Nortel Networks 4500 Series - Manual (Page 11)

Care of fiber optic equipment 11
If you suspect damage to a fiber optic cable, either due to mishandling
or an abnormally high error rate observed in one direction, reverse the
cable pairs. If the high error rate appears in the other direction, replace
the cable.
CAUTION
Risk of equipment damage
Do not crush fiber optic cable. If fiber optic cable is in the
same tray or duct with large, heavy electrical cables, it can be
damaged by the weight of the electrical cable.
Fiber optic connector care
Before connecting them to transmission equipment, test equipment, patch
panels, or other connectors, ensure fiber optic connectors are clean. The
performance of an optical fiber connector depends on how clean the
connector and coupling are at the time of connection.
A damaged or dirty connector can damage a connector with which it is
mated. A connector must be absolutely clean before it is inserted into a
transmitter or receiver.
Never clean an optical connector that is carrying light. Optical power can
cause ignition of the cleaning material when it contacts the end of the
optical connector, destroying the connector. Typical cleaning materials, for
example, tissues saturated with alcohol, combust almost instantaneously
when exposed to optical power levels of +15 dBm or higher.
Visually inspect the connector to determine cleanliness and to determine if
it needs replacing. Any connector that has a scratch across the core, or a
scratch that appears to end in the core, must be replaced.
The proper connector cleaning method depends on the connector
contaminants:
• Cleanliness is best judged by visual inspection with a fiber microscope.
First inspect the connector, then clean as required.
WARNING
Risk of eye injury
When inspecting a connector, ensure that light sources are
off. The light source used in fiber optic cables can damage
your eyes.
• If you suspect only the possibility of dust particles (for example, which
can occur when a connector is left uncapped in a clean environment),
use high-quality canned air or a reel ceaner (for example, a Cletop) to
Nortel Ethernet Routing Switch 4500 Series
Installation — SFPs and XFPs
NN47205-301 02.01
20 October 2008
Copyright © 2007-2008 Nortel Networks
.