There are reports on the BBC of numerous house fires after a power
surge on Saturday night in North Lanarkshire. 

"About 400 houses were affected by the surge which caused some
electricity meters and fuses to blow in the Summerlee area of
Coatbridge. 

Firefighters said they were 'inundated' with calls and attended a
number of small fires on Saturday night."
http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm

Would the house wiring be suspect after a surge like that? Or would
the main fuse blow? What about older properties with old wiring?

MM

MM formulated on Sunday :
> There are reports on the BBC of numerous house fires after a power
> surge on Saturday night in North Lanarkshire. 
>
> "About 400 houses were affected by the surge which caused some
> electricity meters and fuses to blow in the Summerlee area of
> Coatbridge. 
>
> Firefighters said they were 'inundated' with calls and attended a
> number of small fires on Saturday night."
> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
>
> Would the house wiring be suspect after a surge like that? Or would
> the main fuse blow? What about older properties with old wiring?
>
> MM

Very unlikely to damage the wiring, the fires were probably the result 
of equipment fed with too high voltage bursting into flames.

-- 
Regards,
        Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

In message , Harry 
Bloomfield  writes
>MM formulated on Sunday :
>> There are reports on the BBC of numerous house fires after a power
>> surge on Saturday night in North Lanarkshire.
>> "About 400 houses were affected by the surge which caused some
>> electricity meters and fuses to blow in the Summerlee area of
>> Coatbridge.
>> Firefighters said they were 'inundated' with calls and attended a
>> number of small fires on Saturday night."
>> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
>>
>> Would the house wiring be suspect after a surge like that? Or would
>> the main fuse blow? What about older properties with old wiring?
>>
>> MM
>
>Very unlikely to damage the wiring, the fires were probably the result 
>of equipment fed with too high voltage bursting into flames.
>

Isn't there a CE requirement for withstanding overvoltage ?


-- 
geoff

"Harry Bloomfield"  wrote in message 
news:mn.ec467d864e2fbe0d.86812@NOSPAM.tiscali.co.uk...
> MM formulated on Sunday :
>> There are reports on the BBC of numerous house fires after a power
>> surge on Saturday night in North Lanarkshire.
>> "About 400 houses were affected by the surge which caused some
>> electricity meters and fuses to blow in the Summerlee area of
>> Coatbridge.
>> Firefighters said they were 'inundated' with calls and attended a
>> number of small fires on Saturday night."
>> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
>>
>> Would the house wiring be suspect after a surge like that? Or would
>> the main fuse blow? What about older properties with old wiring?
>>
>> MM
>
> Very unlikely to damage the wiring, the fires were probably the result of 
> equipment fed with too high voltage bursting into flames.
>
> -- 
> Regards,
>        Harry (M1BYT) (L)
> http://www.ukradioamateur.co.uk
>
>

In my experience in the case of a serious overvoltage wiring damage in a 
proportion of properties in highly likely.

Regards

Steve Dawson

Stephen Dawson has brought this to us :
> In my experience in the case of a serious overvoltage wiring damage in a 
> proportion of properties in highly likely.

Modern mains wiring will normally withstand several thousands of volts, 
before breaking down. The only large scale breakdown of wiring 
insulation I have seen was due to lightning strike. I have seen lots of 
damage to appliances due to over voltage.

-- 
Regards,
        Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"MM"  wrote in message 
news:1i3f64lmjj2fqe091dtn5k3tjb39stboh8@4ax.com...
> There are reports on the BBC of numerous house fires after a power
> surge on Saturday night in North Lanarkshire.
>
> "About 400 houses were affected by the surge which caused some
> electricity meters and fuses to blow in the Summerlee area of
> Coatbridge.
>
> Firefighters said they were 'inundated' with calls and attended a
> number of small fires on Saturday night."
> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
>
> Would the house wiring be suspect after a surge like that? Or would
> the main fuse blow? What about older properties with old wiring?

