Replacement Of Melted Fuse Links; Investigate And Clear A Fault - ABB Uniswitch Operation And Maintenance Manual

5.5.2 Replacement of melted fuse links

5.5.2.1 Investigate and clear a fault

General
Instructions
Figure 5.1
Position indicator in
O-position
ABB
Uniswitc h Operation and
Maintenanc e Manual
The fuse links cannot be regenerated. According to IEC Publication
60282-1, all three fuse links should be replaced, even if only one or two
of the fuse links in the three-phase system have operated. Exceptions
are allowed when it can be verified that the fuse link(s) have not
experienced any overcurrent.
If the fused switch-disconnector cubicles, type SDF, are equipped with a
fuse tripping mechanism, the switch-disconnector opens automatically
by means of the striker pin(s) of the fuse link(s) and tripping mechanism.
Check that the color of fuse indicator (62.5) is red and the position
indicator (62.4) is in O-position.
Check that the interlocking selector is in the 'Operation' (2) position (see
4.3.1.2)
Put the operating handle into the hole (62.2) so that the guide key goes
into the notch on the shaft. Turn the operating handle anti-clockwise
about 80 degrees until the notch on the operating shaft is pointing
downwards.
Operate the switch-disconnector to the earthed position (see 4.3.1.3)
The upper and lower fuse holders are earthed and the fuse links can
be removed and installed by hand.
Move the interlocking selector to 'Door open' position.
Open the door.
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UNI S14GB 05-02