The service will be 208V, 3-phase, 4-wire.
Main service disconnect will be 100 Amp

The service entrance equipment will be located in an outdoor, weatherproof and heated enclosure. The enclosure also encloses a control system for a concrete sewage lift station with a bottom at 18 feet below grade.

One of the main considerations is that the ground freezes during the winter. I've also heard that the permafront is 1800 feet deep in places around Skagway.

Do you have any thoughts the design of a good grounding electrode system be that provides the necessary grounding (earthing) protection year round??

Thanks for your comments, your expert help is much appreciated.
Rich Thomas

I'm not sure how freezing would be a problem for the GES? Though I live and work in sunny SoCal

eight foot ground rods?

Using a concrete encased electrode would be a good bet.

The requirement for footings to be below frost depth would help out with your concerns.

Chris

Stop in the chat room one evening after 10pm EST we have a few electricians from that area.

It may be too late for this one but a Ufer in the bottom of that collection tank is probably as good as it gets.

Thanks to all those who responded.

Since posting my question I've found that the ground in Skagway doesn't freeze very deeply, so an industry standard type grounding electrode system is adequate.

However, gfretwell's idea using the wet well rebar as a ufer will be part of the system.

Thanks again,
Rich

Just to bump dmattox's question, because I'd like to know more.


My understanding is that the conductivity of soil/clay/earth depends upon the ionic conduction, where ionized atoms physically _move_, rather than metallic conductivity. If the ground freezes, then the conductivity can drop in much the same way as a GES in soil that becomes very dry. At least that is my weak understanding. I'd love to learn more on this topic.

-Jon

How about Conducrete??
http://www.saeinc.com/Conducrete

I'll give Conducrete a looksee. Thanks distributor x.

Rich