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AC switch fault current philosophy

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  AC switch fault current philosophy Piglet <erichpwagner@hotmail.com> - 2017-12-28 12:29 +0000
    Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-28 04:47 -0800
      Re: AC switch fault current philosophy Piglet <erichpwagner@hotmail.com> - 2017-12-28 16:53 +0000
      Re: AC switch fault current philosophy George Herold <gherold@teachspin.com> - 2017-12-28 13:16 -0800
        Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-28 16:51 -0800
    Re: AC switch fault current philosophy "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-12-28 09:03 -0600
      Re: AC switch fault current philosophy Piglet <erichpwagner@hotmail.com> - 2017-12-28 17:00 +0000
        Re: AC switch fault current philosophy Piotr Wyderski <peter.pan@neverland.mil> - 2017-12-28 20:21 +0100
        Re: AC switch fault current philosophy Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-12-28 11:57 -0800
          Re: AC switch fault current philosophy Piglet <erichpwagner@hotmail.com> - 2017-12-29 12:45 +0000
            Re: AC switch fault current philosophy Winfield Hill <hill@rowland.harvard.edu> - 2017-12-29 05:13 -0800
            Re: AC switch fault current philosophy Piotr Wyderski <peter.pan@neverland.mil> - 2017-12-31 10:57 +0100
    Re: AC switch fault current philosophy Don Kuenz <g@crcomp.net> - 2017-12-28 18:45 +0000
      Re: AC switch fault current philosophy "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-12-28 14:16 -0600
        Re: AC switch fault current philosophy Don Kuenz <g@crcomp.net> - 2018-01-03 17:57 +0000
          Re: AC switch fault current philosophy "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-01-03 14:29 -0600
            Re: AC switch fault current philosophy Don Kuenz <g@crcomp.net> - 2018-01-03 20:54 +0000
              Re: AC switch fault current philosophy "Tim Williams" <tiwill@seventransistorlabs.com> - 2018-01-03 15:05 -0600
                Re: AC switch fault current philosophy Don Kuenz <g@crcomp.net> - 2018-01-03 22:07 +0000
      Re: AC switch fault current philosophy pcdhobbs@gmail.com - 2017-12-28 12:27 -0800
        Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-28 13:16 -0800
          Re: AC switch fault current philosophy pcdhobbs@gmail.com - 2017-12-28 14:42 -0800
            Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-28 15:25 -0800
              Re: AC switch fault current philosophy pcdhobbs@gmail.com - 2017-12-28 19:04 -0800
                Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-29 06:20 -0800
                Re: AC switch fault current philosophy George Herold <gherold@teachspin.com> - 2017-12-29 15:48 -0800
                  Re: AC switch fault current philosophy krw@notreal.com - 2017-12-29 18:59 -0500
                  Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-29 17:03 -0800
                    Re: AC switch fault current philosophy Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-12-30 07:49 -0800
                  Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-29 19:47 -0800
                  Re: AC switch fault current philosophy upsidedown@downunder.com - 2017-12-30 11:42 +0200
                    Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-30 02:01 -0800
                      Re: AC switch fault current philosophy upsidedown@downunder.com - 2017-12-30 22:12 +0200
                        Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-30 15:20 -0800
                          Re: AC switch fault current philosophy upsidedown@downunder.com - 2017-12-31 14:12 +0200
                        Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-30 16:33 -0800
                    Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-31 18:30 -0800
                  Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2017-12-30 19:00 -0500
                    Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-30 21:13 -0800
                      Re: AC switch fault current philosophy upsidedown@downunder.com - 2017-12-31 14:36 +0200
                        Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-31 04:47 -0800
                        Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-31 06:00 -0800
                        Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-31 17:39 -0800
                          Re: AC switch fault current philosophy Jasen Betts <jasen@xnet.co.nz> - 2018-01-01 04:19 +0000
                            Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-31 21:38 -0800
                      Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-31 05:54 -0800
                      Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2018-01-01 22:25 -0500
                      Re: AC switch fault current philosophy George Herold <gherold@teachspin.com> - 2018-01-02 06:27 -0800
                        Re: AC switch fault current philosophy Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-01-02 10:10 -0500
                Re: AC switch fault current philosophy Piotr Wyderski <peter.pan@neverland.mil> - 2017-12-31 11:29 +0100
              Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2017-12-30 19:44 -0500
                Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-30 16:52 -0800
                  Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2017-12-30 23:14 -0500
                    Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2017-12-30 20:33 -0800
                      Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2018-01-01 18:11 -0500
                        Re: AC switch fault current philosophy Phil Allison <pallison49@gmail.com> - 2018-01-01 17:26 -0800
                          Re: AC switch fault current philosophy tabbypurr@gmail.com - 2018-01-01 18:51 -0800
                          Re: AC switch fault current philosophy ehsjr <ehsjr@verizon.net> - 2018-01-02 23:51 -0500
                Re: AC switch fault current philosophy tabbypurr@gmail.com - 2017-12-31 05:51 -0800
        Re: AC switch fault current philosophy Don Kuenz <g@crcomp.net> - 2017-12-29 14:19 +0000
        Re: AC switch fault current philosophy glen walpert <nospam@null.void> - 2017-12-29 16:03 +0000
        Re: AC switch fault current philosophy "Paul Hovnanian P.E." <paul@hovnanian.com> - 2017-12-29 20:01 -0800
          Re: AC switch fault current philosophy Michael A Terrell <mike.terrell@earthlink.net> - 2017-12-29 23:49 -0500
    Re: AC switch fault current philosophy Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-12-28 12:48 -0700
    Re: AC switch fault current philosophy George Herold <gherold@teachspin.com> - 2017-12-28 13:28 -0800

