[TowerTalk] Shack wiring

[Paul Christensen]

> Something we have to remember that is often taken for gospel and that is
> the whole house rising to a given voltage together, which isn't quite
> true as it's phrased and isn't true at all in some older homes.

Take a look at the Cutler-Hammer product description, and Figures 4-1 and 
4-2.

http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=56325

The product brochure even goes on to state that IEEE recommends two-stage 
(secondary MOV) protection at outlets in addition to a whole-house TVSS 
unit.  My own home uses a whole-house device at the service panel as well as 
secondary protection devices in the shack (Leviton Hospital-Grade 
receptacles with integrated MOVs).

What's confusing is to hear that placement of the secondary protection at 
receptacles will cause an asymmetrical rise of the ground potential between 
branch circuit grounds.   I get the theory of that concept but is that what 
really occurs during most surge events?  I cannot imagine the IEEE and 
respected commercial vendors like Leviton, Hubbell, Square-D, Cutler-Hammer, 
etc. -- all recommending a practice that's counter-productive, even if that 
practice helps them sell more product.

Paul, W9AC