Operation - Megger AVOMETER 8 Mk7 Guia Del Usuario

CAUTION:
TESTING CURRENT TRANSFORMERS
It is undesirable to use a fuse protected meter for
testing current transformers (CTs). A fuse rupture
would cause an open circuit on the CT which
could give rise to a safety hazard by producing a
high voltage situation.
G
WARNING
1. Before and after making a measurement,
check that the instrument's 10 A fuse is
intact by selecting the 'x 1 Ω' resistance
range and performing a continuity test
with the leads shorted together.
2. Ensure that when measuring voltages the
instrument is not switched to any of the
current or resistance ranges.
3. Use extreme care when measuring voltages
above 50 V.
4. Avoid connecting the test leads to a 'live'
circuit whenever possible.
5. When making current measurements ensure
that the circuit is not 'live' before opening it
in order to connect the test leads.
6

OPERATION

6. Before making resistance measurements
ensure that the circuitry is completely
de-energized.
7. Do not leave the instrument exposed to direct
heat from the sun for long periods.
Instruments used in dusty atmospheres should
be stripped and cleaned periodically.
8. Ensure that the test leads are in good
condition with no damage to the insulation.
9. Do not switch off by rotating either of the
range selection knobs to a blank position.
10. Special care must be taken when using the
instrument to service television receivers or
other apparatus employing capacitors or large
capacitance, for the inclusion of such
components in a circuit may mean that very
heavy peak currents may flow when the
apparatus is switched on. Such surges
produce a peak wave form and although
these peaks are only of a few milli-seconds
duration, they may, never-the-less, damage
the instrument diodes.
11. The AVO Model 8mk7 is fitted with a 1 A
®
and a 10 A HIGH BREAKING CAPACITY