Merrychef MICROAIRE Service Manual

Microaire

SERVICE MANUAL

For all Microaire models manufactured fr om January 2001

Part No. 32Z3311e Issue No. 6

CAUTION MICROWAVE EMISSIONS

DO NOT BECOME EXPOSED TO EMISSIONS FROM THE MICROWAVE

GENERATOR OR PARTS CONDUCTING MICROWAVE ENERGY

Page 1 Microaire Ovens 32Z3311e Issue 5

SERVICE MANUAL

Table of Contents

Safety Code ........................................................................... 3

Product Specifications ........................................................... 4

Principles of Operation .......................................................... 5

Installation Instructions .......................................................... 6

Error Codes and Diagnostics ................................................ 7

Main Features ........................................................................ 8

Electronic Controls ................................................................9

Manual Controls ..................................................................10

A – Power Output Testing to EN 60335-2-90:1996 ............. 11

B - Power Output Testing ....................................................12

C - Power Transformer Test ................................................ 12

D - High Voltage Capacitor Test .......................................... 13

E - High Voltage Rectifier Test ............................................ 13

Diagram - Casework ............................................................ 14

Diagram - Door Mechanism ................................................ 15

Oven Cavity Components & Hot Air System .......................16

Oven Door Assembly ........................................................... 17

Magnetron & Door Interlock Components ........................... 18

F - Interlock Operation ......................................................... 19

Error Light Operation .......................................................... 19

Major Electrical Components .............................................. 20

Input Filters and Fuses ...................................................20-21

Input Wiring Details ........................................................22-23

HT Components ..................................................................24

Electronic Control Panel Assembly .....................................25

Manual Controls Panel Assembly ........................................ 26

Membrane Panel Circuit ...................................................... 27

Complete Spare Part Listing ..........................................28-29

Electrical Diagram - RMC1003xxEE5 / XE5 ........................30

Electrical Diagram - RMC1003RS RF / HST ....................... 31

Merrychef Limited,
Station Road West,
Ash Vale, Aldershot
Hampshire GU12 5XA
United Kingdom
Tel: [phone] Fax: [phone]
Internet address: http://www.merrychef.co.uk
E-mail: [e-mail]

[e-mail]

or

Page 2 Microaire Ovens 32Z3311e Issue 5

SAFETY CODE

This manual is designed to assist engineers who have been on a recognised product familiaris ation
and training course run by Merrychef Limited. It has been prepared to of fer tec hnical guidance f or the
Merrychef Microaire Series 5 range of Combination Microwave Ovens.

Please remember that it is wiser
complete it competently, quickly, and above all

To avoid injury to yourself, and to protect the appliance from possible damage, please follow this
Safety Code when servicing these ovens.

Before attempting to repair the oven, check it for microwave leakage.

Check that the oven is not emitting microwaves, even when supposedly not in operation.

Check that the oven is not operating continuously, whether the display indicates cooking or

Always discharge the HT capacitors before working on the oven using a suitably insulated 10

Before removing the rear cover from the oven, do all of the following:

Switch off the mains supply and remove the plug from the wall socket.

•

or

If the oven is hard wired, ensure that the power is turned off at the isolator switch.

•

Note:

the On/Off switch on the oven is

isolate all of the internal wiring from the mains.

Upon completion of a service on a Microaire Series 5 oven, or before reconnecting the applianc e to
the mains supply for testing, check all of the following points:

All internal electrical connections are correct.

•

All wiring insulation is correct and is not touching a sharp edge.

•

All Earth connections are electrically and mechanically secure.

•

All four door safety interlocks are secure and mechanically sound.

•

The door operation is smooth, and the arms run freely in the slots.

•

The door activates all four of the door interlock switches

•

All fuse-holder safety covers are correctly fitted.

•

The temperature sensor is correctly connected to the Power PCB.

•

Before finishing the service call, recheck the following points:

All of the electronics are functioning correctly, and all of the touch pads are working.

•

The turntable is rotating freely.

•

The power output of the oven is correct (see pages 11 & 12 ).

•

Microwave emission is below permissible limit - 5 mW/cm² (see BS EN 60335-2-90:1998).

•

Oven has correct 50mm air gap all round and 150mm above. Air flow should not be restricted.

•

not

to attempt a service task if you are unsure of being able to

safely

.

not.

MΩ Resistor

not

adequate protection against electric shock, as it does not

in the correct order

.

Page 3 Microaire Ovens 32Z3311e Issue 5

PRODUCT SPECIFICATIONS

ELECTRONIC CONTROLS

Model Number: RMC1003 + Voltage + Frequency + Current + Controls + Extras

Model prefix Voltage Frequency Current Control Type

RMC1003

2 = 220-230V a.c.
4 = 230-240V a.c

Rail spec: RMC1003 + RS + Carriage Type RF/HST

5 = 50 Hz
6 = 60 Hz

EE=Reduced Cur-

rent

XE = Full

Current

5 = Series 5

MANUAL CONTROLS

Model Number: RMC1003 + Voltage + Frequency + Current

Model prefix Voltage Frequency Current

RMC1003

Power
Requirements

2 = 220-230V a.c.
4 = 230-240V a.c.

