Need some help, what is percentage US voltages on 115V, 208V

[John Robertson]

On 2019/10/31 6:07 p.m., Steve Wilson wrote:

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

fredag den 1. november 2019 kl. 00.50.47 UTC+1 skrev Steve Wilson:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

he's Canadian but, https://youtu.be/kfHB5AoAAbs

Bad design.

ofcourse and he said so


1. Use a stepdown transformer to drive the 120V dust collector.


when you need several 100W that's gets big and expensive

eBay has stepdown transformers at reasonable prices. Here's a 3kW
transformer for US $84.97

3000 Watt Voltage Converter Transformer Heavy Duty Step Up/Down 3000W
110/220V
US $84.97
shipping : US $6.07
Weight: 15 lbs
http://www.ebay.com/itm/143243241212

That step down transformer you referenced is typical Chinese junk. Not
UL or CSA certified so illegal to run in either the US (UL) and Canada
(CSA or ULc).

Really, the plug alone is crap (look at the pins, and observe the
clamp), the power cord is probably unrated and the case is probably made
of light weight steel or aluminum that will bend or pop open at the
first time you drop it more than six inches.

There is a reason that good quality products cost more - they are better
built!

I bet they don't high-pot test this unit.

If you want a SAFE step-down or step-up transformer look at something
like Hammond:

https://www.hammfg.com/electronics/transformers/line

A Hammond 298GT step-up xformer rated at 1500KVA, weighs around 17
kilo/39 lbs. How much does the Chinese unit weigh? 15 lbs? Can't have
much copper in the core. That's going to run rather hot when near its
'rated' output!

John :-#(#

 

[Lasse Langwadt Christense]

fredag den 1. november 2019 kl. 01.28.34 UTC+1 skrev Rick C:

On Thursday, October 31, 2019 at 8:14:19 PM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 1. november 2019 kl. 01.06.56 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 7:28:53 PM UTC-4, klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 15:36:10 UTC+1, Piotr Wyderski wrote:
Whoey Louie wrote:

Voltage in just about all of the US has been spec'd at 120V/240V not 115V/230V
for half a century or more.

And what's the allowed range? In Poland it is 230V +6%/-10%, in the EU I
think 230V +/- 10%.


Our products are normally rated +10/-15%, for the EU 230V, US 115V

Your products don't determine the spec in the US.


115V +10/-15% looks close enough to spec

https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf

Lol! What part of "specification" says "close enough"?

115V +10/-15% is ~ 98-127

worst case in the spec for 120V is 103.5 - 127.2

 

[Steve Wilson]

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

fredag den 1. november 2019 kl. 00.50.47 UTC+1 skrev Steve Wilson:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

he's Canadian but, https://youtu.be/kfHB5AoAAbs

Bad design.

ofcourse and he said so

1. Use a stepdown transformer to drive the 120V dust collector.

> when you need several 100W that's gets big and expensive

eBay has stepdown transformers at reasonable prices. Here's a 3kW
transformer for US $84.97

3000 Watt Voltage Converter Transformer Heavy Duty Step Up/Down 3000W
110/220V
US $84.97
shipping : US $6.07
Weight: 15 lbs
http://www.ebay.com/itm/143243241212

Lower power transformers are correspondingly less expensive.

He has maybe several hundred invested in the table saw and dust collector.
He can certainly afford a stepdown transformer.

OTOH he plans to run the dust collector on a separate 120V circuit. He
could tie the neutrals together so if he loses one, he will still have the
other. Then he could get the 120V from one phase of the 240V as per the
original, and would not need the stepdown transformer. A single DPST switch
would turn everything on and off.

 

[Whoey Louie]

On Thursday, October 31, 2019 at 1:29:01 PM UTC-4, Lasse Langwadt Christensen wrote:

torsdag den 31. oktober 2019 kl. 18.07.09 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 12:16:47 PM UTC-4, Piotr Wyderski wrote:
Rick C wrote:

So the current is very limited on this 400 volt power?

It is limited by the agreement with the power company. They install a
sufficiently rated fuse at the entry. This is stupid, BTW, but it is
that way.

