ABB OJON, Installation And Operating Manual

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.

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.