RMC100345EE5/CD2
RMC100325EE5/CD2
RMC100345XE5/XD2
RMC1003RSRF
RMC1003RSHST

5 = 50 Hz
6 = 60 Hz

230-240V ac 50 Hz 13.0A Single Phase 2 Wire + Earth.
220-230V ac 50 Hz 14.2A Single Phase 2 Wire + Earth.
230-240V ac 50 Hz 19.2A Single Phase 2 Wire + Earth.
2 x Single Phase + Earth. See rating plate for full details.
2 x Single Phase + Earth. See rating plate for full details.

CD2 = 13amp
XD2 = 30amp

controls

Power Output Microwave 100%

Convection
Combination

External
Dimensions

Height
Width
Depth

Internal
Dimensions

Height
Width
Depth
Turntable
Capacity

Weight Nett

Gross packed

Construction Cavity

Casework

Settings Microwave

Temperature
Timer

700W (IEC 705)
3000W
700W + 1500W (EE)
700W + 3000W (XE, RS RF, RS HST)

530 mm (Plus 150 mm minimum clearance above)
550 mm (Plus 50 mm minimum clearance each side)
575 mm (Plus 50 mm clearance behind)

315 mm
330 mm
330 mm
300 mm Diameter

34.3 litres (1.21 ft³)
45 kg

58 kg
Vitreous Enamel Coated Steel

304 Stainless Steel
Anodised Aluminium Extrusions

100%,75%,50%,25%, Convection only
Off, 175°, 200°, 225°, 250°, 275°
Up to 30 minutes

Up to 3 cooking stages of up to 30 minutes each
(Programmed)

Page 4 Microaire Ovens 32Z3311e Issue 5

Page 5 Microaire Ovens 32Z3311e Issue 5

INSTALLATION INSTRUCTIONS

Power Supply Requirements

The

Microaire Series

the switching-on surge that occurs with certain types of catering equipment, such as
microwaves. Because of this requirement, we strongly recommend that a separate, suitably
rated supply is installed for the oven.

The supply for the oven should be fitted with a
20 Amp for Microaire 13A/ CD² or 30 Amp for Microaire 30A/ XD²
If the oven is hard-wired to the supply, a double-pole isolator switch with a contact gap of at

least 3 mm should be fitted.

Custom ovens for Railway Use only

Microaire Series 5 RS RF and RS HST Power Supply Requirements

These versions of the oven are custom Rail Specification designs for use on two separate
phases of a mains supply, with isolated neutrals and a common earth connection.The full
power supply and circuit breaker requirem ents for these ovens is listed on the label aff ixed to
the rear of the oven casing.

mains supply.

should be connected to a suitable electricity supply, which can cope with

Type "C"

These ovens are NOT suitable for connection to a standard

circuit breaker, rated at:

Positioning the Oven

In order to maintain adequate ventilation for air intake and exhaust, and to allow access for
cleaning filters, you must allow a minim um of 50 mm clearance at the sides and rear of the
oven, and at least 150 mm above. Air intake temperature should not exceed 35°C.
Excessive temperature will lead to reduced operating duty cycle or premature ageing of internal
components.

NEVER
NEVER
ALWAYS

vitreous enamel coating.

Install an oven above fryers, grills, griddles or any other major heat source.

Stack machines on top of each other - always use a double stand.

Place containers in the cavity carefully - impact damage may chip the

Page 6 Microaire Ovens 32Z3311e Issue 5

Error Codes and Diagnostics

The Microaire Series 5 will identify some of the most common problems by flashing an error
message code in the time display window.

These are the error messages, and suggestions for repairing them.

1
2

1

2
3

1
2

1

Door not fully shut.
Possible electrical fault

No time has been set.
Invalid time has been set.
Invalid program has been

set.

Oven not heating up.
Possible Heater fault.
Possible Sensor fault.

Oven Cavity overheating.

Close door fully.
Door switch inoperative.

Set a time.
Set a valid time.
Use call-back to check program.

Check heater fuse.
Confirm operation of heater cir-

cuit.
(RS units) Check slave heater
relay and second supply.

Confirm heater relay is operat­ing.

(RS units) Check slave heater
relay .

1

Oven is not at correct
temperature to start pro­gram.

1 Magnetron overheating. Check air filters.

1

1

Magnetron has over­heated but has now re­covered.

2

Internal diagnostic fault.

Oven control area is
overheating.

