600/1000v cable for 690V IT system

[davva]

Are you permitted to use 600/1000V grade cable on a 690V IT system that would run with earth fault for >8hrs? or should you use 1900/3300V cable?

 

[7anoter4]

I don't think the Electricity Supply Regulations in any country permit the use of this system with one phase
grounded for public supply network.
For UK see BS7430 ch. 4.3(c):
"An IT system has the source either unearthed
or earthed through a high impedance and the
exposed-conductive-parts of the installation are
connected to an electrically independent earth
electrode (see Figure 2). Attention is drawn to the
requirements of the current Electricity Supply
Regulations, which do not permit the use of this
system for public supply networks in the UK."