Inline Electric Timer Switch...

[bud--]

On 3/29/2022 2:22 PM, Rickster wrote:

On Tuesday, March 29, 2022 at 3:35:04 PM UTC-4, David Brown wrote:


Surge protector socket adaptors or outlet
strips are common and cheap.

I don\'t agree with that. Most \"surge\" protectors are nearly worthless, such as the one the microwave was plugged into when it stopped working. It was a bit funny, in that it came on and I started warming up something that didn\'t get warm. After a few tries of resetting and unplugging for a bit, it still didn\'t cook, but started to give an error code after a bit. Now it gives the error code as soon as you start it cooking. H98 means a problem in the power supply.

The IEEE guide, cited elsewhere, does not indicate that \"Most \'surge\'
protectors are nearly worthless\". Buy one from a competent company. And
UL listed provides at least a minimum floor.

MOVs fail by the voltage at which they start to conduct lowering after
hits totaling at least the joule rating to the source voltage, and the
MOV goes into thermal runaway. All UL listed suppressors should have a
disconnect for failing MOVs that operates at least partly on heat.
Recent UL listed suppressors disconnect the connected load with the MOVs
(or inform you that they don\'t). UL listed suppressor? Do you know it
failed? Was there a surge? Is there a reason to believe the microwave
didn\'t just fail (fairly new is not a guarantee)?

Suppressors with protected equipment warranties are available. They are
possible because of the disconnect feature above, and the low amount of
energy that can actually reach a suppressor (in another post).

 

[bud--]

On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC. Or one of those surge suppressor bars (but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).

I have not read that \"they have a relatively short lifespan\".

The NIST surge expert investigated how much energy can reach MOVs in a
plug-in suppressor (with no service panel suppressor). Branch circuits
were 10m and longer, and surges coming in on power wires were up to 10kA
(which is the maximum probable surge). The maximum energy was a
surprisingly small 35 joules. In 13 of 15 cases it was 1 joule or less.
Plug-in protectors with much higher ratings are readily available. (This
is US, and there are a couple features that may be different. One is the
neutral-ground bond in services. The other is arc-over described below.)

There are 2 reasons the energy is so small. One is that at about 6,000V
there is arc-over from the service panel busbars to the enclosure. After
the arc is established the voltage is hundreds of volts. Since the
enclosure/ground/neutral are connected to the earthing system that dumps
most of the incoming surge energy to earth. (This would also limit the
voltage across switch contacts.)

The second reason is the impedance of the branch circuit wiring. A surge
is a very short event. That means the current components are relatively
high frequency. That means the wire inductance is more important than
the resistance. The branch circuit impedance greatly limits the current
to the MOVs, which greatly limits the energy that can make it to the MOVs.

 

[Martin Brown]

On 31/03/2022 06:34, bud-- wrote:

On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC.  Or one of those surge suppressor bars (but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).


I have not read that \"they have a relatively short lifespan\".

They last until they encounter a surge that is close to or above their
tolerance. They don\'t always work though. I have known industrial grade
surge suppression for mainframe terminals save itself by allowing the
much more expensive I/O drivers on cards in the terminal adapter to fry.

It was a fairly impressive looking thing big chunk of well earthed
copper but against the direct hit to the building strike which entered
and destroyed the phone wiring it made not one jot of difference.

The NIST surge expert investigated how much energy can reach MOVs in a
plug-in suppressor (with no service panel suppressor). Branch circuits
were 10m and longer, and surges coming in on power wires were up to 10kA
(which is the maximum probable surge). The maximum energy was a
surprisingly small 35 joules. In 13 of 15 cases it was 1 joule or less.
Plug-in protectors with much higher ratings are readily available. (This
is US, and there are a couple features that may be different. One is the
neutral-ground bond in services. The other is arc-over described below.)

There are 2 reasons the energy is so small. One is that at about 6,000V
there is arc-over from the service panel busbars to the enclosure. After
the arc is established the voltage is hundreds of volts. Since the
enclosure/ground/neutral are connected to the earthing system that dumps
most of the incoming surge energy to earth. (This would also limit the
voltage across switch contacts.)

