Erection; Maintenance - ABB OJON Installation And Operating Manual

Interlocking coils
The interlocking coils are available in two different
designs, one for fitting to the side of a disconnector; the
other to the front lever. The operation of the disconnector
is prevented when the magnet coil is dead. While the
voltage is disconnected the interlocking can be released
by pulling the hook (in the disconnector) or the 3 mm
screw (in the front lever) which come through the cover.
The available coil voltages are 24 VDC, 30 VDC,
48 VDC, 60 VDC, 110 VDC, 125 VDC and 220 VDC.
Power consumption is 12 W.
Locking device
The locking device is fixed to the frame of a 3-pole dis-
connector to prevent a horizontaly mounted discon-
nectors from closing through its own weight when the
eye-holed operating arm is used.
Shaft extension
The half can be provided with an extension if required.
This necessitates normally also 1-2 bearing supports.

1.4 Erection

The disconnectors must be firmly fixed on a level base.
Care should be taken in tightening not to twist the frame
e.g. due to uneven base. Unnecessarily high torques
must be avoided in connecting the busbars as these
may turn the contacts and insulators. In order to main-
tain the given short-circuit strenghts, the distance of the
nearest support insulator from the disconnector must
not exceed the corresponding figure specified (normaly
appr. 3 x phase distance).
During the fixing of the interlocking coil, the free move-
ment of the magnet core must be checked in exterme
positions of the disconnecting switch.
The shaft extensions, if used, is fixed by 8 mm spring
cotter pins, for which two 8 mm holes have to be drilled
through the operating shaft the hole outlines in the sleeve
of the extension. The shaft extension is cut to the right
length at the site. The bearing supports are normally
positioned next to the controlling lever.
2

1.5 Maintenance

The contact grease of disconnectors with lower rated
currents (630...1600 A) should be renewed at about
two years intervals. Grease type "Retinax A" is recom-
mended.
The contacts of disconnectors with higher rated currents
(2500 A and 4000 A) are greased by a special paraffin
type OJDZ 60 and normally no greasing is required during
service. If the friction during opening is higher than
normal the contacts may be rubbed using a grease bar
OJDZ 60. Other grease qualities may cause contacts
sticking fast. The wrong grease shall be washed out by
a suitable solvent.