Moffat, Inc. E311 Service Manual

E311 / E311MS

CONVECTION OVEN

SERVICE

MANUAL

Max Series
S/N Begins 258733

Revision 3/F3535

October, 2003

Manual P/N M0ME311

CONTENTS

This manual is designed to take a more in depth look at the E311 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............................................................................................................................. 10

3. OPERATION.................................................................................................................................. 12

3.1 Description of Controls—Not US/Can Models

3.2 Description of Controls—US/Can Models Only

3.3 Explanation of Control System

4. MAINTENANCE ............................................................................................................................ 16

4.1 Cleaning

4.2 Routine Procedures

5. TROUBLE SHOOTING GUIDE ..................................................................................................... 18

6. SERVICE PROCEDURES ............................................................................................................. 21

6.1 Fault Diagnosis

6.2 Access

6.3 Replacement

6.4 Adjustment / Calibration

7. ELECTRICAL SCHEMATICS ....................................................................................................... 39

8. ELECTRICAL WIRING DIAGRAMS ............................................................................................. 41

9. SPARE PARTS ............................................................................................................................. 43

10. ACCESSORIES / OPTIONS.......................................................................................................... 45

11. PARTS DIAGRAM......................................................................................................................... 46

11.1 Main Assembly

11.2 Control Panel Assembly

11.3 Glass Door Assembly

11.4 Stainless Steel Door Assembly

IMPORTANT: MAKING ALTERATIONS MAY VOID WARRANTIES AND APPROVALS.

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12. SERVICE CONTACTS .................................................................................................................. 54

APPENDIX A. POWER RELAY UPGRADE KIT.................................................................................... 56

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MODEL: E311 - NOT US/CAN

1. SPECIFICATIONS

796

FRONT

600

580

ELECTRICAL ENTRY

45

E

1

SIDE

E

1

120

E

1

PLAN

LEGEND

- Electrical connection entry point

Dimensions shown in millimetres.

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MODEL: E311 - US/CAN ONLY

31

3

"

8

"

8

7

WATER ENTRY

23

5

"

8

22

5

1

"

8

FRONT

3

4

"

4

5

"

8

3

1

"

4

ELECTRICAL ENTRY

SIDE

PLAN

LEGEND

- Electrical connection entry point

- Water entry - 9mm /

Dimensions shown in inches.

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3

/8” I.D male hose connection

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MODEL: E311MS NOT US/CAN

796

FRONT

600

580

ELECTRICAL ENTRY

45

E

1

SIDE

E

1

120

LEGEND

E

1

PLAN

- Electrical connection entry point

- Water entry - 9mm /

3

/8” I.D male hose connection

Dimensions shown in millimetres.

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MODEL: E311MS - US/CAN ONLY

31

3

"

8

"

8

7

WATER ENTRY

23

5

"

8

22

5

"

1

8

3

"

4

4

FRONT

5

"

8

3

"

1

4

ELECTRICAL ENTRY

SIDE

PLAN

LEGEND

- Electrical connection entry point

- Water entry - 9mm /

Dimensions shown in inches.

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3

/8” I.D male hose connection

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LOCATION

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

Top 200mm / 8”
Rear 25mm / 1”
Left-hand side 25mm / 1”
Right-hand side 25mm / 1”

OVEN INTERNAL DIMENSIONS

Width 544 mm / 21.4”
Height 418 mm / 16.5”
Depth 432 mm / 17”
Oven Volume 0.12 m³ / 4.25 ft³

OVEN RACK SIZE

Width 530 mm / 20
Depth: 370 mm / 14

7

1

/8”
/2”

ELECTRICAL SUPPLY SPECIFICATION
OPTIONS

208 V AC 60 Hz, 14.6 A, 3.2kW @ 208 V
220-240 V AC 60 Hz, 13.0 A, 3.1kW @ 240 V
208-220 V AC 50 Hz, 14.6 A, 3.2kW @ 220 V
230-240 V AC 50 Hz, 13.0 A, 3.1kW @ 240 V

ELECTRICAL PLUG SPECIFICATION
REQUIREMENTS

Australia 3-pin 250V 15A, AS/NZ 3112
Canada 3-pin 250V 15A, NEMA 6-15
New Zealand 3-pin 250V 15A, AS/NZ 3112
United Kingdom 3-pin 250V 13A fused, BS 1363A
United States 3-pin 250V 15A, NEMA 6-15
Other Countries 3-pin 250V 13A minimum, type

to meet country standards

WATER SUPPLY CONNECTION
(US/CAN ONLY)

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 THE 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 (refer figure

2.3).

