# Energy savings, do you care?...

T

#### Tabby

##### Guest
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?
UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

NT

P

#### Piotr Wyderski

##### Guest
Klaus Kragelund wrote:

> Do you care about the efficiency of that one, say instead of using 30W, you could buy a more expensive one that consumes 25W for the same pump performance?

It all depends on what is going to happen with the waste heat. This kind
of pumps are used for heating anyway, so with the less efficient pump
effectively you end up with a distributed heater. So I probably wouldn\'t
care.

For the same reason, the incandescent light bulbs weren\'t that bad in
the colder parts of Europe. Just a fancy heater, emitting light with low
efficiency as a byproduct. Without them, another system needs to
compensate that lack of heat, so the global savings may not be that big.
Exactly the opposite in the warmer region, one had to get rid of that
excessive heat.

> Would you spend +10 USD more on that pump, for a payback period of less than 4 years?

Not really, at least in this case. Otherwise, I do care for the idle
power/efficiency specs. 1W-year is about 1.2 USD here. If the device is
of sufficiently high power and has a sufficiently high duty cycle, the
saving here can be a significant fraction of that device\'s price.

> Also, would a IOT connected pump be a sales parameter?
IOT can be added to anything externally, and the Chinese will make the
gadget at 1 dollar with free shipping. Wasted effort, IMO.

Best regards, Piotr

P

#### Piotr Wyderski

##### Guest
Klaus Kragelund wrote:

Anything IOT connected in the house is a hacking danger,

Yeah, that needs to be ultra secure
It does. It allows for both external access due to the lack of security
and is most likely connected to your LAN â a perfect relay bridging
these two worlds.

The \"intelligent\" kitchen scales have already been (ab)used that way.

Best regards, Piotr

D

#### Don Y

##### Guest
On 8/6/2020 10:28 AM, Piotr Wyderski wrote:
Klaus Kragelund wrote:

Anything IOT connected in the house is a hacking danger,

Yeah, that needs to be ultra secure

It does. It allows for both external access due to the lack of security and is
most likely connected to your LAN â a perfect relay bridging these two worlds.

The \"intelligent\" kitchen scales have already been (ab)used that way.
Yes, but that\'s something that can be remedied with a security-minded design
(instead of naively thinking \"Hey, we can just run Linux on it and get
that connectivity for near-zero development costs!\")

P

#### Pimpom

##### Guest
On 8/6/2020 10:52 PM, Piotr Wyderski wrote:
Klaus Kragelund wrote:

Do you care about the efficiency of that one, say instead of using 30W, you could buy a more expensive one that consumes 25W for the same pump performance?

It all depends on what is going to happen with the waste heat. This kind
of pumps are used for heating anyway, so with the less efficient pump
effectively you end up with a distributed heater. So I probably wouldn\'t
care.

For the same reason, the incandescent light bulbs weren\'t that bad in
the colder parts of Europe. Just a fancy heater, emitting light with low
efficiency as a byproduct. Without them, another system needs to
compensate that lack of heat, so the global savings may not be that big.
They are used here as a simple source of warmth and light for
raising poultry, especially for the younger chicks. Effective and
easy to set up.

Also, would a IOT connected pump be a sales parameter?
IOT can be added to anything externally, and the Chinese will make the
gadget at 1 dollar with free shipping. Wasted effort, IMO.
Living in a country where labour is much cheaper than in the
West, I still wonder how the Chinese do it. Many smokers here use
Chinese piezo cigarette lighters that have an LED torchlight
profit-making hands since they left a Chinese factory, they sell
for Rs.10. That\'s about 13 US cents.

D

#### Don Y

##### Guest
On 8/6/2020 8:38 AM, Tabby wrote:
On Thursday, 6 August 2020 14:22:25 UTC+1, Don Y wrote:

Bottled water ALWAYS seems foolish -- as it inevitably is just \"tap water\"
bottled elsewhere!

AIUI it\'s a good bit worse. A lot of quality standards apply to tap water
that bottled water generally doesn\'t meet. Spring water is worse than
mineral water, here in UK anyway. They\'re not normally bottled tap water,
though spring water could be legally.
Here, that might not be a slam-dunk conclusion.

We are supplied by wells located around the metropolitan area.
The wells push water into the distribution network, directly.
I.e., the water doesn\'t first go to some \"treatment and
testing facility\" before being distributed back to their
consumers.

At each well site (there\'s one ~300 ft from here), there is
a \"treatment facility\" (of sorts). I notice a large barrel
of chlorine. And, a \"large doghouse\" which likely contains
metering/control equipment for the pump... maybe a UV disinfectant?

But, the point is, we only know what the water quality *was*,
when it is tested, not what it *is*, at any given time.

[Being ground water sourced, we worry about things like arsenic
levels, industrial/hazardous waste infiltrants, etc. (there are
some wells located adjacent to a landfill!)]