Page 3 of 4 — ← Prev page 1 2 [3] 4  Next page →

#489848

upsid...@downunder.com wrote:

--------------------------------

> 
> What is the point of including an overcurrent device in the power
> strip end of the extension cable ?
> 

** You tell us - seeing as you invented the idea. 

Seriously, you have lost contact with any prior context and are raving like a mad man. 



> In countries using ring mains (such as the UK) There is a single loop
> of heavy wire zig-zagging around the building with big e.g. 35 A fuses
> at each end of the loop.
> 

** Just one breaker of fuse is used for each ring. 

   Are you on drugs ? 


> Each device to be plugged into the ring mains loop socket must have a
> fuse in the plug. Thus, the extension cable plug end should have a 13
> or 20 A overcurrent protector, not the power strip end.
> 


** No-one here has said otherwise. 

  You good at shadow boxing, by any chance  ? 



.... Phil 

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#489860

On Sunday, 31 December 2017 12:36:35 UTC, upsid...@downunder.com  wrote:
> On Sat, 30 Dec 2017 21:13:27 -0800 (PST), Phil Allison


> >Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 

most of ours don't in uk

> What is the point of including an overcurrent device in the power
> strip end of the extension cable ?

to stop it overheating and melting. We have them now in reel extension leads, but not others.

> In countries using ring mains (such as the UK) There is a single loop
> of heavy wire zig-zagging around the building with big e.g. 35 A fuses
> at each end of the loop.

ring circuits use a single 32A breaker or 30A fuse. Only pre-1955 installs sometimes have 2 fuses for one ring, or in some cases 4!


> Each device to be plugged into the ring mains loop socket must have a
> fuse in the plug. Thus, the extension cable plug end should have a 13
> or 20 A overcurrent protector, not the power strip end.

13A maximum


NT

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#489932

On Sunday, 31 December 2017 12:36:35 UTC, upsid...@downunder.com  wrote:
> On Sat, 30 Dec 2017 21:13:27 -0800 (PST), Phil Allison


> >Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 

most of ours don't in uk

> What is the point of including an overcurrent device in the power
> strip end of the extension cable ?

to stop it overheating and melting. We have them now in reel extension leads, but not others.

> In countries using ring mains (such as the UK) There is a single loop
> of heavy wire zig-zagging around the building with big e.g. 35 A fuses
> at each end of the loop.

ring circuits use a single 32A breaker or 30A fuse. Only pre-1955 installs sometimes have 2 fuses for one ring, or in some cases 4!


> Each device to be plugged into the ring mains loop socket must have a
> fuse in the plug. Thus, the extension cable plug end should have a 13
> or 20 A overcurrent protector, not the power strip end.

13A maximum


NT

[toc] | [prev] | [next] | [standalone]

#489948

On 2018-01-01, tabbypurr@gmail.com <tabbypurr@gmail.com> wrote:
> On Sunday, 31 December 2017 12:36:35 UTC, upsid...@downunder.com  wrote:
>> On Sat, 30 Dec 2017 21:13:27 -0800 (PST), Phil Allison
>
>
>> >Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 
>
> most of ours don't in uk
>

yeah, but aren't yours fused in the plug? That would be even better from a
safety standpoint if you discount the inconvenience of a blown fuse.