The second reason is the impedance of the branch circuit wiring. A surge
is a very short event. That means the current components are relatively
high frequency. That means the wire inductance is more important than
the resistance. The branch circuit impedance greatly limits the current
to the MOVs, which greatly limits the energy that can make it to the MOVs.

I\'d say they mostly do work, but you can still get black swan events
where they manage not to stop damage to the things that they are
supposed to protect. I have surge protection on my kit...

--
Regards,
Martin Brown

 

[Jeroen Belleman]

Martin Brown wrote:

On 31/03/2022 06:34, bud-- wrote:
On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC. Or one of those surge suppressor bars (but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).


I have not read that \"they have a relatively short lifespan\".

They last until they encounter a surge that is close to or above their
tolerance. They don\'t always work though. I have known industrial grade
surge suppression for mainframe terminals save itself by allowing the
much more expensive I/O drivers on cards in the terminal adapter to fry.

It was a fairly impressive looking thing big chunk of well earthed
copper but against the direct hit to the building strike which entered
and destroyed the phone wiring it made not one jot of difference.

Respect for the designers of those mountaintop radio relays that
get hit by lightning all the time and keep working nevertheless.

Jeroen Belleman

 

[Martin Brown]

On 31/03/2022 10:29, Jeroen Belleman wrote:

Martin Brown wrote:
On 31/03/2022 06:34, bud-- wrote:
On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC.  Or one of those surge suppressor bars
(but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).


I have not read that \"they have a relatively short lifespan\".

They last until they encounter a surge that is close to or above their
tolerance. They don\'t always work though. I have known industrial
grade surge suppression for mainframe terminals save itself by
allowing the much more expensive I/O drivers on cards in the terminal
adapter to fry.

It was a fairly impressive looking thing big chunk of well earthed
copper but against the direct hit to the building strike which entered
and destroyed the phone wiring it made not one jot of difference.


Respect for the designers of those mountaintop radio relays that
get hit by lightning all the time and keep working nevertheless.

Indeed! I used to live within sight of such a tall mast for atmospheric
research in Tsukuba. One day it took a direct hit from a major summer
thunderstorm while I was watching. It was just like the firing of the
Death Star in Starwars with three bolts from clouds above it joining to
one and crashing down onto the top. It was still OK afterwards.

Knocked out for just a couple of seconds but otherwise OK.

I narrowly missed seeing ball lightning once - it had the temerity to
appear in a university physics department and attacked the photocopier.

Shareable direct link to short article in Nature \"Ball of Fire?\":
https://rdcu.be/cKhqY

Actual article in Nature (subscribers only)
www.nature.com/articles/298702b0.epdf

--
Regards,
Martin Brown

 

[Dan Purgert]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

bud-- wrote:

On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC. Or one of those surge suppressor bars (but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).


I have not read that \"they have a relatively short lifespan\".

My understanding is such that the MOVs used in the cheapo 4- or 6-outlet
bars have a finite lifespan in general terms (even if it\'s just from
internal heat buildup), which may be further shortened by power surges.

Now, that \"finite lifespan\" is merely for expectation of the MOVs to do
their job -- long as the bar itself is still physically sound, it\'ll
work as an extension cord (etc.) practically forever (albeit without any
\"safety features\").

Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


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--
|_|O|_| Github: https://github.com/dpurgert
|_|_|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
|O|O|O| Former PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281

 

[Ricky]

On Thursday, March 31, 2022 at 12:25:31 AM UTC-4, bud-- wrote:

On 3/29/2022 12:14 PM, Rich S wrote:
First THANK YOU, RC, for an on-topic post.

Whats the total cost of what you\'re trying to protect? (including risk, cost accrued if out of service)

Nothing will save you from a direct lightning hit of course.
Lightning rod systems will. They include more protection than just the
rods (now called \"air terminals\"). Not cost-effective for most of us,
but very useful for some.

