Changing Draw Bar - ABB NAL Series Mounting And Operation Manual

2. The contact screw is detached and the contact knives are
removed, see Fig. 73.
3. Replacement contact knifes are lubricated with ISOFLEX
TOPAS NCA 52 and fited to the contact block with the con-
tact screw.
4. Check that the contact knives can move easily and operate
correctly over the opposite contacts.
5. Before the drawbar is connected to the crank arm of the
operating shaft, see Fig. 72 ensure that the auxiliary knives
run easily in the individual arc extinguishing chambers, and
that the main knives make proper contact.
6. Put contact grease on the main contacts before the first test
operation. The contact position is adjusted by the eccentric
bolt on the operating shaft. It can also be adjusted by adju-
sting the support insulator.
18.2 Changing draw bar. Fig. 74
1. Disconnect the switch disconnector.
2. Pull out the bolt b.
3. Pull down the auxiliary knife such that the drawbar bolt (a)
can be pushed out and upper hold for the drawbar is free.
4. The lower mounting for the drawbar is freed by removing
circlips on eccentric bolt, see Fig. 72.
5. New drawbar to be fitted in sequence a-b, see Fig. 74.
Fig. 73 Detached contact screw | Fig. 74 Contact knife
Fig. 73
a
26 NAL/NALF – Mounting and operation manual
Fig. 74
b