-- 
This email has not been checked by half-arsed antivirus software 

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#489951

On Monday, 1 January 2018 04:31:10 UTC, Jasen Betts  wrote:
> On 2018-01-01, tabbypurr wrote:
> > On Sunday, 31 December 2017 12:36:35 UTC, upsid...@downunder.com  wrote:
> >> On Sat, 30 Dec 2017 21:13:27 -0800 (PST), Phil Allison
> >
> >
> >> >Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 
> >
> > most of ours don't in uk
> >
> 
> yeah, but aren't yours fused in the plug? That would be even better from a
> safety standpoint if you discount the inconvenience of a blown fuse.

Every mains plug is fused here (OK there are exceptions but not that are relevant). Max 13A, also often 3A. Most sockets are on 32A rings.


NT

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#489859

On Sunday, 31 December 2017 05:13:36 UTC, Phil Allison  wrote:
> ehsjr TROLL wrote:
> 
> ------------------
> 
> > 
> > Here's a link to a power strip rated 10 amps:
> > https://www.amazon.com/GOGOLUCK-Strips-Outlets-Protector-Extension/dp/B077QLW2S5/ref=sr_1_20_sspa?ie=UTF8&qid=1514676442&sr=8-20-spons&keywords=power+strip+bulk&psc=1#CustomerImages
> > 
> > I'll draw 13 amp rated power strips below:
> > 
> > panel
> > 20 amp ==powerstrip1==powerstrip2==powerstrip3==powerstrip4==powerstrip5
> > 
> > 5 amp loads plugged into power strips 2,3,4 and 5 = 20 amps total, 
> > breaker does not trip. Power strip 1, rated at 13 amps, "sees" a 20 amp 
> > load, overheats.
> > 
> 
> ** So fucking what ? 
> 
> Plug two 10 amp loads into ONE strip and you have a similar overload. 
> 
> Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 
> 
> FYI:
> 
> Cable rated at 13amps ( ie 16G) will not melt & burn at 20amps - it merely gets a bit warmer. There is a LARGE safety factor included in all cable and mains power plug/socket ratings. 
> 
> FYI: 
> 
> I did some bench tests not long ago using 10amp (1sqmm) mains cable, deliberately overloading it:
> 
> At rated load it was just warm ( circa 15C temp rise) 
> 
> At 2x rated, it was quite warm ( circa 35C temp rise).
> 
> At 3x rated the plastic softened and it was a bit too hot to touch.
> 
> I used a K-thermocouple to monitor temps. 
> 
> 
> 
> > Same for daisy chained extensions:
> 
> 
> ** Same reply. 
> 
>  No such issue exists in the UK or Australia. 
> 
>  George Herold lives in the UK. 
> 
> 
> 
> ....  Phil

I've also tried this with mains flex, and as Phil says it can IRL handle far more than its rating.


NT

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#490023

On 12/31/2017 12:13 AM, Phil Allison wrote:
> ehsjr TROLL wrote:
> 
> ------------------
> 
>>
>> Here's a link to a power strip rated 10 amps:
>> https://www.amazon.com/GOGOLUCK-Strips-Outlets-Protector-Extension/dp/B077QLW2S5/ref=sr_1_20_sspa?ie=UTF8&qid=1514676442&sr=8-20-spons&keywords=power+strip+bulk&psc=1#CustomerImages
>>
>> I'll draw 13 amp rated power strips below:
>>
>> panel
>> 20 amp ==powerstrip1==powerstrip2==powerstrip3==powerstrip4==powerstrip5
>>
>> 5 amp loads plugged into power strips 2,3,4 and 5 = 20 amps total,
>> breaker does not trip. Power strip 1, rated at 13 amps, "sees" a 20 amp
>> load, overheats.
>>
> 
> ** So fucking what ?


"Phil, (or someone) can you explain about the daisy chained power strips.
We got yelled at, at a trade show, but never quite understood the 
explanation."

That is the "so ******* what ?": it's an answer to the question
George posted and you snipped.

You argue from the standpoint of lack of knowledge of the laws
and practices in the USA regarding the safeguarding of personnel
using electrical devices. And you argue with the experience
and the pictures that show overloaded power strips and extension
cords burned up.  Overloaded means used beyond the listed and
labelled rating regardless of the large safety factor included
in that rating.  Overheated means the conductor temperature
rise will be higher than it would have when operated within
ratings.  The limits/ratings/specifications/whatever term you
wish to use are not based on what you or I think. They are
established by the rules and regs.