208 V AC 60 Hz, 14.6 A, 3.2kW @ 208 V
220-240 V AC 60 Hz, 13.0 A, 3.1kW @ 240 V
208-220 V AC 50 Hz, 14.6 A, 3.2kW @ 220 V
230-240 V AC 50 Hz, 13.0 A, 3.1kW @ 240 V

LOCATION

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

Top 200mm / 8”
Rear 25mm / 1”
Left-hand side 25mm / 1”
Right-hand side 25mm / 1”

IMPORTANT: THE OVEN VENT
LOCATED ON THE CABINET TOP MUST
NEVER BE OBSTRUCTED.

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.

DOUBLE STACKING UNITS

When it is desired to mount one unit on top of
another the 31mm (1¼") high spacer feet must be
used. These short feet should be screwed on,
and the unit lifted on top of the bottom unit, where
it locates safely under its own weight, for normal
applications.

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

E311 convection ovens are supplied with
pre-fitted cords. Ensure unit is fitted with the
correct cord and plug for the installation (refer
specifications section).

L1 L2

Phase

RED

BROWN

BLACK

WARNING:

Neutral

BLACK

BLUE

WHITE

THIS APPLIANCE MUST

BE GROUNDED / EARTHED

Ground

GREEN

GREEN/YELLOW

Figure 2.1

Should changing of the cord be necessary, gain
access to the electrical connection terminal block
and strain relief by removing the back panel (four
screws).

WATER CONNECTION - US/CAN ONLY

A cold water supply should be fitted to the
water inlet (9mm /

3

/8” hose connection) which is
located on the rear of the left hand side of the
unit.

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

Turn on water supply to check for leaks.

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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.

1

3

2

Figure 2.2

RATING PLATE LOCATION

The rating plate for the E311 convection oven is
located at the bottom left corner of the RH side
panel.

Rating Plate

Figure 2.3

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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—NOT US/CAN MODELS

1. POWER

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

2. THERMOSTAT

Temperature range 50 - 280°C.

1

2

3

4

5

Indicator illuminates when elements are cycling
ON to maintain set temperature.

GRILL POSITION - The GRILL indicator will
illuminate indicating that the GRILL function has
been set. The HEATING indicator will also
illuminate whenever the elements are on.

3. BAKE TIMER

1 Hour bake timer.
(Indicator illuminates when “time up” (0) is
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.
Indicator illuminates when “time up” (0) is
reached, and product held at 75°C.

6. LIGHT SWITCH

Push switch to activate oven light.

(Light illuminates while button latched in the down
position) (From S/N 258733 “E311MS” models)
(From S/N 260862 “E311” models).

(Light illuminates while button depressed) (Up to
S/N 260861).

6

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3.2 DESCRIPTION OF CONTROLS—US/CAN MODELS ONLY

1

2

3

4

5

6

1. POWER

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

2. THERMOSTAT

Temperature range 120 - 550°F.
Indicator illuminates when elements are cycling
ON to maintain set temperature.

BROIL POSITION - The BROIL indicator will
illuminate indicating that the BROIL function has
been set. The HEATING indicator will also
illuminate whenever the elements are on.

3. BAKE TIMER

1 Hour bake timer.
(Indicator illuminates when “time up” (0) is
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.
Indicator illuminates when “time up” (0) is
reached, and product held at 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 oven light.

(Light illuminates while button latched in the down
position) (From S/N 258733 “E311MS” models)
(From S/N 260862 “E311” models).

(Light illuminates while button depressed) (Up to
S/N 260861).

7

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3.3 EXPLANATION OF CONTROL

SYSTEM

The E311 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
power to the controls of the oven. With the power
switch Off all functions of the oven are
inoperable.

NOTE:

input side of the power relay whenever the
electrical supply is on.

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 hold switch circuit. (On units
manufacture prior to serial number 232053 power
is also supplied directly to the temperature control
circuit). Accordingly the oven circulation fan will
operate when the door is closed, and with door
open the oven light will come on and the circula­tion fan will shut down, as these are controlled via
the door microswitch. The control panel light
switch will turn the oven light on when the door is
closed. On units from S/N 260862 the switch is
latching and will activate the light while latched in
the down position. On units prior to S/N 260861
the switch is momentary and will need to be held
in to activate the light.

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.

US/Canada only: The steam (water injection)
switch on the control panel can be operated
whenever the power switch is On. The switch is
momentary and when depressed, will operate the
electric solenoid valve at the rear of the oven and
inject water into the water trough at the bottom of
the left hand side rack in the oven. Releasing the

The supply voltage is fed directly to the

steam button will close the solenoid valve. This
feature is used to instantaneously add moisture
into the oven cavity, or to introduce a reservoir of
water in the water trough to maintain humidity in
the oven chamber and minimise product’s
moisture loss during cooking.