K

#### Klaus Kragelund

##### Guest
On Thursday, August 6, 2020 at 12:06:47 PM UTC+2, Tabby wrote:
On Thursday, 6 August 2020 03:04:15 UTC+1, Don Y wrote:
On 8/5/2020 5:57 PM, Tabby wrote:
On Wednesday, 5 August 2020 12:48:10 UTC+1, Don Y wrote:

Now, if the pump could PREDICT it\'s imminent failure and alert me to that
fact, it adds real value in that it lets me avoid living without heat
while looking for a replacement pump!

Wouldn\'t be hard to do when the failure is the main bearing, or blockage
from muck. Speed irregularity & reduced resistance respectively.

I don\'t know if sensor(s) that could deduce this would inherently
be part of the design (?) -- possibly speed but how would it
\"inexpensively\" sense drag/resistance?

[I try to deduce stuff from sensors that are already in place for
some other purpose]

I mounted an accelerometer on the side of our furnace (which is
a superfluous sensor as it isn\'t needed to control the furnace\'s
operation) and it was able to alert me to a failing blower motor.

But, that\'s a hefty motor spinning a sizeable load -- very easy
to get a \"wobble\" going as the motor fails.

become audible as the furnace would shake/tremble)

I assume the electonic supply already knows the v, i, f going to the motor. From that it could deduce uneven speed, much reduced drag & stall.

It\'s field oriented control. So if the motor stalls or cannot start, then the SW will know it
Cheers

Klaus

D

#### Don Y

##### Guest
On 8/6/2020 1:17 PM, Klaus Kragelund wrote:
On Thursday, August 6, 2020 at 12:06:47 PM UTC+2, Tabby wrote:
On Thursday, 6 August 2020 03:04:15 UTC+1, Don Y wrote:
On 8/5/2020 5:57 PM, Tabby wrote:
On Wednesday, 5 August 2020 12:48:10 UTC+1, Don Y wrote:

Now, if the pump could PREDICT it\'s imminent failure and alert me to
that fact, it adds real value in that it lets me avoid living
without heat while looking for a replacement pump!

Wouldn\'t be hard to do when the failure is the main bearing, or
blockage from muck. Speed irregularity & reduced resistance
respectively.

I don\'t know if sensor(s) that could deduce this would inherently be
part of the design (?) -- possibly speed but how would it
\"inexpensively\" sense drag/resistance?

[I try to deduce stuff from sensors that are already in place for some
other purpose]

I mounted an accelerometer on the side of our furnace (which is a
superfluous sensor as it isn\'t needed to control the furnace\'s
operation) and it was able to alert me to a failing blower motor.

But, that\'s a hefty motor spinning a sizeable load -- very easy to get a
\"wobble\" going as the motor fails.

become audible as the furnace would shake/tremble)

I assume the electonic supply already knows the v, i, f going to the
motor. From that it could deduce uneven speed, much reduced drag & stall.

It\'s field oriented control. So if the motor stalls or cannot start, then
the SW will know it
But, at that point, the pump has already *failed*. Sort of like noticing that
you have no lights in the house and deducing that the FUSE has blown! :>

What has value is being able to PREDICT that this is (likely) imminent, so
the customer can take proactive measures to avoid being left without the
service that is being provided.

E.g., in my blower motor example, *eventually*, the motor would have become
very noisey -- \"What the hell is that noise?\". Or, if we were deaf, the
house would have become very cold (in our case, the \"alert\" came in the
winter months) or hot (had it been in the summer).

Having to wait for the failure to manifest means you\'re now under-the-gun
to get a replacement installed (e.g., on a weekend when the part needs to
be trucked from a depot 100 miles to the north).

If it means losing hot water, you might grumble a bit. OTOH, if it meant
losing household heat, you might grumble a LOT!

R

#### Ricketty C

##### Guest
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.
Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

--

Rick C.

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

K

#### Klaus Kragelund

##### Guest
On Thursday, August 6, 2020 at 10:49:19 PM UTC+2, Don Y wrote:
On 8/6/2020 1:17 PM, Klaus Kragelund wrote:
On Thursday, August 6, 2020 at 12:06:47 PM UTC+2, Tabby wrote:
On Thursday, 6 August 2020 03:04:15 UTC+1, Don Y wrote:
On 8/5/2020 5:57 PM, Tabby wrote:
On Wednesday, 5 August 2020 12:48:10 UTC+1, Don Y wrote:

Now, if the pump could PREDICT it\'s imminent failure and alert me to
that fact, it adds real value in that it lets me avoid living
without heat while looking for a replacement pump!

Wouldn\'t be hard to do when the failure is the main bearing, or
blockage from muck. Speed irregularity & reduced resistance
respectively.

