Of a Facebook group a person with an unspecified broadband issue has beenadvised to get the house earth checked as <quote> ?Believe me, it happensall the time in office premises I used to be a network engineer in anotherlife). Some houses effectivelydon't have earthing at all.? </quote>.This has got to be bollocks hasn?t it? In the first place I?ve never met arouter with an earth and secondly, surely lack of earthing in a domesticsituation must be a rare event? Tim-- Please don't feed the trolls
Of a Facebook group a person with an unspecified broadband issue has been >advised to get the house earth checked as <quote> “Believe me, it happens >all the time in office premises I used to be a network engineer in another >life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never
met a
router with an earth and secondly, surely lack of earthing in a domestic >situation must be a rare event?
Tim
On 10/12/2023 in message <1457894023.723937301.553986.timdownieuk-yahoo.co.youkay@news.individual.net>
Tim+ wrote:
Of a Facebook group a person with an unspecified broadband issue has
been advised to get the house earth checked as <quote> “Believe me,
it happens all the time in office premises I used to be a network
engineer in another life). Some houses effectively don't have
earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve
never met a
router with an earth and secondly, surely lack of earthing in a
domestic situation must be a rare event?
Tim
Broadband will work even if one of the copper legs is open circuit,
it seems somehow to find its own earth, the 'phone won't work at all
in that situation.
I belong to a Facebook group that discusses American "old" houses and
a lot have knob and tube wiring which seems astonishing compared to
what's required here:
https://en.wikipedia.org/wiki/Knob-and-tube_wiring
Of a Facebook group a person with an unspecified broadband issue has been advised to get the house earth checked as <quote> “Believe me, it happens all the time in office premises I used to be a network engineer in another life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it?
In the first place I’ve never met a
router with an earth and secondly,
surely lack of earthing in a domestic
situation must be a rare event?
On 10/12/2023 in message <1457894023.723937301.553986.timdownieuk-yahoo.co.youkay@news.individual.net> Tim+ wrote:
Of a Facebook group a person with an unspecified broadband issue has been
advised to get the house earth checked as <quote> “Believe me, it happens >> all the time in office premises I used to be a network engineer in another >> life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic
situation must be a rare event?
Tim
Broadband will work even if one of the copper legs is open circuit, it seems somehow to find its own earth, the 'phone won't work at all in that situation.
I belong to a Facebook group that discusses American "old" houses and a lot have knob and tube wiring which seems astonishing compared to what's required here:
https://en.wikipedia.org/wiki/Knob-and-tube_wiring
Of a Facebook group a person with an unspecified broadband issue has been advised to get the house earth checked as <quote> “Believe me, it happens all the time in office premises I used to be a network engineer in another life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic situation must be a rare event?
Tim
Of a Facebook group a person with an unspecified broadband issue has been advised to get the house earth checked as <quote> “Believe me, it happens all the time in office premises I used to be a network engineer in another life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic situation must be a rare event?
Tim
Am 10/12/2023 um 21:47 schrieb Tim+:
Of a Facebook group a person with an unspecified broadband issue has been
advised to get the house earth checked as <quote> “Believe me, it happens >> all the time in office premises I used to be a network engineer in
another
life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never >> met a
router with an earth and secondly, surely lack of earthing in a domestic
situation must be a rare event?
Tim
Feck. Is Farcebook still a things? Doesn't everybody Tik the Tok now?
Then there was this betting shop that had been extended into the unit next door, and I discovered half of the installation was on a different phase.
Of a Facebook group a person with an unspecified broadband issue has been advised to get the house earth checked as <quote> “Believe me, it happens all the time in office premises I used to be a network engineer in another life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic situation must be a rare event?
On 10/12/2023 22:34, Graham. wrote:
Then there was this betting shop that had been extended into the unit next door, and I discovered half of the installation was on a different phase.
Where I used to work, the server room and lab had a series of benches as >spines that stuck out from a backbone (like a multi-legged letter E).
Someone in Site Facilities had decided to put each bench on a different
mains phase, which meant there were big signs telling people not to
connect data cables (Ethernet, RS-232 etc) between equipment on
different benches. It had been fine until that floor of the building was >refurbished and the lab was put onto lots of separate phases instead of
(as previously) all being on one phase.
