Blodgett MT2136E Service Manual

MT2136 SERIES

CONVEYOR OVEN

SERVICE AND REPAIR MANUAL

BLODGETT OVEN COMPANY

www.blodgettcorp.com

50 Lakeside Avenue, Box 586, Burlington, Vermont 05402 USA Telephone (802) 658Ć6600 Fax: (802)864Ć0183

PN M9884 A (6/01)

Duplication of the information in this manual is prohibited without the consent of the Blodgett Service Department.

 1999 - G.S. Blodgett Corporation All rights reserved.

TABLE OF CONTENTS

1. INTRODUCTION

Oven Specifications 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ventilation Requirements 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical Specifications 1-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Gas Specifications 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Illustrated Parts Lists 1-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2. ASSEMBLY

Oven Assembly Procedures 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Nozzles 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conveyor Supports 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Drive Chain 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wire Conveyor Belt 2-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air Plates 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conveyor Tunnel Extensions 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conveyor Belt Tensioners 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crumb Pans 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mount remote control 2-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. OPERATION

Standard Control Options 3-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

U.E. Temperature Controller with Open Loop DC Drive System 3-1. . . . . . . . . . . . . . . . . . . . .

Athena Temperature Controller with Open Loop DC Drive System 3-2. . . . . . . . . . . . . . . . . . .

Computer Controller 3-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sequence of Operation 3-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MT2136E Domestic with Athena controls - M2190 Rev H 3-5. . . . . . . . . . . . . . . . . . . . . . . . . .

MT2136E General Export with Athena controls - M2341 Rev F 3-7. . . . . . . . . . . . . . . . . . . . .

MT2136G Australian Unit with Athena Control - M2847 Rev C 3-9. . . . . . . . . . . . . . . . . . . . . .

MT2136G CE with Athena Control - M3163 Rev C 3-11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MT2136G Domestic with Remote Computer control - M3476 Rev b 3-13. . . . . . . . . . . . . . . . .

MT2136G Domestic with Open Loop Computer Control - M3717 Rev B 3-15. . . . . . . . . . . . .

MT2136G Domestic with Closed Loop Computer Control - M7287 Rev A 3-17. . . . . . . . . . . .

MT2136E CE with Closed Loop Computer Control - M6476 Rev B 3-19. . . . . . . . . . . . . . . . . .

MT2136G CE with Computer Control - M7290 Rev E 3-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MT2136G General Export - M7295 Rev B 3-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oven Adjustments for Cooking 3-35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Temperature 3-35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conveyor Speed Time vs. Temperature 3-35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air Flow Adjustments 3-35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

i

TABLE OF CONTENTS

4. CALIBRATION AND ADJUSTMENT

Convection Blower Motors 4-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Regulated Gas Pressure 4-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Standard Controller Configuration 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Belt Speed Calibration - Open Loop 4-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Temperature Calibration - United Electric Controller 4-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Temperature Calibration - Athena Controller 4-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Computer Controller Configuration 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Computer Controls 4-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Temperature Calibration 4-9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Belt Speed Calibration 4-10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Motor Control Board Adjustment 4-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Rerating the Appliance 4-15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Checking the Firing Rate 4-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5. TROUBLESHOOTING

DC Drive System 5-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Convection System 5-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Heating System 5-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Computer Control System 5-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6. TECHNICAL APPENDIX

Intermittent Ignition System 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Principles of Operation 6-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Service Procedures 6-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cooking Computer - Temperature vs Resistance 6-4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Thermoelectric Voltage in Absoluter Millivolts - Type J Thermocouple 6-5. . . . . . . . . . . . . . . . . .

Conversion Factors 6-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pressure Conversion 6-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ii

CHAPTER 1

INTRODUCTION

MT2136

OVEN SPECIFICATIONS

VENTILATION REQUIREMENTS

The hood should completely cover the unit with an
overhang of at least 6" (15 cm) on all sides not adjaĆ
cent to a wall. The distance from the floor to the
lower edge of the hood should not exceed 7' (2.1
m). The ventilation system should replace 80% of
the exhaust volume with fresh make up air.
TABLE 1 should be used as a guideline.

Single Double Triple

CFM 500Ć600 1000Ć1200 1500Ć1800

M3/min 14 Ć 17 28Ć34 42Ć51

TABLE 1

L1

N

L2

ELECTRICAL SPECIFICATIONS

NOTE: Three Phase hookup is not permitted on

gas models.

WARNING: DO NOT INSTALL A HIGH LEG" TO
ANY CONVEYOR OVEN!

Installations within the U.S.

MT2136G ovens require a 15 amp, 60HZ, 1F,
120/208Ć240 VAC, 4 wire service consisting of L1,
L2 neutral and ground. See FIGURE 1. Use 90C
wire and size to National Electric or local codes.

MT2136E ovens are available in either 1F or 3F opĆ
tions. Single phase models require a 15 amp, 60
HZ, 208Ć240 VAC 3 wire service consisting of L1, L2
and ground. Three phase units require a 15 amp,
60 HZ, 208Ć240 VAC 4 wire service consisting of L1,
L2, L3, and ground. See FIGURE 1. Use 90C wire
and size to National Electric or local codes.

120

120

208Ć240

OvenSupply

MT2136G - U.S. Installations

L1

L2

208Ć240

OvenSupply

L1

L2

L3

208Ć240

OvenSupply

MT2136E - Single Phase U.S. Installations MT2136E - Three Phase U.S. Installations

FIGURE 1

1-1

INTRODUCTION

Installations outside the U.S.

MT2136G ovens require a 15 amp, 50HZ, 1F,
220Ć240VAC, 3 wire service consisting of L1, neuĆ
tral and ground. See FIGURE 2. Use 90C wire and
size to National Electric or local codes.