Remove food.
Allow oven to reach correct tem ­perature.

Operator Error !!

Check location, air inlet tempera­ture and air filters.
Note : this will lead to condition
shown below.

Check that magnetron cooling
fan and turntable are working
correctly.
Check installation, air inlet tem­perature and air filters.

Check air filters.
Check axial fan.
Check installation for hot air in­take.

Page 7 Microaire Ovens 32Z3311e Issue 5

Main Features

o

a

b

c

f

h

i

m

a STEAM OUTLET

Allows steam and excess pressure to escape

from the oven cavity. It must be kept clear.

b AIR OUTLET

Hot air is vented here. It must be kept clear.

c TRAY HANDLE RESTS

There is one on each side of the oven for
convenient storage of the tray handle.

d BAFFLE PLATE

Forms the inside rear of the oven and covers
the hot air circulation fan. Removable for
cleaning by unscrewing the four wing nuts
which hold it in place. This must be cleaned on
a regular basis, and kept free of debris.

e RUNNERS

These mounted on each side of the oven
cavity to support the rectangular racks or oven
trays, and are for use in

.

only

Convection mode

f HOT AIR FAN

Situated behind the baffle plate, and circulates
the hot air through the baffle plate, over the
heating element, and around the edge of the
baffle plate back into the cavity.

g OVEN CAVITY

The oven cavity is mainly constructed form
vitreous enamelled steel panels. It must be
kept clean.

d

e

g

n

j

L

k

h TURNTABLE TRAY

The vitreous enamelled turntable tray fits onto

the turntable disc in the bottom of the oven
cavity, and rotates during cooking to ensure an
even distribution of microwave energy.

i AIR INLETS

Additional air inlets are situated along the lower
edge of the left-hand side panel, and must not
be obstructed.

j RATING PLATE

The rating plate is situated on the rear of the
oven, and states the Model, Serial Number,
Electrical Ratings and Manufacturers tel no.

k DOOR

The door consists of a thermally insulated inner
section, and an additional air gap provided by a
twin skinned door front to lower the surface
temperature.

l ON/OFF SWITCH

This is used to turn the oven On or Off.

IT

DOES NOT ISOLATE INTERNAL WIRING

FROM THE ELECTRICAL SUPPLY

.

m FEET

These feet are fitted to ensure adequate airflow
under the oven. They must not be removed. On
RS units, these are also the means of anchoring
the oven to the work surface.

n ELECTRICAL SUPPLY LEAD
o AIR FILTER (REF 27)

Main intake for cooling air for internal
components. Must be clear of obstructions.

Page 8 Microaire Ovens 32Z3311e Issue 5

Electronic controls: Microaire Series 5

a Stage LED's

a

b

c

d

e

b Service Indicator
c Air Filter Block Indicator
d Operator error indicator
e Program Display

f Temperature Set Pads
g Time / Precept Pads
h Cancel/ Callback Pad

i Program Pad

j Convection Pad
k Microwave power Pads
L On/Off switch (Ref. No. 97)

f

J

i

j

h

k

L

Page 9 Microaire Ovens 32Z3311e Issue 5

Manual controls: Model No.s CD2, XD2

a Timer Amber Neon

a

b

b Control Knob
c Start Pushbutton
d Cook cycle Red Neon
e Power Amber Neon

f On/Off switch

b

b

c
d

e

f

Page 10 Microaire Ovens 32Z3311e Issue 5

Procedure A - Power Output Test in accordance with
BS EN 60335-2-25:1996 Annex AA

This test is given in the BSI test standard for m icrowave ovens. It is reproduced below - not so that
you can follow it, but to show you why it is impractical in nor mal conditions. A simplified procedure,
which gives a good approximation to the BSI power output, is given in Procedure B which follows.

Note:

This test can only be carried out on a
only a few seconds, the power given will be lower than the oven rating. This test m us t als o be carr ied
out at a stable voltage - the voltage in most k itchens var ies consider ably even within the period of the
test. If the oven has been operating, go to

Procedure B.

You will need:

A thermometer capable of reading to ±0.1°C.
A cylindrical borosilicate glass container, 190 mm diameter, with a wall thickness of 3 mm or less.
A calculator.
A set of scales capable of reading 1 kg to an accuracy of ± 1 g.
A glass or plastic stirrer.
A jug capable of holding over 1 litre of water.
Drinkable water which is at a temperature of 10°C ± 1°C.
A “Variac” or similar variable transformer capable of supplying the oven to ensure a stable voltage.

oven. If the oven has been operating, even for

COLD

WARNING:

The Borosilicate Glass container has thin walls and is therefore fragile - take c ar e not

to break it during use.

Method

A cylindrical container of borosilicate glass is used for the test. It has a maximum thickness of
3m m, an external diameter of approximately 190 mm and a height of approximately 90 mm. The
mass of the container is determined.

