Welbilt Merrychef eikon e1s, Manual

Page: 105 / 148

105
eikon e1s
Service and repair guide
High Voltage Magnetron test
Ensure the following requirements have been met before starting the test:
• The appliance has been disconnected from the power supply and protective measures have been taken to ensure
the power cannot be switched on again.
• The appliance is cool.
• The high voltage capacitors are discharged before commencing work.
• Anti-static precautions have been taken.
• The casing of the appliance has been removed.
1. Remove all electric connections from the magnetron.
2. Using a DMM, check for continuity.
Results should be as follows:
• Connect the DMM to both filament terminals of the magnetron.
•
The test is passed if the megger display reads 1 Ω or less.
• Connect the DMM to one filament terminal and the metal outer
case of the magnetron.
• The test is passed if the megger display reads "open circuit".
• Repeat the test for the other filament terminal and the metal outer
case.
Mains voltage components (casing removed)
Convection fan: motor
The convection fan motor is a 3-phase AC motor having a maximum speed of 5000 rpm controlled by a motor speed
controller.
The windings are thermally protected and in the event of a thermal fault, a trip inside the motor will operate and shut down
the motor speed controller.
Convection fan: motor speed controller
The convection motor speed controller provides a 3-phase AC switched mode drive to the convection motor and is
controlled by a 0 - 10 VDC signal from the SRB.
This allows the motor to be adjusted from approximately 1100 rpm to 5000 rpm in steps of 1%.
•
Door open 1100 rpm (20% @ 2V).
•
Door closed (not cooking), 1600 rpm (30% @ 3V).
•
Door closed (cooking), speed as specified by program or setting up to a maximum of 5000 rpm (100% @ 10V).
Convection fan: LED status display
During normal operation the convection fan LED should be ON and NOT flashing. In an error state the LED will flash and the
convection fan will operate in safe mode (limited to 1500 RPM). The number of flashes per second indicates the current
error state which are summarized in the table below.
Once the condition that caused the error state has been resolved, the LED will take 10 seconds to recover.