Merrychef MICROAIRE Service Manual

M ic ro a ir e

S E R V I C E M A N U A L

For all Microaire models manufactured from January 2001

Part No. 32Z3311e Issue No. 6

CAUTION MICROWAVE EMISSIONS

M A N U A L

S E R V I C E

DO NOT BECOME EXPOSED TO EMISSIONS FROM THE MICROWAVE

GENERATOR OR PARTS CONDUCTING MICROWAVE ENERGY

Microaire Ovens 32Z3311e Issue 5

Page 1

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] or [e-mail]
Microaire Ovens 32Z3311e Issue 5	Page 2

SAFETY CODE

This manual is designed to assist engineers who have been on a recognised product familiarisation and training course run by Merrychef Limited. It has been prepared to offer technical guidance for the Merrychef Microaire Series 5 range of Combination Microwave Ovens.

Please remember that it is wiser not to attempt a service task if you are unsure of being able to complete it competently, quickly, and above all safely.

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 not.

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

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 not adequate protection against electric shock, as it does not isolate all of the internal wiring from the mains.

Upon completion of a service on a Microaire Series 5 oven, or before reconnecting the appliance 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 in the correct order.

•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.

Microaire Ovens 32Z3311e Issue 5

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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.	5	= 50 Hz		EE=Reduced Cur-			5 = Series 5
			4 = 230-240V a.c	6	= 60 Hz		rent			controls
							XE = Full
							Current
	Rail spec:		RMC1003 + RS + Carriage Type RF/HST
MANUAL CONTROLS
	Model Number:		RMC1003 + Voltage + Frequency + Current
	Model prefix		Voltage	Frequency			Current
	RMC1003		2 = 220-230V a.c.	5	= 50 Hz		CD2 = 13amp
			4 = 230-240V a.c.	6	= 60 Hz		XD2 = 30amp
	Power	RMC100345EE5/CD2		230-240V ac 50 Hz 13.0A Single Phase 2 Wire + Earth.
	Requirements	RMC100325EE5/CD2		220-230V ac 50 Hz 14.2A Single Phase 2 Wire + Earth.
		RMC100345XE5/XD2		230-240V ac 50 Hz 19.2A Single Phase 2 Wire + Earth.
		RMC1003RSRF		2 x Single Phase + Earth. See rating plate for full details.
		RMC1003RSHST		2 x Single Phase + Earth. See rating plate for full details.
	Power Output	Microwave 100%		700W (IEC 705)
		Convection		3000W
		Combination		700W + 1500W (EE)
				700W + 3000W (XE, RS RF, RS HST)
	External	Height		530 mm (Plus 150 mm minimum clearance above)
	Dimensions	Width		550 mm (Plus 50 mm minimum clearance each side)
		Depth		575 mm (Plus 50 mm clearance behind)
	Internal	Height		315 mm
	Dimensions	Width		330 mm
		Depth		330 mm
		Turntable		300 mm Diameter
		Capacity		34.3 litres (1.21 ft³)
	Weight	Nett		45 kg
		Gross packed		58 kg
	Construction	Cavity		Vitreous Enamel Coated Steel
		Casework		304 Stainless Steel
				Anodised Aluminium Extrusions
	Settings	Microwave		100%,75%,50%,25%, Convection only
		Temperature		Off, 175°, 200°, 225°, 250°, 275°
		Timer		Up to 30 minutes
				Up to 3 cooking stages of up to 30 minutes each
				(Programmed)

Microaire Ovens 32Z3311e Issue 5

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Microaire Ovens 32Z3311e Issue 5		Page 5

INSTALLATION INSTRUCTIONS

Power Supply Requirements

The Microaire Series should be connected to a suitable electricity supply, which can cope with 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 Type "C" circuit breaker, rated at:

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 requirements for these ovens is listed on the label affixed to the rear of the oven casing. These ovens are NOT suitable for connection to a standard mains supply.

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

NEVER Stack machines on top of each other - always use a double stand.

ALWAYS Place containers in the cavity carefully - impact damage may chip the vitreous enamel coating.

Microaire Ovens 32Z3311e Issue 5

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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	Door not fully shut.		Close door fully.
			2	Possible electrical fault		Door switch inoperative.
			1	No time has been set.		Set a time.
			2	Invalid time has been set.		Set a valid time.
			3	Invalid program has been		Use call-back to check program.
				set.
				Oven not heating up.		Check heater fuse.
			1	Possible Heater fault.		Confirm operation of heater cir-
						cuit.
			2	Possible Sensor fault.		(RS units) Check slave heater
						relay and second supply.
			1	Oven Cavity overheating.		Confirm heater relay is operat-
						ing.
						(RS units) Check slave heater
						relay .
			1	Oven is not at	correct	Remove food.
				temperature to start pro-		Allow oven to reach correct tem-
				gram.		perature.
						Operator Error !!
			1	Magnetron overheating.		Check air filters.
						Check location, air inlet tempera-
						ture and air filters.
						Note : this will lead to condition
						shown below.
			1	Magnetron has	over-	Check that magnetron cooling
				heated but has now re-		fan and turntable are working
				covered.		correctly.
						Check installation, air inlet tem-
			2	Internal diagnostic fault.		perature and air filters.
			1	Oven control	area is	Check air filters.
				overheating.		Check axial fan.
						Check installation for hot air in-
						take.

Microaire Ovens 32Z3311e Issue 5

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Main Features

a

b

c

f

h

i

m

aSTEAM OUTLET

Allows steam and excess pressure to escape from the oven cavity. It must be kept clear.

bAIR OUTLET

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

cTRAY HANDLE RESTS

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

dBAFFLE 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.

eRUNNERS

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

fHOT 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.

gOVEN CAVITY

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

o

d

e

g

n

j

L

k

hTURNTABLE 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.

iAIR INLETS

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

jRATING PLATE

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

kDOOR

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.

lON/OFF SWITCH

This is used to turn the oven On or Off.

IT DOES NOT ISOLATE INTERNAL WIRING FROM THE ELECTRICAL SUPPLY.

mFEET

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.

nELECTRICAL SUPPLY LEAD

oAIR FILTER (REF 27)

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

Microaire Ovens 32Z3311e Issue 5

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Electronic controls: Microaire Series 5

	a	Stage LED's
	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
	i	Program Pad
				j
	j	Convection Pad
	k	Microwave power Pads
	L	On/Off switch (Ref. No. 97)

a

b

c

d

e

f

J

h

k

L

Microaire Ovens 32Z3311e Issue 5

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Manual controls: Model No.s CD2, XD2

a

b

a	Timer Amber Neon
b	Control Knob
					b
c	Start Pushbutton
d	Cook cycle Red Neon
e	Power Amber Neon
f	On/Off switch
					b

c d

e

f

Microaire Ovens 32Z3311e Issue 5

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