I don\'t know if sensor(s) that could deduce this would inherently be
part of the design (?) -- possibly speed but how would it
\"inexpensively\" sense drag/resistance?

[I try to deduce stuff from sensors that are already in place for some
other purpose]

I mounted an accelerometer on the side of our furnace (which is a
superfluous sensor as it isn\'t needed to control the furnace\'s
operation) and it was able to alert me to a failing blower motor.

But, that\'s a hefty motor spinning a sizeable load -- very easy to get a
\"wobble\" going as the motor fails.

become audible as the furnace would shake/tremble)

I assume the electonic supply already knows the v, i, f going to the
motor. From that it could deduce uneven speed, much reduced drag & stall.

It\'s field oriented control. So if the motor stalls or cannot start, then
the SW will know it

But, at that point, the pump has already *failed*. Sort of like noticing that
you have no lights in the house and deducing that the FUSE has blown! :

What has value is being able to PREDICT that this is (likely) imminent, so
the customer can take proactive measures to avoid being left without the
service that is being provided.
Certainly a nicr idea. Very hard to do, since there is a LOT of noise in the measurements

Cheers

Klaus

D

#### Don Y

##### Guest
On 8/6/2020 4:10 PM, Klaus Kragelund wrote:
On Thursday, August 6, 2020 at 10:49:19 PM UTC+2, Don Y wrote:

What has value is being able to PREDICT that this is (likely) imminent, so
the customer can take proactive measures to avoid being left without the
service that is being provided.

Certainly a nicr idea. Very hard to do, since there is a LOT of noise in the measurements
Yes. And, if you have to start ADDING sensors and/or smarts, then
it\'s no longer a \"free feature\" -- you have to assign some real
value to it to offset the added cost/price.

S

#### server

##### Guest
On Thu, 6 Aug 2020 15:32:51 -0700 (PDT), Ricketty C
<gnuarm.deletethisbit@gmail.com> wrote:

On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 °F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???
In the UK ring mains system the ring itself is protected with
something like 32 A, However, each plug connected to a ring mains
socket is protected by a much smaller fuse relevant to the individual
load current. Without this small fuse, e,g, a razor cord would have to
be so thick that the cord is capable of burning the 32 A fuse, i.e
several hundred Ampere peak current.

J

#### Jasen Betts

##### Guest
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???
That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

--
Jasen.

R

#### Ricketty C

##### Guest
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.
So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?

--

Rick C.

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

L

##### Guest
fredag den 7. august 2020 kl. 15.24.24 UTC+2 skrev Ricketty C:
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?
no, the plug and socket is only rated for max 13A.
the fuse is in the appliance plug

R

#### Ricketty C

##### Guest
On Friday, August 7, 2020 at 9:35:40 AM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 7. august 2020 kl. 15.24.24 UTC+2 skrev Ricketty C:
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 16:05:14 UTC+1, Ricketty C wrote:
On Thursday, August 6, 2020 at 6:11:40 AM UTC-4, Tabby wrote:
On Thursday, 6 August 2020 04:53:03 UTC+1, Ricketty C wrote:
On Wednesday, August 5, 2020 at 9:08:08 PM UTC-4, Tabby wrote:
On Wednesday, 5 August 2020 18:29:10 UTC+1, Ricketty C wrote:

Yeah, that\'s a very simple trouble free approach... really??? What\'s wrong with instant on? In the households in the EU the house current provides for more power availability in a standard circuit, over 2 kW vs about 1.4 kW here. That\'s plenty for instant on.

240v 32A is 7.7kW.

I was thinking more of the 9 amp circuits that I believe are common in the UK. We tend to have 15 amp 120 volts in the US, sometimes 20 amps in certain uses. 20 amps at 120 volts is practically the same as 9 amps, 240 volts and is a fair amount of water heating. It may not be enough for a shower though. I did some not so quick calculations that show 9 amp, 240 volts will raise about a third of a gallon by 25 Â°F each minute.. The average shower uses around 2 gal a minute, so more power is needed, around 6 times as much or more like 60 amps at 240 volts!

But then who cares if they need to wait 30 seconds to get hot water for the shower? When having forgotten to turn the hot water heater back on the other day, I found the water in the tank is sufficiently hot to take a shower in just a few minutes, less than 10. I\'m curious as to just how much the water heater is actually on when no water is drawn.

My utility provides hour by hour usage data and I see intermittent spikes in my usage that are likely the water heater. There is some granularity in the kWhr reading but it looks like 0.4 kWHr each 5 hours for around 80 watts consumption not counting hot water drawn.

I\'m glad I did this calculation. Installing a timer on the hot water heater will save me around \$40 a year on my TOU bill. Marginally worth it since it\'s not something I can just buy and install without either spending a bunch of money (240 volt stuff tends to be commercial \$\$\$) or having to rig up a relay to control the 240 from a 120 volt device. Not going to worry with that just now.