MT2136E ovens are available in either 1F or 3F opĆ
tions. Single phase units require a 15 amp, 50 HZ,
240VAC 3 wire service consisting of L1, L2 and
ground. Three phase units require a 15 amp, 50
HZ, 220Ć240 VAC 4 wire service consisting of L1,
L2, L3 and ground. See FIGURE 1. Use 90C wire
and size to National Electric or local codes.

L1

N

220Ć240

OvenSupply

MT2136G - Export Installations

L1

L2

L3

240

OvenSupply

CE approved installations

The MT2136G requires a 15 amp 50Hz, 1F, 230
VAC, 3 wire service consisting of L1, neutral and
ground. Connect exhaust fan connector 1 and 2.
See FIGURE 2. Use 90C wire and size according
to local codes.

NOTE: If the phase and neutral are switched the

control locks out.

The MT2136E requires a 15 amp, 50Hz, 3F, 230
VAC, 5 wire service consisting of L1, L2, L3, neutral
and ground. See FIGURE 2. Use 90C wire and
size according to local codes.

L1

L2

240

OvenSupply

MT2136E - Single Phase Export Installations

L1

400

L2

L3

N

400

400

230

OvenSupply

MT2136E - Three Phase Export Installations

L3
L2
L1

N

Blodgett

Connector

L1

N

N

L

Connector

230

1
2

OvenSupply

MT2136G CE Approved Installations

FIGURE 2

MT2136E - CE Approved Installations

s

2

A2

Fan

21Air Pressure Regulator

Burner Control Solenoid

1-2

2Ć4Ć92

A1

Relay A

1

MT2136

GAS SPECIFICATIONS

GAS CONNECTIONS

Domestic and General Export installations

The gas line should be large enough to accommoĆ
date the peak demand of all the gas appliances.
TABLE 2 reflects a straight line, 50 foot run with no
coupling restrictions and no other appliances
drawing service. Gas line installations MUST conĆ
form to National Fuel Gas Code NFPA 54/ANSI
Z223.1 Sec. 1.4 (Latest Edition). TABLE 2 should
be used as a guideline only.

NOTE: For any pipe runs over 50 feet (15 m), conĆ

sult the factory.

CE approved installations

1. Connect the oven to the gas line with the propĆ
er type of gas according to Local and National
Installation Standards. See TABLE 2.

DOMESTIC AND GENERAL EXPORT

Natural Gas Propane Gas

Gas Line Sizing

GAS REQUIREMENTS

The firing rate for the MT2136G is 55,000 BTU/Hr.
(16 kW/Hr.)

NOTE: For natural gas meter sizing, consult your

local gas company to ensure that your meĆ
ter will provide the proper supply.

Installations within the U.S.

1. Add the total BTU's/hr of all the gas
appliances.

2. Convert BTU's to cubic ft/hr using the formula
Cu Ft/Hr = 1000 BTU/Hr for natural gas.

3. Size the meter accordingly.

Installations outside the U.S.

1. Add the total M3/min of all the appliances.

2. Size the meter accordingly.

Single

Double

Triple

Orifice Size #1 #29

Incoming Gas Pressure W.C. kPa mbar W.C. kPa mbar

Static

Operational

CE APPROVED UNITS

Type of

Gas

G25 25 12 3,30 2 x 16 2 x 0,63 16,3 Nat. Gas

G20 20 8 3,30 2 x 16 2 x 0,63 16,3 Nat. Gas

G20/G25 20/25 Totally Inscrewed

G31 30/37/50 24 2,10 2 x 16 2 x 0,30 16,3 Propane

Inlet

Pressure

mbars

Burner Pressure

Pressure Regulator

7"

5.5"

mbars

3/4" line

3/4" line

1" line

1.74

1.36

Injector

Diameter

TABLE 2

3/4" line

3/4" line

3/4" line

17.4

13.7

Opening

mm

2,90 2 x 16 2 x 0,63 16,3 Nat. Gas

Air

mm

12.5"

11"

Pilot

Injector

mm

3.11

2.73

Standard

Delivery

Value kW (HS)

31.1

27.4

1-3

ILLUSTRATED PARTS LISTS

CONVEYOR COMPONENTS

NOTE:  = ASAP Distributor Required Stocking Parts

Ref.

Part

No.

No. Description

Ref.

Part

No.

No. Description

INTRODUCTION

M2740 Belt, Wire S/S 21" SB (Per Foot)

(Total 11 FT)

39 M6336 Belt, Wire S/S 10" TB (Per Foot)

(Total 21 FT)

M2388 Tensioner Assy., Belt

22 M2379 Speed Control Board, Bodine

M3301 Capacitor, Speed Control

Board, 200WVDC

M3145 Potentiometer, Bodine, 10K

23 M2316 Fuse, Armature, Bodine Board,

200 MA, 250V

7  M2254 Fuse, Line, Bodine Board, 5

AMP, 125V

M5770 Conversion Kit, Digital Time

(Open Loop) to MicroĆDrive
(Closed Loop)

M7202 Conversion Kit, Open Loop to

Closed Loop (Computerized)

M3146 Time Display, Digital

M3147 PickĆUp, PVĆ10 (For M3146)

M0200 Lock, Speed Control PotentiomĆ

eter

M0201 Dial, Speed Control PotentiomeĆ

ter

21169 Knob, Speed Control PotentiomĆ

eter

M2378 Motor, Conveyor Drive, Bodine

130V

M2500 Brush Set, Bodine

M2738 Chain, Drive

M2011 Conveyor Assy., Drive Side SB

M2012 Conveyor Assy., Idle Side SB

M2207 Conveyor Assy., Drive Side TB

M2208 Conveyor Assy., Idle Side TB

M0109 Sprocket, Motor Drive, 12 Tooth

SB/TB

M0108 Sprocket, Conveyor Belt, 11

Tooth SB/TB (Bore Diameter
3/4" ) (Qty 1)

M0110 Sprocket, Conveyor Drive, 15

Tooth SB/TB (Bore Diameter
3/4")

M1865 Sprocket, Conveyor Drive, 15

Tooth TB (Bore Diameter 1/2")

M0112 Masterlink, Drive Chain

M0122 Bearing, Conveyor Drive

1-4

MT2136

TEMPERATURE CONTROLS

Computer solid state controls for ovens manufactured after mid sept., 1993

NOTE:  = ASAP Distributor Required Stocking Parts

Part

Ref.

