Re: MOVs and surge suppressors

On Sep 2, 12:46 pm, craigm <n...@xxxxxxxxxxxxxx> wrote:
A MOV works by limiting the voltage between two nodes of a circuit. It does
nothing else. It does not know about 'ground' or 'earth'. Devices
connected to the nodes are protected from surges greater than the
specifications of the MOV.

A surge has energy. If voltage is limited, then where is the energy
dissipated? Do you really believe that 100 joule MOV is dissipating
energy of a direct lightning strike? That energy must be dissipated
somewhere. Where? Go back to Page 42 Figure 8. An MOV limited
voltage. Therefore protector was at 8000 volts on all wires.
Therefore protector earthed that 8000 volts destructively via adjacent
appliances (what craigm ignored) as voltage between those wires was
limited to something between 250 and 900 volts (what craigm defines as
protection). Why does craigm only post a half fact? Why does craigm
ignore where that energy was dissipated - 8000 volts destructively to
adjacent appliances because energy must be dissipated in earth.

craigm, how many protector systems have you designed and actually
seen the results? When you get to your third decade of experience,
then let me know. You are simply speculating same myths we debunked
decades ago by actually doing the work. You have even ignored the
typically destructive type of surge by assuming all surges are the
other typically non-destructive type. Your type of surge make
irrelevant by 'voltage limiting' is also made irrelevant by circuits
inside electronics.

MOV limits voltage between black, white and green wires (maybe to
500 volts). But the typically destructive surge entering on black
wire and is shunted to white and green wire is still seeking earth
ground. Its still seeking earth ground - simply has more wires to
destructively find earth. Having shunted (clamped, connected,
limited, diverted) that surge current to other wires means that surge
current stop seeking earth ground? Of course not. But that is what
you have claimed. Having shunted that surge current to other wires
means the energy need not be dissipated? Of course not. But that is
also what you have claimed.

A surge shunted from black wire to white and green wire (what you
call voltage limiting) now has many times more paths to destructively
seek earth ground via appliance. No way around that realty. If not
via one adjacent TV, then destructively via another appliance: Page
42 Figure 8. Why do you even ignore the facts demonstrated on Page 42
Figure 8? You must to keep promoting the myths.

Two facts (and there are many more): both demonstrate why your
reasoning is bogus. Why do you ignore both reasons; therefore promote
myths? A surge protector does not do as you have claimed. Shunt mode
protectors shunt surge energy to earth ground. Ineffective protector
sold as massive profits with insufficient MOVs don't even have an
earth ground. But you promoting ridiculous myths that even the
manufacturer will not claim. Why does the protector manufacturer not
make your protection claims in their numeric specs? They don't need
to. They have you even pretending that surge energy completely
disappears - need not be dissipated.

A protector without earth ground to shunt that energy into may
instead dissipate that energy into adjacent appliances - Page 42
Figure 8. No earth ground means no effective protection. No wonder
the responsible manufacturers make 'whole house' protector with that
dedicated earthing wire. They don't need you to promote myths for
them. Instead, protectors from responsible manufactures earth that
surge before it can even enter the building.

Provided is how to kludge a completely ineffective plug-in protector
into something that might earth a surge. You have no idea how a
protector works. Telco switching computers everywhere in the world
suffer surges from overhead wires all over town - and must never
suffer damage. Critical is locating the protector distant from
electronics - typically less than 50 meters. Important is for the
surge to be earthed long before getting near to electronics. Telcos
don't was money on what craigm recommends because it is ineffective -
makes damage to electronics easier.

So which one of us designed, built, and tested these solutions as an
engineer for many decades? Not you. Your have even assumed the non-
destructive type of surge is the only type of surge. A protector is
only as effective as its earth ground. Craigm denies what is well
proven where people learned science - not promote half truths. Craigm
even assumes the surge that typically does not do damage is the only
surge. Craigm completely ignores where that surge energy must be
dissipated.

.

Relevant Pages

  • Re: How to ground electric outlets over a slab?
    ... box contains a 'whole house' protector that must be earthed. ... Second function is surge protection. ... Separated from other wires. ... Only meets all other ground wires at the same earth electrode. ...
    (alt.home.repair)
  • Re: Surge protection without grounded plugs
    ... like 130 ohms impedance to the surge. ... protector attempts to earth a trivial 100 amp surge via neutral wire? ... The effective protector earths before that surge gets anywhere near ... Surge that damaged electronics seeks earth ground. ...
    (sci.electronics.basics)
  • Re: Whole house phoneline surge protection
    ... I'd have to install quite a few surge ... "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005. ... Your symptoms sound like high voltage between phone wires and the power system ground. ... Wall warts generally are more immune to voltage from phone wires to power/ground wires - might point to a phone entrance protector. ...
    (alt.home.repair)
  • Re: MOVs and surge suppressors
    ... It does not know about 'ground' or 'earth'. ... A surge has energy. ... Therefore protector was at 8000 volts on all wires. ...
    (sci.electronics.basics)
  • Re: http://h71000.www7.hp.com/?
    ... and the increased inductance wouldn't block a lightning induced surge. ... essentially an open circuit until the voltage goes past a knee in the characteristic curve, then the current rises very rapidly with increasing voltage. ... Ground potential to 'absolute earth potential' can rise thousands of volts, but phone, CATV and other signal wires are clamped to the grounded neutral through phone NID and CATV entrance block and all the wires ride up with the power conductors. ... Plug-in surge suppressors clamp the voltage H-N, H-G, N-G (and signal wires should go through the protector and be clamped to surge protector ground). ...
    (comp.os.vms)