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an applicable NEBS test in the Telco world



Title: an applicable NEBS test in the Telco world

As we discussed at the cable discharge Adhoc in Portland,
I just wanted to let everyone know of a similar test that NEBS (Network Equipment Building Systems)
has which tests the immunity of a telco port to a lightning surge.

The pulses applied to the port remind me of what happens during a cable discharge on ethernet.
Perhaps we can use some or all of the NEBS test.
Unfortunately I cannot send out the pdf file for this spec, since it is sold by Telcordia.

http://www.telcordia.com/

The specific spec is called GR-1089-CORE.
The spec tests ports by applying a certain set of pulses from dedicated test equipment.
The equipment under test is expected to fully recover after each test is complete.

The pulse shape is defined in Appendix A in the spec, it is applied to the TX pair and then the RX pair.
It is a unipolar pulse with a certain 10% to 90% rise time, and then a longer 100% to 50% fall time.
The pulse height, rise time and fall time are all controlled for each test.
The driving impedance is not specified but the fixture simulates a wiring plant.

The test section that applies to intrabuilding installations is 4.5.9.
In this section there are 4 tests with one pulse each:
pulse height: +800V,            rise time 2us,  fall time 10us
pulse height: -800V,            rise time 2us,  fall time 10us
pulse height: +1500V,           rise time 2us,  fall time 10us
pulse height: -1500V,           rise time 2us,  fall time 10us

There are more stringent tests with voltages up to 2500 and 5000.
Perhaps we can use some of the knowledge here for UTP cable plants in the telco environment?

thanks,
- Rick