Sorry, I\'m not familiar with lightning rod \"systems\". I do know that lightning rods won\'t do diddly in this case because they reduce damage to structures from a direct lightning strike, while the typical damage to electronics is from the magnetic field of a strike inducing very large currents in exterior conductors connected to equipment. Are you referring to something to prevent the surge from an external line from getting into the house? They exist, but are very, very expensive. They also don\'t protect equipment inside the house from a very close lightning strike (such as to the lightning rod) from inducing currents directly in the house.

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Ricky]

On Thursday, March 31, 2022 at 12:29:25 AM UTC-4, bud-- wrote:

On 3/29/2022 2:22 PM, Rickster wrote:
On Tuesday, March 29, 2022 at 3:35:04 PM UTC-4, David Brown wrote:


Surge protector socket adaptors or outlet
strips are common and cheap.

I don\'t agree with that. Most \"surge\" protectors are nearly worthless, such as the one the microwave was plugged into when it stopped working. It was a bit funny, in that it came on and I started warming up something that didn\'t get warm. After a few tries of resetting and unplugging for a bit, it still didn\'t cook, but started to give an error code after a bit. Now it gives the error code as soon as you start it cooking. H98 means a problem in the power supply.

The IEEE guide, cited elsewhere, does not indicate that \"Most \'surge\'
protectors are nearly worthless\". Buy one from a competent company. And
UL listed provides at least a minimum floor.

MOVs fail by the voltage at which they start to conduct lowering after
hits totaling at least the joule rating to the source voltage, and the
MOV goes into thermal runaway. All UL listed suppressors should have a
disconnect for failing MOVs that operates at least partly on heat.
Recent UL listed suppressors disconnect the connected load with the MOVs
(or inform you that they don\'t). UL listed suppressor? Do you know it
failed? Was there a surge? Is there a reason to believe the microwave
didn\'t just fail (fairly new is not a guarantee)?

There are no guarantees in life, or even in death, except that it will happen someday.
There\'s no guarantees at all for birth, most of which never happen.

Suppressors with protected equipment warranties are available. They are
possible because of the disconnect feature above, and the low amount of
energy that can actually reach a suppressor (in another post).

The $10 surge protectors come with warranties, including coverage of the connected equipment. Need I say more?

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[bud--]

On 3/31/2022 2:28 PM, Ricky wrote:

On Thursday, March 31, 2022 at 12:25:31 AM UTC-4, bud-- wrote:
On 3/29/2022 12:14 PM, Rich S wrote:
First THANK YOU, RC, for an on-topic post.

Whats the total cost of what you\'re trying to protect? (including risk, cost accrued if out of service)

Nothing will save you from a direct lightning hit of course.

Lightning rod systems will. They include more protection than just the
rods (now called \"air terminals\"). Not cost-effective for most of us,
but very useful for some.

Sorry, I\'m not familiar with lightning rod \"systems\".

Any lightning rod installation, except a barn, will be a \"system\". In
the US the relevant standard is NFPA 780. The system will include a
service panel surge suppressor (the IEEE guide says the minimum rating
is 40kA). Also includes features like metal within 6 ft. of rod wiring
and down conductors may need to be bonded to the conductors. That is
because of the high voltage drop at earthing electrodes and in the
inductance of the conductors may result in voltages that will flash
across 6 ft.

> I do know that lightning rods won\'t do diddly in this case because they reduce damage to structures from a direct lightning strike, while the typical damage to electronics is from the magnetic field of a strike inducing very large currents in exterior conductors connected to equipment. Are you referring to something to prevent the surge from an external line from getting into the house? They exist, but are very, very expensive.

Most damaging after a direct strike is surges coming in on power and
signal wires.

The NIST surge expert investigated how much energy can enter a residence
from a near strike. The strike was 200kA to the distribution wire at the
top of a utility pole adjacent to a house with typical urban overhead
distribution. This is a very near strike. And only 5% of strikes are
stronger. For practical purposes this is a worst case. The current was
10kA per service wire (mentioned yesterday, and also in the IEEE guide).
Service panel surge suppressors are readily available with ratings far
larger. The IEEE guide suggests a rating (per wire) of 20kA to 70kA
unless in a high lightning area. I would not call these suppressors
\"very expensive\". Protection is also needed for incoming signal wires.