No. Description

No.

M3149 Controller, Digital Temperature

M3439 Relay, Digital Temp. Controller,

10 AMP, 250V

M3150 Control Board, Temperature HiĆ

Lo Limit

M3151 Thermocouple, Dual Lead

M3152 Thermocouple, Single Lead

M6474 Computer Control Kit, Closed

Loop SB

FW525 Computer Control Kit, Closed

Loop SB (Reconditioned)

M5635 Computer Control Kit, Open

Loop TB

M7427 Probe, Temperature RTD, 500

OHMS

M3347 Cable, Computer Control, 25

Pin, 10 Foot

M3348 Cable, Computer Control, 9 Pin,

10 Foot

M3490 Cable, Computer Control, 25

Pin, 50 Foot

M3491 Cable, Computer Control, 9 Pin,

50 Foot

Ref.

Part

No.

No. Description

M3314 Bracket, Computer Wall

M5661 Bracket Assy., Cable Clamp

19 22672 Relay, Control (Ice Cube) (Qty 4)

18 M3295 Thermostat, High Limit (Manual

Reset)

M0152 Contact, Emergency Stop

Switch

M3296 Activator, Emergency Stop

Switch (Mushroom Shape)

M3297 Nameplate, Emergency Stop

20 M3136 Breaker, 7 AMP Circuit (Qty 2)

(Before AB Ver.)

21 M2772 Breaker, 4 AMP Circuit (Qty 2)

(Before AB Ver.)

26 M3352 Transformer, 120V to 24V (Qty 1)

M3349 Harness, InterĆConnecting DC

Drive, 3 Wire (For 9 Pin)

M3353 Harness, Relay Board (Open

Loop) (Qty 1) (For 25 Pin)

M7237 Harness, Relay Board (Closed

Loop) (Qty 1) (For 25 Pin)

1-5

GAS BURNER COMPONENTS

NOTE:  = ASAP Distributor Required Stocking Parts

INTRODUCTION

Part

Ref.

No.

No.

20287 Valve, Single Solenoid 110/120V

M0282 Valve, Manual Gas

3  M0767 Blower Motor, Combustion w/

4  M2383 Blower Motor, Combustion

1  M2381 Transformer, 120V to 24V

2  M2385 Relay, Time Delay

5  M6397 Pilot Burner & Igniter Assy.,

5  M6398 Pilot Burner & Igniter Assy., LP

6 M0248 Tube, Pilot Aluminum 1/4"

7 22258 Burner Assy., Complete

8  M0415 Flame Sensor

9  M0697 Orifice, Pilot Natural

9  M2690 Orifice, Pilot LP

10 M3203 Orifice, Main Burner, Natural

10 M1491 Orifice, Main Burner, LP (MTD

Description

Control Box

Natural

(MTD 29)

45)

Ref.

Part

No.

No.

M2140 Flame Tube Assy.

16 M1054 Spark Box, 24V

11 M5495 Dual Solenoid/Pressure RegulaĆ

11 22190 Dual Solenoid/Pressure RegulaĆ

M3434 Conversion Kit, Natural to LP

M3435 Conversion Kit, LP to Natural

18612 Spring, Solenoid Valve, Natural

23007 Spring, Solenoid Valve, LP to

12 M0279 Union, 1/2 Inch Black

13 1949 Nipple, Pipe 1/2 x 1Ć3/16 Close

M0590 Nipple, Pipe 1/2 x 2Ć1/2

14 M0317 Elbow, 1/2 Inch Street 90 Deg.

15 597 Ell, Black 90 Degree

17874 Ell, Black 1/2 x 3/4

Description

tor, Nat. 24V

tor, LP 24V

(MTD 45)

(MTD 29)

to LP

Natural

1-6

MT2136

ELECTRICAL COMPONENTS

NOTE:  = ASAP Distributor Required Stocking Parts

Part

Ref.

No.

No.

M2571 Element Assy., 208V, 3 PH, 15

M2697 Element Assy., 208V, 1 PH, 15

M2572 Element Assy., 240V, 3 PH, 15

M2698 Element Assy., 240V, 1 PH, 15

M6891 Element, Individual, 208V (Qty 6)

M6892 Element, Individual, 220V (Qty 6)

M6893 Element, Individual, 240V (Qty 6)

20162 Fuse, 10 AMP, 300V, SCĆ10 (Qty

M1821 Fuse, 4 AMP, 300V, SCĆ4 (Qty 2)

M0156 Fuse, 10 AMP, 250V, FMNĆ10

M3389 Fuse, 4 AMP, Ceramic, MDAĆ4

M0158 Fuse Holder for SCĆ10 & SCĆ4

M0702 Fuse Block for FMNĆ10 Fuse

M3390 Fuse Holder, 20 AMP for MDAĆ4

M2453 Snap Disc, L140Ć20F, 3 Pole

M1362 Snap Disc, L140Ć20F, 2 Pole

M0635 Snap Disc, F110Ć20F, 2 Pole

M2734 Snap Disc, L165Ć30F, 2 Pole

M0593 Terminal Block, 2 Pole (Neutrals)

M3714 Terminal Block, 3 Pole (Power)

25 M0708 Contactor, Mechanical, 16 AMP,

M2483 Contactor, Mercury, 60 AMP, 3

M2720 Contactor, Mercury, 100 AMP, 2

Description

KW (Qty 1)

KW (Qty 1)

KW (Qty 1)

KW (Qty 1)

2) (After...)

