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

[Rick C]

On Saturday, November 2, 2019 at 1:57:09 PM UTC-4, Tom Gardner wrote:

On 02/11/19 15:24, Whoey Louie wrote:
On Saturday, November 2, 2019 at 10:10:35 AM UTC-4, Tom Gardner wrote:

Never heard of AFCI breakers, but that's my ignorance.

Google broken?

Irrelevant to whether I had heard of them

It seems that we don't need them here because we have lower
currents due to higher voltages.

Lol! The things people say out of ignorance.

An AFCI breaker detects dangerous conditions that are not detected by either GFCI (RCD in your country?) or overload breakers. If a wire is worn or chewed by rodents or just a loose connection, it will generate a dangerous arc with local heating. This device detects the transients in current consistent with faults but not normal operation.

In your country they appear to be called arc-fault detection device (AFDD).

The need for them has nothing to do with current, it is a safety device, not a regulator.

--

Rick C.

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

 

On Sat, 2 Nov 2019 10:00:46 -0700 (PDT), Whoey Louie
<trader4@optonline.net> wrote:

On Saturday, November 2, 2019 at 12:28:29 PM UTC-4, upsid...@downunder.com wrote:
On Sat, 2 Nov 2019 09:04:08 -0700 (PDT), Whoey Louie
trader4@optonline.net> wrote:

On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240. Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food store,
retirement community parking. These are the ones I recall off the
top of my head. I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

It's not really a special transformer, but more transformers for light/medium
capacity 3 phase. If you're comparing 240/120 split-phase to 3 phase you;d
be talking about light capacity 3 phase. To get that here in the US, typically
they use two transformers, while for split-phase you only need one. For
medium capacity 3 phase, they use three transformers. You see that on
street poles all over.

I have often wondered, why you have three separate pigs in the pole to
get 3 phases. Why don't you use a true 3 phase transformer ? Since
some of the flux cancel out in a true three phase transformer, the
total amount of iron is less than for three separate single phase
transformers.

How much that added cost affects you as the customer,
will depend on the actual power company, but somebody has to pay for it,
one way or the other. Which is one reason that 3 phase into homes makes
no sense to me.

IDK, but my guess would be that one transformer of the same capacity as
the three separate ones would be so heavy that it would be a balancing
problem on the pole and they don't want leaning, falling over poles.

Here is a small 20/0.4 kV three phase transformer feeding four LV
lines https://commons.wikimedia.org/wiki/Fileole_Transformer.JPG

Larger ones 100-300 kVA are installed between two poles.

 

>I would expect that both fuses must blow at the same time.

NO, they will not,

Got any sense ? Put it this way, when one blows there is no current there to blow the other.

Simple enough ?

 

On Sunday, 3 November 2019 12:53:41 UTC, jurb...@gmail.com wrote:

I would expect that both fuses must blow at the same time.

NO, they will not,

Got any sense ? Put it this way, when one blows there is no current there to blow the other.

Simple enough ?

None of this is relevant because ring final circuits in the UK
NEVER have two fuses or circuit breakers. It is forbidden.
Socket outlets can be on either ring circuits, usually protected
with 32A circuit breakers or radial circuits where the circuit
breakers are typically 20 or 32A depending on the thickness of the
wire used.
Lighting circuits are usually radial, and often have a tree structure.
They are separate from socket circuits and are typically protected
at 6A with no additional fuses in the appliances.
John

 

[Joerg]

On 2019-11-02 09:09, Whoey Louie wrote:

On Saturday, November 2, 2019 at 12:04:13 PM UTC-4, Whoey Louie wrote:
On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:

[...]

Hardwired equipment such as a built-in kitchen oven or range often does
not have neutral either but there you cannot legally connect anything
else without having an electrician run cable and a new outlet.

--
Regards, Joerg


Not so sure about that. I've never seen an oven, range, etc circuit
that didn't have a neutral. There probably are some, but I don't think
it's common.