What is stupid about that? It is to protect the line coming into the home. We do the same here. Most homes are 200 amps.


With US heaters they get some 4500 to 5500 watts from a 240 volt line.

4500W is equivalent to two electric kettles. Not exactly our
understanding of a heater.

There are devices that consume 10kW or more. Induction stoves with 11kW
rating are not uncommon.

We commonly use up to 40 amps or 9.6 kW for various appliances in the house (mostly the stove).

Our mains fuses are typically 16A (outlets) and 6A (lighting). There are
also bigger, of course, but they are reserved for special places like
the kitchen or the heater compartment.

It's hard to imagine a need for three phase power in any appliances.

For me it is pretty usual. In return, it is hard to imagine a 120V-only
system.
Your wires must run red-hot. But somehow you manage to live

Yes, we save on lighting expenses that way. ;-)

You still haven't explained any reason why you would need three phase power in the home. Your 16 amp line at 240 volts is about twice the power of our 15 amp, 120 volt lines we use to power lamps and such.

What do you need with three phase in the home that you can't supply with 240 volts?


nothing, but generation and distribution is three phase because it can transfer more power using less copper

Generation and distribution is 3 phase in the US and just about all of the world. We just don't run 3 phases into houses, it ends at the street.

I get 3*230V using 3+1 wires, you get 2*120V using 2+1 wires


What wattages are used in residences there that require three phase
power?

10kW+ devices are not uncommon. As said, water heating, AC, agricultural
tools, wood saws, welding machines, etc.

You have a welding machine in your home? I have a friend who has a full metal shop in his triple garage including at least one welder. All powered from 240 volts. None three phase.


if he has any big machine tools like a lathe or mill, he most likely have
a big noisy rotary phase converter to get three phase

and even for a welder or variable frequency drive three phase is an
advantage because rectifying to DC is easier

 

[Rick C]

On Thursday, October 31, 2019 at 9:07:30 PM UTC-4, Steve Wilson wrote:

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

fredag den 1. november 2019 kl. 00.50.47 UTC+1 skrev Steve Wilson:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

he's Canadian but, https://youtu.be/kfHB5AoAAbs

Bad design.

ofcourse and he said so


1. Use a stepdown transformer to drive the 120V dust collector.


when you need several 100W that's gets big and expensive

eBay has stepdown transformers at reasonable prices. Here's a 3kW
transformer for US $84.97

3000 Watt Voltage Converter Transformer Heavy Duty Step Up/Down 3000W
110/220V
US $84.97
shipping : US $6.07
Weight: 15 lbs
http://www.ebay.com/itm/143243241212

Lower power transformers are correspondingly less expensive.

He has maybe several hundred invested in the table saw and dust collector..
He can certainly afford a stepdown transformer.

OTOH he plans to run the dust collector on a separate 120V circuit. He
could tie the neutrals together so if he loses one, he will still have the
other. Then he could get the 120V from one phase of the 240V as per the
original, and would not need the stepdown transformer. A single DPST switch
would turn everything on and off.

The trouble with using two neutrals is that if you lose one, you no longer have the protection of a dual system and no indication that it is no longer protected. Actually, this guy doesn't have two neutrals anyway. His 240 volt connection is two hot and a protective ground (PE). That's the problem. Tying any load to the PE invalidates its use as a protective earth.

--

Rick C.

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

 

[Whoey Louie]

On Thursday, October 31, 2019 at 7:10:54 PM UTC-4, klaus.k...@gmail.com wrote:

On Thursday, 31 October 2019 12:32:04 UTC+1, Phil Hobbs wrote:
On 2019-10-31 04:33, klaus.kragelund@gmail.com wrote:
Hi

I am working on a US variant on a small pump (below 75W)

But, I am unable to find the percentage of distribution of different US mains voltage

My guess is that most is 115V, but I have also heard about 208V (phase phase), and 240V (120V, 180 degrees phase inverted)

Any inputs of how much is 115V grid, how much 208, how much 240V?

