Replacing The Fuses - Megger Lt5 Gebrauchsanleitung

OPERATION
prospective short-
phase—neutral circuit current at
measurements ( ) 230 V a.c. supply (kA)
0,01 14,30
0,02 9,70
0,03 7,00
0,04 5,50
0,05 4,60
0,06 3,70
0,07 3,30
0,08 2,70
0,09 2,50
0,10 2,30
0,20 1,20
0,30 0,77
0,40 0,58
0,50 0,46
0,60 0,38
0,70 0,33
0,80 0,29
0,90 0,26
1,00 0,23
Fig. 8. Table of prospective short-circuit current
values against instrument readings.
20
supplying sub-station is nearer or further away from
the installation or when the sub-station capacity is
increased.
When very low values of phase to neutral impedance
are obtained, an average of three or four readings
should be taken.

REPLACING THE FUSES

The fuse fitted into the test lead three pin plug of UK
instruments is changed in the normal way. This fuse is
a 10 A ceramic H.B.C. fuse 25 x 6 mm (to BS 1362).
The internal 10 A ceramic H.B.C. 32 x 6 mm fuse is
fitted in the compartment under the cover on the rear of
the case. It is a 440 V high breaking capacity type, and
should never be replaced by one of lower specification.
(A spare fuse is provided in the fuse compartment.)
If a fuse ruptures then carefully carry out the following
p r o c e d u r e : —
Disconnect the instrument from any external circuit,
turn it on to its face and remove the fuse cover by
releasing the screw in the centre and lifting off.
Remove the ruptured fuse from its clips, replace with a
new one of the correct size and rating, refit, and secure
the cover.