE,

natural gas on propane gas or a gas control set

for propane gas on natural gas

These gas controls are shipped with protective seals

until ready to connect piping

FIRE OR EXPLOSION HAZARD

SEVERE INJURY OR DEATH

No replaceable components. Attempted disassembl

y Or repair may damage the gas control.

Middleby Marshall

Part Number88210

0068

Middleby Marshall Inc. ·8300 Austin Ave. ·Morton Grove, IL 60053·(708)966-8300·TWX9102330211·FAX (708)966-8701

Intermittent Pilot Combination Gas Control Kit (Kit Number 42810-0121) Installation Instructions

WARNING

SEVERE INJURY OR DEATH.

Do Not attempt to use a gas control set for

IMPORTANT

over Inlet and outlet tapping. Do Not remove seals

WARNING

CAN CAUSE PROPERTY DAMAGE,

Do Not Disassemble the gas control; It Contains

The following Instructions describe the Installation of the Middleby Marshall gas control kit, MMP/N 42810-0121, which is the replacement for the discontinued gas control MMP/N 28092-0013. The new gas control kit consists of four (4) parts:

1 28092-0017 Gas Control 2 33300-0226 Pilot Tube 3 23070-0085 Compression Nut w/Sleeve 4 89210-0068 Instruction Sheet

The new control will fit in all existing applications of the discontinued control, however, due to the new pilot outlet location it is necessary to install the longer pilot tube supplied in the kit.

Middley Marshall Inc.· 8300 Austin · Morton Grove IL. 60053· TWX9102230211· FAX (708)966-8701

P1/92

Page 88

Page 89

56E

Page 90

SECTION 2 SERVICING

2 3 3 4 5 6 7 9 10 12

5 7 8 9 10 12 13 14 15 17

9 11 12 12 13 14 16 17 18 19

12 13 14 15 16 17 17 18 19 20

15 16 17 17 18 19 20 20 22 24 16 17 18 18 19 19 20 22 23 25

18 19 19 20 21 22 23 24 26 27

20 22 22 23 24 25 26 27 28 29 21 23 23 24 25 26 27 28 28 29

23 25 25 26 27 27 28 29 29 30

26 27 28 28 28 29 29 30 30 30

28 29 29 29 30 30 30 30 31 31 29 29 30 30 30 30 31 31 31 32

33 35 35 36 36 37 38 38 40 41

36 37 38 38 39 40 41 41 42 43

39 40 41 41 42 42 43 43 44 44

41 42 42 42 43 43 44 44 45 46

44 45 45 45 46 47 47 48 48 49 45 46 47 47 47 48 48 49 49 50

Equivalent Orifice Sizes at High Altitudes

(Includes 4% Input Reduction for Each 1,000 Feet)

COMPONENTS

Size at

Sea Level

1 2 2 3 3 4 5 7 8 10

3 4 5 7 8 9 10 12 13 15 4 6 7 8 9 11 12 13 14 16

6 8 9 10 11 12 13 14 16 17 7 9 10 11 12 13 14 15 16 18 8 10 11 12 13 13 15 16 17 18

10 12 13 13 14 15 16 17 18 19 11 13 13 14 15 16 17 18 19 20

13 15 15 16 17 18 18 19 20 22 14 16 16 17 18 18 19 20 21 23

17 18 19 19 20 21 22 23 24 26 19 20 20 21 22 23 25 26 27 28

22 23 24 25 26 27 27 28 29 29 24 25 26 27 27 28 28 29 29 30

25 26 27 27 28 28 29 29 30 30

2000 3000 4000 5000 6000 7000 8000 9000 10000

Orifice Size Required at Other Elevations Orifice

27 28 28 29 29 29 30 30 30 31

30 30 31 31 31 31 32 32 33 35 31 32 32 32 33 34 35 36 37 38 32 33 34 35 35 36 36 37 38 40