If there was a fault in the the supply wiring where 2 or more phases  came 
together, you may see 415V AC for a short time, that could cause a few 
problems for the end user! The quality of some electrical equipment can be a 
bit suspect.
It has happened in the past though the leccy boards have a habit of  denying 
liability!

Des

MM wrote:
> There are reports on the BBC of numerous house fires after a power
> surge on Saturday night in North Lanarkshire.
>
> "About 400 houses were affected by the surge which caused some
> electricity meters and fuses to blow in the Summerlee area of
> Coatbridge.

Electricity meters are designed/approved to withstand a 6kV surge, so
I would be amazed if any failed.

Jon.

Tournifreak wrote:
> 
> Electricity meters are designed/approved to withstand a 6kV surge, so
> I would be amazed if any failed.

"Surge" in this context tends to refer to transient overvoltage on a 
time scale of a few tens of microseconds, such as can occur when 
lightning strikes nearby.  OTOH this thread seems to be about one of 
those sustained fault conditions in the supply network such as an open 
circuit neutral or crossed phase and neutral which results in some 
houses receiving close to the full 400 V line voltage of the 3-phase 
system for a long period.

-- 
Andy

On Jun 29, 9:32 am, MM  wrote:
> Would the house wiring be suspect after a surge like that? Or would
> the main fuse blow? What about older properties with old wiring?

  Fuses don't stop surges.  First the surge exists everywhere in a
circuit.  Eventually, a fuse blows long after the surge was ongoing.
Generally, blows as a result of the damage . Fuses are to protect
humans from further damage such as fire.

 Depends how large that transient voltages is. Locally, a 33,000 volts
wire fell upon a 4,000 volt distribution wire.  240 volts could have
risen to 2000 volts.  Probably higher since meters exploded upwards of
10 meters from their pans.  Meters were scattered in pieces.

  Some suffered appliance damage.  Others did not.  GFCIs (RCDs) were
also victims.  Some circuit breakers tripped; others did not.  No wire
damage was identified.  In this case, no fires were apparent.

  One homeowner with 'whole house' protector had no damage other than
an exploded meter and damaged meter mounting pan.  Of course, that
'whole house' protector protected household wiring as well as
appliances.

On Sun, 29 Jun 2008 13:32:30 UTC, MM  wrote:

> There are reports on the BBC of numerous house fires after a power
> surge on Saturday night in North Lanarkshire. 
> 
> "About 400 houses were affected by the surge which caused some
> electricity meters and fuses to blow in the Summerlee area of
> Coatbridge. 
> 
> Firefighters said they were 'inundated' with calls and attended a
> number of small fires on Saturday night."
> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
> 
> Would the house wiring be suspect after a surge like that? Or would
> the main fuse blow? What about older properties with old wiring?
> 
> MM

NOw look what you've done. You've set w_tom off again.
-- 
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
   http://www.diybanter.com

On 1 Jul 2008 06:47:20 GMT, "Bob Eager"  wrote:

>On Sun, 29 Jun 2008 13:32:30 UTC, MM  wrote:
>
>> There are reports on the BBC of numerous house fires after a power
>> surge on Saturday night in North Lanarkshire. 
>> 
>> "About 400 houses were affected by the surge which caused some
>> electricity meters and fuses to blow in the Summerlee area of
>> Coatbridge. 
>> 
>> Firefighters said they were 'inundated' with calls and attended a
>> number of small fires on Saturday night."
>> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
>> 
>> Would the house wiring be suspect after a surge like that? Or would
>> the main fuse blow? What about older properties with old wiring?
>> 
>> MM
>
>NOw look what you've done. You've set w_tom off again.

It hasn't happened here yet and probably never will, as this was
doubtless a one-in-a-million event. Nevertheless, it is useful to know
what the response of (a) the insurers and (b) the power company would
be. For example, whether the power company might cough up for a new
meter but wash its hands of any house wiring claims (or for
appliances).