(Before...)

Fuses (Qty 2)

Fuse

SPDT

SPST

SPST

w/ Push On Terminals

MT2136E w/ Allen Head Screws

3 Pole,120V Coil (Motor)

Pole, 120V Coil (Heat)

Pole, 120V Coil (Heat)

Ref.

Part

No.

No.

M7170 Transformer, 240V to 115V

M2469 Fan, Axial 110 CFM 4Ć1/2" (Qty

M0571 Guard & Hardware, Fan (Qty 3)

M0572 Cord Set, Axial Fan (Qty 3) or (AB

M0152 Selector Switch, Heat & ConveyĆ

M0153 Selector Switch, Blower

M0151 Knob, Selector Switch (Heat/

M1694 Cord Set & Plug Assy., 10 Foot

M0772 Receptacle, Twist Lock

4168 Lug, Grounding

CONVECTION COMPONENTS

Ref.

Part

No.

No. Description

M2871 Motor & Blower Assy., 60 HZ,

M2870 Motor & Blower Assy., 60 HZ,

36 M2100 Nozzle Assy. (Aluminum) (Qty 5)

36 M3456 Nozzle Assy. (S/S) (Qty 5)

M2741 Plate Assy., Air (Aluminum) (LH

37 M7490 Air Plate, LH (Aluminum)

38 M7493 Air Plate, RH (Aluminum)

M7492 Plate Assy., Block Off

M3125 Upgrade Kit, Cooling Fan (DoĆ

Description

3) or (AB Qty 4)

or (AB Qty 4)

Qty 4)

or

Conveyor/Blower)

CW (Qty 1)

CCW (Qty 1)

& RH)

mestic)

1-7

EXTERIOR COMPONENTS

NOTE:  = ASAP Distributor Required Stocking Parts

 = Doors Are Not Returnable

INTRODUCTION

Part

Ref.

No. Description

No.

M2085 Decal, Control Panel, SB, Red

M2087 Decal, Control Panel, TB, Red

M2524 Decal, Racing Strip, Red

M2722 Decal, Control Panel, SB, Black

M2723 Decal, Black

M2769 Decal, Control Panel, TB, Black

28 M4306 Crumb Pan, Idle (Remote & InĆ

tergal)

27 M4372 Crumb Pan, Drive w/ Remote

27 M4305 Crumb Pan, Drive w/ Intergal

M4309 Stop, Product

29 M3121 Extension Assy., Product 6"

29 M3122 Extension Assy., Product 12"

26 M2059 Drip Pan (Aluminum)

26 M5008 Drip Pan (S/S)

30 M2450 Access Panel, Combustion

Compartment (Manual) Element
Assy., 240V, 3 PH, 15 KW (Qty 1)

30 M3376 Access Panel, Combustion

Compartment
(Computer Controls)

30 M3553 Access Panel, Control Box

(Integral)

31 M4580 Access Panel, Front w/ Door

M2072 Access Panel, Front w/o Door

M2514 Bolt, Front Access Panel (Allen

Head Decoration)

M3420 Gasket Assy., Front Access PanĆ

el

M3574 Retainer, Gasket Top/Bottom w/

Door

Ref.

Part

No.

No. Description

M3575 Retainer, Gasket LH/RH w/ Door

M2731 Retainer, Gasket Top/Bottom

w/o Door

M2732 Retainer, Gasket LH/RH w/o

Door

M2801 Hinge Pin & Plate Assy.

16470 Nameplate, Blodgett 10"

32  M4587 Door Assy., Sandwich

M2188 Handle Assy., Sandwich Door

M6035 Latch, Sandwich Door

33 M4581 Plate, Pivot RH Slotted

34 M4582 Plate, Pivot LH Slotted

M6970 Retrofit Kit, Sandwich Door

(To Add Sandwich Door)

M2515 Allen Key

21826 Installation Hose, 36"

21242 Installation Hose, 48"

M7273 Body Top w/ Hardware

M2678 Body Back

M2361 Pin, Stacking

M2486 Stacking Rails

M2439 Stacking, 24" Stand & Caster

Assy.

M3123 Stacking, Single to Double

M3124 Stacking, Double to Triple

M2532 Triple Base w/ Casters

M3998 Heat Shield Kit

35 M2075 Tunnel Extension

1-8

MT2136

EXCLUSIVE TO VERSION AB

Serial number model identification code of BK=MT2136G or FB=MT2136E.

NOTE:  = ASAP Distributor Required Stocking Parts

Part

Ref.

No. Description

No.

1 M5070 Conveyor Assy., Drive Side SB

M5066 Conveyor Assy., Idle Side SB

M5069 Conveyor Assy., Drive Side TB

M5067 Conveyor Assy., Idle Side TB

M6044 Snap Disc, L110Ć20F, 3 Pole

M5302 Nozzle Assy. (Aluminum) (Qty 5)

M5288 Nozzle Assy. (S/S) (Qty 5)

M2741 Plate Assy., Air (Aluminum) (LH

& RH)

M7490 Air Plate, LH (Aluminum)

M7493 Air Plate, RH (Aluminum)

M4674 Air Plate, LH (S/S)

M4675 Air Plate, RH (S/S)

M4163 Plate Assy., Block Off

(Aluminum)

M4673 Plate Assy., Block Off (S/S)

M5071 Crumb Pan, Idle (Remote & inteĆ

gral) (Bottom Section)

M5335 Crumb Pan, Drive w/ Remote

(Bottom Section)

M5068 Crumb Pan, Drive w/ Integral

(Bottom Section)

M6996 Crumb Pan, Idle (Remote & InteĆ

gral) (Top & Middle Section Ć
Vented)

M6995 Crumb Pan, Drive w/ Remote

(Top & Middle Section Ć Vented)

M5068 Crumb Pan, Drive w/ Intergal

(Top & Middle Section)

M7002 Extension Assy., Product 6"

M6997 Extension Assy., Product 12"

M7000 False Front w/o Door

Ref.