To clarify the above, while I haven't seen ovens or ranges that don't
use a neutral, what you say is true of other circuits, eg water heaters,
well pumps and the like. The issue with ovens, ranges, dryers, etc
is that every one I've seen has some 120V requirement, eg light bulbs
in older units and electronics in modern ones. They could use 240V bulbs
and run the electronics off 240V, but for whatever reasons they don't
seem to do so.

It's the separate ranges that sometimes do not have neutral. There are
only the burners, no bulbs or accessory outlets.

In Europe this is rare. Kitchens are smaller and people have ovens where
the range is an integal part of it up top or at least connected to its
controls.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

On 2019-11-02 09:28, upsidedown@downunder.com wrote:

On Sat, 2 Nov 2019 09:04:08 -0700 (PDT), Whoey Louie
trader4@optonline.net> wrote:

On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240. Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food store,
retirement community parking. These are the ones I recall off the
top of my head. I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

It's not really a special transformer, but more transformers for light/medium
capacity 3 phase. If you're comparing 240/120 split-phase to 3 phase you;d
be talking about light capacity 3 phase. To get that here in the US, typically
they use two transformers, while for split-phase you only need one. For
medium capacity 3 phase, they use three transformers. You see that on
street poles all over.

I have often wondered, why you have three separate pigs in the pole to
get 3 phases. Why don't you use a true 3 phase transformer ? Since
some of the flux cancel out in a true three phase transformer, the
total amount of iron is less than for three separate single phase
transformers.

They do have three-phase transformers, at least in our area.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Joerg]

On 2019-11-02 10:59, Rick C wrote:

On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots
of locations and some 90% of them are 208 volts (give or
take) rather than 240. Instead of getting 7 kW charging
rate, I usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food
store, retirement community parking. These are the ones I recall
off the top of my head. I'm sure I've seen 240 volt level 2
charging, but I don't recall where that would have been.


Even among those commercial operations most of the small ones will
only have 120/240V wiring, two-phase 180 degrees. 208V three-phase
is pricey, needs a special transformer and is typically only used
in larger places or ones with a high electric energy demand.

Not sure what you mean by "small". A "small" hospital?

For example, nursing homes. Smaller facilities up to 12 beds are usually
fed two-phase while the larger ones have a three-phase feed.

... I suppose a
retail food store could be small and the ones I've been to were small
but had 208 volts at the car chargers.

Small retail stores never have car chargers around where I live.

I think you don't realize how pervasive 3 phase power is in the US.
Why would it take a special transformer? It's three phase on the
distribution line, three phase on both sides of the transformer.

What was meant is not the distribution, that is generally three-phase.
It's about the feed into the building. That is generally tow-phase 120/240V.

Klaus, in the US you will usually see ground distributed to 240V
outlets even though it is often not used by the equipment that is
plugged in. So there are four connections, 120V phase 1, 120V phase
2, neutral, protective ground. What you need to keep in mind is
that such outlets are generally fused at much more than the usual
15A or 20A. So the cable from the outlet to the fuse in your pump
circuitry must be rated for the highest expected circuit breaker
current rating.

It entirely depends on the connector. Some have a neutral pin, some
don't. Standard 120 volt outlets here have a neutral pin and a
ground, but because our 240 volt line is two hots, the NEMA 6 series
of connectors have no neutral, only a protective earth ground.

AFAIK that only goes for older buildings, in newer ones (as in "this
century") I have never seen 240V receptacles without neutral.

Probably more common are the NEMA 14 series connectors which include
a neutral and a ground for 120/240 volt applications meaning it can
provide both 120 and 240 volts. That's the only reason to include
the neutral, to provide 120 volts.


Older homes can have 240V three-prong outlets where you don't have
neutral, for example for dryers and in the kitchen for a
free-standing oven/range. AFAIK that is no longer allowed for new
construction in many states.

This is not accurate. The TT-30 connectors used for older dryers
have a neutral, but no protective ground. They are deprecated, but
not required to be removed. It is now expected such a connection
would include a separate protective ground for the frame of the
appliance. No new appliance will support this connection method.