Ed

https://media.defense.gov/2016/Jan/22/2001336711/-1/-1/0/160120-F-ZZ999-223.JPG

http://dailyinbox.com/firefighters-blame-overloaded-extension-cords-for-apartment-fire/




> 
> Plug two 10 amp loads into ONE strip and you have a similar overload.
> 
> Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times.
> 
> FYI:
> 
> Cable rated at 13amps ( ie 16G) will not melt & burn at 20amps - it merely gets a bit warmer. There is a LARGE safety factor included in all cable and mains power plug/socket ratings.
> 
> FYI:
> 
> I did some bench tests not long ago using 10amp (1sqmm) mains cable, deliberately overloading it:
> 
> At rated load it was just warm ( circa 15C temp rise)
> 
> At 2x rated, it was quite warm ( circa 35C temp rise).
> 
> At 3x rated the plastic softened and it was a bit too hot to touch.
> 
> I used a K-thermocouple to monitor temps.
> 
> 
> 
>> Same for daisy chained extensions:
> 
> 
> ** Same reply.
> 
>   No such issue exists in the UK or Australia.
> 
>   George Herold lives in the UK.
> 
> 
> 
> ....  Phil
> 

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#490039

On Sunday, December 31, 2017 at 12:13:36 AM UTC-5, Phil Allison wrote:
> ehsjr TROLL wrote:
> 
> ------------------
> 
> > 
> > Here's a link to a power strip rated 10 amps:
> > https://www.amazon.com/GOGOLUCK-Strips-Outlets-Protector-Extension/dp/B077QLW2S5/ref=sr_1_20_sspa?ie=UTF8&qid=1514676442&sr=8-20-spons&keywords=power+strip+bulk&psc=1#CustomerImages
> > 
> > I'll draw 13 amp rated power strips below:
> > 
> > panel
> > 20 amp ==powerstrip1==powerstrip2==powerstrip3==powerstrip4==powerstrip5
> > 
> > 5 amp loads plugged into power strips 2,3,4 and 5 = 20 amps total, 
> > breaker does not trip. Power strip 1, rated at 13 amps, "sees" a 20 amp 
> > load, overheats.
> > 
> 
> ** So fucking what ? 
> 
> Plug two 10 amp loads into ONE strip and you have a similar overload. 
> 
> Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 
> 
> FYI:
> 
> Cable rated at 13amps ( ie 16G) will not melt & burn at 20amps - it merely gets a bit warmer. There is a LARGE safety factor included in all cable and mains power plug/socket ratings. 
> 
> FYI: 
> 
> I did some bench tests not long ago using 10amp (1sqmm) mains cable, deliberately overloading it:
> 
> At rated load it was just warm ( circa 15C temp rise) 
> 
> At 2x rated, it was quite warm ( circa 35C temp rise).
> 
> At 3x rated the plastic softened and it was a bit too hot to touch.
> 
> I used a K-thermocouple to monitor temps. 
> 
> 
> 
> > Same for daisy chained extensions:
> 
> 
> ** Same reply. 
> 
>  No such issue exists in the UK or Australia. 
> 
>  George Herold lives in the UK. 

No, (near) Buffalo, NY USA.  

Thanks for all the responses.  (Phil, Ed, others.)  

The case in point was at a trade show where we had wired up several
(let's say three, at a guess) power stripes in a row.. all in series.

There was some fault in the electrical distribution, that shut off our 
booth power.  (Maybe a ground fault?)  And the electrician on site blamed 
the long daisy chain of power stripes.  

George H. 
> 
> 
> 
> ....  Phil

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#490043

On 01/02/2018 09:27 AM, George Herold wrote:
> On Sunday, December 31, 2017 at 12:13:36 AM UTC-5, Phil Allison wrote:
>> ehsjr TROLL wrote:
>>
>> ------------------
>>
>>>
>>> Here's a link to a power strip rated 10 amps:
>>> https://www.amazon.com/GOGOLUCK-Strips-Outlets-Protector-Extension/dp/B077QLW2S5/ref=sr_1_20_sspa?ie=UTF8&qid=1514676442&sr=8-20-spons&keywords=power+strip+bulk&psc=1#CustomerImages
>>>
>>> I'll draw 13 amp rated power strips below:
>>>
>>> panel
>>> 20 amp ==powerstrip1==powerstrip2==powerstrip3==powerstrip4==powerstrip5
>>>
>>> 5 amp loads plugged into power strips 2,3,4 and 5 = 20 amps total, 
>>> breaker does not trip. Power strip 1, rated at 13 amps, "sees" a 20 amp 
>>> load, overheats.
>>>
>>
>> ** So fucking what ? 
>>
>> Plug two 10 amp loads into ONE strip and you have a similar overload. 
>>
>> Power strips SHOULD all have thermal beakers included, been the law here for over 20 years. You Yanks are behind the times. 
>>
>> FYI:
>>
>> Cable rated at 13amps ( ie 16G) will not melt & burn at 20amps - it merely gets a bit warmer. There is a LARGE safety factor included in all cable and mains power plug/socket ratings. 
>>
>> FYI: 
>>
>> I did some bench tests not long ago using 10amp (1sqmm) mains cable, deliberately overloading it:
>>
>> At rated load it was just warm ( circa 15C temp rise) 
>>
>> At 2x rated, it was quite warm ( circa 35C temp rise).
>>
>> At 3x rated the plastic softened and it was a bit too hot to touch.
>>
>> I used a K-thermocouple to monitor temps. 
>>
>>
>>
>>> Same for daisy chained extensions:
>>
>>
>> ** Same reply. 
>>
>>  No such issue exists in the UK or Australia. 
>>
>>  George Herold lives in the UK. 
> 
> No, (near) Buffalo, NY USA.  
> 
> Thanks for all the responses.  (Phil, Ed, others.)  
> 
> The case in point was at a trade show where we had wired up several
> (let's say three, at a guess) power stripes in a row.. all in series.
> 
> There was some fault in the electrical distribution, that shut off our 
> booth power.  (Maybe a ground fault?)  And the electrician on site blamed 
> the long daisy chain of power stripes.  
> 

