Megger MIT30, Инструкция по эксплуатации

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M
AVTMMIT30-EN Rev E02 June 2009
30
sources with voltages between 110 VDC and 350
VDC can be used.
The input power is fed through 3.15A ceramic-
body fuses and the mains switch to a 24 VDC
power supply. The power supply output is directly
fed to the control PCB where it is also converted
to +15 VDC and +5 VDC. All power bussing is
done on the control PCB.
When high voltage is desired, the green front
panel button is activated. If the zero-start and
cable interlocks are satisfied and the over current
sensor is not tripped, a relay on the control board
enables the high voltage power supply and opens
the discharge switch. If the cable interlock or the
over current sensor is activated during operation,
the high voltage power supply is immediately
disabled and the discharge switch is closed. The
discharge switch is ballasted with a 33 M
Ω
resistor.
As mentioned above, the MIT30 indicates
voltage, current and has an audible ionization
indicator. Voltage measurement is accomplished
through a highly protected, 2 G
Ω input
impedance circuit. The current is measured across
a heavily protected 1 k
Ω shunt. Ionization is
detected by filtering the output voltage through a
series of filters, the output of which is fed to an
audio amplifier.