Mounting Of Fuse Base; The Switch Must Be Open And The Main Springs Not Charged; Mounting Of The Fuse Tripping; Adjustment Of The Fuse Tripping - ABB NAL Series Mounting And Operation Manual

6.0 Mounting of fuse base

6.1 The switch must be open and the main springs not
charged
When mounting a fuse base with three post insulators, one set
of fuse contacts and possibly fuse trip accessories are mounted
directly on the switch terminals, see Fig. 26 or 27.
6.2 Mounting of the fuse tripping. Fig. 30
1. Lower part of bearing (8) is fixed to terminal (10) by one
screw (9).
2. The lever (13) together with the fuse trip flap (15) are placed
in the lower bearing (8) and locked by means of upper part of
bearing (14).
3. The released rod (11) is mounted in the lever (13).
4. The drive ring (2) is mounted to the release shaft (1) on the RHS.
5. The bearing (5) and washer (6) is mounted on the release shaft
(1) on the LHS and secured by split-pin (7).
6. Disc (3) is mounted to the release shaft (4) of the mechanism.
7. The release rods (11) are mounted onto the hooks (12) on the
release shaft (1).
Fig. 26 Switch-disconnector type NALF mounted on the pivot side
10 NAL/NALF – Mounting and operation manual
6.3 Adjustment of the fuse tripping. Fig. 30.
– the adjustment applies to switch disconnectors with fuse links
and fuse tripping,
– the adjustment must be made with both operating springs in the
mechanism in uncharged position, but the releasing spring in
the mechanism has to be charged as mentioned under control
point 6.4 point 1.
1. The split pin (7) is removed and the release shaft (1) together
with the drive ring (2) is pushed in the direction of the arrow
until the tapped connection is free from disc (3).
2. The release rod (1) with the drive ring (2) is turned and ajusted
to a hole in the disc (3), while the ajustment of the fuse trip flap
(15) and its distance to the strike pin of the fuse link must be
checked, see Fig. 28.
Remark:
– Following adjustment according to above the fuse switch di-
sconnector must open by when tested in all phases,
Fig. 27 Switch-disconnector type NALF mounted on the oppening side
E