Thanks

Klaus


Go with 120V single phase. Residential power here is mostly 2-phase, so
that you can have an electric stove or clothes dryer working on 240V.
Getting 208V requires a 3-phase service, which is common in commercial
installations but not elsewhere.

Round here, requiring three-phase power for a 75 W pump would get you a
bit of a reputation.

So you don't have situations where you have 240V, with no neutral. That is to say you would always have the option to use the line neutral 120V?

Cheers

Klaus

No, like I said, if the loads are only 240v, then you don't need to run the neutral. Most cases though there is a neutral for 120 for lights, 120 receptacles, etc. But if you have a 240v well pump, you would not run the neutral.

 

[Rick C]

On Thursday, October 31, 2019 at 9:34:57 PM UTC-4, Lasse Langwadt Christensen wrote:

fredag den 1. november 2019 kl. 01.28.34 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 8:14:19 PM UTC-4, Lasse Langwadt Christensen wrote:
fredag den 1. november 2019 kl. 01.06.56 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 7:28:53 PM UTC-4, klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 15:36:10 UTC+1, Piotr Wyderski wrote:
Whoey Louie wrote:

Voltage in just about all of the US has been spec'd at 120V/240V not 115V/230V
for half a century or more.

And what's the allowed range? In Poland it is 230V +6%/-10%, in the EU I
think 230V +/- 10%.


Our products are normally rated +10/-15%, for the EU 230V, US 115V

Your products don't determine the spec in the US.


115V +10/-15% looks close enough to spec

https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf

Lol! What part of "specification" says "close enough"?


115V +10/-15% is ~ 98-127

worst case in the spec for 120V is 103.5 - 127.2

That's fine. But +10% of 115 volts is 126.5 volts. So, close enough is engineering speak for, "We don't quite make the spec, but we won't worry with that."

--

Rick C.

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

 

[Rick C]

On Thursday, October 31, 2019 at 9:44:59 PM UTC-4, Whoey Louie wrote:

On Thursday, October 31, 2019 at 6:21:15 PM UTC-4, Rick C wrote:
On Thursday, October 31, 2019 at 3:37:03 PM UTC-4, keith wright wrote:
On Thursday, 31 October 2019 09:24:47 UTC-7, Piotr Wyderski wrote:
jlarkin@highlandsniptechnology.com wrote:

Oh, that's the European standard, isn't it?

Yes, it is. It used to be 220V in the past, they changed it to 230V
(with the asymetric tolerance band, 220*1.1=230*1.06 up to an epsilon,
which is good for older devices). The UK went down to 230V from 240V.

No, the UK remained at 240v - the asymmetric EU standard of 230+10%/-6% allows both 220v and 240v to be within the standard with no physical change.

That makes more sense than
what we do here

I like yours, it is inherently much safer. But it is too late to change.

The British ones, giant cubes with fuses inside, look worse.


I like the UK ones, robust, don't get hot even at 13A, allow 3kW from an outlet. The fuse within the plug can be appropriate for the load.

The US ones are convenient because they are small but they are very limiting for high-power portable devices such as kitchen appliances.

No John, the British are small compared to that. These are of the size
of a Pepsi can, more or less. They are super-robust.

Do residences get all three phases?

Yes. Newer flats as well.

Electric vehicles sold in the EU (such as Rick's Tesla Model X) have a 3-phase input that allows up to 43kW input power in some vehicles. In the case of the Tesla there are essentially 3 separate chargers in the car.
Best regards, Piotr

I can't say you are wrong about the EU Teslas charging from the 3 phase input at 43 kW, but that would be pretty amazing if they did. The chargers you are talking about handle 24 amps each, so 17.2 kW total... at least in the US version. My car has three of these chargers, but since my car was made they dropped back to two units each which still gives 48 amps, plenty of power and more than most connections will support.

While I can't say they are using the same charger boards in the EU, it would seem odd for them to do that. Bottom line is I can't find any info on the max charging rate in Teslas from 3 phase power in the EU. The Tesla site doesn't easily provide that info since I'm not in the EU.

Of course, this has nothing to do with other vehicles.