They also don\'t protect equipment inside the house from a very close lightning strike (such as to the lightning rod) from inducing currents directly in the house.

A near strike can induce high voltages between power and signal wires
with the loop formed by the wires acting as a loop antenna. It is a case
where service entrance suppressors are not complete protection. But
plug-in suppressors, with all wires going through the suppressor,
provide protection.

 

[bud--]

On 3/31/2022 2:31 PM, Ricky wrote:

On Thursday, March 31, 2022 at 12:29:25 AM UTC-4, bud-- wrote:

Suppressors with protected equipment warranties are available. They are
possible because of the disconnect feature above, and the low amount of
energy that can actually reach a suppressor (in another post).

The $10 surge protectors come with warranties, including coverage of the connected equipment. Need I say more?

I have never seen a suppressor with warranty for $10.

UL listed plug-in suppressors are reliable (and probably not $10 without
a warranty).

Surge protection is not rocket science. Businesses, for instance in
Florida, do not shut down for thunderstorms. Highly unlikely residents
of Florida haven\'t figured out how to protect their equipment. Read the
IEEE guide

 

[bud--]

On 3/31/2022 8:25 AM, Dan Purgert wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

bud-- wrote:
On 3/29/2022 4:04 PM, Dan Purgert wrote:

A UPS, such as from APC. Or one of those surge suppressor bars (but, as
you noted, they have a relatively short lifespan -- once the internals
get burned out, they need replaced).


I have not read that \"they have a relatively short lifespan\".

My understanding is such that the MOVs used in the cheapo 4- or 6-outlet
bars have a finite lifespan in general terms (even if it\'s just from
internal heat buildup), which may be further shortened by power surges.

Is not what I have read anywhere.

And not true of suppressors with a UL listing. They are tested as
plug-strips. And have at least a specified minimum (also tested) surge
rating. And much higher ratings are readily available. And, as explained
yesterday, the amount of energy that can make it to a suppressor is
surprisingly small.

Now, that \"finite lifespan\" is merely for expectation of the MOVs to do
their job -- long as the bar itself is still physically sound, it\'ll
work as an extension cord (etc.) practically forever (albeit without any
\"safety features\").

As I wrote yesterday, a UL listed suppressor is likely to not work as a
plug strip if the MOVs fail (IEEE guide pg. 38).

Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.

The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.

 

[Martin Brown]

On 31/03/2022 06:24, bud-- wrote:

On 3/29/2022 12:14 PM, Rich S wrote:
First THANK YOU, RC, for an on-topic post.

Whats the total cost of what you\'re trying to protect? (including
risk, cost accrued if out of service)

Nothing will save you from a direct lightning hit of course.

Lightning rod systems will. They include more protection than just the
rods (now called \"air terminals\"). Not cost-effective for most of us,
but very useful for some.

The building I was in had proper external lightning protection but it
didn\'t make that much difference. Afterwards the conductor was the funny
colour that copper goes after being at red heat but the strike still
managed to enter the building and vapourise (parts of) the internal
phone wiring.

I suspect it was ground currents and magnetic coupling loops of cable
between terminals and mains wiring that took out the line drivers.
Whatever it was the expensive surge protection kit saved itself by
letting the more expensive IO driver boards in the terminal concentrator
get fried.

The max surge with any reasonable probability of occurring, US,
residential, typical overhead urban distribution, is 10kA per service
wire. Pg 18 has recommendations for service panel protection. (also see
joules that can make it to a plug-in suppressor elsewhere)

UK has spark gaps on the local mains down transformers so that anything
much over 150kV on a nominally 33kV line will arc over on the HT side.
The arc looks like a dead short and takes out the breakers.

Nothing can help you if lightning strikes an overhead local mains line
the injection of current has to go somewhere and fast.

When using a plug-in surge suppressor all wires (power and signal) to a
set of protected equipment needs to go through the suppressor. The
voltage on all wires is clamped to the ground at the suppressor. (The
same thing happens at a service panel suppressor, which needs voltage
clamps on incoming signal wires adjacent.)

