ABB NAL Series Mounting And Operation Manual page 22

Control of NAL knives after mounting Fig. 66-68
Due to possible differences in the straightness of the wall and
support frame, it is necessary to check the position of the main
knives on the fixed contact.
1. Switch with A-mechanism. On delivery the draw bars (1.1)
are detached,
a) test by hand that each arcing knife (1.2) moves freely in the
arc chamber (1.3),
b) pull the main contacts by hand (1.4) to open position,
see Fig. 66. Attach the draw bars to the main shaft (1.5) by
the eccentric bolt (1.6), and secure with washer and circlip.
2. Switch with K-mechanism. On delivery the draw bars are
connected.
3. Before operating the switch, check that the surfaces of the
main contacts are covered by contact grease in the contact
area. The grease type Isoflex Topas NCA 52 must be used if
additional grease is required.
4. Close the switch by operating the mechanism. Check the
engagement and the contact overlap. All four contact points
on the main contacts must be in touch with the fixed con-
tacts. The depth between the fixed and the moving contacts
must be adjusted by the eccentric bolt (see Fig. 67) if the
moving contact is outside the limit of 4 mm! See Fig. 68.
Fig. 66 Control of NAL knives after mounting
22 NAL/NALF – Mounting and operation manual
Fig. 67 Adjustment of eccentric bolt