6.5 Topping up grease-filled cable boxes for
paper-insulated lead-covered cables
• When performing work on the cable box, the
relevant cable(s) must always be earthed.
• Never work on a live or partly live installation.
1. Check the cable grease level, using a lamp if
necessary.
The cable box will require to be topped up once its
grease level has dropped to a point below the cable
core clamps, due to the grease being absorbed by
the cable.
Should this be the case, the hose of the filling
device - prior to being inserted into the cable box –
must be filled completely with grease so as to
prevent the ingress of air.
2. Undo the hose clip and slide the cable box far enough
down for the nylon vent threads to be fitted.
If the sliding action is difficult due to the grease
having become too viscous, you can apply a little
heat to the cable box, using a hot air gun for
instance.
2.
Never heat the cable box with a naked flame.
3. Hang a double folded nylon thread (a) over the edge of
each opening in the cable box (b), with the ends
hanging inside.
4. Now slide the cable box completely back onto the cast
resin insulation.
5. Fit the protection covers (c) at the rear side and secure
them.
3..5.
Make sure that the clamping edge of the cable box
adequately rests on the bearing face of the
protection covers.
6. Fit the hose clamp (d) to the end of the cable box and
torque it
to 5 Nm (3.7 lbf).
7. Fill the cable box with grease (see Chapter 3.7).
6.
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