At the start of the test, the oven and the empty container are at am bient temper ature. Potable water
having an initial temperature of 10°C ± 1°C is used for the test. The temperature of the water is
measured immediately before it is poured into the container.

A quantity of 1000 g ± 5g of water is added to the container and its actual mass obtained. The
container is then immediately placed in the middle of the oven shelf which is in its lowest normal
position. The appliance is supplied at rated voltage and operated at the m axim um power s etting. T he
time for the water temper ature to attain 20°C ± 2°C is measured. The oven is then s witched off and
the final water temperature is measured within 60’s.

NOTES

1 The water is stirred before its temperature is measured.
2 Stirring and measuring devices are to have a low heat capacity.

The microwave power output is calculated from the formula:

4.187 M

(T2-T1) + 0.55 MC (T2-T0)

W

P =
t
where

P is the microwave power output, in watts;

is the mass of the water, in grams;

M

W

is the mass of the container, in grams;

M

C

is the ambient temperature, in °C;

T

0

is the initial temperature of the water, in °C;

T

1

is the final temperature of the water, in °C;

T

2

t is the heating time in seconds, excluding the magnetron filament heat-up time.

Page 11 Microaire Ovens 32Z3311e Issue 5

Procedure B - Simplified Pow er Test

You will need:

A thermometer capable of reading to ±0.1°C.
A Polypropylene tray approximately 200 mm x 200 mm.
A measuring jug.
A calculator.
Water which is at a temperature of 10°C ± 2°C.

1 Measure 1 litre of cold water into the tray using the measuring jug.
2 Measure the water temperature, and record it as T[s].
3 Place the tray on the turntable in the oven and close the door.
4 Turn the oven on.
5 Set the timer to 1:02.
6 Press the “100%” pad.
7 When the oven bleeps, open the door and remove the tray.
8 Stir the water thoroughly, and measure its temperature. Record this as T[e].

Calculation:

1 T[r] = T[s] - T[e].
2 Power = 70 x T[r]. Power is in Watts.

The power given by the above test should be within ±10% of the rated power.

Procedure C - Power Transformer Test

You will need:

A Digital Multi-meter (D.M.M.)
A Megger or similar resistance meter using 500V d.c.

WARNING:

WARNING:

1 Isolate the oven from the mains supply.
2 Ensure that the High Voltage Capacitor is discharged before commencing work.
3 Remove all connections from the Power Transformer.
4 Using a D.M.M., check the resistance of the windings. Results should be as follows:

Mains winding (between tags)
High Voltage winding (between tag & chassis)
Filament winding (between terminals)

5 Using a Megger, test the insulation resistance between:

One end of the High Voltage winding is connected to the chassis, so this is not tested.

High voltages and large currents are present at the secondary winding and filament

winding of the Power Transformer. It is very dangerous to work near this part when the
oven is on. NEVER make any voltage measurements at the High Voltage circuits,
including the magnetron filament.

Even when the oven is not cooking, the Power Transformer has High Voltages present

because of the Soft Start circuit. Isolate the oven before testing.

Approximately 1.1 Ω

Approximately 60 Ω

Less than 1 Ω

Primary winding and chassis
Filament winding and chassis

Pass if over 10 MΩ
Pass if over 10 MΩ

Page 12 Microaire Ovens 32Z3311e Issue 5

Procedure D - High Voltage Capacitor Test

You will need:

A Digital Multi-meter (D.M.M.)
A Megger or similar resistance meter using 500V d.c.

WARNING:

WARNING:

1 Isolate the oven from the mains supply.
2 Ensure that the High Voltage Capacitor is discharged before commencing work.
3 Remove all connections from the High Voltage Capacitor.
4 Using a D.M.M., check for continuity between the terminals & compare results with table.

5 Using a Megger, test the insulation resistance between the terminals and the case.
Between Terminals
Between Terminals and Case Pass if open circuit

Between Terminals and Case

High voltages and large currents are present at the High Voltage Capacitor. It is very

dangerous to work near this part when the oven is on. NEVER make any voltage
measurements at the High Voltage circuits, including the magnetron filament .

Even when the oven is not cooking, the High Voltage Capacitor has High Voltages

present because of the Soft Start circuit. Isolate the oven before testing.

Pass if approximately 10 MΩ

Pass if over 100 MΩ

Procedure E - High Voltage Rectifier Test

You will need:

A Megger or similar resistance meter using 500V d.c.

WARNING:

WARNING:

1 Isolate the oven from the mains supply.

2 Ensure that the High Voltage Capacitor is discharged before commencing work.

3 Remove all connections from the High Voltage Rectifier.

Open Circuit both ways
Conducts one way only PASS

Short Circuit both ways
Conducts one way, leaks the other

High voltages and large currents are present at the High Voltage Rectifier. It is very

dangerous to work near this part when the oven is on. NEVER make any voltage
measurements at the High Voltage circuits, including the magnetron filament .

