Internal wiring standards for electronic enclosure

[thinker]

Please advise: are there any standards (in US) that govern internal wiring ampacity selection and protection for electronic enclosures (like 19" rack mounted industrial PC).

 

[hendersdc]

We design rack mounted equipment to IEC/UL 60950. I am a mechanical guy so I don't know if it has exactly what you are looking for but it should be a good place to start.

Doug

 

[zappedagain]

I concur. IEC/UL 61010 for measurement equipment. 61010 is similar to 60950.

Z

 

[DRWeig]

Either of the above UL standards will get you there.

Best to you,

Goober Dave

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[thinker]

Thank you all for responses. I was able to look through UL 6010, but could not find the answer to my original question: how to size conductors inside small enclosure. I expected to find design guidelines, something similar to UL 508A Standard for Industrial Control Panels/Enclosures.

 

[zappedagain]

For mains circuitry you need to be 18 AWG or larger wire (<= 18 AWG); that is specified in NFPA 70 (NEC) somewhere.

Once you are in ELV (Extra Low Voltage -

http://en.wikipedia.org/wiki/Extra-low_voltage)

circuitry on the other side of the power supply I don't believe UL has guidelines. As long as your wire is one or two AWG lower (larger diameter) than the minimum wire diameter/max AWG to safely carry the current limited by the upstream protection it is acceptable. I vaguely recall some limits on how large the wire can be, but that probably isn't applicable here.

For higher voltages, the clearance and creepage distances also come into play.

That's all I have off the top of my head at this time of the day.

Z