480v ungrounded delta service

[bob52]

My company has been hired to replace a 3000a switchboard at an old paper mill. The gear is fed from a company owned delta/delta transformer. currently it appears there is no grounding or bonding done any where in the plant. Per article 250.30 (B) we are to size the egc per 250.66,my question is where does this conductor get run to, are we required to run to the water main? Are there any other issues with this service we must consider such as fault indicators? We are working on the 2014 issue of the NEC. This is not something anyone around here has seen before , so any help would be greatly appreciated

 

[iwire]

Everything you do for a grounded SDS is required for an ungrounded service except for the main bonding jumper.

I say SDS as this does not sound like a service due the customer owned transformer.

Don't forget ground fault indication may be needed.

 

[bob52]

where do I find out weather or not that is required?

Everything you do for a grounded SDS is required for an ungrounded service except for the main bonding jumper.

I say SDS as this does not sound like a service due the customer owned transformer.

Don't forget ground fault indication may be needed.

 

[jumper]

I would look at 250.21(B).

 

[bob52]

Thanks for all you help