Part

No.

No. Description

M7001 False Front w/ Door

M6213 Access Panel, Combustion

Compartment

M6035 Latch, Combustion Compartment

Access Panel

M4580 Access Panel, Front w/ Door

M6389 Access Panel, Front w/o Door

M2733 Bolt, Front Access Panel

M2599 Gasket, Front Access Panel

M3574 Retainer, Gasket Top/Bottom w/

Door

M3575 Retainer, Gasket LH/RH w/ Door

M6383 Retainer, Gasket w/o Door

M2801 Hinge Pin & Plate Assy.

16470 Nameplate, Blodgett 10"

M4587 Door Assy., Sandwich

M2188 Handle Assy., Sandwich Door

M6035 Latch, Sandwich Door

M4581 Plate, Pivot RH Slotted

M4582 Plate, Pivot LH Slotted

M7274 Body Top w/ Hardware

M6220 Body Back

21390 Legs, 17Ć1/4" w/ Casters

(Double Oven)

21391 Legs, 23Ć1/4" w/ Casters

(Single Oven)

M3828 Pin, Stacking

M5537 Triple Base w/ Casters

NOTE: MT2136 AB version is only available with

legs (Part #'s 21390 & 21391). There is no
stand available for this oven.

1-9

EXCLUSIVE TO EXPORT 50 HZ (ZA VERSION)

NOTE:  = ASAP Distributor Required Stocking Parts

INTRODUCTION

Part

Ref.

No. Description

No.

M2246 Burner Assy., Complete

M2386 Blower Motor, Combustion

M2384 Transformer (Burner Assy.)

M2245 Valve, Single Solenoid, 240VAC

M2573 Element Assy., 220/380V, 3 PH,

15 KW

M2699 Element Assy., 220/380V, 1 PH,

15 KW

M2574 Element Assy., 240/415V, 3 PH,

15 KW

M2698 Element Assy., 240/415V, 1 PH,

15 KW

M6892 Element, Individual, 220/380V

M6893 Element, Individual, 240/415V

M2630 Fuse, Bodine Speed Control, 5

AMP, 250V

23034 Axial Fan, 230V (Qty 3)

M2247 Contactor, Mechanical, 16 AMP,

3 Pole, 250V (Motor) 50 HZ

R1530 Contactor, Mercury, 60 AMP, 3

Pole (Heat)

M2591 Contactor, Mercury, 100 AMP, 1

Pole (Heat)

M7170 Transformer, 208/460Ć120V,

300VA (Step Down)

M2873 Motor & Blower Assy., 50 HZ,

CW

M2872 Motor & Blower Assy., 50 HZ,

CCW

M3154 Time Display, Digital 50 HZ

M3126 Upgrade Kit, Cooling Fan (ExĆ

port)

M3153 Speed Control Board, Digital

180VDC

M3128 Motor, Conveyor Drive, 180VDC

M3155 Controller, Temperature C§/50

HZ

M2819 Switch, Air Pressure Differential

(in W.C) (Qty 1) (Australia)

Ref.

Part

No.

No. Description

M7880 Computer Control Kit, Closed

Loop SB (CE)

M3237 Burner Assy. (CE)

16 M7334 Pilot Burner & Igniter Assy., NatĆ

ural (CE)

16 M7333 Pilot Burner & Igniter Assy., LP

(CE)

M2497 Switch, Push Button (CE)

M2498 Switch, Contact (CE)

M0595 Switch, Air Pressure SPDT (CE)

40 M3172 Timer, Fixed, 2 Second (CE)

41 M3173 Timer, Fixed, 10 Second (CE)

M3166 Fuse, 4 Amp., 250V (CE)

M3167 Fuse Holder (CE)

M2549 Strip, Terminal (CE)

43 M3168 Spark Box, 240V (Landis & Gyr)

(CE)

R1586 Terminal Block, Power (CE)

R0166 Terminal Block, Ground (CE)

R1580 Stop, End (CE)

16037 Indicator Light, 250V, Red,

Round (CE & Australia)

90250 Relay, 240V 3PDT (CE)

42 16775 Relay, 240V SPST, 30 AMP (CE)

17 M6000 Dual Solenoid/Pressure RegulaĆ

tor, Nat. (CE)

17 M6001 Dual Solenoid/Pressure RegulaĆ

tor, LP (CE)

M3330 Switch, Air Pressure Differential

(mbr) (CE)

M6649 Noise Filter (G&E)

M6648 Noise Filter (E Only)

M7282 Relay Board (All CE ComputerĆ

ized Ovens)

M6025 Fuse, 250V 80 MA (For M7282)

1-10

MT2136

EXTERIOR COMPONENTS

35

30

29

35

27

26

39

28

38

33

36

37

32

3431

FIGURE 3

1-11

DOMESTIC GAS BURNER COMPONENTS

(Control Box not Shown)

1

INTRODUCTION

15

13

13

13

12

2

3

5

4

11

14

7

8

6

10

FIGURE 4

1-12

9

MT2136

CE GAS BURNER COMPONENTS

(Control Box not Shown)

17

16

FIGURE 5

1-13

24

INTRODUCTION

CONTROL PLATE ASSEMBLY

22

18

23

25

19

20

21

26

16

EXCLUSIVE TO CE

40

41

42

FIGURE 6

1-14

43

MT2136

This page intentionally left blank.

1-15

CHAPTER 2

ASSEMBLY

MT2136

OVEN ASSEMBLY PROCEDURES

NOZZLES

1. Install the nozzles from the center of the oven
working toward the ends. Make sure the top
tongue of each nozzle fits into the upper recĆ
tangular cutĆout in the nozzle support plate at
the top rear of the oven.