Because then it wasn't his fault. ;)

Seriously, though, as I've said several times before, electrical codes
contain a lot of non-obvious and very expensive wisdom.

Refraining from deliberately shorting the mains is one of the less
non-obvious parts of that. ;)

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
https://hobbs-eo.com

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#489845

pcdhobbs@gmail.com wrote:

> Or the wiring might be marginal, but good enough for many more years unless somebody did something idiotic like shorting the mains.

I'd say that the short-circuit behaviour of the mains is one of the
most important parameters of the wiring. In Poland exactly this 
parameter (the short-circuit loop resistance) must be measured every
5 years by a qualified technician in order to allow the further 
operation of the flat/house installation. The wiring just can't be
barely enough, something in the order of 5-10x current capacity
for a short period must be ensured in order to make the fuses blow.
My worst-case is 0.5Ohm, with 0.38Ohm being the most frequent value.

	Best regards, Piotr

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#489816

On 12/28/2017 6:25 PM, tabbypurr@gmail.com wrote:
> On Thursday, 28 December 2017 22:43:05 UTC, pcdh...@gmail.com  wrote:
>> NT:
>>> On Thursday, 28 December 2017 20:27:43 UTC, pcdh...@gmail.com  wrote:
> 
>>>>> You might limit the current and trip the mains breaker to cope with the
>>>>> short. That way you simultaneously protect the shorted device and send
>>>>> users a dramatic message that something's wrong.
>>>
>>>> You mean the breaker at the _panel_? How do you know if it's magnetic or thermal?
>>>>
>>>> And then somebody plugs it into daisy-chained extension cords and your 'safety
>>>> device' burns down the building. Brilliant all round. :(
>>
>>> don't implement it stupidly. The current limiter must have overheat protection.
>>
>> How are you going to do that if you don't know how it's connected?
> 
> I'm not making sense of that question
> 
>> Building a known fast breaker into the box, I get. Relying on the capabilities of a hypothetical breaker at an unknown upstream point, not so much.
>>
>> Cheers
>>
>> Phil Hobbs
> 
> Mains supply breakers aren't hypothetical. In UK they're well defined. I presume they are in all other 1st world countries too.
> 

The mains supply breaker is NOT intended nor designed to protect the 
power using equipment.  That breaker is there to protect the permanent 
wiring from the panel to the outlet to which the power using equipment 
is connected.  Relying on the mains breaker to make the power using 
equipment safe in the event of a fault in that equipment is wrong, 
unsafe and stupid everywhere, and is illegal in the USA.


> And the whole point of overheat cutout is that it interrupts the current if for any reason the supply fails to. That could be as simple as a fusible resistor.
> 

No.  The overheat cutout, or any other equipment power safety device, 
must be designed to interrupt the current before the mains supply 
over-current device does.  You must NOT rely on the mains panel breaker
to protect the equipment, or personnel using the equipment.  The
panel breaker's job is to protect the building wiring up to the
point where the external equipment draws power from it.

Ed

> 
> NT
> 

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#489818

ehsjr troll wrote:

----------------

> 
> The mains supply breaker is NOT intended nor designed to protect the 
> power using equipment.  That breaker is there to protect the permanent 
> wiring from the panel to the outlet to which the power using equipment 
> is connected. 
>

** Essentially true, but the nest bit is not. 


> Relying on the mains breaker to make the power using 
> equipment safe in the event of a fault in that equipment is wrong, 
> unsafe and stupid everywhere,


** Bollocks. 

  

> and is illegal in the USA.



