Condition And Warning Indicators - AVO MEGGER BM25 Guide De L'utilisateur

Operation
is allowed to discharge before touching any connections. If
necessary, switch the instrument off, and then on again to reset
the display.

Condition and Warning Indicators

FS2
Fuse (FS2) located in the charger recess protects the low
impedance guard circuit against the application of external
voltage. Guard fuse failure will be indicated on the display only
when the guard circuit is in use. To check whether the fuse has
ruptured, connect the positive terminal to the guard terminal and
start a 500 V test. If the 'FS2' display cursor flashes, the fuse has
ruptured. If the cursor flashes when the guard lead is not
connected, it indicates failure of one of the batteries or a battery
fuse (which is not externally accessible). The instrument will
operate in this condition, but the operating time between charges
will be reduced; capacitance readings will not be displayed, and
no warning will be given if the guard fuse subsequently ruptures.
BREAKDOWN
If a breakdown occurs between the test leads, the test will
terminate and the 'BREAKDOWN' cursor will flash. Selecting
'BURN' mode disables the 'BREAKDOWN' warning indicator.
EXT VOLTS
A flashing cursor below the 'EXT VOLTS' label combined with the
flashing LED on the front of the instrument, and the flashing high
voltage symbols indicates that the voltmeter is reading a
hazardous voltage which originates from an external source. The
voltmeter will show d.c. voltage of either polarity, or a.c. voltage.
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NOISE
If external interference (normally 50 Hz or 60 Hz hum current)
is excessive (>2 mA at 5 kV), testing will terminate and the
flashing cursor below the 'NOISE' label will be displayed.
LAST TEST
This cursor flashes on completion of a test in conjunction with the
repetitive sequence of final readings.
Error Numbers
Internal faults and errors will cause the display to show 'E'
followed by a number. While these error numbers are designed
to aid internal fault diagnosis, they can also be triggered by
extreme cases of electromagnetic interference. Error numbers
E5 and E11 indicate that a negative current has been measured.
Calibration Errors
At switch-on, the calibration check automatically adjusts the
measurement system against an internal voltage and resistor.
The calibration sequence will not finish unless the measurement
system is giving consistent results within preset limits. If the
startup screen does not progress beyond the segment check or
stops with 'CAL' displayed, calibration has failed.