Cleaning The Fiber-Optic Connectors - Cisco Catalyst 4900 Series Installation Manual

Cleaning the Fiber-Optic Connectors

Connector loss, or insertion loss, is a critical performance characteristic of a
fiber-optic connector. Return loss is also an important factor. Return loss specifies
the amount of reflected light; the lower the reflection, the better the connection.
The best physical contact connectors have return losses greater than –40 dB,
although –20 to –30 dB is more common.
The connection quality depends on the type of connector and the proper cleaning
and connection techniques. Dirty fiber connectors are a common source of light
loss. Keep the connectors clean at all times, and keep the dust covers installed
when the connectors are not in use.
Before installing any type of cable or connector, use a lint-free alcohol pad from
a cleaning kit to clean the ferrule, the protective white tube around the fiber, and
the end-face surface of the fiber.
As a general rule, whenever there is a significant, unexplained loss of light, clean
the connectors.
Use extreme care when removing or installing connectors so that you do not
Caution
damage the connector housing or scratch the end-face surface of the fiber. Always
install protective covers on unused or disconnected components to prevent
contamination. Always clean fiber connectors before installing them.
To clean the optical connectors, use a CLETOP cassette cleaner (type A for SC
connectors or type B for MT-RJ connectors) and follow the product directions. If
a CLETOP cassette cleaner is not available, follow these steps:
Step 1 Use a lint-free tissue soaked in 99 percent pure isopropyl alcohol to gently wipe
the faceplate. Wait five seconds for the surfaces to dry, and repeat.
Step 2 Remove any residual dust from the faceplate with clean, dry, oil-free compressed
air.
Invisible laser radiation may be emitted from disconnected fibers or
Warning
connectors. Do not stare into beams or view directly with optical instruments.
Statement 1051
Catalyst 4900 Series Switch Installation Guide
4-6
Chapter 4 Transceiver Modules
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