Shielded cable requirements

[posttoasties]

It is my understanding that under NEC requirements you must use shielded cable when running above 2400V. Someone also told me that if you have a transformer that has a voltage tap above 2400V you must use shielded cable whether or not you are using the tap or not. For example if I have a transformer that has a 2000V tap and 5000V tap, they claim that I need to run shielded cable coming out of the transformer no matter which tap I am using because the transformer has at least one tap that is rated greater than 2400V. I have not been able to find any code to support this claim and was hoping someone had some information, thanks.

 

[dpc]

Sounds like an interpretation by local AHJ. I don't think this is spelled out in the NEC. They only talk about actual operating voltage.

Of course, you'd also need to provide insulation rated for the higher voltage in addition to the shield.