34 35 36 36 37 37 38 39 40 42 35 36 36 37 37 38 39 40 41 42

37 38 39 39 40 41 42 42 43 43 38 39 40 41 41 42 42 43 43 44

40 41 42 42 42 43 43 44 44 45 42 42 43 43 43 44 44 45 46 47

43 44 44 44 45 45 46 47 47 48

46 47 47 47 48 48 49 49 50 50

Page 91

SECTION 2 SERVICING

Sea Level

COMPONENTS

Size at

47 48 48 49 49 49 50 50 51 51 48 49 49 49 50 50 50 51 51 52 49 50 50 50 51 51 51 52 52 52 50 51 51 51 51 52 52 52 53 53 51 51 52 52 52 52 53 53 53 54 52 52 53 53 53 53 53 54 54 54 53 54 54 54 54 54 54 55 55 55 54 54 55 55 55 55 55 56 56 56 55 55 55 55 56 56 56 56 56 57 56 56 56 57 57 57 58 59 59 60 57 58 59 59 60 60 61 62 63 63 58 59 60 60 61 62 62 63 63 64 59 60 61 61 62 62 63 64 64 65 60 61 61 62 63 63 64 64 65 65 61 62 62 63 63 64 65 65 66 66 62 63 63 64 64 65 65 66 66 67 63 64 64 65 65 65 66 66 67 68 64 65 65 65 66 66 66 67 67 68 65 65 66 66 66 67 67 68 68 69 66 67 67 68 68 68 69 69 69 70 67 68 68 68 69 69 69 70 70 70 68 68 69 69 69 70 70 70 71 71 69 70 70 70 70 71 71 71 72 72 70 70 71 71 71 71 72 72 73 73 71 72 72 72 73 73 73 74 74 74 72 73 73 73 73 74 74 74 74 75 73 73 74 74 74 74 75 75 75 76 74 74 75 75 75 75 76 76 76 76 75 75 76 76 76 76 77 77 77 77 76 76 76 77 77 77 77 77 77 77 77 77 77 77 78 78 78 78 78 78 78 78 78 78 79 79 79 79 80 80 79 79 80 80 80 80 .013 .012 .012 .012 80 80 .013 .013 .013 .012 .012 .012 .012 .011

Equivalent Orifice Sizes at High Altitudes

(Includes 4% Input Reduction for Each 1,000 Feet)

Orifice Size Required at Other Elevations Orifice

2000 3000 4000 5000 6000 7000 8000 9000 10000

Page 92

SECTION

SERVICING

IX. PROPANE CONVERSION KIT (MM P/N 42810-0027)

All ovens can easily be convened from Natural to Propane or Propane to Natural gas by ordering and installing the proper Conversion Kit.

ORIFICE KITS See Conversion Kit breakdown below:

CONVERSION KITS PS200 NATURAL TO PROPANE GAS, KIT NO. 49810-0003

QTY PART NO. DESCRIPTION 1 22176-0007 Orifice, Main Burner 5/8 x 27 Thd - .1285" (#30 drill) 1 22174-0009 Orifice, Bypass #62 1 22174-0010 Orifice.Pilot.014 1 28092-0015 Regulator, Set Propane 11.0" WC 1 22500-0065 Label - Propane

PS200 PROPANE TO NATURAL GAS, KIT NO. 49810-0011 CONSISTS OF:

COMPONENTS

NOTE: Propane ovens shipped from the factory will have the old natural gas orifice enclosed in a plastic container. This is in the event that the oven may have to be converted back to natural gas at some future date. If an oven is field convened from natural to propane please leave the old natural gas orifices in a propane container inside the machinery compartment of the oven. Refer to Figure 46 or 47 for the location of the low flame, main burner and pilot orifice.