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?

no, the plug and socket is only rated for max 13A.
the fuse is in the appliance plug
Ok, then why did anyone bring 32 amps into this discussion? The issue being discussed was for instant on hot water. I suppose that would be a direct wired application, so then why are people talking about ring circuits and plugs?

I\'m sorry I don\'t know more about how UK homes are wired. I\'ve always found it to be very confusing with a lot of terms I don\'t know that appear to mean something but often just another term for the same thing as in the US.

I suppose the term \"ring\" circuit is a bit different because in the UK it is a higher current circuit than any one appliance is rated for. In the US any one appliance can draw the full current of a circuit which is typically 15 amps. The only real change in many, many years that affects compatibility is the use of three prong, grounded connectors. It used to be common to see a three prong to two prong plus ground wire adapters with their ground wire hanging loose. If the screw on a two prong outlet was grounded it was most likely through the neutral which was the problem the ground wire was intended to correct! What crap!

I do think the UK efforts at saving a few pennies is counter productive. I used to post in a UK ham group but they would be all over the map. The grounding methods are diverse in the UK but it is common to have no safety ground to the house, combining it with the neutral from the pole and having a ground connection at the house. The open neutral problem was exacerbated by an era of wiring with a thin aluminum foil safety ground that deteriorated in use leaving no safety grounds in those homes. In my homes there is a ground connection at the house AND a separate safety ground wire from the transformer.

It\'s all so messy.

--

Rick C.

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

T

#### Tabby

##### Guest
On Friday, 7 August 2020 14:53:59 UTC+1, Ricketty C wrote:
On Friday, August 7, 2020 at 9:35:40 AM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 7. august 2020 kl. 15.24.24 UTC+2 skrev Ricketty C:
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?

no, the plug and socket is only rated for max 13A.
the fuse is in the appliance plug

Ok, then why did anyone bring 32 amps into this discussion? The issue being discussed was for instant on hot water. I suppose that would be a direct wired application, so then why are people talking about ring circuits and plugs?
You asked. It started out with a standard power circuit supplying a point of use heater: 32A is the usual breaker rating. You can go higher, but no need to for instant sink hot water.

I\'m sorry I don\'t know more about how UK homes are wired. I\'ve always found it to be very confusing with a lot of terms I don\'t know that appear to mean something but often just another term for the same thing as in the US..

I suppose the term \"ring\" circuit is a bit different because in the UK it is a higher current circuit than any one appliance is rated for. In the US any one appliance can draw the full current of a circuit which is typically 15 amps. The only real change in many, many years that affects compatibility is the use of three prong, grounded connectors. It used to be common to see a three prong to two prong plus ground wire adapters with their ground wire hanging loose. If the screw on a two prong outlet was grounded it was most likely through the neutral which was the problem the ground wire was intended to correct! What crap!

I do think the UK efforts at saving a few pennies is counter productive.
They\'re called ring circuits because they are. The cable leaves the breaker, travels to lots of sockets around the house then returns to the breaker. The result is saved costs, improved safety & easier to add more sockets. That pretty much nowhere else in the world has adopted this system is it\'s own bit of weirdness. From what I\'ve read it seems no foreigner understands it. I don\'t know why though, it\'s not complex.

When introduced in 1947 it was to save costs in a country that was on its knees & half bombed to bits after the war. It was very successful in that respect, and its safety features were well ahead of its time. Our earlier electrical wiring systems were not so good on safety and had proven to be inherently bonkers.

I used to post in a UK ham group but they would be all over the map. The grounding methods are diverse in the UK but it is common to have no safety ground to the house, combining it with the neutral from the pole and having a ground connection at the house. The open neutral problem was exacerbated by an era of wiring with a thin aluminum foil safety ground that deteriorated in use leaving no safety grounds in those homes. In my homes there is a ground connection at the house AND a separate safety ground wire from the transformer.

It\'s all so messy.
Sounds like you\'ve misunderstood what you read.

We have 3 earthing or as you call it grounding systems. They are TT, TN-S, TN-C-S. All extremely good wrt safety.
http://wiki.diyfaq.org.uk/index.php/Earthing_Types

TT is the oldest system. There is no supplier earth/ground, houses each have their own earth rod and there is RCD(GFCI) or on older installs ELCB protection on every circuit.

TN-S came next, with supplier earth.

TN-C-S (aka PME) combines N&E on the supplier\'s side. It goes to great/excessive lengths to protect against the open neutral issue.

The only place I\'ve ever seen ali foil used for an earth connection is inside historic appliances, many of which have safety practices that would be jailworthy in today\'s society.

