9.5 - Installing data cabling
Twisted-pair and optical fibre cables must
be tested before installation in accordance with the manufacturer’s
specification. Great care must be taken to avoid electrostatic
discharge damage, which can result from the charge held
by the operator, which may be due, for example, to walking
on certain types of carpet which include man-made fibres.
The chassis of the equipment on which work is intended must
be securely earthed, and an earthed wrist strap worn by
the operator.
The following lists of good and bad practices
should be followed.
|
Good practice – things to
DO
|
| Locate the main cross-connect near
the centre of the area concerned so that cable distances
are limited. |
| Always use more cable than you need.
Leave plenty of slack. |
| Each horizontal cable should be terminated
on a dedicated telecommunications outlet. |
| Ensure that cables are at a sufficient
distance from equipment that may generate heat or electromagnetic
interference. |
| Maintain the twist of all cable pairs
right up to the point of termination. |
| Label both ends of each cable. |
| Use connecting hardware that is compatible
with the installed cable. |
| Tie and dress cables neatly with
a minimum bending radius of four times the cable diameter. |
| Test each part of the network as
it is installed. |
| All metallic conduit or trunking
must be earthed. |
|
Bad practice – things to
AVOID
|
| Do not allow cable lengths to exceed
the allowable maximum. |
| Do not create multiple appearances
of the same cable at several distribution points (bridge
taps). |
| Do not leave wire pairs untwisted. |
| Do not over-tighten cable ties, do
not use staples and do not bend cables sharply. |
| Do not use connecting hardware that
is of a lower category than the cable being used. |
| Do not join cables to increase their
length – replace with a longer cable. |
| Do not secure cables so that there
is stress on the terminations. |
| Limit cable bundles to 50 cables
to avoid crushing the lower cables. |
| Prevent kinks occurring in cables
during pulling. |
| Do not use undue strain when cable
pulling. |
| When cable routes pass through walls,
the hole should be suitably sleeved and cables should
enter and leave the hole at 90o to the wall. |
| Make sure that the network is thoroughly
tested on completion. |
|