Geeting technical support from Cisco RE 4431

[richardb]

Can anyone help explain to me how to get technical help regarding the specification of the Cisco 4431 from Cisco Technical Support please?

I am working on a project for anew product we are designing for a customer who has specified a Cisco 4431, I need more information about this unit but Cisco technical support won't answer as we are not a customer! The fact we are never going to be unless they talk to us and they are saying goodbye to sales of hundreds of units doesn't bother them.

They are insisting I ask the question to their "partners". I have contacted 20 of these with no response so far.

My question is:

Our customer has specified a Cisco 4431 router in a product we are developing for them , but wants to use it up to an altitude of 3500m where as the Cisco specification specifies 3050 m operational and 4750 non operational. Can you clarify what is the limiting factor behind the operational altitude and what the effects of higher altitude are?

I would be very grateful if anyone could answer this question or let me know how I can get Cisco to answer the question.

Regards

Richard Brooks

[Leo Laohoo]

Richard, 

I'm going to ask the moderators to find someone from Cisco product team to "reach out" to you. 

Hang tight. 

Best Regards/Leo

[Monica Lluis]

Leo,

Thank you for letting us know about this question.

Sam,

Thank you for promptly providing the answer. We appreciate it.

Richard,

Thank you for posting in the Community. I hope this answers your question. If so, don't forget to mark the answer as "Correct Answer"

Kindest Regards,

Monica Lluis

Community Manager

[litrenta]

It is 2 fold, first the dielectric (insulating strength) of air decreases with altitude so where air gaps are part of a design from an insulation standpoint this needs to be a consideration.

Secondly as altitude increases air is less dense and does not conduct heat as well so you would need larger heat sinks or increase air flow.

China is limited to 2000 meters due to Chinese safety standard GB 4943.1-2011 requiring strict specs for creepage and clearance .

For a complete explanation take a look at:

http://power-topics.blogspot.com/2012/10/how-does-altitude-affect-ac-dc-power.html

[richardb]

Thanks for the answer.

Can I just clarify, are you stating on behalf of Cisco that 3000m is the limit and it is limited by the air gaps in the design?

Regards

[litrenta]

Not necessarily air gaps per-se cooling plays a part as well. however design specs are in conformance with UL 60950-1 operation above 3000M would be outside the safety parameters of UL 60950-1.

[richardb]

Thanks for the quick reply.

Just to ask for clarification once more:

Are you speaking as a representative of Cisco?

Are Cisco confirming the 4431 will not meet it's specification above an altitude of 3000m?

Regards

[litrenta · Accepted solution]

Correct I am speaking as a Representative of Cisco and stating that operation above the altitude stated in the datasheet is outside of the stated safety conformance of UL 60950-1. The environmental specifications in the datasheet are the definitive limits of operation from a safety and conformance standpoint.

[Leo Laohoo]

Are Cisco confirming the 4431 will not meet it's specification above an altitude of 3000m?

The only Cisco appliance, that I know of, that operates above 30km above sea level is the IRIS.

[richardb]

Thanks for the help and the clarification.

Guess we will have to start the search again for a suitable alternative from another manufacturer.

[secclest]

Hello Richard

 I am the Director of Networking (including the ISR platform) for the UKI and will email you seperately to assist,

Email to follow,

 Sarah