On Mon, 11 Dec 2023 21:29:13 +0000, NY <me@privacy.net> wrote:
On 10/12/2023 22:34, Graham. wrote:
Then there was this betting shop that had been extended into the unit next door, and I discovered half of the installation was on a different phase.
Where I used to work, the server room and lab had a series of benches as >spines that stuck out from a backbone (like a multi-legged letter E).
Someone in Site Facilities had decided to put each bench on a different >mains phase, which meant there were big signs telling people not to
connect data cables (Ethernet, RS-232 etc) between equipment on
different benches. It had been fine until that floor of the building was >refurbished and the lab was put onto lots of separate phases instead of
(as previously) all being on one phase.
In the early days of networking we contracted a company to install
10Base2 ethernet throughout two houses converted into offices.
The network would fall over more often than was acceptable bearing in
mind those BNC connections etc got knocked and we got the company back
to check their installation including the repeater in the centre of
the premises. Meanwhile I was going around with my 10 multimeter
with no particular plan in mind and saw earth voltage fluctuations on
the cable connections.
The front house was connected to a transformer on the main road, the
back of the house was connected to a transformer at the rear of the
house. Once the customer understood the problem and the potential
risks he got the main board rewired. Network problems disappeared.
On 10/12/2023 22:34, Graham. wrote:
Then there was this betting shop that had been extended into the unit
next door, and I discovered half of the installation was on a different
phase.
Where I used to work, the server room and lab had a series of benches as spines that stuck out from a backbone (like a multi-legged letter E).
Someone in Site Facilities had decided to put each bench on a different
mains phase, which meant there were big signs telling people not to
connect data cables (Ethernet, RS-232 etc) between equipment on
different benches. It had been fine until that floor of the building was refurbished and the lab was put onto lots of separate phases instead of
(as previously) all being on one phase.
On 10/12/2023 21:47, Tim+ wrote:
Of a Facebook group a person with an unspecified broadband issue has been
advised to get the house earth checked as <quote> “Believe me, it happens >> all the time in office premises I used to be a network engineer in another >> life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic
situation must be a rare event?
Facebook is a place where you take everything with a pinch of salt.
The incoming line will be isolated from your house mains. The router will use a double insulated power supply. If you use an Ethernet port this will also be isolated, as will Wi-Fi.
In short it doesn't matter how effective, or ineffective, your earth is.
Most of FB is BS, so no change there.
On Tuesday 12 December 2023 at 21:51:30 UTC, Bob Eager wrote:
On Mon, 11 Dec 2023 21:29:13 +0000, NY wrote:
On 10/12/2023 22:34, Graham. wrote:
Then there was this betting shop that had been extended into the
unit next door, and I discovered half of the installation was on a
different phase.
Where I used to work, the server room and lab had a series of benches
as spines that stuck out from a backbone (like a multi-legged letter
E).
Someone in Site Facilities had decided to put each bench on aSome time ago, my wife worked in a fairly prestigious grammar school in Kent. She was head of computing.
different mains phase, which meant there were big signs telling
people not to connect data cables (Ethernet, RS-232 etc) between equipment on different benches. It had been fine until that floor of
the building was refurbished and the lab was put onto lots of
separate phases instead of (as previously) all being on one phase.
She set up a sixth form Linux lab in an available room. She found out
that the room next door was on a different phase, and someone had
added extra power points in *her* room ("for the computers") by back
wiring through the common wall. She put up big warning notices and
reported it as a health and safety matter.
All it did was mark her card. The Head worked hard at getting rid of
her, and he succeeded. In the long run, she did well out of it as she
is now a senior lecturer in a university!
Its good that she got a better job, but why is there so much concern
about mixing phases in a single room? Each appliance should be properly insulated so it seems very unlikely that anyone could connect themselves between two phases without first dismantling appliances connected to each phase and then holding on to both. How is this different from using a
UPS? This provides an output whose phase is likely to be random relative other nearby devices if its input happens to get switched off. The
maximum voltage difference between lives from a UPS and a nearby mains powered device could be 2x240V whereas that between two phases of a
3-phase system is only sqrt(3) x 240V. John
quite some years ago, I was at the TV ehibition in Montreaux. I was
showing the newly developed CEEFAX. Our signal source was from a VTR
2 floors below. There was a 10v difference between the earths.