I never said it has to be removed. It's grandfathered. What I said is
that it is AFAIK no longer allowed in new construction or after a major
remodel job. So it'll depend on where Klaus' products go. If it's new
construction that one can usually assume the presence of the neutral
connection.

Hardwired equipment such as a built-in kitchen oven or range often
does not have neutral either but there you cannot legally connect
anything else without having an electrician run cable and a new
outlet.

Ranges are typically hard wired without a connector. Dishwashers I
believe are now required to be on an outlet, at least that is what I
was told. They are also 120, not 240 volts.

Bottom line is for a 75 watt device there is no reason to consider
240 volts for US usage.

Depends on where it goes. If at or near an A/C and heating system that
can be a situation where there is no neutral. It's hard-wired with a
pull-out shut-off but an electrician cannot easily install a 120V
connection there unless he runs a new circuit.

... Here appliances use 120 volts unless there
is a compelling need for higher power than can be found in a typical
outlet, 120 volts, 15 amps.

I became sorely aware of that when moving to the US. Neitehr the printer
nor the copier I brought from Europe worked because no enough juice in a
circuit. Now that I started home-brewing it's the same. I have to use
two 1kW burners back to back under the brew kettle, plugged into
different circuits. Oh how I wish I could use one of those European 3kW
burners.


For "continuous" loads the current must

be derated to 80%. Not sure if your pump would be a continuous load
or not, but 75 watts is well within the 80% rating.

If you try to sell a 240 volt pump here it will be a specialty
product requiring a special wiring run to bring power to it.

Yup, unless always in a particular location.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Rick C]

On Sunday, November 3, 2019 at 10:15:29 AM UTC-5, Joerg wrote:

On 2019-11-02 10:59, Rick C wrote:
On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots
of locations and some 90% of them are 208 volts (give or
take) rather than 240. Instead of getting 7 kW charging
rate, I usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food
store, retirement community parking. These are the ones I recall
off the top of my head. I'm sure I've seen 240 volt level 2
charging, but I don't recall where that would have been.


Even among those commercial operations most of the small ones will
only have 120/240V wiring, two-phase 180 degrees. 208V three-phase
is pricey, needs a special transformer and is typically only used
in larger places or ones with a high electric energy demand.

Not sure what you mean by "small". A "small" hospital?


For example, nursing homes. Smaller facilities up to 12 beds are usually
fed two-phase while the larger ones have a three-phase feed.

I don't think there is a 12 bed nursing home anywhere around here. They typically aren't profitable and end up going out of business. I guess there might be some boutique places.

... I suppose a
retail food store could be small and the ones I've been to were small
but had 208 volts at the car chargers.


Small retail stores never have car chargers around where I live.

Sorry, I forgot that where you live is the typical for the world.

I think you don't realize how pervasive 3 phase power is in the US.
Why would it take a special transformer? It's three phase on the
distribution line, three phase on both sides of the transformer.


What was meant is not the distribution, that is generally three-phase.
It's about the feed into the building. That is generally tow-phase 120/240V.

Yes, for residences. The majority of businesses of any size receive 3 phase.

Klaus, in the US you will usually see ground distributed to 240V
outlets even though it is often not used by the equipment that is
plugged in. So there are four connections, 120V phase 1, 120V phase
2, neutral, protective ground. What you need to keep in mind is
that such outlets are generally fused at much more than the usual
15A or 20A. So the cable from the outlet to the fuse in your pump
circuitry must be rated for the highest expected circuit breaker
current rating.

It entirely depends on the connector. Some have a neutral pin, some
don't. Standard 120 volt outlets here have a neutral pin and a
ground, but because our 240 volt line is two hots, the NEMA 6 series
of connectors have no neutral, only a protective earth ground.


AFAIK that only goes for older buildings, in newer ones (as in "this
century") I have never seen 240V receptacles without neutral.