--

What's the big deal about charging at 43kw? Tesla super chargers here do several times that.

DC charging from a Tesla supercharger does not use the same electronics in the car that AC charging does. In reality, the charger is in the car when AC charging. The external "charger" is really just a smart outlet that prevents problems from wrong charging rates and disconnecting while powered. It doesn't actually do anything with the power other than run it through a relay to prevent hot contacts in the connector.

--

Rick C.

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

 

[Lasse Langwadt Christense]

fredag den 1. november 2019 kl. 02.37.57 UTC+1 skrev John Robertson:

On 2019/10/31 6:07 p.m., Steve Wilson wrote:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

fredag den 1. november 2019 kl. 00.50.47 UTC+1 skrev Steve Wilson:
Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:

he's Canadian but, https://youtu.be/kfHB5AoAAbs

Bad design.

ofcourse and he said so


1. Use a stepdown transformer to drive the 120V dust collector.


when you need several 100W that's gets big and expensive

eBay has stepdown transformers at reasonable prices. Here's a 3kW
transformer for US $84.97

3000 Watt Voltage Converter Transformer Heavy Duty Step Up/Down 3000W
110/220V
US $84.97
shipping : US $6.07
Weight: 15 lbs
http://www.ebay.com/itm/143243241212

That step down transformer you referenced is typical Chinese junk. Not
UL or CSA certified so illegal to run in either the US (UL) and Canada
(CSA or ULc).

Really, the plug alone is crap (look at the pins, and observe the
clamp), the power cord is probably unrated and the case is probably made
of light weight steel or aluminum that will bend or pop open at the
first time you drop it more than six inches.

There is a reason that good quality products cost more - they are better
built!

I bet they don't high-pot test this unit.

If you want a SAFE step-down or step-up transformer look at something
like Hammond:

https://www.hammfg.com/electronics/transformers/line

A Hammond 298GT step-up xformer rated at 1500KVA, weighs around 17
kilo/39 lbs. How much does the Chinese unit weigh? 15 lbs? Can't have
much copper in the core. That's going to run rather hot when near its
'rated' output!

that is with isolation, the 1500VA autotransformer is "only" 22lbs

 

On Thu, 31 Oct 2019 14:40:49 -0700 (PDT), Rick C
<gnuarm.deletethisbit@gmail.com> wrote:

On Thursday, October 31, 2019 at 3:19:15 PM UTC-4, upsid...@downunder.com wrote:
On Thu, 31 Oct 2019 09:03:35 -0700 (PDT), Rick C
gnuarm.deletethisbit@gmail.com> wrote:

On Thursday, October 31, 2019 at 11:54:10 AM UTC-4, Piotr Wyderski wrote:
Rick C wrote:

Do residential water heaters actually run on three phase?

Some do, some don't. You can buy anything you like.
I think there are 3 internal heaters inside, that is the star connection
of heating elements. That way you can have a universal 230V heating
element, good for either application.

So the current is very limited on this 400 volt power? With US heaters they get some 4500 to 5500 watts from a 240 volt line.

With the red IEC 309 shown in this thread, you get 11 kW.

We commonly use up to 40 amps or 9.6 kW for various appliances in the house (mostly the stove). It's hard to imagine a need for three phase power in any appliances. What wattages are used in residences there that require three phase power?

In my country house, the electric sauna is 7.5 kW three phase, the
electric stove is three phase 2-3 kW. Even in my top floor city
apartment, the stove is three phase.

For a sauna, that means three elements, one on each phase. Likely this is done to help keep the 3 phase balanced.

The stove almost certainly uses separate phases for the different heating elements. So again, the three phase connection is being done to keep the load more balanced.

So the three phase appliances are because the three phase is installed, not that the three phase is needed for any particular reason?

I have newer seen here single phase induction motors greater than
about 1 kW, they are all three phase. No starter capacitor needed, you
can change between CW and CCW rotation simply by swapping two phases.

Induction motors starting current is up to six times compared to
normal running current. This could be reduced by using wye/delta
starter (no neutral connection needed) by first connecting the winding
in wye (240 V) and when the motor starts to rotate, the windings are
connected into delta (400 V). These days SCR based soft starters are
also used.

