Switch Operating Temperature

[danieldiaz]

Can someone help understand whether the Cisco environmental specification "operating temperature" refer to the internal system temperature or the ambient temperature? If it refers to internal temperature, can anyone refer me to a document that indicates recommended ambient temperature.

[jasonrandolph]

Internal temperature.

This would vary depending on switch model and is listed in the technical specs document of each model.

[danieldiaz]

The confusing part is that I have found "operating temperature" for a 3750 from 30-113F, while the the install guide indicates the same range for the "ambient temperature". So if the ambient temperature is 113F, how could a switch stay at 113F operating temperature internally? Typically electronics run much hotter internally than externally. Im hoping to find clearer documentation.

[jasonrandolph]

Well, ambient temperature refers to the outside temperature.

In this case it looks as if they use that interchangeably to state that the equipment is rated to function normally until ambient temperature crosses the upper or lower threshold.

However most Cisco devices I have encountered are able to operate for a short period of time above or below the range as long as the critical internal temperature isn't exceeded. Which would be based upon device load, airflow, etc.

Then again, the temperature may not be rated at the chip or heatsink level, and may be an indication of rate of cooling vs general internal chassis temp.

[danieldiaz]

Thank you.