On 12/12/2023 1:49 PM, Fredxx wrote:
On 10/12/2023 21:47, Tim+ wrote:
Of a Facebook group a person with an unspecified broadband issue has been >>> advised to get the house earth checked as <quote> “Believe me, it happens >>> all the time in office premises I used to be a network engineer in another >>> life). Some houses effectively don't have earthing at all.” </quote>.
This has got to be bollocks hasn’t it? In the first place I’ve never met a
router with an earth and secondly, surely lack of earthing in a domestic >>> situation must be a rare event?
Facebook is a place where you take everything with a pinch of salt.
The incoming line will be isolated from your house mains. The router will use a double insulated power supply. If you use an Ethernet port this will also be isolated, as will Wi-Fi.
In short it doesn't matter how effective, or ineffective, your earth is.
Most of FB is BS, so no change there.
The four twisted-pair Ethernet cable, has no ground in it, no shield, and
is transformer isolated at both ends. A quick search on Google,
indicates a "withstand" of a bit more than 2kV. For that to be true,
the creepage and clearance around certain areas must be done properly.
Modern Ethernet is "one of the nicest interfaces" on a modern computer.
And is a definite improvement after doubly-terminated coax cable
and Vampire Taps in first generation.
It's a wonder any of those sort of website is still around. Doubly terminated coax, with ground only on one end.Out of interest I found this https://web.archive.org/web/20160419080105/https://www.ti.com/lit/ds/symlink/dp8392.pdf
https://www.mattmillman.com/projects/10base5/
Paul
As I recall, there should be 2m between outlets on different phases. Of
course, using extension leads might create problem.
There was once such a rule, but I think it was removed over 30 years ago.
As far as I know there has been no restriction on adjacent sockets being connected to different phases in recent decades.
In article <d6ad8e58-409d-4d37-b0ee-74145b6ebe3dn@googlegroups.com>, John >Walliker <jrwalliker@gmail.com> wrote:
On Tuesday 12 December 2023 at 21:51:30 UTC, Bob Eager wrote:
On Mon, 11 Dec 2023 21:29:13 +0000, NY wrote:
On 10/12/2023 22:34, Graham. wrote:Some time ago, my wife worked in a fairly prestigious grammar school in
Then there was this betting shop that had been extended into the
unit next door, and I discovered half of the installation was on a
different phase.
Where I used to work, the server room and lab had a series of benches
as spines that stuck out from a backbone (like a multi-legged letter
E).
Someone in Site Facilities had decided to put each bench on a
different mains phase, which meant there were big signs telling
people not to connect data cables (Ethernet, RS-232 etc) between
equipment on different benches. It had been fine until that floor of
the building was refurbished and the lab was put onto lots of
separate phases instead of (as previously) all being on one phase.
Kent. She was head of computing.
She set up a sixth form Linux lab in an available room. She found out
that the room next door was on a different phase, and someone had
added extra power points in *her* room ("for the computers") by back
wiring through the common wall. She put up big warning notices and
reported it as a health and safety matter.
All it did was mark her card. The Head worked hard at getting rid of
her, and he succeeded. In the long run, she did well out of it as she
is now a senior lecturer in a university!
Its good that she got a better job, but why is there so much concern
about mixing phases in a single room? Each appliance should be properly
insulated so it seems very unlikely that anyone could connect themselves
between two phases without first dismantling appliances connected to each
phase and then holding on to both. How is this different from using a
UPS? This provides an output whose phase is likely to be random relative
other nearby devices if its input happens to get switched off. The
maximum voltage difference between lives from a UPS and a nearby mains
powered device could be 2x240V whereas that between two phases of a
3-phase system is only sqrt(3) x 240V. John
As I recall, there should be 2m between outlets on different phases. Of >course, using extension leads might create problem.
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