CONSISTS OF:

QTY PART NO. DESCRIPTION 1 22176-0006 Orifice, Main Burner 5/8 x 27 Thd - .1960" (#9 drill) 1 22174-0006 Orifice, By pass #53 1 22174-0011 Orifice, Pilot .020 1 28092-0016 Regulator, Set Natural 3.5" WC 1 22500-0064 Label - Natural

PS310/360 NATURAL TO PROPANE GAS, KIT NO. 42810-0027 CONSISTS OF:

QTY PART NO- DESCRIPTION 1 22176-0003 Orifice, Main Burner 5/8 x 27 Thd - 3.44 mm 1 22174-0009 Orifice, By pass #62 1 22174-0010 Orifice, Pilot .014 1 28092-0015 Regulator, Set Propane 11.0" WC 1 22500-0065 Label-Propane

PS310/360 PROPANE TO NATURAL GAS, KIT NO. 49810-0026 CONSISTS OF:

QTY PART NO. DESCRIPTION 1 22176-0004 Orifice, Main Burner 5/8 x 27 Thd - 7/32' 1 22174-0006 Orifice, By pass #53 1 22174-0011 Orifice, Pilot .020 1 28092-0016 Regulator, Set Natural 3.5" WC 1 22500-0064 Label - Natural

Page 93

SECTION 2 SERVICING

A. Converting Gas Valve from Natural to Propane

CAUTION: Turn OFF gas at manual shutoff

Loosen two Philips screws from Propane

CAUTION: Turn OFF gas at manual shutoff

COMPONENTS

Gas.

valve on incoming gas line before attempting to loosen any gas fitting on the oven. Also shut OFF main electrical breaker for oven.

1. Loosen two Philips screws from Natural pressure regulator and remove regulator and gasket.

2. Attach Propane gas pressure regulator (MM P/N 28092-0015) as shown in Figure 52. DO NOT use old gasket, a new gasket is supplied with kit.

3. Attach gas pressure manometer to inlet and outlet pressure taps of the gas valve.

4. Turn on gas supply and electrical power.

5. Incoming gas pressure MUST BE between 11" WC and 14" WC.

6. Remove cover screw on regulator, turn on Blower and Heat switches and allow oven to fire. Adjust pressure regulator adjustment screw so outlet pressure is 10.5"WC.

2. Attach Natural gas pressure regulator (MM P/N 28092-0016) as shown in Figure 52. DO NOT use old gasket, a new gasket is supplied with kit.

3. Attach gas pressure manometer to inlet and outlet pressure taps of the gas valve.

4. Turn on gas supply and electrical power.

5. Incoming gas pressure MUST BE between 6"WCand12"WC.

6. Remove cover screw on regulator, turn on Blower and Heat switches and allow oven to fire. Adjust pressure regulator adjustment screw so outlet pressure is 3.5"WC.

7. If incoming gas pressure drops below 6"WC with oven and all gas appliances in store on high flame condition this indicates a problem with the incoming gas supply.

8. Replace pressure regulator cover screw.

7. If incoming gas pressure drops below 11"WC with oven burner ON this indicates a problem with the incoming gas supply.

8. Replace pressure regulator cover screw.

9. IMPORTANT: Place adhesive backed Propane sticker on visible side of gas valve,

10. With a felt tip pen change the marked setting on the serial plate from Natural to Propane and the pressure from 3.5" WC to 10.5" WC.

11. Check all gas connections for leaks.

B. Natural Conversion Kit Converting Gas Valve from Propane to Natural

Gas

valve on incoming gas line before attempting to loosen any gas fitting on the oven. Also shut OFF main electrical breaker for oven.

pressure regulator and remove regulator and gasket.

Page 94

Middleby Cooking Systems Group

1400 Toastmaster Drive • Elgin, Illinois 60120 (708)741-3300 • Service & Parts (708) 741-4406

Service Bulletin

Bulletin No. 13 2 A

Date: 12/19/94

SUBJECT: PS360WB GAS CONVERSION KIT

GENERAL:

This bulletin is issued to alert the service technician that the PS360WB can be converted from natural to propane, or from propane to natural as is possible with any other Middleby Marshall gas fired conveyorized oven. This bulletin updates the natural to propane instructions, P/N 88210-0069, presented in Service Bulletin 132.