** Really ?? 

  So all US appliances have fuses fitted ?? 


....  Phil

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#489835

On 12/30/2017 7:52 PM, Phil Allison wrote:
> ehsjr troll wrote:
> 
> ----------------
> 
>>
>> The mains supply breaker is NOT intended nor designed to protect the
>> power using equipment.  That breaker is there to protect the permanent
>> wiring from the panel to the outlet to which the power using equipment
>> is connected.
>>
> 
> ** Essentially true, but the nest bit is not.
> 
> 
>> Relying on the mains breaker to make the power using
>> equipment safe in the event of a fault in that equipment is wrong,
>> unsafe and stupid everywhere,
> 
> 
> ** Bollocks.
> 
>    
> 
>> and is illegal in the USA.
> 
> 
> 
> ** Really ??
> 
>    So all US appliances have fuses fitted ??

No. If the equipment is listed by a certified testing laboratory such
as the UL (Underwriters Laboratory) (or other accepted testing lab)
the lab is saying, in effect, it was manufactured in accordance with
the rules and meets electrical (and other) safety requirements. If
a fuse (or breaker or whatever) is required and the device doesn't
have it, it won't be listed, nor will it be legal for the manufacturer
to sell it in the US.

You could spend months reading all the applicable rules and regulations
concerning product electrical safety, but I believe the precis above
captures the essence.  If you want to do some wading through it, it's
probably best to start with the NEC and the UL White Book.
(links below)

Ed

You can wade through the wording of our National Electrical Code
article 90-7 (et al) if you like:
https://www.mikeholt.com/mojonewsarchive/EES-HTML/HTML/LabeledListedNECOSHA~20030107.htm

and the UL white book:
https://www.ul.com/wp-content/uploads/2014/09/UL-White-Book.pdf?utm_source=multiple&utm_medium=vanity&utm_campaign=codeauthoritieswhitebook



> 
> 
> ....  Phil
> 

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#489837

ehsjr TROLL wrote:

-------------------------
>
>
> >>
> >> The mains supply breaker is NOT intended nor designed to protect the
> >> power using equipment.  That breaker is there to protect the permanent
> >> wiring from the panel to the outlet to which the power using equipment
> >> is connected.
> >>
> > 
> > ** Essentially true, but the next bit is not.
> > 
> > 
> >> Relying on the mains breaker to make the power using
> >> equipment safe in the event of a fault in that equipment is wrong,
> >> unsafe and stupid everywhere,
> > 
> > 
> > ** Bollocks.
> > 
> >    
> > 
> >> and is illegal in the USA.
> > 
> > 
> > 
> > ** Really ??
> > 
> >   So all US appliances have fuses fitted ??
> 
>
> No.


** Then at least some of them are dangerous - according to YOU. 


> If the equipment is listed by a certified testing laboratory such
> as the UL (Underwriters Laboratory)


** Non compulsory, AFAIK. 

  Wot a load of crapology. 




....  Phil 

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#490004

On 12/30/2017 11:33 PM, Phil Allison wrote:
> ehsjr TROLL wrote:
> 
> -------------------------
>>
>>
>>>>
>>>> The mains supply breaker is NOT intended nor designed to protect the
>>>> power using equipment.  That breaker is there to protect the permanent
>>>> wiring from the panel to the outlet to which the power using equipment
>>>> is connected.
>>>>
>>>
>>> ** Essentially true, but the next bit is not.
>>>
>>>
>>>> Relying on the mains breaker to make the power using
>>>> equipment safe in the event of a fault in that equipment is wrong,
>>>> unsafe and stupid everywhere,
>>>
>>>
>>> ** Bollocks.
>>>
>>>     
>>>
>>>> and is illegal in the USA.
>>>
>>>
>>>
>>> ** Really ??
>>>
>>>    So all US appliances have fuses fitted ??
>>
>>
>> No.
> 
> 
> ** Then at least some of them are dangerous - according to YOU.

So you think an appliance must have a fuse must be fitted to make
it safe?

Don't be silly. Dishwashers, electric stoves, clothes washer/dryers,
refrigerators et al have grounded metal cabinets. No fuse is required 
for electrical safety for people using them. Double insulated tools
prevent people from contacting an electrical fault.

