Is it possible to repair a whole house surge suppressor?

[tm]

Here in Israel they are required by the electric company BEFORE main
breakers.

You can't get a new connection without one, and every few years there is
an advertising campaign to get people to install them in old homes.

We have 230 volt single phase service, and 230 volt 3 phase split into
three
separate circuits, so we don't have the 120/240 problem in the US that
was previously discussed.

Geoff.

I did a brief web search and was surprised that as many as 500 children (?)
a year in the US
are electrocuted. Before the GFIs were required in wet areas by code, it was
over 800 per year.


tm

 

[Fred]

Here in Israel

Sorry, Geoff. It's not your fault, but I cannot forget my 3 friends who
died....ever.

http://gtr5.com/

It was no accident.
By the luck of the draw, I wasn't one of the dead.

 

[Geoffrey S. Mendelson]

Sorry, Geoff. It's not your fault, but I cannot forget my 3 friends who
died....ever.

http://gtr5.com/

To quote the website:

"the Johnson administration never sought the prosecution of the guilty
parties or otherwise attempted to seek justice for the victims. They
concealed and altered evidence in their effort to downplay the attack.
Though they never formally accepted the Israeli explanation that it was
an accident, they never pressed for a full investigation either. They
simply allowed those responsible literally to get away with murder."

Israel is a democracy, and has a very active High Court of Justice. The concept
of people suing the state for compensation is very much alive here.

Although it is over fourty years, and it might be impossible to find
anyone who was in charge that can testify, you might want to consider,
as a group, filing a law suit against the IDF for compensation and
information.

Geoff.


Geoff.

 

[bud--]

I have yet to see suppressor not intended to be connected to breakers
in a service
panel.

I also don't like to call these surge, but SPIKE yes.
Surges to me a re very slow increases in voltage over the
safe limit.

A surge is defined (IEEE) as a "subcycle disturbance"

A "swell" is a disturbance that lasts from 1/2 cycle to a few seconds.

Longer is "temporary overvoltage".

A "spike" is essentially the same as "surge".

You can usually make local neutrals by connecting ground
to a neutral,

Not obvious to me what you are saying, but in the US connections
between ground and neutral downstream from the service not allowed (some
specific exceptions).

 

[bud--]

<...>
If your house if FIRMLY attached to the pole transformer, "surges" are
virtually impossible UNLESS you get hit by lightning.

"You" don't have to get hit. Strikes to power lines can cause damaging
surges into a building. So can close strikes. Surges can also enter on
cable and phone wires. And there are other sources of damaging surges.

NO surge
protector, no matter how expensive, says anything about LIGHTNING
PROTECTOR, ever. That would be a lie.

The surge guru at the NIST looked at essentially a worst case event - a
100,000A lightning strike to the high voltage wire on a utility pole
(with transformer) behind a house with typical urban overhead
distribution. There are multiple paths to earth. The surge to the house
was 10,000A max for each service wire to the house. Service panel
suppressors are readily available with higher ratings. The probability
of a worse strike is close to zero.

You can protect from very close lightning strikes.

Lightning strikes to a building, of course, require lightning rods.

The 23KV primary phase of
America's 3 phase Tesla multiphase AC power system is quite stable. The
natural magnetic hysteresis of the 60 hz core in your distribution
transformer prevents any pulses from being sent to your house until the
lightning protector in its primary fuse holder explodes in defeat.

Doesn't need the transformer. In the example above, a utility lightning
arrestor (installed on all the distribution transformers around here)
dumps the strike to earth via the grounding electrode on the pole. Since
the resistance to earth of that electrode is a few ohms at best, the
"ground potential" at the pole rises thousands of volts above "absolute
earth potential", and more particularly, above the earth potential at
the house. Since the secondary neutrals are connected to the "ground" at
the pole, this causes a large surge on the neutral to the house. A
significant portion of that surge is transferred to the hot wires by
inductive and capacitive coupling.

Usually the next worst to lightning for surges are normal and abnormal
utility operations. Potentially one of the worst of these is switching
of power factor correction capacitors. Utility produced surges can also
get into a building and cause damage to equipment.

