Moffat E32-2 Service Manual

E32 CONVECTION

OVEN

SERVICE MANUAL

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CONTENTS

This manual is designed to take a more in depth look at the E32 convection oven for the purpose of making the unit more understandable to service people.

There are settings explained in this manual that should never require to be adjusted, but for completeness and those special cases where these settings are required to change, this manual gives a full explanation as to how, and what effects will result.

SECTION PAGE NO.

1. SPECIFICATIONS .........................................................................................................5

2. INSTALLATION .............................................................................................................7

3. OPERATION ...................................................................................................................10

3.1 Description of Controls

3.2 Explanation of Control System

4. MAINTENANCE .............................................................................................................13

4.1 Cleaning

4.2 Routine Procedures

5. TROUBLE SHOOTING GUIDE ......................................................................................15

6. SERVICE PROCEDURES ..............................................................................................18

6.1 Fault Diagnosis

6.2 Access

6.3 Replacement

6.4 Adjustment / Calibration

7. ELECTRICAL SCHEMATICS ........................................................................................34

8. ELECTRICAL WIRING DIAGRAMS ..............................................................................35

9. SPARE PARTS ..............................................................................................................36

10. ACCESSORIES / OPTIONS ..........................................................................................37

11. PARTS DIAGRAM .........................................................................................................38

11.1 Main Assembly

11.2 Control Panel Assembly

12. SERVICE CONTACTS ..................................................................................................42

IMPORTANT: MAKING ALTERATIONS MAY VOID WARRANTIES AND APPROVALS.

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MODEL: E32

1. SPECIFICATIONS

FRONT

710

(28.0)

(1.95)

(2.95)

800

(31.5)

645

(25.4)

260

(10.2)

(2.35)

SIDE

PLAN

LEGEND

- Electrical connection entry point

- Water entry - 3/4” BSP hose connection

Dimensions shown in millimetres. Dimensions in inches shown in brackets.

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LOCATION

To ensure correct ventilation for the motor and controls the following minimum installation clearances are to be adhered to:

Rear 40mm / 1.5“ Left-hand side 40mm / 1.5” Right-hand side 40mm / 1.5”

OVEN INTERNAL DIMENSIONS

Width 468 mm / 18.5” Height 533 mm / 21” Depth 711 mm / 28” Oven Volume 0.18 m³ / 6.3 ft³

OVEN RACK SIZE

Width: 460 mm / 18” Depth: 660 mm / 26”

No of rack positions: 4 Rack position spacing: 125 mm / 5”

ELECTRICAL SUPPLY SPECIFICATION OPTIONS

208 V AC 60 Hz, 28.8 A , 6.0 kW@ 208 V 220-240 V AC 60 Hz, 27.8 A, 6.7 kW @ 240 V 208-220 V AC 50 Hz, 28.8 A, 6.0 kW @ 208 V 230-240 V AC 50 Hz, 27.8 A, 6.7 kW @ 240 V

ELECTRICAL CONNECTION WIRE CONDUCTOR SIZES

Minimum: 4mm² / 16 AWG

WATER SUPPLY CONNECTION Max Pressure 550 kPa / 5.5 bar / 80 psi Min Pressure 100 kPa / 1.0 bar / 15 psi

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2. INSTALLATION

WARNING: THIS APPLIANCE MUST BE GROUNDED.

WARNING: ALL INSTALLATION AND SERVICE REPAIR WORK MUST BE CARRIED OUT BY QUALIFIED PERSONS ONLY.

It is most important that the oven is installed correctly and that the operation is correct before use. Installation shall comply with local electrical, health and safety requirements.

BEFORE CONNECTION TO POWER SUPPLY

Unpack and check unit for damage and report any damage to the carrier and dealer. Report any deficiencies to your dealer. Fit the feet which are packed inside the oven. Fit door handle to oven door. Check that the available power supply is correct to that shown on the rating plate located on the right-hand side panel.

208 V AC 60 Hz, 28.8 A , 6.0 kW@ 208 V 220-240 V AC 60 Hz, 27.8 A, 6.7 kW @ 240 V 208-220 V AC 50 Hz, 28.8 A, 6.0 kW @ 208 V 230-240 V AC 50 Hz, 27.8 A, 6.7 kW @ 240 V

LOCATION To ensure correct ventilation for the motor and controls the following minimum installation clearances are to be adhered to:

Rear 40mm / 1.5“ Left-hand side 40mm / 1.5” Right-hand side 40mm / 1.5”

Position the oven in its allocated working position. Use a spirit level to ensure the oven is level from side to side and front to back. (If this is not carried out, uneven cooking could occur). The feet/legs used with bench or floor mounting or provided with stands are adjustable and will require adjusting in levelling the unit. It should be positioned so the operating panel and oven shelves are easily reachable for loading and unloading.

