Poor grounding electrode???

[kwired]

On pole mounted transformers, the state of California considers any ground within reach of a lineman a signifigant hazard. Cases of tranformers, guy wires, etc. are required to be isolated from ground to reduce the possibility of incidental contact. All transformers used in California (as far as I know) are two bushing transformers. Some utilities allow "common neutrals" where the primary and secondary neutrals are tied together and grounded and some do not. This applies to overhead only.

When a separate neutral is used, the primary neutral is considered a phase.

Getting a little off the original post, but a good topic anyway.

Everywhere I have been they not only ground transformer case, but they ground guy wires, and almost every thing else non current carrying that is conductive. That way all the non current carrying items are at same potential and you know that the ungrounded conductors is all you can't touch without proper equipment. I can't recall seeing any hot work being done in recent years by a guy on the pole - they are always in bucket truck if handling anything live and have gloves, blankets, and anything else you can think of to help isolate things.

 

[hurk27]

I think we must realize that things will be different in each part of the country, and different POCO's will have different installs, like here we only have 7200v Y's for local feeds while we will have 69kv deltas feeding point of use sub stations, also our MGN is the bottom line many times with cable or phone just below it, while in Florida will have static lines above the phase lines to intercept lightning, so there are many different requirements and we just need to keep an open mind.

Also it is common to find egg insulators in the guys on poles around here.

 

[meternerd]

The industry is changing seemingly every year. Rules change, arc flash becomes the big focus, equi-potential grounding on poles is now the standard, AFCI breakers are required, etc. All are based on accidents that may have been preventable. Bottom line.....be safe and retire with all of your body parts intact!