APPLICATION: To convert a PS360WB from natural to propane gas, use Kit ff 42810-0124. To convert a

PS360WB from propane to natural gas, use Kit it 42810-0127.

COMPATIBILITY:

The PS360WB gas conversion kits are the same as those used on the PS570 and PS570S ovens.

AVAILABILITY: Kits 42810-0124 and 42810-0127 are available now for immediate shipment.

60A

Page 95

Authorized Service Or

ganization In accordance with the manufacturer's

instructions and all codes and requirements of the authority having

jurisdiction. Failure to follow Instructions could result

in serious injury or property damage. The authorized service organiza

- tion

performing this work assumes responsibility for this conversion.

Middleby Marshall Inc, • 8300 Austin Ave, •Morton Grove, IL 60063 • (708)966-8300 • 1-800-238-M44 • FAX(708)966-8701

Oven Gas Conversion Kit-

Natural Gas to Propane Gas

Installation Instructions

IMPORTANT KITS LISTED BELOW ARE FOR USE WITH OVENS EQUIPPED WITH OAS CONTROL VALVE MM/PN 28092-0017 ONLY!

PS360WB......…....................................... MM/PN 428104124

The following Instructions cover the Installation of the MIddleby Marshall Oven - Natural to Propane Gas Conversion Kit. The Kit consists of the following parts:

DESCRIPTION PART NUMBER

Complete Gas Kit Natural to Propane Gas 428104119 428104122 428104123 428104124 Orifice, Main Burner 221784003 221764007 221784017 221764015

Orifice, Bypass 221744009 (IK32 with red dot) (same for all models/series) Orifice, Pilot 221744010 (0.014” with red dot) (same for all models/series) Gas Control Valve Conversion Kit 280924018 (same for all models/series) Propane Label 225004005 (same for all models/series) Oven Conversion Label 225004123 (same for all models/series) Gas Control Conversion Gas Oven Conversion Instructions 882104009 (same for all models/series)

PS200 Kit ...............................................MM/PN 42810.0122

PS200-20 Kit........................................…MM/PN 428104123

PS300 Series (except P8333) Kit ....….....MM/PN 428104119

PS570 Kit .........................................…....MM/PN 428104124

WARNING

PS300 Series (except PS333)

3.44mm 0.1285' 0,113' 0.152'

PS200 PS200-20 PS570 &

225014007 (same for all models/series)

P8360WB

Page 96

CAUTION

Figure

Turn Off The Electrical Power Supply To The Oven

Before Performing Any Service Or Conversion Work

CAUTION

Turn Off The Gas Supply At The Service Valve Behind The Oven

Before Performing Any Service Or Conversion Work

MANIFOLD AND VENTURI REMOVAL

1. Turn off the electric power

supply to the oven.

2. Turn off the gas supply at the

service valve behind the oven.

3. Unscrew the gas pipe union located on the Inlet side of the gas control, Refer to Figure 1.

4. Unscrew the four venturi mounting plate screws. Refer to Figure 1.

5 Remove the manifold and venturi assembly from the oven. Refer to Figure 1.

NOTE: The Manifold and venturi assembly shown in Figure1 is from a PSSOO Series Oven. The disassembly procedure is the same for all three series ovens (PS200, PS300andPS500). The pipe union that is loosened is always at the inlet side o the gas control valve.

GAS CONTROL VALVE CONVERSION NOTE: The parts Installed In the following Steps 1-6 are found in the Gas Control Conversion Kit M M/PN 2BW2-W1B, which Is Included here in this kit.

1. Remove regulator cap screw and

pressure regulator adjusting

screw. Refer to Figure 2.

2. Remove the existing spring.

3. Insert the red replacement spring with the tapered and down. Refer to Figure 2.

4. Install the new plastic pressure regulator adjustment screw. Ensure that the screw top is flush with the regulator top,

5. Turn pressure regulator adjust ment screw clockwise six complete turns. The preliminary pressure setting Is approximately 10.5 In. w.c.