If you mean 2000, yes, that is most likely true. The rule was changed by the NEC in 1996 I believe. Not sure how long it took the states to adopt that rule change since it is the states that make the laws. So about 20 years. But the connectors are still widely in use. Actually, it is the 10 series that is affected by this. The 6 series have a ground and no neutral. The 10 series has a neutral and no ground. lol

Probably more common are the NEMA 14 series connectors which include
a neutral and a ground for 120/240 volt applications meaning it can
provide both 120 and 240 volts. That's the only reason to include
the neutral, to provide 120 volts.


Older homes can have 240V three-prong outlets where you don't have
neutral, for example for dryers and in the kitchen for a
free-standing oven/range. AFAIK that is no longer allowed for new
construction in many states.

This is not accurate. The TT-30 connectors used for older dryers
have a neutral, but no protective ground. They are deprecated, but
not required to be removed. It is now expected such a connection
would include a separate protective ground for the frame of the
appliance. No new appliance will support this connection method.


I never said it has to be removed. It's grandfathered. What I said is
that it is AFAIK no longer allowed in new construction or after a major
remodel job. So it'll depend on where Klaus' products go. If it's new
construction that one can usually assume the presence of the neutral
connection.


Hardwired equipment such as a built-in kitchen oven or range often
does not have neutral either but there you cannot legally connect
anything else without having an electrician run cable and a new
outlet.

Ranges are typically hard wired without a connector. Dishwashers I
believe are now required to be on an outlet, at least that is what I
was told. They are also 120, not 240 volts.

Bottom line is for a 75 watt device there is no reason to consider
240 volts for US usage.


Depends on where it goes. If at or near an A/C and heating system that
can be a situation where there is no neutral. It's hard-wired with a
pull-out shut-off but an electrician cannot easily install a 120V
connection there unless he runs a new circuit.

LOL I don't know what you are reaching for.

... Here appliances use 120 volts unless there
is a compelling need for higher power than can be found in a typical
outlet, 120 volts, 15 amps.


I became sorely aware of that when moving to the US. Neitehr the printer
nor the copier I brought from Europe worked because no enough juice in a
circuit.

There's your problem. We don't have juice in our circuits. We have electricity. A 240 volt connection is not hard to provide, it's just not common because we standardized on 120 volts in the home about a hundred years ago. Did no one tell you about that?

Now that I started home-brewing it's the same. I have to use
two 1kW burners back to back under the brew kettle, plugged into
different circuits. Oh how I wish I could use one of those European 3kW
burners.

You could if you just ran a 240 volt line.

It sometimes seems like you go out of your way to make things difficult.

BTW, you do know you can get up to 1440 watts on a 15 amp circuit, no? You can get up to 1,920 watts on a 20 amp, 120 volt circuit. So you just need a 20 amp, 120 volt circuit, no 240 volt European heaters required.

--

Rick C.

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

 

[John S]

On 11/2/2019 9:55 AM, Joerg wrote:

On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

<https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power>

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in. So
there are four connections, 120V phase 1, 120V phase 2, neutral,
protective ground. What you need to keep in mind is that such outlets
are generally fused at much more than the usual 15A or 20A. So the cable
from the outlet to the fuse in your pump circuitry must be rated for the
highest expected circuit breaker current rating.

Older homes can have 240V three-prong outlets where you don't have
neutral, for example for dryers and in the kitchen for a free-standing
oven/range. AFAIK that is no longer allowed for new construction in many
states.

Hardwired equipment such as a built-in kitchen oven or range often does
not have neutral either but there you cannot legally connect anything
else without having an electrician run cable and a new outlet.

 

[Klaus Kragelund]

On Saturday, November 2, 2019 at 3:55:41 PM UTC+1, Joerg wrote:

On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240. Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food store,
retirement community parking. These are the ones I recall off the
top of my head. I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in. So
there are four connections, 120V phase 1, 120V phase 2, neutral,
protective ground. What you need to keep in mind is that such outlets
are generally fused at much more than the usual 15A or 20A. So the cable
from the outlet to the fuse in your pump circuitry must be rated for the
highest expected circuit breaker current rating.