Even when the oven is not cooking, the High Voltage Rectifier has High Voltages

present because of the Soft Start circuit. Isolate the oven before testing.

FAIL

FAIL
FAIL

Page 13 Microaire Ovens 32Z3311e Issue 5

Principal components: Casework

1 Side Panel (L/H) MC3134
2 Ferrite (2) RMC6773
3 Upper Trim MC3120X01
4 Top Plate RMC6759E
5 Exhaust Gallery RMC73372
6 Rear Panel MC3129

7 Grease Filter MC3155

8 Side Panel (R/H) MC3133
9 Handle Hanger (2) RCK6319

10 Rubber Foot (EE,XE) (4)

Foot (RF, HST) (4)

11 Front Lower Panel MC3047
12 Lower Trim MC3122

RMC6104

40H0092

Page 14 Microaire Ovens 32Z3311e Issue 5

Door Mechanism

13 Door Stay (R/H) MC3040
14 Hinge Body MC30121
15 Hook (A) RMC66171
16 Hook (B) RMC66172
17 Door Spring (B) MC3068X01
18 Hinge Body (L/H) MC30122
19 Door Spring (A) MC3067
20 Door Stay (L/H) MC3046
21 Microswitch Guide 40H0076
22 Microaire Solid Door Assy 11H0031

Page 15 Microaire Ovens 32Z3311e Issue 5

Oven Cavity Components and Hot Air System

23 Turntable Disc RMC7340X01
24 Baffle Plate Bolt CP30326
25 Baffle Plate MC3018
26 Fan Fixing Cap RCK7617
27 Fan MC3111
28 Partition Plate 11H0007
29 Cavity Sealing Glass RMC7043
30 Oven Body MC3013

31 Gearbox MC3216
32 Shaft RMC7391X01
33 Cooling Fan RMC7310
34 Motor Bracket RMC7307X01
35 Cushion Rubber RCK8273
36 Motor Fixing Screw CP30310
37 Hot Air Motor MC3110

Page 16 Microaire Ovens 32Z3311e Issue 5

Oven Door Assembly

38 Black Handle Microaire RBR12852
39 Door Frame (A) Black MC30503
40 Door Cover Outer Skin 40H0080
41 Insulation Panel 40H0081
42 Door Reinforcement RMC70722
43 Door Frame (B) MC3055
44 Insulation Wrap 32Z0001
45 Window Screen 40H0082
46 Door Base Silver MC3031KX04
47 Door Cover MC3064
48 Plate - Door Switch MC3056
49 Screen MC3061
50 Packing (A) MC3063
51 Inner Door Glass MC3062
52 Packing (B) MC3065
53 Door Rear Plate MC3066

Page 17 Microaire Ovens 32Z3311e Issue 5

Magnetron and Door Interlock Components

54 Door Switch Bracket Ass 11H0033
55

Primary Microswitch

56

Low Voltage Microswitch

57

Secondary Microswitch

58

Monitor Microswitch

59 Microswitch Insulator 31Z0115
60 Outlet Duct MC3037
61 Foam Tape 31Z0042

30Z0240
30Z0240
30Z0240
30Z0240

62 Inlet Duct RMC7193X01
63 Magnetron 30Z0264
64 Magnetron Cut-out 30Z0088
65 Switch Bracket RMC7100X01
66 Blower Assembly MC3141
67 M3 x 25 Pan Head Pozi 31Z3093
68 M3 x 30 Pan Head Pozi 31Z3113

Page 18 Microaire Ovens 32Z3311e Issue 5

Door Interlock Operation

The door on the Microaire Series 5 oven is m onitored by four microswitches. T hree of these are
used in the conventional “Primary, Secondary and Monitor” switch arrangement shown below,
while the fourth is a low-voltage switch linked directly to the control circuitry.
The switches operate as follows:

Door Interlock Arrangement

L

Power In Power Out

N

Primary Interlock [ 55 , Top Left-Hand ] and Low voltage [ 56 , Top Right-Hand ]

1.

Switches

Operate simultaneously. Either will cut off the microwave emissions from the oven when the
door is opened: the Primary switch by breaking the mains supply circuit to the transformers,
and the Low-Voltage switch by breaking the relay circuit on the Power / Relay PCB.

Monitor [ 58 , Bottom Outer ] and Secondary Inter lock [ 57 , Bottom Inner ] Switches.

2.
Operate simultaneously. The Monitor switch will produce a short circuit across the mains
supply if the Primary interlock switch is faulty, thus blowing the microwave fuse and
rendering the oven inoperative. The Secondary interlock switch will cut off the microwave
emission if all three of the other switches have failed.