2. Pull the nozzle slightly forward to engage the
hole in the alignment flange with the conveyor
rail pin. To make sure that the nozzle is seated
properly, try to move it from side to side. The
nozzle should not move any appreciable disĆ
tance.

CONVEYOR SUPPORTS

1. Slide the left conveyor belt support (with the
sprocket on the end of the shaft) into the supĆ
port tracks. The sprocket must be located next
to the control panel after being pushed into the
oven.

2. Slide the right conveyor belt support into the
support tracks.

3. Install the 1/4-20 (6m x 1) hex head screw
through the conveyor rack and into the control
box.

WIRE CONVEYOR BELT

NOTE: The conveyor belt has loops on both sides.

The belt must be installed so the loops travĆ
el as shown in FIGURE 1.

1. Thread the wire belt from the right side of the
oven, lower level first.

2. After pushing the belt through on the lower levĆ
el, leave about 12" (30.5 cm) hanging out on
the left side.

3. Take the remainder of the belt, loop it around
the right shaft, and push it through on the upĆ
per level. The two ends of the belt should be
approximately 6Ć9" (15Ć22 cm) past the left
shaft (right shaft if right to left travel is required)
on the upper level of the belt support.

Side Belt Loops

Direction of

Travel

DRIVE CHAIN

1. Install the drive chain around the drive motor,
through the opening in the control panel door,
and then around the sprocket on the conveyor
belt support.

2. Push the conveyor motor to tighten the drive
chain and lock it into position by tightening the
hex socket head screws.

NOTE: Twin belt models have a double sprocket,

chain and motor.

FIGURE 1

4. Install the inner and outer master links as
shown in FIGURE 2.

Master
Link

Direction of

Travel

FIGURE 2

2-1

ASSEMBLY

Unless otherwise specified, the conveyor travel is
factory set for leftĆtoĆright operation when facing
the front of the oven. If a direction change is reĆ
quired, the polarity of the drive motor must be reĆ
versed. To change the polarity of the drive motor,
disconnect the oven from the power source and inĆ
terchange the black and white motor leads at the
D.C. Controller Board located within the control
box. If the polarity of the motor is changed to

rightĆtoĆleft belt travel, the conveyor belt must
be installed from the left side of the oven inĆ
stead of the right side.

NOTE: Reconfigure the air plates whenever the

conveyor belt direction of travel is
changed.

AIR PLATES

1. Inspect the orientation of the air plates. Refer
to FIGURE 3.

Right Air Plate

CONVEYOR BELT TENSIONERS

Each tensioner installs between the idle end of the
conveyor (the side opposite the drive) and the
oven's body side.

1. The belt tensioner contain a spring to adjust
the length. Compress the spring to shorten the
length of the belt tensioner.

2. Insert the pin on the end of the tensioner into
the hole in the oven's body side.

3. Expand the tensioner to engage the pin loĆ
cated on the conveyor support.

Conveyor

Support

Oven Body

Front

Left Air Plate

FIGURE 3

CONVEYOR TUNNEL EXTENSIONS

1. Install the conveyor tunnel extensions over the
conveyor on each end of the oven.

Belt

Tensioner

Shown without conveyor belt for clarity

FIGURE 4

CRUMB PANS

1. Install the crumb pans under each end of the
conveyor.

NOTE: On stacked ovens, either use perfoĆ

rated crumb pans or install the pans on
the lower oven only.

MOUNT REMOTE CONTROL

1. Mount the remote control unit on a wall within
reach of the computer cables.

2. Connect the computer cables from the controlĆ
ler's rear connector to the connector located at
the rear of the oven.

2-2

MT2136

This page intentionally left blank.

2-3

CHAPTER 3

OPERATION

MT2136

STANDARD CONTROL OPTIONS

U.E. TEMPERATURE CONTROLLER WITH OPEN LOOP DC DRIVE SYSTEM

1 53 42

COOK TIME

ON OFF

TEMPERATURE

7

CONVEYOR

FIGURE 1

CONTROL DESCRIPTION

1. COOK TIME DISPLAY - Gives the belt speed.

2. CONVEYOR ADJUSTMENT KNOB - Turn to
adjust the conveyor speed.

3. TEMPERATURE CONTROL KNOB - Turn to
set cook temperature.

4. HEAT LIGHT - Indicates the control is calling
for heat.

5. HEAT SWITCH - Controls power to the burner.

6. BLOWER SWITCH - Controls power to the
blowers.

7. CONVEYOR SWITCH - Controls power to the
conveyor motor.

CONTROL OPERATION

1. Turn the manual gas valve to the OPEN posiĆ
tion. This is only necessary on initial startĆup.

2. Turn the BLOWER SWITCH (6) to ON.

3. Push and turn the TEMPERATURE CONTROL
KNOB (3) clockwise to the desired setting.

4. Turn the HEAT SWITCH (5) to ON. The burner
purge timer will be energized. After approxiĆ
mately thirty (30) seconds, a spark ignites the
burner. Initial start may require longer due to air
in the gas line.

6

ON OFF

HEAT

ON OFF

BLOWER

SWITCH (5) to OFF and wait 5 minutes
before turning back to ON.

5. Turn the CONVEYOR SWITCH (7) to ON. The
conveyor belt starts to travel through the oven.
This circuit is independent and can be turned
on or off without affecting any other operaĆ
tions. Adjust the conveyor speed as follows:

Turn the ADJUSTMENT KNOB (2) clockwise to
increase speed, counterĆclockwise to deĆ
crease speed. Turn the knobĆlock behind the
control knob to hold the desired belt speed

6. Turn the BLOWER (6), CONVEYOR (7) and
HEAT (8) SWITCHES to OFF. The Cool Down
circuit is energized. The blower motor(s) conĆ
tinue to run until the oven temperature is beĆ
tween 135-170F (57-77C). The digital
temperature display remains lit until the cool
down circuit deĆenergizes.

