Juniper MX240 Hardware Manual page 102

MX240 Ethernet Services Router Hardware Guide
Maintaining DPC Cables
To maintain DPCs and DPC cables, follow these guidelines:
The following guidelines apply specifically to fiber-optic cable:
Handling and Storing DPCs
This section explains how to avoid damaging the DPCs that you install into the router.
Many components on the DPC are fragile.
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Maintaining Packet Forwarding Engine Components
Use the cable management system (shown in Figure 11 on page 17) to support
cables and prevent cables from dislodging or developing stress points.
Place excess cable out of the way in the cable management system. Do not allow
fastened loops of cable to dangle from the connector or cable management
system, because this stresses the cable at the fastening point. Putting fasteners
on the loops helps to maintain their shape.
Keep the cable connections clean and free of dust and other particles, which can
cause drops in the received power level. Always inspect cables and clean them
if necessary before connecting an interface.
Label both ends of DPC cables to identify them.
When you unplug a fiber-optic cable from a DPC, always place a rubber safety
plug over the transceiver on the DPC faceplate and on the end of the cable.
Anchor fiber-optic cable to avoid stress on the connectors. When attaching fiber
to a DPC, be sure to secure the fiber so it is not supporting its own weight as it
hangs to the floor. Never let fiber-optic cable hang free from the connector.
Avoid bending fiber-optic cable beyond its bend radius. An arc smaller than a
few inches can damage the cable and cause problems that are difficult to
diagnose.
Frequent plugging and unplugging of fiber-optic cable into and out of optical
instruments can cause damage to the instruments that is expensive to repair.
Instead, attach a short fiber extension to the optical equipment. Any wear and
tear due to frequent plugging and unplugging is then absorbed by the short fiber
extension, which is easy and inexpensive to replace.
Keep fiber-optic cable connections clean. Small microdeposits of oil and dust in
the canal of the transceiver or cable connector could cause loss of light, reducing
signal power and possibly causing intermittent problems with the optical
connection.
To clean the transceivers, use an appropriate fiber-cleaning device, such as
RIFOCS Fiber Optic Adaptor Cleaning Wands (part number 946). Follow the
directions for the cleaning kit you use.
After you have cleaned the transceiver on the fiber-optic DPC interface or port,
make sure that the connector tip of the fiber-optic cable is clean. Use only an
approved alcohol-free fiber-optic cable cleaning kit, such as the Opptex Cletop-S
Fiber Cleaner. Follow the directions for the cleaning kit you use.