Note:

If operation of the Monitor switch has caused the Microwave Fuse to blow, the

Primary and Monitor microswitches must be changed, as they may have been
damaged by the high short-circuit currents involved.

55

56

57

58

Error Light Operation

The “Air Filter Blocked” light and “Service” light are triggered by the internal circuitry. If the m agnetron
overheats, the error code “E:7” is disp layed on the front panel, and both the “Air Filter Bloc ked” and
the “Service” indicators will light. Once the magnetron has cooled sufficiently to allow the oven to
restart, the “Service” light will remain illuminated until the oven is turned off.

This fault may have been triggered by one of the following causes:

- Air inlet on rear of machine being obstructed.

- High air inlet temperature.

- Slow running cooling fan, jammed turntable or broken gearbox
(cooling fan also drives turntable).

- Faulty magnetron overheat ‘stat or associated wiring.

Note that the customer may not have noticed that the oven displayed “E:7” , and so the
reported fault may be misleading.

Page 19 Microaire Ovens 32Z3311e Issue 5

Major Electrical Components

All Variants

RMC100345 EE/XE 5

Page 20 Microaire Ovens 32Z3311e Issue 5

RMC100345 RS RF

69 Cavity Overheat Switch 30Z1031
70 Bridge Rectifier (EE only) 341520
71 N0. 8 Screw 31Z3107
64 Magnetron Overheat Switch 30Z0088
72 M5 Screw 101825
73 240V Heating Element (UK/RF)

220V Heating Element (EEC)

276V Heating Element (HST)
74 Temperature Sensor 50E123
75 HV Diode Assembly 11H0010
76 High Voltage Capacitor 30Z0989
77

Microwave Mains Filter 16A
78

Heater Mains Filter 16A

40H0009
40H0077
40H0091

30Z0997
30Z0997

RMC100345 RS HST

79 Fuse Cover 20Z1080
80 Fuse 10A HRC 30Z0217
81 Fuse Holder 1” 30Z0231
82 Fuse 13A Anti-surge 30Z0168
83 Relay 30Z1063
84 Mutual Inductor 30Z1068
85 HST Mains Filter Assy. 11H0030
86 Fuse 16A 1¼” 30Z1066

87 Fuse Holder 1¼” 30Z0285
117 80mm Axial Fan 310010
118 PP3 Battery Clip 31Z0414
119 PP3 Battery NiMH 30Z1064
120 PP3 Battery Holder 31Z0413

Page 21 Microaire Ovens 32Z3311e Issue 5

Input Wiring Details: Microaire Series 5 EE5

Green / Yellow

Blue

Brown

Input Wiring Details: Microai r e Seri es 5 XE5

111 Mains Input Block 31Z0328
112 Cable Gland 31Z1070

Green / Yellow

Blue

Brown

113 Input Cable Assembly 31Z0220
115 XE5 Input Cable Assembly 302030
116 Strain Relief Grommet 31Z1036

Page 22 Microaire Ovens 32Z3311e Issue 5

Input Wiring Details: Microai r e Seri es 5 RS RF

Black

Brown

Green / Yellow

Black

N4

N4

Input Wiring Details: Microai r e Series 5 RS HST

Blue

Black

Black

Brown

Green / Yellow

N4

80 Fuse 10A HRC 30Z0217
82 Fuse 13A Anti-surge 30Z0168
86 Fuse 16A 1¼” 30Z1066

112

Cable Gland

112a

Cable Gland Nut

114 Rail Spec. Input Cable Assy 11H0032

31Z1070
31Z1082

Blue

Page 23 Microaire Ovens 32Z3311e Issue 5

HT Components

88 HT Transformer Top Bracket MC3127
89 HV Lead Assembly 11H0025
75 HV Diode Assembly 11H0010
90 Unitran HT Transformer 240V

Unitran HT Transformer 220V

91 HT Transformer Bottom Bracket 40H0070
76 HT Capacitor 30Z0989
92 Capacitor Band RMC7215
93 Filter Bracket 40H0065
94 HT Transformer Support Bracket MC3024

30Z0992
30Z1018

Page 24 Microaire Ovens 32Z3311e Issue 5

Electronic Control Panel Assembly: Microaire Series 5

95 Membrane Assembly 11H0024
96 Microaire 5 Extrusion LH 40H0083
97 On/Off Switch 30Z0503
98 Microaire S5 Logic Assy.

Microaire S5 RS Logic Assy.

99 Support Shield Microaire 5 40H0075
100 M3 x 5 Screw 31Z3106
101 No. 4 x 3/8” Screw 31Z3112
102 470R 50W Resistor 30Z0283

11C0285
11H0029

103 Microaire S5 Relay Assy.

Microaire S5 RS Relay Assy.