The oven will hold these parameters daily and will
require no further adjustments unless a different
product is placed in the oven.

NOTE: Each oven contains different components

and must be adjusted individually.

NOTE: If the oven fails to ignite after the thirty

(30) second purge, turn the HEAT

3-1

OPERATION

ATHENA TEMPERATURE CONTROLLER WITH OPEN LOOP DC DRIVE SYSTEM

1 2

COOK TIME

ON OFF

ACTUAL SETPOINT HEAT

TEMPERATURE

10

CONVEYOR

FIGURE 2

CONTROL DESCRIPTION

1. COOK TIME DISPLAY - Gives the belt speed.

2. CONVEYOR ADJUSTMENT KNOB - Turn to
adjust the conveyor speed.

3. ACTUAL TEMPERATURE KEY - Press to disĆ
play the actual oven temperature.

4. ACTUAL TEMPERATURE LIGHT - When lit inĆ
dicates the control is displaying the actual
oven temperature.

5. SETPOINT LIGHT - When lit indicates control
is displaying desired cook temperature.

6. HEAT LIGHT - When lit indicates that the conĆ
trol is calling for heat.

7. UP and DOWN ARROW KEYS - Used to inĆ
crease/decrease desired cook temperature.

8. HEAT SWITCH - Controls power to the burner.

9. BLOWER SWITCH - Controls power to the
blowers.

10. CONVEYOR SWITCH - Controls power to the
conveyor motor.

CONTROL OPERATION

1. Turn the manual gas valve to the OPEN posiĆ
tion. This is only necessary on initial startĆup.

2. Turn the BLOWER SWITCH (9) to ON.

3. Press the UP or DOWN ARROW keys (7) to enĆ
ter the desired cook temperature.

4. Turn the HEAT SWITCH (8) to ON.

6

83 4 5 7

ON OFF

HEAT

9

ON OFF

BLOWER

NOTE: If the oven fails to ignite after the thirty

(30) second purge, turn the blower
switch OFF and wait 5 minutes before
turning back ON.

5. Press the ACTUAL TEMPERATURE KEY (3). If
the actual temperature matches the setpoint
the oven is ready to cook.

NOTE: The display will flash until the actual

temperature is within the preset deviĆ
ation alarm band. The default setting is

 20F of the setpoint.

6. Turn the CONVEYOR SWITCH (10) to ON. The
conveyor belt starts to move. Turn the CONĆ
VEYOR ADJUSTMENT KNOB (2) clockwise to
increase speed, counterĆclockwise to deĆ
crease speed. Turn the knobĆlock behind the
control knob to hold the desired belt speed

7. Turn the BLOWER (6), CONVEYOR (7) and
HEAT (8) SWITCHES to OFF. The Cool Down
circuit is energized. The blower motor(s) conĆ
tinue to run until the oven temperature is beĆ
tween 135-170F (57-77C). The digital
temperature display remains lit until the cool
down circuit deĆenergizes.

The oven will hold these parameters daily and will
require no further adjustments unless a different
product is placed in the oven.

NOTE: Each oven contains different components

and must be adjusted individually.

3-2

MT2136

COMPUTER CONTROLLER

9

1

2

3

45678

FIGURE 3

CONTROL DESCRIPTION

1. DIGITAL DISPLAY - Displays the time, temĆ
perature and controller related information.

2. OVEN ON/OFF - Controls power to the oven.

3. NUMERIC KEYS - Used to enter numerical
data in the programming mode.

4. CLEAR KEY - Used to clear the display if an
error is made in the programming mode.

5. SET TEMP KEY - Used to view or program the
temperature setpoint.

6. ACT TEMP KEY - Used to view the current
oven temperature.

7. TIME KEY - Used to view or program the cook
time.

8. PROG/ENTER KEY - Used to enter and exit
the programming mode. Also used to lock in
programmed settings.

9. STATUS LAMPS - When lit indicate that the
fan or burners are operating.

This oven, supplied with remote control, is
equipped with an emergency shut down
switch. Should you need to stop the belt,
fans, or heat press the emergency switch.

CONTROL OPERATION

To turn the oven on:

1. Press and hold the ON/OFF key (2). The disĆ
play reads OFF when the oven is idle.

2. The display flashes WAIT  LOW  SET  TIME.

3. The FAN and HEAT status lamps (9) light. The
fans begin to run. The heat rises to the proĆ
grammed temperature. The conveyor belt
travels at the programmed speed.

To view the cook time setting:

1. Press the TIME key (7). The LED on the key
lights and the display flashes SET  TIME.

To display the actual oven temperature:

1. Press the ACT TEMP key (6). The LED on the
key lights and the display reads ACTUAL  F.

To view the temperature set point:

1. Press the SET TEMP key (5). The LED on the
key lights and the display flashes SET  TEMP

 F.

To turn the oven off:

1. Press the ON/OFF key (2). The blower moĆ
tor(s) continue to run regardless of the controlĆ
ler status until the temperature drops below
180F (82C).

Do not use the emergency switch as a
GENERAL on/off switch!

3-3

OPERATION

PROGRAMMING PROCEDURES

Programming the Cook Time:

1. Press the PROGRAM/ENTER key (8).

2. Press the TIME key (7). The display reads

PROGĆ?

 SET  TIMEĆ?  _ _ _ _.

3. Use the NUMERIC keys (3) to enter the desired
cook time. The display will read the numbers
as they are entered. If an error is made, press
the CLEAR key (4) and reĆenter the number.

4. Press the PROGRAM/ENTER key (8) a second
time to lockĆin the new time. The new cook time
will be stored in the computer's memory.

Programming the Temperature:

1. Press the PROGRAM/ENTER key (8).

2. Press the SET TEMP key (5). The display reads

PROGĆ?  SET  TEMPĆ?  _ _ _ _F.