Of course if large DC loads are used (such as welding machines), the
simple six pulse rectifier is handy, In many cases, you do not even
need storage capacitors on the DC bus, the ripple is often
sufficiently low without it. Usually no neutral connection is used.

>Certainly a 7 kW heater does not require being on 3 phase circuits and cooking appliances work fine on 240 volts.

 

[Piotr Wyderski]

Rick C wrote:

> What is stupid about that? It is to protect the line coming into the home.

Stupid is that they are rated WAY below the capacity of the line and
their value reflects the maximal allocated power budget, as per ones
contract. E.g. a typical older flat has 20A fuse, because the contract
specifies 4.5kW power budget. You can get at most 32A on a single phase
and on this very same line -- this is entirely a contractual update. If
you need more, you need to upgrade to a three-phase system. Then you get
3x20A.

The building lines are protected separately.

In case of houses the limits are higher, usually 3x63A, but I have never
heard of 200A. This rating is typical for buildings.

> We do the same here.

No, you protect the lines, not throttle the consumption level. This is OK.

> Yes, we save on lighting expenses that way. ;-)

But come on, you claimed 90A wiring capability elsewhere in the thread.
Do you use busbars for that? 90A is 8W waste power per milliohm -- creepy.

> You still haven't explained any reason why you would need three phase power in the home.

Nothing needs to be explained, because this is whay you are given
without asking. You don't need to explain the need for a water pipe as well.

> What do you need with three phase in the home that you can't supply with 240 volts?

The kitchen equipment can use enormous amount of power. Waer heaters
even more.

> You have a welding machine in your home?

I don't, but many of my friends do. I am considering buying one.

Best regards, Piotr

 

jrwalliker@gmail.com wrote in
news:ddddf422-4068-4422-bad2-c414bde89e9a@googlegroups.com:

On Thursday, 31 October 2019 14:37:16 UTC,
DecadentLinux...@decadence.org wrote:
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qper4u02nge@drn.newsguy.com:

DecadentLinuxUserNumeroUno@decadence.org wrote...

Doesn't anyone look at the power requisite placards
ALL AC powered consumer products have nowadays?

I have not seen "115V" listed since the fucking sixties!

They usually say something like 95 to 250V, not helpful.


Yes, the auto-switcher types do. I even had to make a server
supply
that would go down to 85 Volts so that a user at the end of the
line in Japan would still get operation on a line that has
drooped down to near 80 to 90 Volts.

Just to add to the fun, Japan has both 50Hz and 60Hz supplies in
different regions.

John

And you can thank CE for the whole thing, when we should have made
Japan boost their transformers on their grid residential branches,
but that is another argument. Even if they could maintain even close
to their stated voltage it would be better.

Or maybe we should all move to 100 V.

Switchers are typically a bit less noisy at 'low line' than 'high
line' voltages, but that can vary as switcher designs vary. Our were
not only less noisy, but were a bit more efficient as well.

 

[Michael Terrell]

On Thursday, October 31, 2019 at 7:32:04 AM UTC-4, Phil Hobbs wrote:

On 2019-10-31 04:33, klaus.kragelund wrote:
Hi

I am working on a US variant on a small pump (below 75W)

But, I am unable to find the percentage of distribution of different US mains voltage

My guess is that most is 115V, but I have also heard about 208V (phase phase), and 240V (120V, 180 degrees phase inverted)

Any inputs of how much is 115V grid, how much 208, how much 240V?

Thanks

Klaus


Go with 120V single phase. Residential power here is mostly 2-phase, so
that you can have an electric stove or clothes dryer working on 240V.
Getting 208V requires a 3-phase service, which is common in commercial
installations but not elsewhere.

Round here, requiring three-phase power for a 75 W pump would get you a
bit of a reputation.

A local company had a pipe bending machine for over a decade. It was really wimpy on 208V. I finally got a manual in English (Italian OEM) and found that it was actually 240 V A boost transformer brought the line up to 245V, and it had amazing torque. I got involved when they moved to a new building, and it didn't work. the 'Industrial' electrician they hired had wired it for 120V in the breaker box. The outlet was OK, but the moron had connected the red wire to
Neutral, because he didn't have the right dual pole breaker with him.