104 Microaire 5 Extrusion RH 40H0084
105 Side Trim MC31211
106 M5 Flat Washer 31Z5004
107 PCB Stand-off 31Z7010
108 15 Way Ribbon Connector 11Z0298
109 Twin 0.25” Blade 309610
110 M3 Nylon Support 31Z0206

11C0286
11H0028

Page 25 Microaire Ovens 32Z3311e Issue 5

Manual Control Panel Assembly: Microaire CD2, XD2

104

123

121

122

97

123A

123B

123C

123D

125

126

123

105

106

97 On/Off Switch 30Z0503

121 PCB Assembly 11H0027
122 Timer 30Z0991

123 Amber Neon 316031
124A Control Knob 313020
124B Control Knob Skirt 313160

124C Control Knob Cap 313220
124D Control Knob Shaft Adaptor 313030

125 Pushbutton (Start) 31Z0349

126 Red Neon 316030

127 Potentiometer 40C0892

127

Control Board not
shown for clarity

Page 26 Microaire Ovens 32Z3311e Issue 5

Membrane Panel Circuit: Microaire Series 5

You will need:

A Digital Multi-meter (D.M.M.)

1. Isolate the oven from the mains supply.

2. Remove the Logic Assembly from the Control
Panel Housing.

3. Unplug the membrane “tail” from the Logic
PCB Assy.

4. Using a D.M.M., check for continuity between
the correct terminals when the pads are
pressed.

5. When the panel has been tested, re­assemble and re-test the control housing.

Page 27 Microaire Ovens 32Z3311e Issue 5

Part Number Identification Chart: Microaire series ovens

1 SIDE PANEL (L/H) MC3134
2 FERRITE (2) RMC6773
3 UPPER TRIM MC3120X01
4 TOP PLATE RMC6759E
5 EXHAUST GALLERY RMC73372
6 REAR PANEL MC3129
7 GREASE FILTER MC3155
8 SIDE PANEL (R/H) MC3133

9 HANDLE HANGER (2) RCK6319
10 RUBBER FOOT (EE,XE) (4) RMC6104
11 FRONT LOW ER PANEL MC3047
12 LOWER TRIM MC3122
13 DOOR STAY (R/H) MC3040
14 HINGE BODY MC30121
15 HOOK (A) RMC66171
16 HOOK (B) RMC66172
17 DOOR S PRING (B) MC3068X01
18 HINGE BODY (L/H) MC30122
19 DOOR S PRING (A) MC3067
20 DOOR STAY (L/H) MC3046
21 MICROSWITCH GUIDE 40H0076
22 MICROAIRE SOLID DOOR 11H0031
23 T URNT ABLE DISC RMC7340X01

24 BAFFLE PLATE BOLT CP30326
25 BAFFLE PLATE MC3018
26 F AN FIXING CAP RCK7617
27 FAN MC3111
28 PARTITION PLATE 11H0007
29 CAVITY SEALING GLASS RMC7043
30 OVEN BODY MC3013

31 GEARBOX MC3216
32 SHAFT RMC7391X01
33 COOLI NG FA N RMC7310
34 MOTOR BRACKET RMC7307X01
35 CUSHION RUBBER RCK8273
36 MOTO R F IXING SCREW CP30310
37 HOT AIR MOTOR MC3110
38 BLACK HANDLE MICROAIRE RBR12852
39 DOOR FRAME (A) BLACK MC30503
40 DOOR COV ER OUTER SKIN 40H0080
41 INSULATION PANEL 40H0081
42 DOOR RE INFORCEMENT RMC70722
43 DOOR FRAME (B) MC3055

44 INSULATION WRAP 32Z0001
45 WINDOW S CRE EN 40H0082
46 DOOR BASE SILVER MC3031KX 04
47 DOOR COVER MC3064
48 PLATE - DOOR SWITCH MC3056
49 SCREEN MC3061
50 PACKING (A) MC3063
51 INNER DOOR GLASS MC3062
52 PACKING (B) MC3065
53 DOOR REAR PLATE MC3066
54 DOOR SW ITCH BRACKET ASSBLY 11H0033
55

PRIMARY MICROSWITCH

56

LOW VOLTAGE MICROSWITCH

57

SECONDARY MICROSWITCH

58

MONITOR MICROSWI T CH
59 MI CROSWITCH INSULATOR 31Z0115
60 OUT L E T DUCT MC3037
61 FOAM TAPE 31Z0042
62 INLET DUCT RMC7193X01
63 MAGNETRON 30Z0264
64 MA GNE T RON CUT -OUT 30Z0088
65 SWITCH BRACKET RMC7100X01
66 BLOWER ASSEMBLY MC3141
67 M3 X 25 PAN HEAD POZI 31Z3093
68 M3 X 30 PAN HEAD POZI 31Z3113
69 CAVITY OVERHEAT SW ITCH 30Z1031
70 BRIDGE RECTIFIER (EE ONLY) 341520
71 N0. 8 SCREW 31Z3107
72 M5 S CREW 101825
73 240V HEATING ELEMENT (UK/RF)

