Cisco CAB-SS-449MT= Data Sheet
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DATA SHEET
SURGE PROTECTION CABLES FOR SMART SERIAL INTERFACES
Surge events, including ElectroStatic Discharge (ESD) and lightning surges, are common in many parts of the world,
especially during electrical storms. These energy surges can damage electrical equipment and lead to network down time.
Cisco surge protection cables for Smart Serial interfaces help protect your network from down-time due to these surge
events. If you protect your router from surges via the power input (surge protectors, Uninterruptible Power Supplies, or
power conditioners), you should also protect your router serial interfaces.
Figure 1. CAB-SS-SURGE Surge Protection Cable
HOW SURGE EVENTS HAPPEN
In a normal equipment environment there are reasonable threats from Electrostatic Discharge (ESD) and lightning transients which can cause loss of
data integrity and permanent damage to equipment if not controlled.
ESD threats are generated by personnel movement, which causes triboelectric (rubbing causing a separation of charge) charges to accumulate on
equipment or clothing and then be discharged through hand or tool “touch”. This discharge can represent several thousand volts at 10 to 30 amps of
current. There are two primary threats from an ESD event. These are the peak current of the discharge and the resulting electromagnetic field. Should
the input to the device not be protected from this ESD threat, as little as 100 milli-Joules can cause permanent failure to an input device at the silicon
die level.
Lightning also can create a large disturbance and delivery destructive energy to the equipment. These lightning events cause differential voltages to
develop as a result of inductance in the protective earth ground path to the equipment. During a direct lightning strike it is possible to measure peak
currents into the Kilo Amp range. These events can occur both at the facility as well as outside the facility along utility power lines. When they occur
on the power line outside of the facility peak currents can be extended in time due to the additional inductance of the power line. A normal event may
be 10 usec zero to peak, with a decay of 200 usec. These currents are called longitudinal. The Cisco surge protection cable will adequately prevent
this transient damage from occurring to within the industry standards for lightning protection devices. A good equipment chassis protective ground is
strongly recommended to assure adequate protection.
EFT disturbances occur as a result of arcing contacts in electro-mechanical switches and relays commonly found in an industrial environment. The
electro-mechanical switches are used to connect and disconnect inductive loads. Like ESD, EFT can be especially fatal on data and I/O lines. The
fast rise time of the EFT pulses demand similar protection as ESD pulses.