 

[Michael Terrell]

On Thursday, October 31, 2019 at 4:05:29 PM UTC-4, upsid...@downunder.com wrote:

On Thu, 31 Oct 2019 21:00:43 +0100, Gerhard Hoffmann <dk4xp@arcor.de
wrote:


When we were students, we also had a ham radio linear amplifier
that ran on 3 phase. 2 QB5/1750 tubes, 5.5KV @ 1A+.
That was not exactly legal, but fun. Statute-barred a long time.

At those voltages it is hard to get any big storage capacitors, so
using a 6 pulse, three phase rectifier and the anode voltage is smooth
enough (4 % ripple).

4% would have a noticeable hum and never meet FCC standards. HV capacitors were available for big transmitters. They were large, oil filled with ceramic insulators. Some weighed several hundred pounds, but were still in daily service over 50 years later. Phase correction capacitors used in power distribution were similar but usually lower capacitance.

 

[Lasse Langwadt Christense]

fredag den 1. november 2019 kl. 14.57.15 UTC+1 skrev Michael Terrell:

On Thursday, October 31, 2019 at 1:29:01 PM UTC-4, Lasse Langwadt Christensen wrote:
torsdag den 31. oktober 2019 kl. 18.07.09 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 12:16:47 PM UTC-4, Piotr Wyderski wrote:
Rick C wrote:

So the current is very limited on this 400 volt power?

It is limited by the agreement with the power company. They install a
sufficiently rated fuse at the entry. This is stupid, BTW, but it is
that way.

What is stupid about that? It is to protect the line coming into the home. We do the same here. Most homes are 200 amps.


With US heaters they get some 4500 to 5500 watts from a 240 volt line.

4500W is equivalent to two electric kettles. Not exactly our
understanding of a heater.

There are devices that consume 10kW or more. Induction stoves with 11kW
rating are not uncommon.

We commonly use up to 40 amps or 9.6 kW for various appliances in the house (mostly the stove).

Our mains fuses are typically 16A (outlets) and 6A (lighting). There are
also bigger, of course, but they are reserved for special places like
the kitchen or the heater compartment.

It's hard to imagine a need for three phase power in any appliances.

For me it is pretty usual. In return, it is hard to imagine a 120V-only
system.
Your wires must run red-hot. But somehow you manage to live

Yes, we save on lighting expenses that way. ;-)

You still haven't explained any reason why you would need three phase power in the home. Your 16 amp line at 240 volts is about twice the power of our 15 amp, 120 volt lines we use to power lamps and such.

What do you need with three phase in the home that you can't supply with 240 volts?


nothing, but generation and distribution is three phase because it can transfer more power using less copper

I get 3*230V using 3+1 wires, you get 2*120V using 2+1 wires


What wattages are used in residences there that require three phase
power?

10kW+ devices are not uncommon. As said, water heating, AC, agricultural
tools, wood saws, welding machines, etc.

You have a welding machine in your home? I have a friend who has a full metal shop in his triple garage including at least one welder. All powered from 240 volts. None three phase.


if he has any big machine tools like a lathe or mill, he most likely have
a big noisy rotary phase converter to get three phase

and even for a welder or variable frequency drive three phase is an
advantage because rectifying to DC is easier


A VFD is more likely, these days. Rotary converters are last millenium.

https://www.automationdirect.com/adc/overview/catalog/drives_-a-_soft_starters/ac_variable_frequency_drives_(vfd)

yep a vfd is smaller quieter and variable

but some still use rotary converters because they don't believe in modern electronics, it can run multiple machines and some machines need not just three-phase to run motors but also single phase for a controller

three phase is also a big advantage for VFDs because you don't need nearly as big diodes and capacitors in the input

 

[Michael Terrell]

On Thursday, October 31, 2019 at 10:05:25 PM UTC-4, Whoey Louie wrote:

On Thursday, October 31, 2019 at 7:10:54 PM UTC-4, klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 12:32:04 UTC+1, Phil Hobbs wrote:
On 2019-10-31 04:33, klaus.kragelund wrote:
Hi

I am working on a US variant on a small pump (below 75W)

But, I am unable to find the percentage of distribution of different US mains voltage

My guess is that most is 115V, but I have also heard about 208V (phase phase), and 240V (120V, 180 degrees phase inverted)

Any inputs of how much is 115V grid, how much 208, how much 240V?

