Define nominal voltage to ground in defining working cl

[d-decherd]

What is meant by nominal voltage to ground? is it the phase to phase voltage 2400 or 4160 or 13,800 or is it the phase to ground voltage?1,385V, 2402V, 7,968V?
This makes a large difference in clearance requirements and I get different answers when it is discussed.

 

[rbalex]

Re: Define nominal voltage to ground in defining working cl

Both Voltage, Nominal and Voltage to Ground are defined terms in Article 100

[ April 01, 2005, 04:52 PM: Message edited by: rbalex ]

 

[d-decherd]

Re: Define nominal voltage to ground in defining working cl

I just read art 100. I am applying it to Table 100.34(A) minimum depth of clear working space at electrical equipment.

If I have a 4160 VAC phase to phase and a 2402 phase to ground (4160/2402 wye)which clearance applies? 601-2500 ( Phase to neutral) or 2501-9,000 (phase to phase)?

 

[rbalex]

Re: Define nominal voltage to ground in defining working cl

Making the possibly wild assumption that you have described a grounded neutral, line 1 (601-2500V) applies.

 

[charlie b]

Re: Define nominal voltage to ground in defining working cl

I agree. It's the "2402 volt" figure that you use to determine the clearance requirements.