[Amps] Electrical Distribution Methods

[Paul Christensen]

> ##  here in Canada and the usa,  the  240 vac  is BALANCED.  In Canada + 
> usa, the
> 12.5 kv / 14.4 kv single phase  input to the is UNBALANCED.   In the event 
> of a primary
> to secondary short in the single phase xfmr, the sec needs to be grounded 
> some where
> ....hence the grounded CT on the sec.   In fact the CT on the sec is 
> looped back to the
> Grounded side of the xfmr pirmary..and done right at the xfmr.

Yes, you can.  All up and down major roadways here.  This is the root of my 
concern expressed a few days ago.  And, IMHO, it's a failed system due to 
the potential for dangerous HV primary current to flow on an exposed 
grounding conductor on a utility pole.

Where as a kid who used to use such conductors for the grounding of crystal 
sets, I had not realized at the time the potential death trap set up by the 
MGN distribution.  It's a miracle that more cases of harm are not reported 
as  kids and animals make contact with the utility pole grounding conductor. 
Safety is wholly dependent on crew maintenance to ensure adequate 
distributed grounding of the MGN strand up and down an easement.  However, 
the problem is real.  See this link for a detailed examination of what I'm 
describing:

http://www.ecs.csun.edu/~bruno/MultiGroundedNeutralFinal_4-17-7.pdf

Note a few figures:

Fig. 2 - The MGN set up on the white/grounded conductor.
Fig. 3 - The exposed grounding conductor from the utility MGN.
Fig 10 - The original correct pole mounted wiring scheme from ca. 1926.
Fig. 13 -  The "deadly" bond that VE7RF describes.
Fig. 17 - The classic MGN structure of a split-phase residential 
transformer.
Fig. 18 - Primary HV fault can enter the home in a MGN system.
Fig 20   A proper method of bringing the primary back to ground while 
achieving safety isolation and primary-to-secondary fault protection.

Paul, W9AC