Ed


> 
> 
>> If the equipment is listed by a certified testing laboratory such
>> as the UL (Underwriters Laboratory)
> 
> 
> ** Non compulsory, AFAIK.
> 
>    Wot a load of crapology.
> 
> 
> 
> 
> ....  Phil
> 
> 
> 
> 
> 
> 
> 

[toc] | [prev] | [next] | [standalone]

#490014

ehsjr wrote:

----------------

> 
> >>>>
> >>>> The mains supply breaker is NOT intended nor designed to protect the
> >>>> power using equipment.  That breaker is there to protect the permanent
> >>>> wiring from the panel to the outlet to which the power using equipment
> >>>> is connected.
> >>>>
> >>>
> >>> ** Essentially true, but the next bit is not.
> >>>
> >>>
> >>>> Relying on the mains breaker to make the power using
> >>>> equipment safe in the event of a fault in that equipment is wrong,
> >>>> unsafe and stupid everywhere,
> >>>
> >>>
> >>> ** Bollocks.
> >>>
> >>>     
> >>>
> >>>> and is illegal in the USA.
> >>>
> >>>
> >>>
> >>> ** Really ??
> >>>
> >>>   So all US appliances have fuses fitted ??
> >>
> >>
> >> No.
> > 
> > 
> > ** Then at least some of them are dangerous - according to YOU.
> 
> So you think an appliance must have a fuse must be fitted to make
> it safe?
> 


 ** FFS  -  that is what **YOU** just claimed. 
 
   I say your original premise is FALSE. 



> Don't be silly. Dishwashers, electric stoves, clothes washer/dryers,
> refrigerators et al have grounded metal cabinets. No fuse is required 
> for electrical safety for people using them.


** MASSIVE  RED HERRING ALERT !!!!!!!!!!!!!!!!!!!!!

 That was never the question - you desperate, damn LIAR. 

 Fuses and breakers provide NO protection against electric shock. 

 They provide minimal, fire hazard protection and little more. 


FYI dickhead: 

Earthing of metal cases provides shock protection ONLY if the metal really IS earthed. Lotsa ways it can wind up live instead. 

User replaceable fuses cannot be relied on to provide protection of any kind. 

Installed breakers provide fire protection for installed cables and appliance cables in the vast majority of situations too  -  but no fire protection for appliances themselves. 

Go away you damn fool. 



....  Phil

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#490019

On Tuesday, 2 January 2018 01:26:18 UTC, Phil Allison  wrote:
> ehsjr wrote:
8<

> > > ** Then at least some of them are dangerous - according to YOU.
> > 
> > So you think an appliance must have a fuse must be fitted to make
> > it safe?
> > 
> 
> 
>  ** FFS  -  that is what **YOU** just claimed. 
>  
>    I say your original premise is FALSE. 
> 
> 
> 
> > Don't be silly. Dishwashers, electric stoves, clothes washer/dryers,
> > refrigerators et al have grounded metal cabinets. No fuse is required 
> > for electrical safety for people using them.
> 
> 
> ** MASSIVE  RED HERRING ALERT !!!!!!!!!!!!!!!!!!!!!
> 
>  That was never the question - you desperate, damn LIAR. 

He's just trolling.


>  Fuses and breakers provide NO protection against electric shock. 
> 
>  They provide minimal, fire hazard protection and little more. 
> 
> 
> FYI dickhead: 
> 
> Earthing of metal cases provides shock protection ONLY if the metal really IS earthed. Lotsa ways it can wind up live instead. 
> 
> User replaceable fuses cannot be relied on to provide protection of any kind. 
> 
> Installed breakers provide fire protection for installed cables and appliance cables in the vast majority of situations too  -  but no fire protection for appliances themselves. 
> 
> Go away you damn fool. 
> 
> 
> 
> ....  Phil

but that section contains errors. I don't expect any reasonable response from you, hence it's not even worth getting into it.

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#490127

On 1/1/2018 8:26 PM, Phil Allison wrote:
> ehsjr wrote:
> 
> ----------------
> 
>>
>>>>>>
>>>>>> The mains supply breaker is NOT intended nor designed to protect the
>>>>>> power using equipment.  That breaker is there to protect the permanent
>>>>>> wiring from the panel to the outlet to which the power using equipment
>>>>>> is connected.
>>>>>>
>>>>>
>>>>> ** Essentially true, but the next bit is not.
>>>>>
>>>>>
>>>>>> Relying on the mains breaker to make the power using
>>>>>> equipment safe in the event of a fault in that equipment is wrong,
>>>>>> unsafe and stupid everywhere,
>>>>>
>>>>>
>>>>> ** Bollocks.
>>>>>
>>>>>      
>>>>>
>>>>>> and is illegal in the USA.
>>>>>
>>>>>
>>>>>
>>>>> ** Really ??
>>>>>
>>>>>    So all US appliances have fuses fitted ??
>>>>
>>>>
>>>> No.
>>>
>>>
>>> ** Then at least some of them are dangerous - according to YOU.
>>
>> So you think an appliance must have a fuse must be fitted to make
>> it safe?
>>
> 
> 
>   ** FFS  -  that is what **YOU** just claimed.