IMPORTANT: THE OVEN VENT LOCATED ON THE CABINET TOP

MUST NEVER BE OBSTRUCTED.

BEFORE USE Operate the oven for about 1 hour at 200°C (400°F) to remove any fumes or odours which may be present.

ELECTRICAL CONNECTION

Remove rear cover panel to allow access to the terminal block and strain relief cable clamp. The cable can be fitted through the small grommet and held by the cable clamp. Connect cable to the terminals as marked. Refit cover panel.

Figure 2.1

Refer to specifications section for minimum wire connections required.

WATER CONNECTION A cold water supply should be fitted to the water inlet (3/4” BSP hose connection) which is located on the rear of the right hand side of the unit.

Alternately, a connection elbow and sealing washer is supplied with this unit for direct connection of a 1/2” ID hose, and is recommended for easy installation and service.

Connect water supply - Max inlet pressure 80psi / 550kPa.

Turn on water supply to check for leaks.

IMPORTANT: MAXIMUM INLET WATER

PRESSURE IS 550 kPa / 80 psi.

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DOOR HANDLE INSTALLATION

1. Open oven door.

2. Remove two screws (item 2).

3. Remove the two screws (item 3) from the handle (item 1).

4. Install the handle bracket through the slot on the door side.

5. Screw in the two screws (item 2) fully, then fully screw in the previous two screws (item 3). Ensure that they are tight.

Figure 2.3

DOUBLE STACKING UNITS When it is desired to mount an E32 Turbofan

oven on an E87 prover, a double stacking kit must be used. Available from your dealer or Turbofan distributor. (see Spare Parts).

When mounting one oven on top of another, a double stacking kit is also required.

Figure 2.2

OVEN RACKS The oven is supplied with four general purpose oven racks. These racks incorporate two important safety features:

1. Self Supporting: When fitted, the oven racks are self supporting and will not drop or angle down when the racks are withdrawn during operation, when loading and unloading products on racks or when attending to the product being cooked during it’s cook cycle.

2. Auto Supporting: The oven rack supports incorporate a special retaining tab which provides a positive stop to each oven rack and stops it’s inadvertent removal during normal operation.

To fit the oven racks ensure that the rack back stop is positioned at the rear of the oven and install by following the steps shown in the diagram below. To remove oven racks reverse the procedure.

WARNING: THE ELECTRICAL SUPPLY MUST BE DISCONNECTED

BEFORE UNITS ARE STACKED.

Assembly Steps: Bottom Unit

1. Lay unit on back and remove 1" or 4" feet already fitted to unit. Fit adjustable leg and secure with (16x) M6 x 16 taptite screws. Stand unit up.

2. Unscrew vent hood plate from bottom oven. Remove and discard hood plate and spacer tubes. Replace two vent hood screws on the left hand side from the front and screw in completely to secure outer wrapper to vent tube. Use RTV to seal the other two holes.

3. Position shroud back on top of bottom unit so that it is positioned correctly over oven back. Position flue duct on bottom unit so that it is positioned centrally in shroud back flue cut-out and is flush with the oven back. Check that the oven vent is covered and mark the six hole positions (3 down each side of the flue duct) on the oven wrapper.

4. Drill six ø 3.5mm holes in the oven wrapper where marked.

5. Screw the flue duct to the wrapper with six 1/2" x 8A pozi screws into these holes.

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Top Unit

1. Tip oven onto its back and remove the 1" or 4" feet screwed into the base.

2. Assemble the four sides of the shroud (shroud front, shroud back, shroud sides (x2)) with the 3/16" screws as shown. Do not tighten the screws until the ovens are stacked.

3. Screw the shroud assembly to the base of the oven using the 3/8" screws and washers so that all faces of the shroud are flush with the sides of the oven base. Be sure to have the large flange of the shroud back at the rear of the oven.

Stacking the Ovens

1. Remove the outside two screws along the top rear of the bottom oven.

2. With two or three persons, lift the top oven onto the bottom oven and position so that the down folds on the shroud sides and back all butt hard up around the back and sides of the oven wrapper.

3. Secure top unit into position by replacing the two outside screws of the four previously removed from the top rear of the bottom unit.

4. Screw together with four 1/2" x 8A pozi screws supplied, the chimney to the flue duct of the bottom unit. Drill two Ø3.5mm holes in the top rear of the top unit through the two round holes, one each side of the chimney. Now screw the chimney to the rear of the top unit with the two remaining 1/2" x 8A pozi screws.

5. Adjust the four legs to level ovens.

RATING PLATE LOCATION The rating plate for the E32 convection oven

is located at the bottom right corner of the RH side panel.

Rating Plate

Figure 2.5

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Figure 2.4

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3. OPERATION

NOTE: A full user’s operation manual is supplied with the product and can be used for further

referencing of installation, operation and service.