The thing about the suppressor protection is that it needs to be
connected to a very good earth with a chunky conductor and that
condition isn\'t always met. Particularly in summer after a long dry spell.


--
Regards,
Martin Brown

 

[Dan Purgert]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

bud-- wrote:

On 3/31/2022 8:25 AM, Dan Purgert wrote:
[...]
Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.

So I just looked at my decent-ish $15 (or so) Belkin 6-outlet bars that
are kind of my go-to when I get these things ($10k warranty, UL Listed).
Just picked one up last weekend, has some fine print right on the
package:

\"Please Note: The protective components inside surge protectors absorb
over-voltage spikes to your connected devices which means they will
eventually wear out. Replace this device every 3 years or immediately
after any over-voltage spike event[...]\"

Sure, it could just be boilerplate / not actually true in all cases, but
at the same time, their connected equipment warranty explicitly states
that they\'re not gonna cover something outside its service lifetime
either.


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--
|_|O|_| Github: https://github.com/dpurgert
|_|_|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
|O|O|O| Former PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281

 

[Ricky]

On Friday, April 1, 2022 at 5:50:31 AM UTC-4, Dan Purgert wrote:

bud-- wrote:
On 3/31/2022 8:25 AM, Dan Purgert wrote:
[...]
Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.
So I just looked at my decent-ish $15 (or so) Belkin 6-outlet bars that
are kind of my go-to when I get these things ($10k warranty, UL Listed).
Just picked one up last weekend, has some fine print right on the
package:

\"Please Note: The protective components inside surge protectors absorb
over-voltage spikes to your connected devices which means they will
eventually wear out. Replace this device every 3 years or immediately
after any over-voltage spike event[...]\"

Sure, it could just be boilerplate / not actually true in all cases, but
at the same time, their connected equipment warranty explicitly states
that they\'re not gonna cover something outside its service lifetime
either.

That\'s the point. It\'s like the scene in Tommy Boy, where Tommy is trying to sell his line of brake pads to the retailer who wants to see a guarantee on the box as a sign of quality. Tommy says he can take a crap in the box and put a guarantee on the side. The guarantees are as much BS as the surge suppression on the cheap units. I\'m sure they will stand behind their product if you can meet every single part of the requirements. How are you going to do that?

They took a crap in the box and slapped a guarantee on it.

https://www.youtube.com/watch?v=mEB7WbTTlu4

--

Rick C.

-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209

 

[Dan Purgert]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Ricky wrote:

On Friday, April 1, 2022 at 5:50:31 AM UTC-4, Dan Purgert wrote:
bud-- wrote:
On 3/31/2022 8:25 AM, Dan Purgert wrote:
[...]
Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.
So I just looked at my decent-ish $15 (or so) Belkin 6-outlet bars that
are kind of my go-to when I get these things ($10k warranty, UL Listed).
Just picked one up last weekend, has some fine print right on the
package:

\"Please Note: The protective components inside surge protectors absorb
over-voltage spikes to your connected devices which means they will
eventually wear out. Replace this device every 3 years or immediately
after any over-voltage spike event[...]\"

Sure, it could just be boilerplate / not actually true in all cases, but
at the same time, their connected equipment warranty explicitly states
that they\'re not gonna cover something outside its service lifetime
either.

That\'s the point. It\'s like the scene in Tommy Boy, where Tommy is

No it\'s not. That scene the buyer is saying he won\'t buy the Callahan
brake pads because he doesn\'t get a guarantee on the box (guarantee on
the box makes ya feel warm and fuzzy inside, y\'know?).

The only reason I brought up the Belkin \"warranty\" is that one of the
requirements therein is that the surge protector is within its \"service
life\" (in the case of the particular product I had to hand - 36 months
from date of purchase).

Conversely, the APC ones I have (for $5-10 more) have a little \"I\'m
still working\" indicator. Which, apparently can go out while still
allowing plugged in devices to function -- the wording is such that
while they do have a \"fail safe\" in the event of catastrophic events,
the indicator will go out any time the device can no longer provide
100% protection.

