Operation; Instrument Controls - Megger BM11D Manual Del Usuario

Operation

INSTRUMENT CONTROLS

On/Off Button.
Pressing the On/Off button starts the instrument and initiates a
self check and calibration. All LCD segments appear for 5
seconds, then the word 'CAL' appears for about 5 seconds.
When the word 'CAL' disappears, the instrument is ready for
use, and is in standby mode. To switch the instrument off, press
the on/off button once. (Auto switch off will occur after 10
minutes of non-use).
Selector Keys
The test voltage is selected by moving the cursor. When the
test button is pressed the instrument will operate at the voltage
indicated.
BM21: In addition to the fixed test voltages the cursor can be
used to select the variable voltage and test duration positions.
Range Keys (BM21 only)
The range keys have two purposes. The first purpose is to
select the measuring range, whether insulation resistance,
leakage current or burn mode. The second function is indicated
by two arrows which appear above the keys when either the
variable voltage or test duration positions are selected. Using
the range keys in this mode will raise and lower the applicable
parameter. The change in voltage is shown at the top of the
display, and the change in test duration is indicated in the
bottom left hand corner of the display.
Test Button
Pressing the large 'TEST' button for more than one second will
initiate a test at the selected voltage, simultaneously starting
the timer. Pressing the button again will terminate the test and
connect the internal discharge resistors across the output.
If more than 50 V exists across the terminals, this will be
indicated on the display. If the current flowing into the terminals
7
exceeds 2 mA it will not be possible to start a test.
A test may be terminated if;
1) The test time is exceeded.
2) The insulation under test suffers a complete breakdown.
3) The battery becomes exhausted.
4) Excessive electrical interference (>2mA at 5 kV) (BM21 only).
Battery Symbol
When the battery is fully charged, all segments of the battery
symbol will be indicated. As the battery is used the segments
will recede. The symbol flashes when the battery capacity is
excessively low (See 'Battery').
Cursor
The cursors on either side of the display indicate the ranges
selected.
Condition and Warning Indication
Factors which may affect or inhibit a test are indicated by a
large flashing cursor next to the appropriate warning label.
(See 'Condition and Warning Indicators').
FS1: Mains input fuse.
FS2: Guard fuse.
12 V Charger input
The rechargeable batteries within the instrument can be
charged from a 12 V supply. Connection is made through this
socket. – +
Mains socket
To recharge the internal batteries a mains input of 95-265 V a.c.
(50/60Hz) is required. The socket accepts a "Euro" plug.