3.1 DESCRIPTION OF CONTROLS

1. POWER

Depress to switch power on or off (switch illuminates when power is on).

2. THERMOSTAT Temperature range 50 - 320°C (120 - 600°F). Light illuminates when elements are cycling

ON to maintain set temperature.

3. BAKE TIMER 1 Hour bake timer. (Light illuminates when “time up” (0) reached, and buzzer sounds).

4. ROAST N HOLD Depress switch to activate ’ROAST N HOLD’ function (Switch illuminates when ON).

5. ROAST TIMER 3 Hour roast timer. (Light illuminates when “time up” (0) reached, and product held at 75°C (167°F).

6. STEAM SWITCH Push switch to activate water injection (Water injects into oven while the button is depressed).

7. LIGHT SWITCH Push switch to activate light. (Light illuminates while button depressed).

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3.2 EXPLANATION OF CONTROL SYSTEM

The E32 Turbofan convection oven features multi-function operator controls for which a correct understanding of their operation is required before carrying out any service or fault repair work. The control device functions are explained as follows:

A power switch on the control panel isolates all to the controls of the oven. With the power switch Off all functions of the oven are inoperable.

With the power switch On (illuminated) power is directly supplied to the 60 minute bake timer, steam (water injection) switch, door microswitch, light switch, and the temperature control circuit. The oven circulation fan will operate only when the thermostat is turned on. The control panel light switch will turn the oven lights on when the door is closed only when the light switch is held in. The oven lights will come on automatically when the door is open, as this is controlled by the door microswitch.

The 60 minute timer is a mechanical timer and can therefore be operated with the oven’s power switch On or Off. However, only with the oven’s power switch On will the switch contacts of the 60 minute timer turn on the time-up buzzer and illuminate the time-up indicator on the control panel. The buzzer and time-up indicator provide indication that the time setting has run down to zero and at this point will remain On continuously until the 60 minute timer has been manually set back to the Off (vertical) position. The 60 minute timer does not control any other part of the oven’s operating system as this timer is independent of the temperature control and heating system.

The steam (water injection) switch on the control panel can be operated whenever the power switch is On. The switch is momentary like the light switch and when depressed, will operate the electric solenoid valve at the rear of the oven and inject water across the elements and fan from the flat spray (vertical) nozzle positioned at the rear of the oven elements. Releasing the steam button will close the solenoid valve. This feature is used to instantaneously add steam into the oven.

The temperature control of this oven is with a

capillary type thermostat which can be set to a required cooking temperature.

The thermostat switch has a separate switch body assembled onto the front from the shaft assembly and when the thermostat is set to a cooking temperature, the switch contacts turn on the oven fan. The switch is closed (fan on) whenever the thermostat is not in the Off (vertical) position. The control panel indicator light above the thermostat knob cycles On and Off with the thermostat to indicate when the elements are on and the oven is heating.

The E32 Turbofan convection oven has 6.5 kW of electric heating elements, comprising of a 3 kW inner coil, and a 3.5 kW outer coil, both of which make up the element assembly around the oven fan. The elements are switched on and off by the main oven thermostat or hold thermostat via a four-pole 25 Amp contactor located inside the control housing. Only two poles of the contactor are used, one for each element coil.

The E32 Turbofan convection oven features a Roast-and-Hold system which can be used to automatically set the oven to a fixed holding temperature at the end of a timed cooking period. When the Roast-and-Hold switch is turned On the switch will illuminate and switch on a relay found inside the control panel, at the base of the control housing next to the door microswitch. When the relay is switched ON a normally closed switch pole on the relay is opened and the normal power supply to the oven thermostat is isolated. A second normally open switch pole is closed and this provides power to the 3 hour roast timer.

If the roast timer is in the Hold (vertical) position the timer switch contacts will be in their normally closed position and supply power directly to the Hold thermostat located behind the control panel. The Hold thermostat is factory set to 75°C (167°F) and will supply power to the heating elements through the heating contactor as required to maintain its preset temperature.

The thermostat heating light will also cycle On/Off as the Hold thermostat maintains temperature.

In the Roast-and Hold mode the 3 hour timer can be set to a selected roasting time. During this time period the normally open switch contacts of the timer are closed. The timer has two change over switches and in this

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position one is used to supply power to its timing motor and the other is used to switch power directly to the main oven thermostat. During the 3 hour timer run-down period the oven temperature will be controlled by the main oven thermostat to the set temperature and operate as previously described.

When the 3 hour timer has run down and reached the Hold position the two switch contacts change over to their normally closed position which isolates power from the timer motor and the oven thermostat. It also switches power back to the oven hold thermostat. At this point the temperature control is now maintained by the hold thermostat as previously described. To cancel the hold circuit the Roast-and-Hold switch is turned Off. This turns off the contactor which removes power from the 3 hour timer and closes the contactor pole on the contactor that feeds the main oven thermostat. The Hold indicator light above the 3 Hour timer will illuminate whenever the oven is operating in hold mode (Roast ‘n Hold selected, and 3 Hour timer at zero position).