NT

R

#### Ricketty C

##### Guest
On Friday, August 7, 2020 at 7:46:18 PM UTC-4, Tabby wrote:
On Friday, 7 August 2020 14:53:59 UTC+1, Ricketty C wrote:
On Friday, August 7, 2020 at 9:35:40 AM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 7. august 2020 kl. 15.24.24 UTC+2 skrev Ricketty C:
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?

no, the plug and socket is only rated for max 13A.
the fuse is in the appliance plug

Ok, then why did anyone bring 32 amps into this discussion? The issue being discussed was for instant on hot water. I suppose that would be a direct wired application, so then why are people talking about ring circuits and plugs?

You asked. It started out with a standard power circuit supplying a point of use heater: 32A is the usual breaker rating. You can go higher, but no need to for instant sink hot water.
No, I didn\'t until someone else said, \"32 amps\" to correct my 9 amp number which should have been 13 amps. So the outlets are only 13 amps and a direct feed is needed for 32 amps. That should have been the answer about four posts ago.

I\'m sorry I don\'t know more about how UK homes are wired. I\'ve always found it to be very confusing with a lot of terms I don\'t know that appear to mean something but often just another term for the same thing as in the US.

I suppose the term \"ring\" circuit is a bit different because in the UK it is a higher current circuit than any one appliance is rated for. In the US any one appliance can draw the full current of a circuit which is typically 15 amps. The only real change in many, many years that affects compatibility is the use of three prong, grounded connectors. It used to be common to see a three prong to two prong plus ground wire adapters with their ground wire hanging loose. If the screw on a two prong outlet was grounded it was most likely through the neutral which was the problem the ground wire was intended to correct! What crap!

I do think the UK efforts at saving a few pennies is counter productive..

They\'re called ring circuits because they are. The cable leaves the breaker, travels to lots of sockets around the house then returns to the breaker.. The result is saved costs, improved safety & easier to add more sockets. That pretty much nowhere else in the world has adopted this system is it\'s own bit of weirdness. From what I\'ve read it seems no foreigner understands it. I don\'t know why though, it\'s not complex.
What is the purpose of the last leg returning to the box??? That seems rather odd. I don\'t see any way this arrangement saves in any costs. Does the rating rely on the current flowing in both legs to a given load? That would seem rather dangerous, so it must not be the intent. Every wire has to be sized to take the full load because if a wire or connection failed, instead of a given load not working any longer the full current would be drawn over the remaining link.

Where is the cost savings? Are you talking about electricity I^2R loss savings? That should be pretty microscopic in your utility bill.

> When introduced in 1947 it was to save costs in a country that was on its knees & half bombed to bits after the war. It was very successful in that respect, and its safety features were well ahead of its time. Our earlier electrical wiring systems were not so good on safety and had proven to be inherently bonkers.

What is more cost effective or safer about wasting copper by completing a ring? The last or longest leg (your choice) in the circuit could be eliminated saving money.

I used to post in a UK ham group but they would be all over the map. The grounding methods are diverse in the UK but it is common to have no safety ground to the house, combining it with the neutral from the pole and having a ground connection at the house. The open neutral problem was exacerbated by an era of wiring with a thin aluminum foil safety ground that deteriorated in use leaving no safety grounds in those homes. In my homes there is a ground connection at the house AND a separate safety ground wire from the transformer.

It\'s all so messy.

Sounds like you\'ve misunderstood what you read.

We have 3 earthing or as you call it grounding systems. They are TT, TN-S, TN-C-S. All extremely good wrt safety.
http://wiki.diyfaq.org.uk/index.php/Earthing_Types
I think you mean they all suck and have different risks.

> TT is the oldest system. There is no supplier earth/ground, houses each have their own earth rod and there is RCD(GFCI) or on older installs ELCB protection on every circuit.

This is why I hate discussing UK electrics. Every time they do some new term pops up. Wikipedia doesn\'t give any diagrams for the ELCB so I\'m not going to wade through a bunch of prose to try to figure out what they are saying and exactly what it does. Needless to say it was not adequate because it is replaced by the RCD, no?

In the many conversations I\'ve had about TT it is very clear that if you want to use a power tool outside of the house it becomes dangerous because there is no safe ground. The ground outside the house is not the ground inside the house.

> TN-S came next, with supplier earth.

You mean with the commonly failed aluminum foil protective earth?

> TN-C-S (aka PME) combines N&E on the supplier\'s side. It goes to great/excessive lengths to protect against the open neutral issue.

By \"excessive lengths\" you mean the same local ground connections as TT? Without a local ground all safety depends on no failures of the common PEN. Why not just use TT? No, don\'t answer that. I\'m truly fed up with learning about the multiple choice answer to the question of how does the UK get electricity to homes?

> The only place I\'ve ever seen ali foil used for an earth connection is inside historic appliances, many of which have safety practices that would be jailworthy in today\'s society.

