Simplified Testing Method - Sharp KSH-777DW Service Manual

In case satisfactory cooking of rice is not accomplished (excessively overdone), conduct the temperature test in accordance
with the following procedure.
Simplified Testing Method (Simulated Rice-Cooking)
1. Testing conditions
a. Power voltage 120V.
b. Fill inner bowl with 500 ml of water (Water temperature to be the same as ambient temperature.)
c. Ambient temperature to be 20˚C to 30˚C.
d. RICE COOKER to be sufficiently kept cooled (Cooker body temperature to be the same as ambient temperature.)
2. Testing procedure
a. Fill the inner bowl with 500 ml of water, turn ON the cooking switch (for cooking purpose) to energize the cooker,
and measure the time for cooking.
b. When steam comes out, open the lid and check the bubbling state on the bottom of inner bowl. (Check if the inner
bowl is allowed to be in close and stable contact with the heating plate.
Conduct checking within a short period of time so as not to influence be over the operating time.)
c. Where the bubbling state is satisfactorily, close the lid again and energize the cooker.
3. Judgement criteria
During the course of the simulated cooking with water conducted under the conditions as above, the rice cooker, if
meeting the following requirements, will be considered acceptable.
a. If the bubbling state is such that bubbles occur evenly around the
bottom of inner bowl as shown in Fig. S-1(A), the inner bowl is
satisfactorily in contact with the heating plate.
Where bubbles do not occur more than 1/3 of the bottom periphery as
shown in Figure S-1(B), contaminant deposits on the heating plate or
deformation or damage on the inner bowl may be existing.
(Though such contaminant deposits can be removed by cleaning, the
inner bowl deformed to the extent hardly rectified should be replaced
with new one.
The same applies to the heating plate deformed.)
b. When the lid is opened immediately after the cooking switch is turned OFF, no water should remain in the inner bowl,
or only a small amount of water (approximately 20 cc) is to remain in the recess around the outer periphery
of the bottom face of the inner bowl.
c. Turn ON the power supply, and ensure that the time required for the cooking switch to be turned OFF is approx. 20
minutes.
NOTE: As this test is nothing but a simplified procedure, it should be noted that operating time varies depending
on different conditions such as difference between water temperature and ambient temperature, variations
in the quantity of water, etc.
Where any delicate non-conformance such as the operating time being slightly higher than approx. 20
minutes is observed as a result of the test.
It is recommended to conduct practical rice-cooking test.
Practical Rice-Cooking Test
1. Testing conditions
a. Power voltage 120V.
b. Cooking 10 - 24 cups of rice.
c. Ambient temperature to be 20˚C to 30˚C
d. Water to be maintained at standard level on the level gauge. Based on how to use (See page 3)
2. Judgement criteria
a. Indicator light and switch will turn as follows.
Cook indicator light goes ON.
Cooking switch goes OFF (after 30 - 45 minutes). Based on cooking chart. (See page 4)
b. Check the rice layer on the bowl bottom for the overdone degree.
Light overdone layer: Normal.
Heavy overdone layer: Replace thermostat.

SIMPLIFIED TESTING METHOD

9
Bowl Bottom
Bubbles
Good State of Bubbling Poor state of Bubbling
(A)
Fig. S-1
KSH-777DW
(B)