The factory preset hold thermostat can be adjusted as required to change the holding temperature if necessary. Refer Service section for this procedure.

The following Troubleshooting Guide should be used to identify any incorrect oven operation. On correct identification of the operating fault the Troubleshooting Guide will make reference to the corrective action required, or refer to the Fault Diagnosis section and/or Service section to assist in correction of the fault.

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4. MAINTENANCE

WARNING: ALL INSTALLATION AND SERVICE REPAIR WORK MUST BE CARRIED OUT BY QUALIFIED PERSONS ONLY.

4.1 CLEANING

WARNING: ALWAYS TURN THE

POWER SUPPLY OFF BEFORE CLEANING.

IMPORTANT: THIS UNIT IS NOT

WATER PROOF. DO NOT USE A WATER JET SPRAY TO CLEAN INTERIOR OR EXTERIOR OF THIS UNIT.

EXTERIOR Clean with a good quality stainless steel cleaning compound. Harsh abrasive cleaners may damage the surface.

INTERIOR Ensure that the oven chamber is cool. Do not use wire brushes, steel wool or other abrasive materials. Clean the oven regularly with a good quality oven cleaner. Take care not to damage the fan or the tube at the right side of the oven which controls the thermostat.

OVEN RACKS

To remove, slide out to the stop position, raise the front edge up, and lift out.

SIDE RACKS To remove, lift front top to disengage and slide rack forward. To replace, slide top rear slot in rack onto rear stud, then engage front keyhole on front stud.

LAMP GLASS To remove glasses, unscrew anti-clockwise. To replace, screw in clockwise.

IMPORTANT: DO NOT OVER TIGHTEN LAMP GLASS.

OVEN SEALS

To remove, hold at their centre point and pull forward until they unclip. Remove side seals first, then top and bottom. The seals may be

washed in the sink, but take care not to cut or damage them. To replace, ensure that the lip is facing the oven opening. Fit the top and bottom seals first, then the side seals.

OVEN DOOR GLASS

Clean with conventional glass cleaners.

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4.2 ROUTINE PROCEDURES

PROCEDURE INTERVAL

DOOR SEALS Check for deterioration. 12 months DOOR PIVOT BUSHES Check for wear. 12 months DOOR CATCH Ensure that catch is adjusted such that the door closes

properly.

ELEMENT Check that element resistance is correct to it’s rating

(refer 6.3.15).

WATER NOZZLE Check for liming in water nozzle. 12 months

12 months

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5. TROUBLE SHOOTING

WARNING: ALL INSTALLATION AND SERVICE REPAIR WORK MUST BE CARRIED OUT BY QUALIFIED PERSONS ONLY.

FAULT POSSIBLE CAUSE REMEDY

THE OVEN DOES NOT OPERATE / START

FAN DOESN’T OPERATE Thermostat not on.

OVEN LIGHT NOT ILLUMINATING - DOOR OPEN (AUTOMATICALLY ON)

OVEN LIGHT NOT ILLUMINATING - DOOR CLOSED (MANUALLY SWITCHED ON)

NO WATER INJECTION / STEAM

The mains isolating switch on the wall, circuit breaker or fuses are “off” at the power board.

The power switch on the oven is off.

Incorrect electrical supply.

(Refer fault diagnosis 6.1.1)

Power switch on unit faulty.

(Refer fault diagnosis 6.1.1)

(Fan only operates when the thermostat is on).

Thermostat fan switch faulty.

(Refer fault diagnosis 6.1.2)

Fan motor faulty.

(Refer fault diagnosis 6.1.2)

Wiring.

Blown bulb.

No power to light.

(Refer fault diagnosis 6.1.3)

Blown bulb.

Light switch faulty.

(Refer fault diagnosis 6.1.4)

Water not turned on. Oven water nozzle blocked.

Fault with water valve.

(Refer fault diagnosis 6.1.5)

Steam switch faulty.

Turn on.

Depress switch. Switch will illuminate.

Ensure electrical supply correct.

Replace.

(Refer service section 6.3.4)

Turn thermostat on.

Replace thermostat.

(Refer service section 6.3.9)

Replace.

(Refer service section 6.3.17)

Check and tighten any loose wiring.

Replace.

(Refer service section 6.3.1)

Correct fault.

Replace.

(Refer service section 6.3.1)

Replace.

(Refer service section 6.3.4)

Turn water on at water supply. Remove, clean or replace.

(Refer service section 6.3.14) Service or replace as required.

(Refer service section 6.3.12,

6.3.13)

Replace. (Refer service section 6.3.4)

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