For the US pump, we need to make this funny conduit connection, where there is a regulatory defined minimum space for the connector, so that the service tech with his thick fingers, can mount the wires

Older homes can have 240V three-prong outlets where you don't have
neutral, for example for dryers and in the kitchen for a free-standing
oven/range. AFAIK that is no longer allowed for new construction in many
states.

Hardwired equipment such as a built-in kitchen oven or range often does
not have neutral either but there you cannot legally connect anything
else without having an electrician run cable and a new outlet.

--
Thanks for the info, also to others replying on the thread, I am getting an better overview

Cheers

Klaus

 

[Whoey Louie]

On Sunday, November 3, 2019 at 4:40:01 PM UTC-5, John S wrote:

On 11/2/2019 9:55 AM, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power

It's not referred to as two phase, but that is what is actually present.
There are two hots that are 180 deg out of phase with each other, which
is what you get from a center tapped transformer. You would model it as
cos(wt), cos(wt+180)

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in.

There will be a ground at any code compliant receptacles for over half
a century or more. And rare to find a piece of equipment that doesn't
use a ground, for obvious reasons.

 

[Whoey Louie]

On Sunday, November 3, 2019 at 7:53:41 AM UTC-5, jurb...@gmail.com wrote:

I would expect that both fuses must blow at the same time.

NO, they will not,

Got any sense ? Put it this way, when one blows there is no current there to blow the other.

Simple enough ?

Yes, I have lots of sense. A poster said that the European ring circuit
is fed by fuses on both ends of the ring. Another poster clarified that
is not true, there is only one fuse that feeds both ends of the ring.
But if there were two fuses on each
end of the ring, then when one blows there most certainly would be current
in the second fuse and it would be about twice the previous current.

Simple enough?

 

[Whoey Louie]

On Sunday, November 3, 2019 at 12:13:16 PM UTC-5, Rick C wrote:

On Sunday, November 3, 2019 at 10:15:29 AM UTC-5, Joerg wrote:
On 2019-11-02 10:59, Rick C wrote:
On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots
of locations and some 90% of them are 208 volts (give or
take) rather than 240. Instead of getting 7 kW charging
rate, I usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food
store, retirement community parking. These are the ones I recall
off the top of my head. I'm sure I've seen 240 volt level 2
charging, but I don't recall where that would have been.


Even among those commercial operations most of the small ones will
only have 120/240V wiring, two-phase 180 degrees. 208V three-phase
is pricey, needs a special transformer and is typically only used
in larger places or ones with a high electric energy demand.

Not sure what you mean by "small". A "small" hospital?


For example, nursing homes. Smaller facilities up to 12 beds are usually
fed two-phase while the larger ones have a three-phase feed.

I don't think there is a 12 bed nursing home anywhere around here. They typically aren't profitable and end up going out of business. I guess there might be some boutique places.


... I suppose a
retail food store could be small and the ones I've been to were small
but had 208 volts at the car chargers.


Small retail stores never have car chargers around where I live.

Sorry, I forgot that where you live is the typical for the world.


I think you don't realize how pervasive 3 phase power is in the US.
Why would it take a special transformer? It's three phase on the
distribution line, three phase on both sides of the transformer.


What was meant is not the distribution, that is generally three-phase.
It's about the feed into the building. That is generally tow-phase 120/240V.

Yes, for residences. The majority of businesses of any size receive 3 phase.


Klaus, in the US you will usually see ground distributed to 240V
outlets even though it is often not used by the equipment that is
plugged in. So there are four connections, 120V phase 1, 120V phase
2, neutral, protective ground. What you need to keep in mind is
that such outlets are generally fused at much more than the usual
15A or 20A. So the cable from the outlet to the fuse in your pump
circuitry must be rated for the highest expected circuit breaker
current rating.

It entirely depends on the connector. Some have a neutral pin, some
don't. Standard 120 volt outlets here have a neutral pin and a
ground, but because our 240 volt line is two hots, the NEMA 6 series
of connectors have no neutral, only a protective earth ground.


AFAIK that only goes for older buildings, in newer ones (as in "this
century") I have never seen 240V receptacles without neutral.

