Megger LT5 Gebrauchsanleitung Seite 10

OPERATION
After several repetitive operations the outside of the
tester case may become quite warm to the touch.
This is normal and does not mean that a fault exists.
An alternative method when many sockets in an
installation are to be tested, is to set the range switch
first and then connect to the sockets one at a time.
The action of unplugging from one socket and
plugging into the next is equivalent to switching the
instrument off and on. (The polarity of the installation
s h o u l d b e v e r i f i e d f i r s t , s i n c e w i t h t h e r a n g e
preselected, as soon as the instrument is plugged in it
will begin its test routine provided there is a correct
phase connection).
Loop Tests Using Dual Test Lead Set
Use of one of these lead sets enables any loop tests,
other than those at a socket outlet, to be performed
whether these be phase to earth or phase to neutral.
The basic procedure is as before except that the
range must be selected first and the action of
connecting and disconnecting the test prods onto a
"live' circuit switches the instrument on and off. This
convenient connection method may cause a spark as
connection is made. The spark is limited to 10 ms and
10
is therefore quite safe in ordinary environments. The
sparking can be avoided by making the circuit
connections before selecting the test range. This may
require using the optional black crocodile clip.
NOTE:—
Because a two terminal measurement is being
made, when the test leads are connected only the
'P - E' neon will illuminate, (the 'P - N' neon will
remain out). This occurs for both phase to earth
and phase to neutral tests. If the 'P-E' neon light
does not illuminate no test will be executed and a
fault in the installation wiring or a ruptured fuse in
the instrument should be suspected. The former is
the more likely, therefore switch the supply off and
investigate.
Bonded Metalwork Tests
A special safety earth bond lead is available for bonded
metalwork tests. The basic procedure is as before, but
the lead is connected as detailed on page 17.