GE SCB2000, SCB2001, Technical Service Manual

Page: 23 / 64

– 21 –
Thermal Compensation Test
To better understand this operation, you can
perform the following test (only if the oven cavity is
at room temperature). Remove the pan from the
oven so you can see both the upper and lower
halogen lamps. Select “Speedcook, Meats,
Hamburger, 1/2 inch thick, 1-2 patties.” The
following will show in the display:
GEA00426
OVEN LOCKED SELECT MUTE TIMER
ADJUST TIME or START
3:00 U=10 L=10 M=10
Notice that the display shows power levels of 10
for each cooking component. During this test, you
will be operating the oven with no load. For this
reason, it will be necessary to adjust the
microwave power level to zero (M=00). To do
this, press the power level button on the control
panel. Leave the upper and lower power levels at
10 (U=10, L=10), and adjust the microwave to
zero (M=00).
GEA00427
OVEN LOCKED SELECT MUTE TIMER
Press START to run
3:00 U=10 L=10 M=00
NOTE: Set Microwave to Zero (M=00)
Start the speedcook operation and carefully notice
the cycling of the halogen lamps. At power levels
of 10, both the upper halogen lamp pair and the
lower halogen lamp should be on 100% of the
time. However, remember that the upper rear
halogen lamp always cycles at 85% of the upper
halogen power level setting, so you will be able to
see the upper rear halogen lamp cycle off briefly
(see “UPPER HALOGEN LAMP BALANCE” for
additional information).
With approximately 1 minute remaining, the oven
will stop and you will be instructed to turn over the
food. Briefly open the door and close it, and then
touch START to resume the remainder of the
cooking time. At the end of the cooking cycle,
repeat the steps above using the same
hamburger selection (remember to once again
set the microwave power level to zero (M=00)).
Once again pay attention to the halogen lamp
cycling. Since the oven is now hot, you should be
able to visually see thermal compensation
occurring. You will notice that both the upper and
lower halogen lamp power levels have been
decreased by some amount.
What is important to note is that while the power
levels have been reduced (thermal compensation),
the power levels which will show in the display (if
you touch the power level pad while speedcooking
operation is occurring) will be the original power
levels (U=10, L=10, and M=00).
From a consumer’s point of view, if the consumer
were to cook two hamburger patties, and then
immediately cook two more patties, they could
notice the halogen lamps cycling differently with
the same selection used each time. This is
perfectly normal when thermal compensation
occurs. The consumer’s Owner’s Manual states
the following:
Page 21 - Lights
“The halogen lights will dim and cycle on and off
during a speedcook cycle, sometimes even at full
power levels. This is normal. The oven senses the
heat level and adjusts automatically.”
Page 38 - Troubleshooting, Lights
“Light during a speedcook cycle dims and cycles
on and off, even at full power levels. This is normal.
Power level has been automatically reduced
because the oven is hot. The oven senses the
heat level and adjusts automatically.”
Thermal Protection
If oven cavity temperatures reach somewhere in
the range of 500°F to 600°F, or if a speedcooking
selection is chosen which exceeds 12 minutes of
cooking at halogen lamp power levels (upper and
lower) greater than 7, all power levels (upper,
lower, and microwave) will be reduced to 7 for the
remainder of the speedcooking selection. This
system allows for safe exterior operating
temperatures.
In the unlikely event that thermal protection is
required, the consumer will not notice any change
in the display readout (no power level change
indication); however, they may notice that the
halogen lamps are cycling differently than
expected, due to the change in power levels.
GEA00428