If you mean 2000, yes, that is most likely true. The rule was changed by the NEC in 1996 I believe. Not sure how long it took the states to adopt that rule change since it is the states that make the laws. So about 20 years. But the connectors are still widely in use. Actually, it is the 10 series that is affected by this. The 6 series have a ground and no neutral. The 10 series has a neutral and no ground. lol

That's incorrect. There is no code issue with installing a new circuit
that uses a 240V receptacle without a neutral in the US. Why would there be any
issue? It's widely used for pool pumps as an example. The pump is 240V,
it doesn't need a neutral. You may be confusing that with DRYER receptacles,
which are now required to be 4 wire, ie you can't use the neutral as a ground
for new circuits.

 

On Sun, 3 Nov 2019 18:26:07 -0800 (PST), Whoey Louie
<trader4@optonline.net> wrote:

On Sunday, November 3, 2019 at 4:40:01 PM UTC-5, John S wrote:
On 11/2/2019 9:55 AM, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power

It's not referred to as two phase, but that is what is actually present.
There are two hots that are 180 deg out of phase with each other, which
is what you get from a center tapped transformer. You would model it as
cos(wt), cos(wt+180)

Known as "split phase".

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in.

There will be a ground at any code compliant receptacles for over half
a century or more. And rare to find a piece of equipment that doesn't
use a ground, for obvious reasons.

For 240V circuits, yes. There are all sorts of ungrounded 120V
appliances.

 

On Sun, 3 Nov 2019 15:40:50 -0600, John S <Sophi.2@invalid.org> wrote:

On 11/2/2019 9:55 AM, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power

The whole point with multiphase system is to create a rotating
magnetic fields for motors, so that these will reliably start.

One such system was the two phase used in Niagara Falls with a 90
degree phase shift system. Unfortunately it required moro/thicker
wires than the three phase (120 degree) system for the same power.

The US 120-0-120 V system doesn't create a rotating magnetic field, it
is just a single phase system. To start a single phase motor, a 90
degree phase shift is locally created with a starting capacitor. After
starting a single phase system runs fine without the additional phase.

Even a three phase runs with a single phase if wye connected (or two
phases if delta connected) with significantly reduced power, but it
doesn't start without all three phases.

For some strange reason the US system is called anti-phase or
split-phase system, while it is just single phase. You could as well
have only a single 120 V (no center tap) feed into homes, the L and N
wires would just be thicker.

 

[Rick C]

On Sunday, November 3, 2019 at 9:17:22 PM UTC-5, Whoey Louie wrote:

On Sunday, November 3, 2019 at 12:13:16 PM UTC-5, Rick C wrote:
On Sunday, November 3, 2019 at 10:15:29 AM UTC-5, Joerg wrote:
On 2019-11-02 10:59, Rick C wrote:
On Saturday, November 2, 2019 at 10:55:41 AM UTC-4, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots
of locations and some 90% of them are 208 volts (give or
take) rather than 240. Instead of getting 7 kW charging
rate, I usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food
store, retirement community parking. These are the ones I recall
off the top of my head. I'm sure I've seen 240 volt level 2
charging, but I don't recall where that would have been.


Even among those commercial operations most of the small ones will
only have 120/240V wiring, two-phase 180 degrees. 208V three-phase
is pricey, needs a special transformer and is typically only used
in larger places or ones with a high electric energy demand.

Not sure what you mean by "small". A "small" hospital?


For example, nursing homes. Smaller facilities up to 12 beds are usually
fed two-phase while the larger ones have a three-phase feed.

I don't think there is a 12 bed nursing home anywhere around here. They typically aren't profitable and end up going out of business. I guess there might be some boutique places.


... I suppose a
retail food store could be small and the ones I've been to were small
but had 208 volts at the car chargers.


Small retail stores never have car chargers around where I live.

Sorry, I forgot that where you live is the typical for the world.


I think you don't realize how pervasive 3 phase power is in the US.
Why would it take a special transformer? It's three phase on the
distribution line, three phase on both sides of the transformer.