You can discuss that with the Radio Society of Great Britain. A lot of old timers so they can\'t be questioned without insulting them. More than one spoke of lines in the ground with protective earth on an aluminum foil wrapper that didn\'t last 10 years. They also complained that it was very hard to get the electric company to fix them, claiming there was nothing wrong as long as they could detect any conductivity... or something like that.

Oh yeah, they insisted that EVs will never be practical in the UK because so many people live in housing that can\'t provide a charging outlet. Ok, in 10 years they will have access to all the oil they want because so many others will be powering their cars from solar and wind.

I was out today and noticed the price of gas was only \$1.91 a gallon. That would be about 39 p a liter I think. Or does the UK still use gallons for gas?

I will say that while the US sucks in holding onto the imperial system (or whatever it is we use, gallons, inches, Â°F, bald eagles per glazed donut, etc)... I forget what I was going to say good about the US. lol Oh, yeah, we have a pretty straight forward, safe electrical system with a separate ground wire all the way back to the transformer. Yeah, we used a bit of copper to make it completely safe without requiring the soil to be moist or anything else about the location.

--

Rick C.

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

T

#### Tabby

##### Guest
On Saturday, 8 August 2020 01:30:08 UTC+1, Ricketty C wrote:
On Friday, August 7, 2020 at 7:46:18 PM UTC-4, Tabby wrote:
On Friday, 7 August 2020 14:53:59 UTC+1, Ricketty C wrote:
On Friday, August 7, 2020 at 9:35:40 AM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 7. august 2020 kl. 15.24.24 UTC+2 skrev Ricketty C:
On Friday, August 7, 2020 at 12:35:50 AM UTC-4, Jasen Betts wrote:
On 2020-08-06, Ricketty C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, August 6, 2020 at 11:51:39 AM UTC-4, Tabby wrote:

9A circuits don\'t exist here, and afaik never have. (I\'m reasonably familiar with wiring practices going back to around 1910.) Sockets circuits are mostly 32A, some 20A, some 30A, a few 15A or 16A.

Where is \"here\" and what connectors do you use for these various circuits?

UK. Power sockets are always 13A square pin 3 pin polarised with a fuse in the plug. (There is another type that\'s seldom seen.) Small to medium houses have long typically had all these sockets on 2 ring circuits, but larger places have more & medium houses often get 3 or 4 socket circuits now. We do socket circuits differently to most of the world.

Ok, my faulty memory, 13 amps, not 9. But why are you talking about 32 amps???

That\'s the rating of the breaker they use on the circuit, it\'s a 32A
circuit with 13A outlets.

So can you draw 32 amps from any one outlet? Is the 13 amp fuse in the socket or the appliance plug?

no, the plug and socket is only rated for max 13A.
the fuse is in the appliance plug

Ok, then why did anyone bring 32 amps into this discussion? The issue being discussed was for instant on hot water. I suppose that would be a direct wired application, so then why are people talking about ring circuits and plugs?

You asked. It started out with a standard power circuit supplying a point of use heater: 32A is the usual breaker rating. You can go higher, but no need to for instant sink hot water.

No, I didn\'t until someone else said, \"32 amps\" to correct my 9 amp number which should have been 13 amps. So the outlets are only 13 amps and a direct feed is needed for 32 amps. That should have been the answer about four posts ago.

I\'m sorry I don\'t know more about how UK homes are wired. I\'ve always found it to be very confusing with a lot of terms I don\'t know that appear to mean something but often just another term for the same thing as in the US.

I suppose the term \"ring\" circuit is a bit different because in the UK it is a higher current circuit than any one appliance is rated for. In the US any one appliance can draw the full current of a circuit which is typically 15 amps. The only real change in many, many years that affects compatibility is the use of three prong, grounded connectors. It used to be common to see a three prong to two prong plus ground wire adapters with their ground wire hanging loose. If the screw on a two prong outlet was grounded it was most likely through the neutral which was the problem the ground wire was intended to correct! What crap!

I do think the UK efforts at saving a few pennies is counter productive.

They\'re called ring circuits because they are. The cable leaves the breaker, travels to lots of sockets around the house then returns to the breaker. The result is saved costs, improved safety & easier to add more sockets.. That pretty much nowhere else in the world has adopted this system is it\'s own bit of weirdness. From what I\'ve read it seems no foreigner understands it. I don\'t know why though, it\'s not complex.

What is the purpose of the last leg returning to the box??? That seems rather odd. I don\'t see any way this arrangement saves in any costs. Does the rating rely on the current flowing in both legs to a given load? That would seem rather dangerous, so it must not be the intent. Every wire has to be sized to take the full load because if a wire or connection failed, instead of a given load not working any longer the full current would be drawn over the remaining link.
that\'s a common misunderstanding

> Where is the cost savings? Are you talking about electricity I^2R loss savings? That should be pretty microscopic in your utility bill.

