Measurement Of Microwave Power Output; Disassembly And Adjustment - LG RCS10A Service Manual

MEASUREMENT OF MICROWAVE POWER OUTPUT

• Microwave power output measurement is made with
the microwave oven supplied at its rated voltage and
operated at its maximum microwave power setting with
a load of (1000±5) g of potable water.
• The water is contained in a cylindrical borosilicate glass
vessel having a maximum material thickness of 3 mm
and an outside diameter of approximately 190mm.
• The oven and the empty vessel are at ambient
temperature prior to the start of the test.
• The initial temperature (T1) of the water is (10±2)°C It
is measured immediately before the water is added to
the vessel. After addition of the water to the vessel,
the load is immediately placed on the center of the
ceramic plate which is in the lowest position and the
microwave power switched on.
• The time T for the temperature of the water to rise by a
value ∆ T of (10±2)°K is measured, where T is the time
in seconds and ∆T is the temperature rise. The initial
and final water temperatures are selected so that the
maximum difference between the final water
temperature and the ambient temperature is 5°K.

DISASSEMBLY AND ADJUSTMENT

A. OUTER CASE REMOVAL
1) Disconnect the power supply cord from the outlet.
2) Remove the screws from the rear of the case.
The outer case must be moved backward to be lifted
off.
B. POWER SUPPLY CORD
1) Remove the outer case.
2) Disconnect two terminals, and remove one screw of
the ground terminal.
C. CONTROL PANEL ASSEMBLY RMOVAL
1) Open the door.
2) Remove the screw for securing the control panel.
3) Disconnect the leadwire from RELAY (RY3)
of the PCB SUB ASS'Y.
4) Disconnect the leadwire from connector (CN1) of the
PCB SUB ASS'Y.
5) Lift up and pull out control panel assembly carefully
from the cavity.
CAUTION: DISCHARGE THE HIGH VOLTAGE
CAPACITOR BEFORE SERVICING
(refer to page 2-1)
• The microwave power output P in watts is calculated
from the following formula :
4187 x (∆T)
P =
is measured while the microwave generator is
operating at full power. Magnetron filament heat-up
time is not included. (about 3 sec)
• The water is stirred to equalize temperature throughout
the vessel, prior to measuring the final water
temperature.
• Stirring devices and measuring instruments are
selected in order to minimize addition or removal of
heat.
WATER LOAD
Lift up and pull out control panel
Lift up and pull out control panel
5-3
T
CERAMIC PLATE
Remove the screw
Remove the screw
securing
screw
securing
screw
ground
screw