3. Use the NUMERIC keys (3) to enter the desired
temperature set point. The control displays the
numbers as they are entered. If an error is
made, press the CLEAR key (4) and reĆenter
the number.

4. Press the PROGRAM/ENTER key (8) a second
time to lockĆin the new temperature. The new
temperature setpoint will be stored in the comĆ
puter's memory.

Operation at the Programmed Settings:

DISPLAY INFORMATION

 WAIT  LOW - indicates that the present oven

temperature is lower than the set point temperĆ
ature. When the oven reaches the set point
temperature the display changes to READY.

 READY - indicates that the oven is ready to acĆ

cept product.

 SET  TEMP  mmss - indicates the current

cook time setting.

 HIGH  TIME - indicates that the temperature

is well above the set point. This usually occurs
when moving from a higher āto a lower temperaĆ
ture. Wait until the display reads ready before
loading product.

 HIGH  TEMP  LIMIT - indicates that the oven

temperature exceeds the high limit from the
2nd level program. The Over Temperature
Alarm buzzer will sound. Shut the oven off and
wait for the unit to cool down.

 HIGH  TEMP  PANEL - indicates that the conĆ

trol area reaches an excessive temperature.
Shut the oven off and wait for the unit to cool
down. Error code generally means loose
ground wire.

 PROBE  OPEN  PROBE  SHORT - indicates

that the temperature sensor has failed. The
Alarm buzzer sounds. Shut the oven off and
contact a service representative.

1. Press and hold the ON/OFF key (2).

2. The FAN and HEAT status lamps (9) light. The
fans begin to run. The heat rises to the temperĆ
ature setting stored in the computer's memory.
The conveyor belt begins to travel at the timed
speed stored in memory.

3. The display will flash WAIT  LOW  SET  TIME
until the programmed bake temperature is
reached. The HEAT lamp (9) will remain lit until
the oven reaches the temperature set point.

4. The display reads READY and the HEAT lamp
(9) goes out.

5. The oven is now ready to accept product.

6. Press and hold the ON/OFF key (2) to turn the
oven off. The fans continue to run while the
oven cools to a safe temperature.

3-4

MT2136

SEQUENCE OF OPERATION

NOTE: The following instructions represent the most common configurations. For questions regarding othĆ

er options call the Blodgett Service Department at (800)331Ć5842.

MT2136E DOMESTIC WITH ATHENA CONTROLS - M2190 REV H

COMPONENT REFERENCE

NOTE: Refer to FIGURE 4 page 3-25 for compoĆ

nent locations.

1. BLOWER SWITCH (M0153)

2. HI/LO BOARD (M3150)

3. TEMPERATURE CONTROLLER (M3149)

4. MOTOR CONTACTOR (M0708)

5. CONVECTION FANS (Clockwise - M2871,
CounterĆclockwise - M2870)

6. THERMOCOUPLES (Dual lead - M3151,
Single - M3152)

7. HEAT SWITCH (M0152)

8. SPST THERMAL SWITCH (M1362, L140Ć20F
or M2734, L165-30F)

9. SPST THERMAL SWITCH (M1362, L140Ć20F
or M2734, L165-30F)

10. ELEMENT CONTACTOR (M2720)

11. HEATING ELEMENTS (208VAC, 3F - M2571
208VAC, 1F - M2697, 240VAC, 3F - M2572,
240VAC, 1F - M2698)

12. SPST THERMAL SWITCH (M0635, F110Ć20F)

13. COOLING FANS ( M2469)

14. SPST THERMAL SWITCH (M0635, F110Ć20F)

15. CONVEYOR SWITCH (M0152)

16. TIME DISPLAY (M3146)

17. 10kW POTENTIOMETER (M3145)

18. D.C. SPEED CONTROL BOARD (M2379)

19. 130 VDC MOTOR (M2378)

20. #10 HALL EFFECT PICKUP (M3147)

21. STEP DOWN TRANSFORMER (M7170)

OPERATION

1. Turn the blower switch (1) to ON. The N.O. conĆ
tacts close, the N.C. contacts open. 115 VAC
runs to terminal #7 of the hi/lo board (2), L1 of
the temperature controller (3) and the coil of
the motor contactor (4). Terminal #7 is an outĆ
put. It remains powered after the oven is shut
down to keep the convection fans (5) operatĆ
ing until the unit reaches 135Ć170F (57Ć77C)
as sensed by the thermocouples (6).

NOTE: Two thermocouples are located beĆ

tween the convection fans in the rear of
the oven. One thermocouple provides
DC millivolts to the Hi/Lo limit board.
The other provides DC milivolts to the
temperature controller. Check thermoĆ
couples with a millivolt meter.

2. Turn the heat switch (7) to ON. 115 VAC is supĆ
plied to terminal #5 of the hi/lo board (2). If the
temperature is below 600F (316C) a switch
is made between terminals #5 and #6 allowĆ
ing power to go to the common terminal of the
temperature controller (3). If the temperature
controller (3) is calling for heat, a switch is
made between common and N.O. Power is
sent to one side of a N.C. SPST thermal switch
(8). The switch toggles if the temperature
passing its face exceeds the rating on the back
of the switch.

NOTE: The switch is located in the slide out

control compartment. It protects the othĆ
er components from hi ambient heat.

If this switch is cold it should be closed, sendĆ
ing power to one side of another N.C. SPST
thermal switch (9). The switch toggles if the
temperature passing its face exceeds the ratĆ
ing on the back of the switch.

3-5

NOTE: The switch is located between two conĆ

vection blowers in the rear convection
fan compartment. It protects the other
components from hi ambient heat.

If this switch is cold it should be closed, sendĆ
ing power to the element contactor (10). When
the element contactor closes it sends power to
the heating elements (11).