600 volt insulation for neutral on medium voltage system

[ath123]

Why does the code allow 600 volt insulation on the neutral on circuits of 1kv and over?

 

[dpc]

Because on a grounded system, the voltage to ground on the neutral should be very low.

"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)

 

[wareagle]

The 2008 NEC requires the insulation to be the same as the phase conductors.

 

[dpc]

wareagle,

Are you sure that requirement applies to solidly-grounded systems?

"Theory is when you know all and nothing works. Practice is when all works and nobody knows why. In this case we have put together theory and practice: nothing works... and nobody knows why! (Albert Einstein)

 

[wareagle]

DPC
I checked and that requirement is for a system with a neutral resistance. Solidly grounded is 600 volt.