On Jul 19, 12:36 pm, "Leonard Caillouet" wrote:
He consistently ignores the fact that clamping does not assume that
ground is always the lowest potential, nor that clamping does not
necessarily require earthing to be effective. MOVs just dump
current when their clamping voltage is exceeded. They require a
voltage difference, not an earth ground. Earthing is important, but
it is not the whole story. He simply does not tell the whole story and
ignores a great deal of context.

If better earthing is not provided, then where does a surge current
go? Clamping (shunting, connecting, bonding, diverting) a surge
current to single point ground is the purpose of a shunt mode
protector. If that earth ground is not sufficient, how do we avoid
future failure? We improve earthing.

Same was the solution to Orange County facilities in FL. They did
not install plug-in protectors. They needed the problem solved. That
means upgrading the earthing so that protectors shunt (clamp) surge
current to earth:
http://www.psihq.com/AllCopper.htm

Why does the telco also not use those plug-in protectors? They also
know what provides the protection. Telcos are fanatical about
shunting surges through properly earthed protectors. Repeat damage
means that earthing system gets immediate attention. They don't waste
money on an ineffective plug-in solution.

An MOV shunts surge currents when voltage to earth is exceeded - as
posted. If that earthing connection is too long or if earthing is not
sufficient, then surge currents will find other destructive paths.
Just another reason why those without surge damage installed or
upgraded the earthing system - to make the protector even better.
Surges earthed where wires enter the building. It is standard
procedure in every professionally installed solution.

Did I discuss other details? Of course not. Those details are not
relevant to this topic - residential electrical protection. But we
know some of the most expensive solutions that don't even claim to
earth destructive surges are plug-in (point of use) products promoted
by Bud.

Bud routinely forgets to mention other facts. It is no accident
that the very first point in Martzloff's conclusions in his 1996 paper
said:
Conclusion:
1) Quantitative measurements in the Upside-Down house clearly
show objectionable difference in reference voltages. These occur
even when or perhaps because, surge protective devices are
present at the point of connection of appliances.

Do we install $25 and $100 protectors on dishwasher, bugler alarm,
smoke detector, furnace, and bathroom GFCIs? These are even more
important than a TV - essential to human life. What protects them?
Bud recommends more plug-in protectors. So much money and so little
protection - that cannot be installed on so many human safety
devices. Instead we earth one 'whole house' protector for everything
- even AC powered telephone appliances (answering machine, portable
phone base station, etc). And if it is not good enough, we enhance
the earthing. Massively superior protection for tens of times less
money.

If earth ground is not sufficient, do we spend $25 or $100 for
everything - or fix the earthing? A surge that does not enter the
house will not overwhelm protection even found standard in TVs. Much
less expensive solution that even works for two wire receptacle
(pre-1960 wired) homes.