In either event -- catastrophic event cutout, indicator going dark, or
the simple passage of time -- the devices have a finite length to their
expected service life. Time is, of course, the most restrictive thing
there, but honestly, the terms of those connected device warranties
always give me the idea that (as a regular consumer), you\'re not
actually ever going to get reimbursed for stuff plugged into the surge
protector.

Then again, I\'ve never had to try invoking one of those clauses
either...


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|_|_|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
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[Ricky]

On Friday, April 1, 2022 at 11:33:32 AM UTC-4, Dan Purgert wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
Ricky wrote:
On Friday, April 1, 2022 at 5:50:31 AM UTC-4, Dan Purgert wrote:
bud-- wrote:
On 3/31/2022 8:25 AM, Dan Purgert wrote:
[...]
Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.
So I just looked at my decent-ish $15 (or so) Belkin 6-outlet bars that
are kind of my go-to when I get these things ($10k warranty, UL Listed).
Just picked one up last weekend, has some fine print right on the
package:

\"Please Note: The protective components inside surge protectors absorb
over-voltage spikes to your connected devices which means they will
eventually wear out. Replace this device every 3 years or immediately
after any over-voltage spike event[...]\"

Sure, it could just be boilerplate / not actually true in all cases, but
at the same time, their connected equipment warranty explicitly states
that they\'re not gonna cover something outside its service lifetime
either.

That\'s the point. It\'s like the scene in Tommy Boy, where Tommy is
No it\'s not. That scene the buyer is saying he won\'t buy the Callahan
brake pads because he doesn\'t get a guarantee on the box (guarantee on
the box makes ya feel warm and fuzzy inside, y\'know?).

The only reason I brought up the Belkin \"warranty\" is that one of the
requirements therein is that the surge protector is within its \"service
life\" (in the case of the particular product I had to hand - 36 months
from date of purchase).

Conversely, the APC ones I have (for $5-10 more) have a little \"I\'m
still working\" indicator. Which, apparently can go out while still
allowing plugged in devices to function -- the wording is such that
while they do have a \"fail safe\" in the event of catastrophic events,
the indicator will go out any time the device can no longer provide
100% protection.

There is no 100% protection. They protect against some level of surge, period. More than that surge and your equipment goes \"poof\". You are left with a worthless warranty as they don\'t warrant your equipment will not be damaged by surges over their threshold.

In either event -- catastrophic event cutout, indicator going dark, or
the simple passage of time -- the devices have a finite length to their
expected service life. Time is, of course, the most restrictive thing
there, but honestly, the terms of those connected device warranties
always give me the idea that (as a regular consumer), you\'re not
actually ever going to get reimbursed for stuff plugged into the surge
protector.

Then again, I\'ve never had to try invoking one of those clauses
either...

Exactly! How may reimbursements are they going to afford selling $15 outlet strips with a $10k warranty? None! They are never going to pay out because they will find some reason you don\'t qualify. The warranty on the box does give you a warm, fuzzy feeling inside though, doesn\'t it? So I guess it *is* the same, eh?

--

Rick C.

-++ Get 1,000 miles of free Supercharging
-++ Tesla referral code - https://ts.la/richard11209

 

[Dan Purgert]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Ricky wrote:

On Friday, April 1, 2022 at 11:33:32 AM UTC-4, Dan Purgert wrote:
[...]
Conversely, the APC ones I have (for $5-10 more) have a little \"I\'m
still working\" indicator. Which, apparently can go out while still
allowing plugged in devices to function -- the wording is such that
while they do have a \"fail safe\" in the event of catastrophic events,
the indicator will go out any time the device can no longer provide
100% protection.

There is no 100% protection. They protect against some level of
surge, period. More than that surge and your equipment goes \"poof\".
You are left with a worthless warranty as they don\'t warrant your
equipment will not be damaged by surges over their threshold.

Yeah, I know. That\'s APC\'s wording in their product insert.

In either event -- catastrophic event cutout, indicator going dark, or
the simple passage of time -- the devices have a finite length to their
expected service life. Time is, of course, the most restrictive thing
there, but honestly, the terms of those connected device warranties
always give me the idea that (as a regular consumer), you\'re not
actually ever going to get reimbursed for stuff plugged into the surge
protector.