Thanks

Klaus


Go with 120V single phase. Residential power here is mostly 2-phase, so
that you can have an electric stove or clothes dryer working on 240V.
Getting 208V requires a 3-phase service, which is common in commercial
installations but not elsewhere.

Round here, requiring three-phase power for a 75 W pump would get you a
bit of a reputation.

So you don't have situations where you have 240V, with no neutral. That is to say you would always have the option to use the line neutral 120V?

Cheers

Klaus

No, like I said, if the loads are only 240v, then you don't need to run the neutral. Most cases though there is a neutral for 120 for lights, 120 receptacles, etc. But if you have a 240v well pump, you would not run the neutral.

I saw a botched wiring job at a church near here. They ran 240 to the pump house, without a neutral. Someone later added a light by connecting to one line, and the well casing instead of Neutral. You can bet it that was never inspected!

My well pump is 240V without a neutral, but I ran two 120 volt circuits to the wellhead. One for tools or a work light, and the other is for a small space heater for the rare occasion it drops well below freezing. I turn off that breaker, except when I need the heater.

 

[Michael Terrell]

On Thursday, October 31, 2019 at 7:35:32 PM UTC-4, John Larkin wrote:

There are roughly 15 different outlet types in use in the USA. Maybe
more! Some are 240 with neutral and ground, some are 240 with ground
but no neutral. I think there is a 120-240 outlet all in one somehow.
It's the Wild West.

The 120-240 outlets are common in some commercial buildings. They are for the custodial service to power floor buffers of either type. I saw a lot of them in schools, in hallways and large rooms when I serviced industrial electronics.

Leviton and Hubbel both sell a wide variety of residential, commercial and industrial power connectors.

 

[Michael Terrell]

On Thursday, October 31, 2019 at 6:30:02 PM UTC-4, Rick C wrote:

On Thursday, October 31, 2019 at 3:38:11 PM UTC-4, Lasse Langwadt Christensen wrote:
torsdag den 31. oktober 2019 kl. 19.57.07 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 1:23:22 PM UTC-4, PeterSchneider wrote:
Am 31.10.2019 um 17:16 schrieb Piotr Wyderski:
Rick C wrote:

So the current is very limited on this 400 volt power?

It is limited by the agreement with the power company. They install a
sufficiently rated fuse at the entry. This is stupid, BTW, but it is
that way.

With US heaters they get some 4500 to 5500 watts from a 240 volt line.

4500W is equivalent to two electric kettles. Not exactly our
understanding of a heater.

There are devices that consume 10kW or more. Induction stoves with 11kW
rating are not uncommon.

 We commonly use up to 40 amps or 9.6 kW for various appliances in the
house (mostly the stove).

Our mains fuses are typically 16A (outlets) and 6A (lighting). There are
also bigger, of course, but they are reserved for special places like
the kitchen or the heater compartment.

  It's hard to imagine a need for three phase power in any appliances.

For me it is pretty usual. In return, it is hard to imagine a 120V-only
system.
Your wires must run red-hot. But somehow you manage to live

What wattages are used in residences there that require three phase
power?

10kW+ devices are not uncommon. As said, water heating, AC, agricultural
tools, wood saws, welding machines, etc.

    Best regrds, Piotr


In europe there a continuous-flow water heaters with up to 21 kW. They
heat "just-intime" without any reservoir

That would be 90 amps which we can do in the US with 240 volts. In fact, Tesla home car chargers can be wired up with 100 amp service to drive 80 amp charging to some of the older cars. Mine will only accept 72 amps, so no point in more than 90 amps on a single charger but they can be used in parallel on a single 100 amp circuit. We derate our socketed connections to 80% for continuous loads, not sure exactly why.

