Merrychef Mealstream, Service Manual

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Page 3 Mealstream Ovens 32Z3387 Issue 2
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 Mealstream 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 M
Ω
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 Mealstream oven, or before reconnecting the appliance to the
mains supply for testing, check all of the following points:
•
All internal electrical connections are correct (see wiring diagram Pages 23-24).
•
All wiring insulation is correct and is not touching a sharp edge.
•
All Earth connections are electrically and mechanically secure.
•
All 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 three 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 power output of the oven is correct.
•
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 50mm above.
Air flow should not be restricted.
SAFETY CODE