"Surge Protector" is a great sales gimmick.

It is a "gimmick" use by the IEEE in an excellent guide on surges and
surge protection at:
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>

And by the US-NIST in a surge guide at.
<http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf>
This one is less technical and aimed at the unwashed masses.

Both say surges from lightning and other sources are a problem and you
can protect against them.
===============

In something that hasn't come up in this thread - the NIST guide, using
US insurance information as one source, suggests that high voltage
between power and cable/telephone/.... wires causes much of the damage,
not just a surge reaching equipment through the power wires. The IEEE
surge guide has an example of such damage starting pdf page 40.

To protect from high voltage between power and phone/cable wires, the
ground wire from the entrance protector for both phone and cable has to
be short and connect to the power earthing system near the power
service. If wires are too long, surges coming in on phone or cable
wiring can produce high voltage between those wires and power wires.
That is what is shown in the IEEE guide example starting pdf page 40.
With a large surge, the building ground can rise thousands of volts
above "absolute earth potential". Much of the protection is that power
and phone and cable wires rise together.

Particularly for expensive equipment with power and phone/cable
connection a plug-in suppressor may be useful. All interconnected
equipment needs to be connected to the same suppressor, and all external
wires - phone/cable/... - need to go through the suppressor. The voltage
on all wires is clamped to the ground at the suppressor. (This is also
in the example in the IEEE guide starting pdf page 40.)

 

[bud--]

No, it isn't. You can get nuisance trips on refrigerators and
freezers. They have grounded cords and they don't need GFCI. I haven't
seen a new copy of the NEC lately, but I was told it is against code in
the US to use a GFCI to power either.

It was never against the code to use GFCIs on refrigeration.

But the NEC used to have exceptions for GFCI requirements in garages and
basements where a refrigerator/freezer would be plugged in. Those
exceptions are gone.

Plug-in refrigerators/freezers using 15/20A 120V receptacles in
commercial kitchens are required to be on GFCI protected receptacles.

The UL allowed leakage for refrigerators/freezers is about 0.5mA.
Tripping a GFCI means the appliance has a problem.

 

[bud--]

AFCIs are the device intended to save the world. They trip on an arc of
about 5A (the old ones needed an arc more like 60A). For new wiring they
are generally required in a home when a GFCI is not required. The 2011
NEC may required AFCI protection when receptacles are replaced. They
also trip on a ground fault of about 30mA - not for protection of people.

Here in Israel they are required by the electric company BEFORE main breakers.

You can't get a new connection without one, and every few years there is
an advertising campaign to get people to install them in old homes.

We have 230 volt single phase service, and 230 volt 3 phase split into three
separate circuits, so we don't have the 120/240 problem in the US that
was previously discussed.

There are several systems for handling "ground" wires. The basic
interest is that "ground" wires essentially be at earth potential, and
that contact between a hot wire and ground trips a breaker.

In the US, the ground wire system is connected to earthing electrode(s)
at the building. This is likely the case in other countries as well.

The US also requires the neutral and ground be bonded at the service
disconnect. If there is a hot-to-ground short the path is ground wire to
service panel, G-N bond to neutral, service neutral back to the utility
transformer. This metal path produces a high current to trip the
breaker. The earth essentially plays no part because the resistance of
the earth path is far to high to trip a breaker.

The UK, from what I have read, has several ways to handle the "ground
system". One is to earth the neutral at the utility transformer, not
have a N-G bond at the building, and not run a ground wire with the hot
and neutral service wires. Ground faults would return through the earth
and not produce enough current to trip a breaker. I believe that these
systems require an RCD (trips on H-N current imbalance like a GFCI) as
the service breaker. The fault current through the earth does trip the
RCD. (The trip level is far higher than the 4-6mA for a GFCI.)

Could be what you have in Israel.

 

[bud--]

Refigerators or freezers are reqired to be on a circuit by
themselves.

Not in the NEC.

 

[William Sommerwerck]

Refigerators or freezers are reqired to be

on a circuit by themselves.

They aren't in my condo. And even a separate circuit doesn't keep the
transients from propagating to lines on the same phase.