SOI 12.06 FV 38/43 599 37 42-75
MICROWAVE MEASUREMENT
After adjustment of door latch switches, monitor
switch and door are completed individually or
collectively, the following leakage test must be
performed with a survey instrument and it must be
confirmed that the result meets the requirements
of the performance standard for microwave oven.
REQUIREMENT
The safety switch must prevent microwave
radiation emission in excess of 5mW/cm2 at any
point 5 cm or more from external surface of the
oven.
PREPARATION FOR TESTING:
Before beginning the actual test for leakage,
proceed as follows;
1. Make sure that the test instrument is operating
normally as specified in its instruction booklet.
Important:
Survey instruments that comply with the
requirement for instrumentations as prescribed
by the performance standard for microwave
ovens must be used for testing.
Recommended instruments are:
NARDA 8100
NARDA 8200
HOLADAY HI 1500
SIMPSON 380M
2. Place the oven tray into the oven cavity.
3. Place the load of 275 ± 15ml of water initially at 20 ± 5°C
in the center of the oven tray. The water container should
be a low form of 600 ml beaker with inside diameter of
approx. 8.5cm and made of an electrically non-conductive
material such as glass or plastic.
The placing of this standard load in the oven is important
not only to protect the oven, but also to insure that any
leakage is measured accurately.
4. Close the door and turn the oven ON with the timer set for
several minutes. If the water begins to boil before the
survey is completed, replace it with 275ml of cool water.
5. Move the probe slowly (not faster that 2.5cm/sec.) along
the gap.
6. The microwave radiation emission should be measured at
any point of 5cm or more from the external surface of the
oven.
TEST DATA AT A GLANCE
Parts Symbol Value / Data
Fuse F1 20A / 250V
Fuse F2 F 8A
Thermal cut-out (OVEN) TC1 125°C Off
Thermal cut-out (OVEN) TC2, TC3 170°C Off / 155 °C On
Thermistor
Approx. 359.9 k
Ω - 152 kΩ at 20°C - 30°C
Grill heating element GH
Approx. 44.4
Ω (22.2 x 2) / Insulation resistance > 10 MΩ
Convection heating
element
CH
Approx. 42.5
Ω / Insulation resistance > 10 MΩ
Oven lamp OL 240-250V 25W
High voltage capacitor C 1.16µF AC 2100V
Magnetron MG
Filament < 1
Ω / Filament – chassis ∞ ohm.
Power transformer T
Filament winding < 1
Ω
Secondary winding Approx. 160 / Primary winding Approx. 2
Ω.
WARNING: DISCONNECT THE PLUG WHEN MEASURING RESISTANCE
Microwave leakage measurement at 5 cm distance
To Next Page
Loading...