6. Install the new black cap screw.

Page 97

MARKING AND LABELING

1. Print the word 'PROPANE" In the space provided on the Gas Control Conversion Tag P/N

25501.0007.

2. Affix the Gas Control Conversion Tag on the gas control.

3. Affix the round, orange, propane label Part Number 22500-0065 over (TIB round, green

natural label on the burner (unction box cover.

4. Pill In the appropriate Information on me oven conversion label P/N 22500-0123 according to

the Instructions In Figure 0.

5. Affix the oven conversion label as close as possible to the existing rating plate.

Figure B

BYPASS ORIFICE CONVERSION

1. Unscrew the bypass tube compression nut and slide out of the way Pull the tube from the fitting to expose the bypass orifice as shown in Figure 3.

2. Remove the existing natural gas bypass orifice

3. Install the propane (K62 with the red dot) bypass orifice by slipping II Into the bypass tube.

4. Push the tube with the bypass orifice In place, Into the solenoid valve fining until It bottoms. While holding the tubing all the way In, slide the compression nut Into place and engage threads, turning ringer tight. Then tighten one more turn with a wrench. Do Not

Overtighten. PILOT ORIFICE CONVERSION

1. Unscrew the pilot lube compression nut and slide out of the way. Pull the lube from the fining to expose the pilot orifice as shown In Figure 4.

2. Remove the existing natural gas pilot orifice.

3. Install the propane pilot orifice (0.014' with the red dot) by slipping It Into the pilot tube.

4. Push the tube with the pilot orifice In place. Into the solenoid valve fitting until it bottoms. While holding the tubing all the way In, slide the compression nut Into place and engage threads, turning finger tight. Then tighten one more turn with a wrench. Do Not Overtighten.

MAIN BURNER ORIFICE CONVERSION

1. Unscrew the two venturi mounting nuts, (Early models equipped with screws). Refer to Figure 4.

2. Separate the venturi, mounting plate, and pipe.

3. Unscrew the existing natural gas main burner orifice from the pipe.

4. Install the correct propane main burner orifice. See Table 1 for orifice size and number.

5. Reinstall the venturi and pipe to the venturi mounting plate.

TABLE 1 P8300 Series P8200 P8200-20 P8S70 &

Orifice Size 3.44mm 0.1285' 0.113" 0.152' Orifice Marking 134 128 113 152 Orifice Part Number 22176-0003 22176-0007 22176-0017 22176-0016

(Except PS333)

P8360WB

Page 98

MANIFOLD REINSTALLATION

1. Verify the pilot ignitor/main burner venturi relationship using Figure 5.

2. Insert the venturt assembly Into the burner tube.

3. Fasten the four venturi mounting plate screws. Refer to Figure 1.

4. Fasten the gas pipe union. Refer to Figure 1.

5. Turn on the electrical power supply to the oven.

6. Turn on the gas supply at the service valve behind the oven.

ADJUST THE PILOT BURNER FLAME

The pilot flame should envelop 3/8 to 1/2 Inch (10 to 13 millimeters) of the lgnitor-sensor dp. Refer to Figure 6. II necessary

adjust the pilot flame;

1. Remove the pilot adjustment cover screw of the gas control. Refer to Figure 7.

2. Turn the Inner adjustment screw clockwise to decrease or counterclockwise to Increase the pilot flame.

3. Always replace the cover screw after adjustment and tighten firmly to ensure proper operation.

Shut off the gas supply at the service valve

behind the oven before removing the outlet

pressure lap plug or before disconnecting the manometer.

ADJUST MANIFOLD PRESSURE

1.The gas control outlet pressure should be 10.5' w.c. (or propane gas.

2. With the main burner operating, check the gas pressure using a manometer connected to the gas control outlet pressure tap. Refer to Figure 7.

3. If necessary, adjust the pressure regulator: a. Remove the pressure regulator adjustment cap and screw. b. Using a screwdriver, turn the Inner adjustment screw clockwise to Increase or counterclockwise to decrease the main burner gas pressure. c. Always replace the cap screw and tighten firmly to ensure proper operation.