You\'re funny, but I\'ll answer that one.
1. Less total cable & copper. We use 1 power circuit where you\'d use half a dozen.
2. Less mcbs & CU (fusebox) space.
3. Less RCDs/GFCIs
4. Adding new sockets later is much cheaper: add all you want where you want with no new circuit back to the CU (fusebox)
5. One of the prime initial motivators was that a householder could take 2 existing 15A radial circuits, connect them together with a cable & add all the new sockets they wanted. The big deal was not just the saving in materials, it was the savings in not needing an electrician.

When introduced in 1947 it was to save costs in a country that was on its knees & half bombed to bits after the war. It was very successful in that respect, and its safety features were well ahead of its time. Our earlier electrical wiring systems were not so good on safety and had proven to be inherently bonkers.

What is more cost effective or safer about wasting copper by completing a ring? The last or longest leg (your choice) in the circuit could be eliminated saving money.
A high R connection in a radial circuit is dangerous.
A high R connection in a ring circuit is safe.

I used to post in a UK ham group but they would be all over the map. The grounding methods are diverse in the UK but it is common to have no safety ground to the house, combining it with the neutral from the pole and having a ground connection at the house. The open neutral problem was exacerbated by an era of wiring with a thin aluminum foil safety ground that deteriorated in use leaving no safety grounds in those homes. In my homes there is a ground connection at the house AND a separate safety ground wire from the transformer.

It\'s all so messy.

Sounds like you\'ve misunderstood what you read.

We have 3 earthing or as you call it grounding systems. They are TT, TN-S, TN-C-S. All extremely good wrt safety.
http://wiki.diyfaq.org.uk/index.php/Earthing_Types

I think you mean they all suck and have different risks.

TT is the oldest system. There is no supplier earth/ground, houses each have their own earth rod and there is RCD(GFCI) or on older installs ELCB protection on every circuit.

This is why I hate discussing UK electrics. Every time they do some new term pops up. Wikipedia doesn\'t give any diagrams for the ELCB so I\'m not going to wade through a bunch of prose to try to figure out what they are saying and exactly what it does. Needless to say it was not adequate because it is replaced by the RCD, no?
Yup. ELCBs monitored voltage between frame (in house earth connections) and an exterior earth rod. If it reached 50v they disconnected the supply. That addresses the high resistance earth issue, but gives no direct contact protection that the RCD/GFCI gives.

> In the many conversations I\'ve had about TT it is very clear that if you want to use a power tool outside of the house it becomes dangerous because there is no safe ground.

on the contrary

The ground outside the house is not the ground inside the house.

TN-S came next, with supplier earth.

You mean with the commonly failed aluminum foil protective earth?
of course not

FWIW our feed looks like it\'s paper insulated. I\'m guessing from some time around WW1. Silly authorities won\'t let them replace it, so they just repair as long a section as they can when it pops.

TN-C-S (aka PME) combines N&E on the supplier\'s side. It goes to great/excessive lengths to protect against the open neutral issue.

By \"excessive lengths\" you mean the same local ground connections as TT?
no

> Without a local ground all safety depends on no failures of the common PEN.

not all, but
a) N&E failure is a hazard
b) N&E failure is pretty much unheard of due to the extra precautions taken with PME supplies.

> Why not just use TT?

Supplier earths are safer than local rods. Low R earth connection means earthed metalwork doesn\'t reach shock voltage during a hard short before a breaker trips. We still have large numbers of ancient TT supplies.

Connecting to a pole pig means your earths are all TT afaik. We\'ve used TN-S since at least the 1930s.

No, don\'t answer that. I\'m truly fed up with learning about the multiple choice answer to the question of how does the UK get electricity to homes?

The only place I\'ve ever seen ali foil used for an earth connection is inside historic appliances, many of which have safety practices that would be jailworthy in today\'s society.

You can discuss that with the Radio Society of Great Britain. A lot of old timers so they can\'t be questioned without insulting them. More than one spoke of lines in the ground with protective earth on an aluminum foil wrapper that didn\'t last 10 years. They also complained that it was very hard to get the electric company to fix them, claiming there was nothing wrong as long as they could detect any conductivity... or something like that.
It\'s BS. Network operators are strongly motivated to be very protective of their supplies\' safe record, and are well aware that a lot of their supply infrastructure predates WW2. Last time I told one their connections were undersize they sent someone over in hours & replaced the lot a few days later.. I don\'t believe there were ever any al foil connections. Our wiring regs go back to 1882:
http://wiki.diyfaq.org.uk/index.php/Wiring_regs_history

> Oh yeah, they insisted that EVs will never be practical in the UK because so many people live in housing that can\'t provide a charging outlet.

that one\'s debated. We don\'t have the national system capacity the US has. Everyone that can park at their home could slow charge overnight, but
a) many in towns & cities can\'t park at home
b) for fast charging the infrastructure isn\'t there

Ok, in 10 years they will have access to all the oil they want because so many others will be powering their cars from solar and wind.