220V HEATING ELEMENT (EEC)

276V HEATING ELEMENT (HST)
74 TEMPERATURE SENSOR 50E123

75 HV DIODE ASSEMBLY 11H0010
76 HIGH VOLTAGE CAPACITOR 30Z0989
77

M’WAVE MAINS FILTER 16A
78

HEATER MAINS FILTER 16A
79 FUSE COVER 20Z1080

80 F USE 10A HRC 30Z0217
81 FUSE HOLDER 1” 30Z0231
82 FUSE 13A ANTI-SURGE 30Z0168
83 RELAY 30Z1063
84 MUTUAL INDUCTOR 30Z1068
85 HST MAINS FILTER ASSY. 11H0030

30Z0240
30Z0240
30Z0240
30Z0240

40H0009
40H0077
40H0091

30Z0997
30Z0997

Page 28 Microaire Ovens 32Z3311e Issue 5

Part Number Identification Chart: Microaire series ovens

86 FUSE 16A 1¼” 30Z1066
87 FUSE HOLDER 1¼” 30Z0285
88 HT TRANSFORMER TOP

BRACKET
89 HV LEAD ASSEMBLY 11H0025
90 UNITRAN HT TRA NSFORMER

240V

UNITRAN HT TRANSFORMER

220V
91 HT TRANSFORMER BOTTOM

BRACKET
92 CAPACITOR BAND RMC7215

93 FILTER BRACKET 40H0065
94 HT TRANSFORMER SUPPORT

BRACKET
95 MEMBRANE ASSEMBLY 11H0024

96 MICROAIRE 5 EXTRUSI O N LH 40H0083
97 ON/OFF SWITCH 30Z0503
98 MICROAIRE S5 LOGIC ASSY.

MICROAIRE S5 RS LOGIC ASSY.
99 SUPPORT SHIELD MICROAIRE 5 40H0075

100 M3 X 5 SCREW 31Z3106

101 NO. 4 X 3/8” SCREW 31Z3112

102 470R 50W RESISTOR 30Z0283

103 MICROAIRE S5 RELAY ASSY.

MICROAIRE S5 RS RELAY ASSY.

MC3127

30Z0992
30Z1018

40H0070

MC3024

11C0285
11H0029

11C0286
11H0028

104 MICROAIRE 5 EXTRUSION RH 40H0084
105 SIDE TRIM MC31211
106 M5 FLAT WASHER 31Z5004
107 PCB STAND-OFF 31Z7010
108 15 WAY RIB B O N CONNECTOR 11Z0298
109 TWIN 0.25” BLADE 309610
110 M3 NYLON SUPPORT 31Z0206
111 MAINS INPUT BLOCK 31Z0328
112

CABLE GLAND

112A

CABLE GLAND NUT

113 INPUT CABLE ASSEMBLY 31Z0220
114 RAIL SPEC. INPUT CABLE ASSY 11H0032
115 XE5 INPUT CABLE ASSEMBLY 302030
116 STRAIN RELIEF GROMMET 31Z1036
117 80mm Axial Fan 310010
118 PP3 Battery Clip 31Z0414
119 PP3 Battery NiMH 30Z1064
120 PP3 Battery Holder 31Z0413
121 PCB Assembly 11H0027
122 Timer 30Z0991

123 Neon Amber 316031
124A Control Knob 313020
124B Control Knob Skirt 313160

124C Control Knob Cap 313220
124D Control Knob Shaft Adapter 313030

125 Pushbutton (Start) 31Z0349

126 Neon Red 316030

127 Potentiometer 40C0892

31Z1070
31Z1082

Page 29 Microaire Ovens 32Z3311e Issue 5

Circuit Diagram: Series 5 EE & XE

Page 30 Microaire Ovens 32Z3311e Issue 5

Circuit Diagram: Series 5 RS

Page 31 Microaire Ovens 32Z3311e Issue 5

Manual Corrections and Modifications

Whilst every effort has been made to ensure that the information contained in this manual is
accurate and complete, if you believe that an error has been made, or if you have any suggestions
for how the manual could be improved, please f ill in and return this form. A review of any form s
returned will be made on a regular basis, and the manual will be updated if required.

Name

Address

Page on which error occurs (if applicable) -

Description of error

Suggestion for improvement to manual

Microaire Series

Please return this form to:

Or Fax it on:

Engineering Department
Merrychef Ltd
Station Road West
Ash Vale
Aldershot
Hampshire
GU12 5XA

[phone]

Page 32 Microaire Ovens 32Z3311e Issue 5