Then again, I\'ve never had to try invoking one of those clauses
either...

Exactly! How may reimbursements are they going to afford selling $15
outlet strips with a $10k warranty? None! They are never going to
pay out because they will find some reason you don\'t qualify. The
warranty on the box does give you a warm, fuzzy feeling inside though,
doesn\'t it?

No. I know it\'s a farce. But I guess if it makes you feel better to
pretend I bought the $15 thing with the \"feelgood box art\" instead of
the $20 one with the \"feelgood LED\", go right ahead.


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--
|_|O|_| Github: https://github.com/dpurgert
|_|_|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
|O|O|O| Former PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281

 

[bud--]

On 4/1/2022 2:46 AM, Martin Brown wrote:

On 31/03/2022 06:24, bud-- wrote:
On 3/29/2022 12:14 PM, Rich S wrote:
First THANK YOU, RC, for an on-topic post.

Whats the total cost of what you\'re trying to protect? (including
risk, cost accrued if out of service)

Nothing will save you from a direct lightning hit of course.

Lightning rod systems will. They include more protection than just the
rods (now called \"air terminals\"). Not cost-effective for most of us,
but very useful for some.

The building I was in had proper external lightning protection but it
didn\'t make that much difference. Afterwards the conductor was the funny
colour that copper goes after being at red heat but the strike still
managed to enter the building and vapourise (parts of) the internal
phone wiring.

I suspect it was ground currents and magnetic coupling loops of cable
between terminals and mains wiring that took out the line drivers.
Whatever it was the expensive surge protection kit saved itself by
letting the more expensive IO driver boards in the terminal concentrator
get fried.

Not having seen how the building was protected....

You can get over 100,000A in a strike, but the duration is microseconds.
Hard to imagine in the US, with at least 2 large gauge downconductors to
earthing systems the wires would get hot enough to discolor.

The max surge with any reasonable probability of occurring, US,
residential, typical overhead urban distribution, is 10kA per service
wire. Pg 18 has recommendations for service panel protection. (also
see joules that can make it to a plug-in suppressor elsewhere)

UK has spark gaps on the local mains down transformers so that anything
much over 150kV on a nominally 33kV line will arc over on the HT side.
The arc looks like a dead short and takes out the breakers.

Sound like fun to watch. But lightning arresters on the primary protect
transformers. They don\'t provide much protection to buildings.

Nothing can help you if lightning strikes an overhead local mains line
the injection of current has to go somewhere and fast.

\"Nothing can help you\"? I just explained what can help you.
A recognized expert in a published paper found that a 200,000A strike to
the primary wire on a utility pole adjacent to a building with typical
overhead urban distribution results in 10kA surges on the power service
wires to the building. Service panel suppressors, with far higher
ratings, limit the voltage from the service wires to the service
\"ground\". The \"ground\" in the US is connected to earthing electrode(s),
which is where most of the energy to the building goes.

When using a plug-in surge suppressor all wires (power and signal) to
a set of protected equipment needs to go through the suppressor. The
voltage on all wires is clamped to the ground at the suppressor. (The
same thing happens at a service panel suppressor, which needs voltage
clamps on incoming signal wires adjacent.)

The thing about the suppressor protection is that it needs to be
connected to a very good earth with a chunky conductor and that
condition isn\'t always met. Particularly in summer after a long dry spell.

Plug-in suppressors do not protect primarily by earthing a surge. They
can\'t - the impedance of the wires is too high. The ground potential at
the suppressor can rise thousands of volts above the ground potential at
the service entrance \"ground\", described in the IEEE guide pg 30-35. The
guide explains, starting pg 35, that plug-in suppressors work primarily
by limiting the voltage on all wires, power and signal, to the ground at
the suppressor. The voltage between wires going to the protected
equipment is safe for the protected equipment (as I wrote above).