For units manufactured from serial number
232054, power to the temperature control circuit
and elements is supplied via a power relay
located near the terminal block at the rear of the
unit. Although the power relay has two poles with
changeover contacts, only the normally closed
contact on one pole is used - the other is
redundant. When the power switch on the control
panel is switched on the power relay is energised
and the normally open contact is closed,
providing power to the temperature control circuit.

The temperature control of this oven is with a
capillary type thermostat which can be set to a
required cooking temperature, or set to the Grill/
Broil position to provide top browning or grilling/
broiling in the oven.

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, one set of contacts is
closed to switch power from the oven thermostat
to the bottom heating element in the oven. The
second switch contact of this switch assembly
remains open in this setting and isolates power
from the top element inner coil. The top element
outer coil is directly switched on from the oven
thermostat. Accordingly only the top outer
element and the bottom element are used when a
cooking temperature is selected. 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.

When the thermostat control is set to the Grill
position the first switch contact opens and the
second switch contact closes. This arrangement
allows power to be provided to the top element
inner coil when the thermostat is On, and isolates
power from going to the bottom heating element.
The top element outer coil which is directly fed
from the oven thermostat switch is therefore On
in conjunction with the top element inner coil
when the thermostat is set to the Grill position.
As both the top inner and outer element coils are
thermostatically controlled, the elements will cycle
On/Off with the door closed as the thermostat
setting in the Grill position is 300°C (600°F). If the
Grill position is selected with the door open, the
elements will remain On continuously and the

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circulation fan will be turned Off. The control
panel Grill indicator will illuminate when the
thermostat is set to the Grill position and will cycle
On and Off with the main heating indicator light.

The E311 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.

From serial number 232054: When the Roast­and-Hold switch is turned On the switch will
illuminate and turn on a relay found on the inside
of the control panel. (This relay has two poles
with changeover contacts, but only one pole is
used). When this relay is switched On the
normally closed contact opens, isolating the
normal power supply to the oven thermostat and
the normally open contact closes supplying power
to the 3 hour roast timer.
To serial number 232053: When the Roast-and­Hold switch is turned On the switch will illuminate
and turn on a mini-contactor found on the inside
of the control panel. When this relay is switched
On a normally closed switch pole on the contactor
is open 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 directly supply power to the bottom
heating element as required to maintain its preset
temperature.

If the main thermostat is turned On, power will
also be supplied to the top outer element coil
through the first switch contact of the thermostat
front switch assembly. In this case 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 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 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

Undo the thumbscrew (anti-clockwise rotation)
securing rack to oven wall, swing rack towards
centre of oven to disengage location pin at front
of side, and pull rack forward to remove. To
replace, engage rack in rear holes, swing towards
side of oven to engage in front hole, and replace
thumbscrew.

FAN BAFFLE

To remove, unscrew the oven lamp glass and lift
the baffle out. To replace, locate the bottom edge
of the baffle over the bottom element terminal
plate and secure in place with the oven 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

IMPORTANT: DO NOT OVER- TIGHTEN
THE LAMP GLASS.

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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.

ELEMENTS Check that element resistances are correct to their rating

(refer 6.3.13)

WATER NOZZLE
(US/CAN ONLY)

Check for liming / scale build-up in water nozzle. 12 months

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 Door not closed.

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 with door
closed).

Door microswitch out of
adjustment.

(Refer fault diagnosis 6.1.2)

Door microswitch faulty

(Refer fault diagnosis 6.1.2)

Fan motor faulty.

(Refer fault diagnosis 6.1.2)

Wiring.

Turn on.

Depress switch. Switch will
illuminate.

Ensure electrical supply correct.

Replace.

(Refer service section 6.3.4)

Close door.

Adjust.

(Refer service section 6.4.2)

Replace.

(Refer service section 6.3.2)

Replace.

(Refer service section 6.3.18

Check and tighten any loose
wiring.

OVEN LIGHT NOT
ILLUMINATING - DOOR OPEN

OVEN LIGHT NOT
ILLUMINATING - DOOR CLOSED

NO WATER INJECTION /
STEAM—US/CAN ONLY

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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.

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Replace.

(Refer service section 6.3.1)

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 6.3.15)

Service or replace as required.

(Refer service section 6.3.13,

6.3.14)

Replace.

(Refer service section 6.3.4)