Replacement Of Fixed Contact On The Opening Side; Replacement Of The Arcing Chamber; Replacement Of Insulators; Hollow Insulators With Arcing Chamber - ABB NAL Series Mounting And Operation Manual

16.2 Replacement of fixed contact on the opening side Fig.
70
Switch-disconnector in open position:
1. Unscrew the two screws 3.1 and lift up the arcing chamber
and the thermal disc 3.4 (for 630 A) while pressing the main
contact 3.5 firmly against the hollow insulator 3.8.
2. Lift up the main contact 3.5 by the arcing contacts 3.6 which
penetrate the main contact. Remove the pressure spring 3.7
and clean the top of the insulator and the hole, and blow out
the threaded holes (use eye protection).
3. Attach the new main contact in reverse order as described
above.
Demaged parts must be replaced:
– take care that the arcing contacts 3.6 are correctly placed
in the pressure spring 3.7,
– by mounting the termal disc 3.4 and the arcing chamber
3.3, the main contact 3.5 must be pressed firmly against
the hollow insulator 3.8. Attach the whole assembly by the
screws 3.1. For correct torque see Fig. 71.
Check correct position of the arcing contact and test correct
function. Grease the contact area with ISOFLEX TOPAS
NCA 52.
17.0 Replacement of the arcing chamber. Fig. 70
Follow instructions under item 16.2.

18.0 Replacement of insulators

WARNING
These operations can be carried out by
specialists only!
18.1 Hollow insulators with arcing chamber. Fig. 70
1. Unscrew 3.9 and detach the insulator.
2. Attach the new insulator to the frame by the two self-tapping
screws.
Remember to mount the piston with piston rod 3.10. For
correct torque see page 29.
Note the washer and spring washer for the screws.
18.2 Pivot side support insulator. Fig. 69
Detach the main contact with contact knives according to item
16.1 point 2.
1. Unscrew 2.5 and detach the insulator,
2. Attach the new insulator to the frame by the two self-tapping
screws 2.5,
For correct torque see page 29.
Note the washer and spring washer for the screws.
3. Attach the main contact with the contact knife to the top of
the insulator and adjust according to item 16.1, page 22.
Fig. 70 Hollow insulator complete
Fig. 71 NAL/VR 12 – 17.5 – 24 kV. Switch-disconnector. Tightening
torque for self tapping screws.
Caution!
In case of complete contact (with current knife) fixing to the
support insulator with inserts, screw tightened with 13 Nm torque
(Fig. 71) should be additionally lubricate using glue Loctite 243.
NAL/NALF/VR – Mounting and operation manual 25