The guide, on pg 28, looks at the ground potential rise of the \"ground\"
at the service (specifically signal, but it the same for power). The
building \"ground\" can rise, in this example 250,000V, above earth
potential distant from the building (that would cause arcing across the
earth from the ground rod away). Much of the protection, again, is that
service panel suppressors and signal entry protectors limit the voltage
to the ground at the panel. The voltage between wires inside the
building is generally safe for the connected equipment (as I wrote
above). (One exception is pg 33, another - induced pick up from a near
strike to wire loop in a previous post.)

Protection likely does not primarily involve earthing the surge.

Read the IEEE surge guide - written for technical people
<http://lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf>

 

[bud--]

On 4/1/2022 3:50 AM, Dan Purgert wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

bud-- wrote:
On 3/31/2022 8:25 AM, Dan Purgert wrote:
[...]
Even assuming my understanding is wrong (i.e. that the MOVs never
actually degrade), they\'re less than $20, it\'s not exactly going to
break the bank to replace them every 3-5 years.


The two suppressors I use are from reputable companies, with high
ratings, protected equipment warranties and ports for relevant signal
wires. I do not have to worry about whether they will fail.

So I just looked at my decent-ish $15 (or so) Belkin 6-outlet bars that
are kind of my go-to when I get these things ($10k warranty, UL Listed).
Just picked one up last weekend, has some fine print right on the
package:

\"Please Note: The protective components inside surge protectors absorb
over-voltage spikes to your connected devices which means they will
eventually wear out. Replace this device every 3 years or immediately
after any over-voltage spike event[...]\"

Sure, it could just be boilerplate / not actually true in all cases, but
at the same time, their connected equipment warranty explicitly states
that they\'re not gonna cover something outside its service lifetime
either.

I haven\'t looked at Belkin for a long time.

I looked at one suppressor (at Belkin site) with the same 3 year
language. It also said \"and a lifetime $75,000 Connected Equipment
Warranty.\" IMHO if sued (could be small claims court here) Belkin would
have trouble denying coverage. One problem with a surge warranty is
people think any damage with an unknown cause, like to a microwave, is
from a surge.

I couldn\'t find warranties at Belkin, or user manuals. UL wording I saw
did not clearly say suppressors were UL LISTED - tested BY UL to UL1449.
Belkin seems to have branched out into other products.

From a previous post, from published research, with up to 10kA surge on
power wires, and no suppressor a the service, the maximum energy
absorbed by a MOV on a branch circuit was 35J. In 13 of 15 cases it was
1 joule or less. The Belkin suppressor I looked at had a rating of 1045J.

Companies in high lightning areas of Florida do not move to Nevada
because of thunderstorm damage. Principles of protection are well
understood. Five engineers experienced in surge protection wrote the
IEEE surge guide, which details the base principles. The guide says
plug-in suppressors are effective and says how to use them. Also lots of
information on other protection elements.

Read the IEEE surge guide
<http://lightningsafety.com/nlsi_lhm/IEEE_Guide.pdf>

 

[Cydrome Leader]

whit3rd <whit3rd@gmail.com> wrote:

On Tuesday, March 29, 2022 at 10:50:55 AM UTC-7, Rickster wrote:
...The problem is lots of electric surges that fry various electronics. One solution is using an outlet strip so power is removed when not in use.

The other solution would be to add a proper surge protector...
but what is typically used to protect computer equipment where the value is less than say, $5,000?

That \'computer equipment\' has sacrificial parts, and the fancy PC only needs a $50 replacement power
brick when the surges kill it. The third solution is to plan, somewhat, for the larger surges by making
the failure modes graceful and repairable.

A friend in an urban home got my last ferroresonant power supply, so I don\'t have a really good
surge protector any more, and for a few decades now, I haven\'t missed it.

Glad somebody brought up ferroresonant power supplies.

Simple, reliable, but terribly expensive and inefficient. I need to move a
2000VA unit soon. The garbage from a line they will block is impressive.
You still have problems is you have devices connected by other means to
other power sources or places. This can be ethernet, and especially
telecom lines.

Isolation transformers work pretty good too, but don\'t help during a
brown-out or with regulation issues if that\'s an key issue.