Phil, You either suffer from a serious reading deficiency,
or you're a liar.

Goodbye.

Ed

>   
>     I say your original premise is FALSE.
> 
> 
> 
>> Don't be silly. Dishwashers, electric stoves, clothes washer/dryers,
>> refrigerators et al have grounded metal cabinets. No fuse is required
>> for electrical safety for people using them.
> 
> 
> ** MASSIVE  RED HERRING ALERT !!!!!!!!!!!!!!!!!!!!!
> 
>   That was never the question - you desperate, damn LIAR.
> 
>   Fuses and breakers provide NO protection against electric shock.
> 
>   They provide minimal, fire hazard protection and little more.
> 
> 
> FYI dickhead:
> 
> Earthing of metal cases provides shock protection ONLY if the metal really IS earthed. Lotsa ways it can wind up live instead.
> 
> User replaceable fuses cannot be relied on to provide protection of any kind.
> 
> Installed breakers provide fire protection for installed cables and appliance cables in the vast majority of situations too  -  but no fire protection for appliances themselves.
> 
> Go away you damn fool.
> 
> 
> 
> ....  Phil
> 
> 
> 
> 
> 
> 

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#489857

On Sunday, 31 December 2017 00:45:04 UTC, ehsjr  wrote:
> On 12/28/2017 6:25 PM, tabbypurr wrote:
> > On Thursday, 28 December 2017 22:43:05 UTC, pcdh...@gmail.com  wrote:
> >> NT:
> >>> On Thursday, 28 December 2017 20:27:43 UTC, pcdh...@gmail.com  wrote:

> >>>>> You might limit the current and trip the mains breaker to cope with the
> >>>>> short. That way you simultaneously protect the shorted device and send
> >>>>> users a dramatic message that something's wrong.
> >>>
> >>>> You mean the breaker at the _panel_? How do you know if it's magnetic or thermal?
> >>>>
> >>>> And then somebody plugs it into daisy-chained extension cords and your 'safety
> >>>> device' burns down the building. Brilliant all round. :(
> >>
> >>> don't implement it stupidly. The current limiter must have overheat protection.
> >>
> >> How are you going to do that if you don't know how it's connected?
> > 
> > I'm not making sense of that question
> > 
> >> Building a known fast breaker into the box, I get. Relying on the capabilities of a hypothetical breaker at an unknown upstream point, not so much.
> >>
> >> Cheers
> >>
> >> Phil Hobbs
> > 
> > Mains supply breakers aren't hypothetical. In UK they're well defined. I presume they are in all other 1st world countries too.
> > 
> 
> The mains supply breaker is NOT intended nor designed to protect the 
> power using equipment. 

In the UK it sometimes does

> That breaker is there to protect the permanent 
> wiring from the panel to the outlet to which the power using equipment 
> is connected.  Relying on the mains breaker to make the power using 
> equipment safe in the event of a fault in that equipment is wrong, 
> unsafe and stupid everywhere, and is illegal in the USA.

you guys seem determined to not get it. Protection can be split between 2 devices, as long as in all scenarios safe protection occurs. That CAN be done, and safely, by using the breaker to trip in some situations. Splitting the protection happens day in day out over here.


> > And the whole point of overheat cutout is that it interrupts the current if for any reason the supply fails to. That could be as simple as a fusible resistor.
> > 
> 
> No.  The overheat cutout, or any other equipment power safety device, 
> must be designed to interrupt the current before the mains supply 
> over-current device does.  You must NOT rely on the mains panel breaker
> to protect the equipment, or personnel using the equipment.  The
> panel breaker's job is to protect the building wiring up to the
> point where the external equipment draws power from it.

I guess you're in America. I'm not.


NT

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#489562

pcdhobbs@gmail.com wrote:
>>You might limit the current and trip the mains breaker to cope with the
>>short. That way you simultaneously protect the shorted device and send
>>users a dramatic message that something's wrong.
>
> You mean the breaker at the _panel_? How do you know if it's magnetic or thermal?
>
> And then somebody plugs it into daisy-chained extension cords and your
> 'safety device' burns down the building. Brilliant all round. :(

You "missed the boat" with my 'safety device.' piglet's semiconductor
switch only makes sense to me when its part of the electrical wiring
and not plugged into either an outlet or a daisy chain of extension
cords. (BTW, isn't a daisy chain of extension cords against the regs?)

Thank you,

--
Don Kuenz, KB7RPU

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