- 2 -
1-2 Special Servicing Precautions (Continued)
16. Always connect a test instrument's ground
lead to the instrument chassis ground before
connecting the positive lead; always remove
the instrument's ground lead last.
17. When checking the continuity of the witches
or transformer, always make sure that the
power is
OFF
, and one of the lead wires is
disconnected.
18. Components that are critical for safety are
indicated in the circuit diagram by
shading,
or
.
1-3 Special High Voltage Precautions
1.
High Voltage Warning !
Do not attempt to measure any of the high
voltages --this includes the filament voltage
of the magnetron. High voltage is present
during any cook cycle.
Before touching any components or wiring,
always unplug the oven and discharge the
high voltage capacitor (See Figure 1-1)
2. The high-voltage capacitor remains charged
about 30 seconds after disconnection. Short
the negative terminal of the high-voltage
capacitor to the oven chassis. (Use a
screwdriver.)
3. High voltage is maintained within specified
limits by close-tolerance, safety-related
components and adjustments. If the high
voltage exceeds the specified limits, check
each of the special components.
PRECAUTION
There exists HIGH VOLTAGE ELECTRICITY
with high current capabilities in the circuits of the
HIGH VOLTAGE TRANSFORMER secondary
and filament terminals. It is extremely dangerous
to work on or near these circuits with the oven
energized.
DO NOT measure the voltage in the high voltage
circuit including filament voltage of magnetron.
PRECAUTION
Never touch any circuit wiring with your hand
nor with insulated tool during operation.
PRECAUTION
Servicemen should remove their watches
whenever working close to or replacing the
magnetron.
Fig. 1-1 Discharging High Voltage Capacitor
19. Use replacement components that have the
same ratings, especially for flame resistance
and dielectric strength specifications. A
replacement part that does not have the
same safety characteristics as the original
might create shock, fire or other hazards.
High Voltage Capacitor
