Changing The Supporting Insulator; Changing The Hollow Insulator - ABB NAL Series Mounting And Operation Manual

20.3 Changing the supporting insulator. Fig. 76
1. Disconnect the switch-disconnector.
2. Contact block with contact knives is dismounted (use span-
nergap 17).
3. The insulators are attached to the switch frame by a screw
M12 (spanner-gap 19).
The insulator is dismounted and a new insulator is fitted to
the switch frame.
4. Contact block with contact knives is fitted to the insulator
and adjusted as described in paragraph 18.1.
20.4 Changing the hollow insulator. Fig. 77
1. Disconnect the switch-disconnector.
2. The spring mechanism is dismounted from the frame.
3. All draw bars are detached from the crank arm of the opera-
ting shaft, see Fig. 73.
4. Turn the operating shaft to one side.
5. Disconnect the piston rod from the operating shaft and
piston can be taken out.
40 Nm
90 Nm
Fig. 76 Support insulator
28 NAL/NALF/VR – Mounting and operation manual
6. Undo the fixing screws on insulator.
7. The hollow insulator is attached to the frame by 4 screws
M10 (spannergap 17). New Insulator is fitted. If contact
blocks and arc extinguishing chambers are to be used again,
these must be fitted to the insulator BEFORE the insulator is
fitted to the switch frame.
8. Add spring mechanism and connect all draw bars to the
crank arms as described in paragraph 18.1.
9. The position of the insulator is checked and adjusted as de-
scribed in paragraph 18.5. (NB! A certain degree of adjust-
ment can be made by moving the hollow insulator).
15 Nm
40 Nm
Fig. 77 Hollow insulator