Installation guide

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Cisco ONS 15530 Hardware Installation Guide
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Chapter 3 Connecting the Cisco ONS 15530
Cleaning the Shelf and Connectors
Cleaning the Shelf and Connectors
If the cleaning process must be done while the system is running, be aware that the airflow system is in
operation. Be careful of the following:
• Do not touch the airflow system while fans are operating.
• Do not use wet tissues for cleaning the chassis.
• Do not use any harsh or abrasive cleaning agents.
Warning Invisible laser radiation may be emitted from the end of the fiber or connector. Do not stare into the
beam or view directly with optical instruments.
Fiber optic connectors are used to connect two fibers together. When these connectors are used in a
communication system, proper connection becomes a critical factor. Fiber optic cable connectors can be
damaged by improper cleaning and connection procedures. Dirty or damaged fiber optic connectors can
result in not repeatable or inaccurate communication.
Fiber optic connectors differ from electrical or microwave connectors. In a fiber optic system, light is
transmitted through an extremely small fiber core. Because fiber cores are often 62.5 microns or less in
diameter, and dust particles range from a tenth of a micron to several microns in diameter, dust and any
contamination at the end of the fiber core can degrade the performance of the connector interface where
the two cores meet. Therefore, the connector must be precisely aligned and the connector interface must
be absolutely free of trapped foreign material.
Connector, or insertion, loss is a critical performance characteristic of a fiber optic connector. Return
loss is also an important factor. It specifies the amount of reflected light; the lower the reflection the
better the connection. The best physical contact connectors have return losses better than –40 dB,
although –20 to –30 dB is more common.
The connection quality depends on two factors: 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 cover installed when not in use.
Before installing any type of cable or connector, refer to Cisco ONS 15530 Cleaning Procedures for
Fiber Optic Connections.
When cleaning fiber components, procedures must be followed precisely and carefully with the goal of
eliminating any dust or contamination. A clean component connects properly; a dirty component may transfer
contamination to the connector, or it may even damage the optical contacts. Inspecting, cleaning, and
re-inspecting are critical steps that must be done before making any fiber connection.
As a general rule, whenever there is a significant, unexplained loss of light, clean the connectors.
Caution Use extreme care when removing or installing connectors so you do not damage the connector housing
or scratch the end-face surface of the fiber. Always install filler modules on unused or disconnected
components to prevent contamination. Always clean fiber connectors before installing them.