Combination Cooking - Panasonic NN-A880WB Service Manual

power relay RY5 resulting in the convection heater turning on.
Note: After the convection process, if the oven temperature is
higher than the predetermined temperature, the fan motor rotates
to cool the electronic components and the oven.

7.5. Combination Cooking

Combination cooking is achieved by operating the microwave and heater modes together during
one cooking cycle. There are three combination modes.
1. Combination (convection and microwave)
2. Combination (grill and microwave)
3. Combination (grill, convection and microwave)
The digital programmer circuit operators the power relays as shown in the figures below.
When the oven temperature reaches the predetermined temperature, the digital programmer
circuit stops supplying power to relay (RY5) resulting in the convection heater turning off. During
this time the digital programmer circuit continues to operate relay (RY1) so that microwave
activity continues at the duty cycle selected. The inverter control signal level is also maintained.
The microwave activity continues to cycle until the entire cooking program is completed.
When the oven temperature drops below the selected temperature, the digital programmer circuit
operates power relay (RY5) switching on the heater elements.
In the case of grill combination the sequence applies with the digital programmer circuit
switching power relay (RY4) to control, the grill elements.
With convection, grill and micro power combination. The grill elements and convection elements
are operated alternatively whilst the oven temperature is above the selected level.
Convection And Microwave Combination Duty Cycles
Figure 1
Convection Cooking Duty Cycles
11