Cisco Aironet 1300 Series Hardware Installation Manual page 135

Load-Dump Protection for Transportation
Vehicles
This appendix describes load-dump protection that is required for access point/bridge operation in some
transportation vehicles.
Load-Dump Protection
The access point/bridge can be installed in vehicles such as automobiles, trucks, and buses. Electronic
equipment in vehicle environments can be subjected to high-energy voltage transients where the vehicle
battery is accidentally disconnected from the alternator charging circuit. In the Society of Automotive
Engineers (SAE) standards SAE J1455 and SAE J1211, this voltage transient is referred to as a
load-dump transient, where the loading of the battery is dumped or removed from the alternator charging
circuits. The access point/bridge does not contain built-in load-dump protection.
The power injector LR2T must be used in vehicles providing DC power to the power injector.
Note
Some vehicles contain centralized electronics that are designed to suppress the load-dump transient and
prevent equipment damage. To protect the bridge in vehicles without built-in load-dump suppression,
you must install an external load-dump protection device, such as the IFM-efector EC2015 for nominal
12-VDC operation or the EC2016 for nominal 24-VDC operation. For additional information refer to the
following URLs:
http://www.ifmefector.com/ifmus/web/dsfs!EC2015.html
http://www.ifmefector.com/ifmus/web/dsfs!EC2016.html
Only trained and qualified personnel should be allowed to install, replace, or service this equipment.
Warning
Statement 1030
Warning A readily accessible two-poled disconnect device must be incorporated in the fixed wiring.
Statement 1022
OL-5048-02
Cisco Aironet 1300 Series Outdoor Access Point/Bridge Hardware Installation Guide
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