MM

On Tue, 1 Jul 2008 07:01:36 UTC, MM  wrote:

> On 1 Jul 2008 06:47:20 GMT, "Bob Eager"  wrote:
> 
> >On Sun, 29 Jun 2008 13:32:30 UTC, MM  wrote:
> >
> >> There are reports on the BBC of numerous house fires after a power
> >> surge on Saturday night in North Lanarkshire. 
> >> 
> >> "About 400 houses were affected by the surge which caused some
> >> electricity meters and fuses to blow in the Summerlee area of
> >> Coatbridge. 
> >> 
> >> Firefighters said they were 'inundated' with calls and attended a
> >> number of small fires on Saturday night."
> >> http://news.bbc.co.uk/1/hi/scotland/glasgow_and_west/7479968.stm
> >> 
> >> Would the house wiring be suspect after a surge like that? Or would
> >> the main fuse blow? What about older properties with old wiring?
> >> 
> >> MM
> >
> >NOw look what you've done. You've set w_tom off again.
> 
> It hasn't happened here yet and probably never will, as this was
> doubtless a one-in-a-million event. Nevertheless, it is useful to know
> what the response of (a) the insurers and (b) the power company would
> be. For example, whether the power company might cough up for a new
> meter but wash its hands of any house wiring claims (or for
> appliances).

True. But w_tom is in the USA, so apart from the fact that he bangs on 
about his hobby horses and you get no useful information, power 
companies may have different attitudes there!

-- 
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
   http://www.diybanter.com

I don't see it as irrelevant, here a broken 25kv overhead line could
drop onto a post-mounted 400v transformer output terminals. Probably
highly unlikely, and I'm sure structures are designed to minimise that
possibility. But I would be surprised if power distribution companies
hadn't tested the probable consequences and figured out how they would
clean up the mess.

On Tue, 1 Jul 2008 02:28:26 -0700 (PDT), "dom@gglz.com" 
wrote:

>I don't see it as irrelevant, here a broken 25kv overhead line could
>drop onto a post-mounted 400v transformer output terminals. Probably
>highly unlikely, and I'm sure structures are designed to minimise that
>possibility. But I would be surprised if power distribution companies
>hadn't tested the probable consequences and figured out how they would
>clean up the mess.

"A Scottish Power spokesman said: 'An extremely rare underground cable
fault caused the damage.' "

MM

On Jul 1, 5:28 am, "d...@gglz.com"  wrote:
>>  I don't see it as irrelevant, here a broken 25kv overhead line could
>>  drop onto a post-mounted 400v transformer output terminals. Probably
>>  highly unlikely, and I'm sure structures are designed to minimise that
>>  possibility.
>
> "A Scottish Power spokesman said: 'An extremely rare underground cable
> fault caused the damage.' "

  It is a rare event.  However so destructive that designs must take
into account this event.  As another noted, meters typically contain a
spark gap to limit these voltages.

  A 33,000v line shorted to distribution caused hundreds of meters to
literally explode from the pan.  Local power utility blamed this fault
on lightning.  As an act of god, the utility denied responsibility.
Rules may be different in Scotland.

 Many who had appliances on plug-in protectors had damaged appliances
and destroyed protectors.  One who had a 'whole house' protector only
had an exploded meter and would have had all internal wiring
protected.

  Some got stuck for $thousands in damage.  Others strangely had
marginal damage or only tripped circuit breakers.  Unknown how high
the actual transient was or if any household wiring was affected.  But
no fires occurred during this event or after power was restored.

  What was voltage on that Scottish Power underground line?  Numbers
provide a useful upper limit.