4. If the desired outlet gas pressure cannot be achieved by adjusting the gas control, check the gas control Inlet pressure using a manometer at the Inlet pressure tap. If the Inlet pressure Is at least 11'w.c. (or propane, replace the gas control. Otherwise, take the necessary steps to provide proper gas pressure to the gas control.

5. Be sure the main burner primary air supply Is properly adjusted (or complete combustion (approximately 1/4' to 3/8' open).

6. Perform gas leak test.

FIRE OR EXPLOSION HAZARD CAN CAUSE PROPERTY DAMAGE.

SEVERE INJURY OR DEATH. Check for gas leaks with rich soap and water

solution any time work Is done on a gas system.

GAS LEAK TEST

1. Paint all pipe connections from the gas union to the venturi mounting plate Including the bypass and pilot tube connections and pressure tap plugs with a rich soap and water solution. Bubbles Indicate a gas leak.

2. If a gas leak Is detected, tighten the pipe connection.

3. Stand clear while lighting main burner to prevent Injury caused from hidden gas leaks which could cause flashback In the machinery compartment. Light the main burner.

4. With the main burner In operation, paint all pipe joints with rich soap and water solution.

5. If another gas leak Is detected, tighten joints and pipe connections,

6. Replace the part If gas leak cannot be slopped.

Page 99

X. PIPE SIZING - Always install a shutoff valve in the gas supply line to the oven (supplied with PS200 ovens). This valve should be the same size as the supply line and should have a full minimum 3/4" throat opening..

The minimum incoming line flow pressure (when oven is on high flame cycle) should be the following:

Natural Gas -6" W.C. Propane Gas -11" W.C.

This pressure reading can be taken by installing a gas pressure gauge on the left hand side of the main gas valve. Outgoing pressure can be measured at the tap at the right hand side of the main gas valve. (See Figure 53).

SECTION 2 SERVICING

COMPONENTS

RECOMMENDED SUPPLY PIPE SIZE FOR NATURAL GAS OVENS AT 6" W.C. INCOMING PRESSURE.

All single ovens: PS200/310/360

1 -1 /2" (38 mm) on runs up to 200 feet (61 m)

Double ovens or Single Tandem: PS200/310/360

2" (51 mm) on runs up to 200 feet (61 m)

Double Tandem: PS200/310/360

2-1/2" (63 mm) on runs up to 200 feet (61 m)

For runs over 200 feet (61 m) consult factory.

NOTE: Gas pressure should always be set when the burner is in the low flame mode. If pressure drops when oven goes to high flame, it is an indication of a gas supply problem.

Natural Gas -3.5" W.C.

Propane Gas -11" W.C. Please remember that the longer the pipe runs, the more the pressure drops. One 90° elbow equals a 4

foot length of pipe. Refer to pipe sizing chart to determine what size gas

pipe to run to the oven.

NOTE: The PS310/360 is rated for 135.000 BTU/hr for each oven cavity. A double oven would use 270,000 BTU/hr. The PS200 is rated for 120,000 BTU/hr for each oven cavity. A double oven would use 240,000 BTU/hr

RECOMMENDED SUPPLY PIPE SIZE FOR PROPANE OVENS AT 12" W.C. INCOMING PRESSURE.

Have owner inform Propane supplier of the following oven requirements and have them size accordingly:

All single ovens: PS200/310/360

1" (25 mm) on runs up to 200 feet (61 m)

Double ovens or Single Tandem: PS200/310/360

1 -1/2" (38 mm) on runs up to 200 feet (61 m)

Double Tandem: PS200/310/360

2" (51 mm) on runs up to 200 feet (61 m)

For runs over 200 feet (61 m) consult factory.

Figure 53. Checking PS310/360 Incoming and Outgoing Pressure with 2 Water Column Gauges

Page 100

SECTION2 SEVICING COMPONENTS

Figure 54. Checking PS200 Incoming and Outgoing Pressure with 2 Water Column Gauges