Viking VMOC205SS Operation, Description of Operating Sequence, OFF Condition, Cooking Condition

DMOC205SS

VMOC205SS

OPERATION

DESCRIPTION OF OPERATING SEQUENCE

The following is a description of component functions during oven operation.

OFF CONDITION

Closing the door activates the door sensing switch and secondary interlock switch. (In this condition, the monitor switch contacts are opened.)

When oven is plugged in, 117 volts A.C. is supplied to the control unit. (Figure O-1).

1.The display will show "WELCOME, PRESS CLEAR". To set any program or set the clock, you must first touch

the STOP/CLEAR pad. The display will clear, and " : " will appear.

NOTE: When the door is opened, the oven lamp comes on.

2.A signal is input to the control unit, energizing the coil of shut-off relay (RY-4). RY4 contacts close, completing a circuit to the damper motor. The damper motor now operates moving the damper to the open position, thereby closing the contacts of the damper switch inputs a signal to the control unit. The coil of relay RY- 4 is de-energized, opening its contacts, thereby turning off the damper motor.

COOKING CONDITION

Program desired cooking time Variable Cooking Control by touching the NUMBER pads and the power level pad. When the START pad is touched, the following operations occur:

1.The contacts of relays are closed and components connected to the relays are turned on as follows.

(For details, refer to Figure O-2)

RELAY	CONNECTED COMPONENTS
RY-1	Oven lamp/Turntable motor
RY-2	Power transformer
RY-3	Heating element
RY-4	Damper motor
RY-5	Convevtion motor
RY-6	Fan motor

2.117 volts A.C. is supplied to the primary winding of the power transformer and is converted to about 3 volts A.C. output on the filament winding, and approximately 2360 volts A.C. on the high voltage winding.

3.The filament winding voltage heats the magnetron filament and the H.V. winding voltage is sent to a voltage doubler circuit.

4.The microwave energy produced by the magnetron is channelled through the waveguide into the cavity feed- box, and then into the cavity where the food is placed to be cooked.

5.Upon completion of the cooking time, the power transformer, oven lamp, etc. are turned off, and the generation of microwave energy is stopped. The oven will revert to the OFF condition.

6.When the door is opened during a cook cycle, third door switch, monitor switch, door sensing switch, the secondary interlock relay and the primary interlock

switch are activated with the following results. The circuits to the turntable motor, the cooling fan motor, and the high voltage components are de-energized, the oven lamp remains on, and the digital read-out displays the time still remaining in the cook cycle when the door was opened.

7.The monitor switch is electrically monitoring the operation of the relay (RY1) and the primary interlock switch and is mechanically associated with the door so that it will

function in the following sequence.

(1)When the door opens from a closed position, the door sensing switch and the primary interlock switch open their contacts, and then the monitor switch contacts close and then the third door switch contacts open.

(2)When the door is closed from the open position, the monitor switch contacts open and the third door switch contacts close first, and then the contacts of the primary interlock switch and the door sensing switch close.

If the relay (RY1) and the primary interlock switch fail with their contacts closed when the door is opened, the closing of the monitor switch contacts will form a short circuit through the monitor fuse, the relay (RY1) and the primary interlock switch, causing the monitor fuse to blow.

POWER LEVEL P-0 TO P-90 COOKING

When Variable Cooking Power is programmed, the 117 volts A.C. is supplied to the power transformer intermittently through the contacts of relay (RY-2). RY-2 is operated by the control unit within an varying time base. Microwave power operation is as follows:

VARI-MODE	ON TIME		OFF TIME
Power 10(P-HI)	32	sec.	0	sec.
(100% power)
Power 9(P-90)	30	sec.	2	sec.
(approx. 90% power)
Power 8(P-80)	26	sec.	6	sec.
(approx. 80% power)
Power 7(P-70)	24	sec.	8	sec.
(approx. 70% power)
Power 6(P-60)	22	sec.	10	sec.
(approx. 60% power)
Power 5(P-50)	18	sec.	14	sec.
(approx. 50% power)
Power 4(P-40)	16	sec.	16	sec.
(approx. 40% power)
Power 3(P-30)	12	sec.	20	sec.
(approx. 30% power)
Power 2(P-20)	8 sec.		24	sec.
(approx. 20% power)
Power 1(P-10)	6 sec.		26	sec.
(approx. 10% power)
Power 0(P-0)	0 sec.		32	sec.
(0% power)

Note: The ON/OFF time ratio does not correspond with the percentage of microwave power, because approx. 2 seconds are needed for heating of the magnetron filament.

8