On Tue, 1 Jul 2008 14:12:21 -0700 (PDT), w_tom  wrote:

>On Jul 1, 5:28 am, "d...@gglz.com"  wrote:
>>>  I don't see it as irrelevant, here a broken 25kv overhead line could
>>>  drop onto a post-mounted 400v transformer output terminals. Probably
>>>  highly unlikely, and I'm sure structures are designed to minimise that
>>>  possibility.
>>
>> "A Scottish Power spokesman said: 'An extremely rare underground cable
>> fault caused the damage.' "
>
>  It is a rare event.  However so destructive that designs must take
>into account this event.  As another noted, meters typically contain a
>spark gap to limit these voltages.
>
>  A 33,000v line shorted to distribution caused hundreds of meters to
>literally explode from the pan.  Local power utility blamed this fault
>on lightning.  As an act of god, the utility denied responsibility.
>Rules may be different in Scotland.
>
> Many who had appliances on plug-in protectors had damaged appliances
>and destroyed protectors.  One who had a 'whole house' protector only
>had an exploded meter and would have had all internal wiring
>protected.
>
>  Some got stuck for $thousands in damage.  Others strangely had
>marginal damage or only tripped circuit breakers.  Unknown how high
>the actual transient was or if any household wiring was affected.  But
>no fires occurred during this event or after power was restored.
>
>  What was voltage on that Scottish Power underground line?  Numbers
>provide a useful upper limit.

I can't find any further details beyond what the BBC reported.

MM

On Jul 1, 4:12 pm, w_tom  wrote:
>  Many who had appliances on plug-in protectors had damaged appliances
> and destroyed protectors.  One who had a 'whole house' protector only
> had an exploded meter and would have had all internal wiring
> protected.
.
w_ must drag the thread into his “whole house protectors work and plug-
in protectors don’t” crusade.
In fact, while both are effective for very short duration surges, MOVs
in both will rapidly be destroyed by “temporary overvoltage” (the
event in this thread). A major researcher in the surge field, Francois
Martzloff, has written "In fact, the major cause of TVSS [surge
suppressor] failures is a temporary overvoltage, rather than an
unusually large surge."

The probability of a ‘whole house’ suppressor providing protection is
close to zero.

--
bud--

On Jul 2, 11:03 am, bud--  wrote:
> w_ must drag the thread into his “whole house protectors work and plug-
> in protectors don’t” crusade. ...
> The probability of a ‘whole house’ suppressor providing protection is
> close to zero.

  A sales promoter for plug-in protectors must turn every discussion
nasty.  Relevant question is how high that fault voltage would be to
cause wire failure and fire. In one location, voltage so high as to
blow meters off the building and still not cause fires. In another
location, reason for one fire is unknown.  One who had a 'whole house'
protector suffered no damage (except to the meter), obviously would
not suffer wiring damage, while neighbors with plug-in protectors did
suffer damage – as should be expected.

  Bud must create a nasty flame war.  Insults gets others to ignore
what the OP asked.  Others then will forget that Bud is not answering
the OP's questions.

 Relevant is how high that fault voltage would be to cause a fire and
why that one fire existed.  Bud, a sales promoter and troll, follows
me everywhere creating flame wars because this poster has factually
identified the scam promoted by Bud: plug-in protectors.  Bud has no
interest in the topic nor providing the OP with a useful answer.
Where the fault was so large as to blow meters off buildings, still no
fire resulted.  Unknown is how much higher that voltage could be to
cause wiring failures.  Those who were not using a 'whole house'
protector did suffer appliance and plug-in protector damage AND would
not suffer wiring damage.   That is what the science says should
happen..

  Bud will reply with more nasty posts irrelevant to the OP's
question.  He is promoting plug-in protector sales.  Bud will not say
how high that voltage must be to blow meters off the building.  When I
posted this event earlier, then Bud denied it happened – post anything
to argue.  Will Bud also deny meters in Scotland were blown off the
building?

  How high must that voltage be to cause wiring damage?  How high was
that voltage to cause meters to blow off the building?  Instead, Bud
wants to change the topic to posting insults - a Rush Limbaugh
tactic.  Insults can cause some to ignore technical facts.

On Wed, 2 Jul 2008 18:54:05 UTC, w_tom  wrote:

(more US-centric ranting)

Oh, give it a rest.

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