The point is we have 240 volt, 100 amp connections for such high current loads. I don't see the need for 3 phase.


so you need 2 wires capable of 100A to get 24kW, we need 3 wires capable of ~30A

Actually, you need four wires. With three phase the neutral is essential for using 240 volt circuits. In the US we only require two conductors for the power and a smaller one for protective earth, the neutral is only required if you need 120 volts. I know in the UK the whole protective earth thing is complicated and allows the use of a system that loses safety if you run an extension cord outside. I don't know what the regulations require in the rest of the EU.

I looked into the US requirements extensively for a car charging port. The Tesla HPWC only requires a pair of heavy gauge wires for the power and a protective earth.

Wye requires a Neutral, Delta doesn't.

 

[Michael Terrell]

On Thursday, October 31, 2019 at 1:29:01 PM UTC-4, Lasse Langwadt Christensen wrote:

torsdag den 31. oktober 2019 kl. 18.07.09 UTC+1 skrev Rick C:
On Thursday, October 31, 2019 at 12:16:47 PM UTC-4, Piotr Wyderski wrote:
Rick C wrote:

So the current is very limited on this 400 volt power?

It is limited by the agreement with the power company. They install a
sufficiently rated fuse at the entry. This is stupid, BTW, but it is
that way.

What is stupid about that? It is to protect the line coming into the home. We do the same here. Most homes are 200 amps.


With US heaters they get some 4500 to 5500 watts from a 240 volt line.

4500W is equivalent to two electric kettles. Not exactly our
understanding of a heater.

There are devices that consume 10kW or more. Induction stoves with 11kW
rating are not uncommon.

We commonly use up to 40 amps or 9.6 kW for various appliances in the house (mostly the stove).

Our mains fuses are typically 16A (outlets) and 6A (lighting). There are
also bigger, of course, but they are reserved for special places like
the kitchen or the heater compartment.

It's hard to imagine a need for three phase power in any appliances.

For me it is pretty usual. In return, it is hard to imagine a 120V-only
system.
Your wires must run red-hot. But somehow you manage to live

Yes, we save on lighting expenses that way. ;-)

You still haven't explained any reason why you would need three phase power in the home. Your 16 amp line at 240 volts is about twice the power of our 15 amp, 120 volt lines we use to power lamps and such.

What do you need with three phase in the home that you can't supply with 240 volts?


nothing, but generation and distribution is three phase because it can transfer more power using less copper

I get 3*230V using 3+1 wires, you get 2*120V using 2+1 wires


What wattages are used in residences there that require three phase
power?

10kW+ devices are not uncommon. As said, water heating, AC, agricultural
tools, wood saws, welding machines, etc.

You have a welding machine in your home? I have a friend who has a full metal shop in his triple garage including at least one welder. All powered from 240 volts. None three phase.


if he has any big machine tools like a lathe or mill, he most likely have
a big noisy rotary phase converter to get three phase

and even for a welder or variable frequency drive three phase is an
advantage because rectifying to DC is easier

A VFD is more likely, these days. Rotary converters are last millenium.

<https://www.automationdirect.com/adc/overview/catalog/drives_-a-_soft_starters/ac_variable_frequency_drives_(vfd)>

 

[Whoey Louie]

On Friday, November 1, 2019 at 10:06:32 AM UTC-4, Michael Terrell wrote:

On Thursday, October 31, 2019 at 7:35:32 PM UTC-4, John Larkin wrote:

There are roughly 15 different outlet types in use in the USA. Maybe
more! Some are 240 with neutral and ground, some are 240 with ground
but no neutral. I think there is a 120-240 outlet all in one somehow.
It's the Wild West.

The 120-240 outlets are common in some commercial buildings. They are for the custodial service to power floor buffers of either type. I saw a lot of them in schools, in hallways and large rooms when I serviced industrial electronics.

For electric dryers in homes too.

Leviton and Hubbel both sell a wide variety of residential, commercial and industrial power connectors.