I was out today and noticed the price of gas was only \$1.91 a gallon. That would be about 39 p a liter I think. Or does the UK still use gallons for gas?

I will say that while the US sucks in holding onto the imperial system (or whatever it is we use, gallons, inches, Â°F, bald eagles per glazed donut, etc)... I forget what I was going to say good about the US. lol Oh, yeah, we have a pretty straight forward, safe electrical system with a separate ground wire all the way back to the transformer. Yeah, we used a bit of copper to make it completely safe without requiring the soil to be moist or anything else about the location.
Ours is safer. It\'s overengineered. We don\'t see bad neutral problems, we have better connectors, insulated plug prongs, proper cordgrips, no flammable card lining lamp holders, all sockets on new installs are GFCIed, etc etc.. 20 or so people a year die from electrocution out of 65 million - nearly always because they were doing something idiotic.

Another example. Years ago BT wanted to use US plugs for mains. They had them officially assessed. They got approval for 50v 2.5A max. They violate nearly every rule in the book for mains use here. We are the nanny state.

NT

J

#### Joerg

##### Guest
On 2020-08-06 05:11, Klaus Kragelund wrote:
On Thursday, August 6, 2020 at 12:04:38 AM UTC+2, Joerg wrote:
On 2020-08-05 13:37, upsidedown@downunder.com wrote:
On Wed, 05 Aug 2020 12:13:33 -0700, Joerg
news@analogconsultants.com> wrote:

On 2020-08-05 11:53, Ricketty C wrote:
On Wednesday, August 5, 2020 at 1:53:32 PM UTC-4, Joerg
wrote:
On 2020-08-05 10:29, Ricketty C wrote:
On Wednesday, August 5, 2020 at 1:09:26 PM UTC-4, Joerg
wrote:
On 2020-08-05 03:11, Klaus Kragelund wrote:
On Wednesday, August 5, 2020 at 12:17:27 AM UTC+2,
Joerg wrote:
On 2020-08-04 00:38, Klaus Kragelund wrote:
Hi

Triggered by the HVAC wiring thread, just out of
curiosity:

Some of you probably have a circulation pump in
the house, or several depending on the system.

Do you care about the efficiency of that one, say
expensive one that consumes 25W for the same pump
performance? (that would correlate to a
electricity savings of maybe 4 USD per year for a
50% duty ratio)

Would you spend +10 USD more on that pump, for a
payback period of less than 4 years?

Yes, but ... in the US circulation pumps are not
popular or sometimes turned off. This has a simple
reason and mostly in left-leaning states where
electricity and gas are expensive. Having to run
out some cold water before it gets warm does waste
water but that is often more than an order of
magnitude cheaper that the energy used by a
recirculating system. Not so much the electricity
for the pump but the loss of thermal energy in the
water going round and round. In our case it\'s
propane which is prohibitively expensive so we
would never consider recirculation.

Correct. New regulation actually demand that the user
press a button before using the faucet, so that the
heat recirculation pump had time to get the water
warm right before the user needs it

Who comes up with such weird laws? Now every house
needs a button wired to each sink and shower? Which, of
course, needs to be very well safety-isolated. That
drives up the cost of homes.

Did you leave your common sense at home today? Low
voltage wiring like this needs NO protection.

And how is that low voltage made? Think!

Through a low voltage transformer that provides protection.

No. That is not enough for bathroom use.

What are YOU thinking of??? Why do I have to do your
thinking for you?

Then start thinking for once

What is wrong with a SELV
https://en.wikipedia.org/wiki/Extra-low_voltage#Separated_or_safety_extra-low_voltage_(SELV)

circuit ?

In the end it\'s expensive, you can\'t just use a doorbell
transformer and call it a day. The stuff must be certified. Then
you have all kinds of electrical codes, different between
countries. For example, in many jurisdictions you must maintain a
significant separation between LV control wires and mains cables
going into the same bathroom. Can become a real headache for
installers. And on and on.

I have designed a lot of stuff for markets with similar rules and
the regulatory work alone is no small feat.

SELV transformer is not expensive at all. Notice for this
application, just getting input from a button, it needs no power at
all. So a coreless transformer on the PCB and your done. Cheap as
sh*t, probably a couple of cents (you can even just look at the
impedance of the transformer, to detect a short of the button)
Yes, that part is easy. It has to be looked at from a system level
though. If national codes require substantial physical distancing
between such LV wiring and mains wiring this can present installation
challenges. For bathrooms and kitchens codes can be very picky.

--
Regards, Joerg

http://www.analogconsultants.com/