What was meant is not the distribution, that is generally three-phase..
It's about the feed into the building. That is generally tow-phase 120/240V.

Yes, for residences. The majority of businesses of any size receive 3 phase.


Klaus, in the US you will usually see ground distributed to 240V
outlets even though it is often not used by the equipment that is
plugged in. So there are four connections, 120V phase 1, 120V phase
2, neutral, protective ground. What you need to keep in mind is
that such outlets are generally fused at much more than the usual
15A or 20A. So the cable from the outlet to the fuse in your pump
circuitry must be rated for the highest expected circuit breaker
current rating.

It entirely depends on the connector. Some have a neutral pin, some
don't. Standard 120 volt outlets here have a neutral pin and a
ground, but because our 240 volt line is two hots, the NEMA 6 series
of connectors have no neutral, only a protective earth ground.


AFAIK that only goes for older buildings, in newer ones (as in "this
century") I have never seen 240V receptacles without neutral.

If you mean 2000, yes, that is most likely true. The rule was changed by the NEC in 1996 I believe. Not sure how long it took the states to adopt that rule change since it is the states that make the laws. So about 20 years. But the connectors are still widely in use. Actually, it is the 10 series that is affected by this. The 6 series have a ground and no neutral. The 10 series has a neutral and no ground. lol


That's incorrect. There is no code issue with installing a new circuit
that uses a 240V receptacle without a neutral in the US. Why would there be any
issue? It's widely used for pool pumps as an example. The pump is 240V,
it doesn't need a neutral. You may be confusing that with DRYER receptacles,
which are now required to be 4 wire, ie you can't use the neutral as a ground
for new circuits.

You didn't read what I wrote. I never said what you think I said. I did respond to Joerge's statement incorrectly. I was talking about the code requiring a separate protective earth while he was talking about the lack of a neutral.

What I said was correct though. I even gave examples of NEMA standard connectors that have no neutral. These are still in use. It is the 10 series with no protective earth that are deprecated.

--

Rick C.

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

 

[Rick C]

On Sunday, November 3, 2019 at 5:29:07 PM UTC-5, Klaus Kragelund wrote:

On Saturday, November 2, 2019 at 3:55:41 PM UTC+1, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240. Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food store,
retirement community parking. These are the ones I recall off the
top of my head. I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in. So
there are four connections, 120V phase 1, 120V phase 2, neutral,
protective ground. What you need to keep in mind is that such outlets
are generally fused at much more than the usual 15A or 20A. So the cable
from the outlet to the fuse in your pump circuitry must be rated for the
highest expected circuit breaker current rating.

For the US pump, we need to make this funny conduit connection, where there is a regulatory defined minimum space for the connector, so that the service tech with his thick fingers, can mount the wires

"Funny conduit connection", do you mean the box the connector mounts in??? The minimum space is for the wires that connect to the connector. You have to have some inches (6 I think) sticking out of the box to give working room to the electrician installing the connector... but that's his job. Are you talking about the space around the receptacle for a person to plug in your plug?

Older homes can have 240V three-prong outlets where you don't have
neutral, for example for dryers and in the kitchen for a free-standing
oven/range. AFAIK that is no longer allowed for new construction in many
states.

Hardwired equipment such as a built-in kitchen oven or range often does
not have neutral either but there you cannot legally connect anything
else without having an electrician run cable and a new outlet.

--
Thanks for the info, also to others replying on the thread, I am getting an better overview

Cheers

Klaus

--

Rick C.

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

 

[Rick C]

On Sunday, November 3, 2019 at 9:26:12 PM UTC-5, Whoey Louie wrote:

On Sunday, November 3, 2019 at 4:40:01 PM UTC-5, John S wrote:
On 11/2/2019 9:55 AM, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power

It's not referred to as two phase, but that is what is actually present.
There are two hots that are 180 deg out of phase with each other, which
is what you get from a center tapped transformer. You would model it as
cos(wt), cos(wt+180)

We all know that, but it isn't the correct terminology just as it isn't factually correct that current in a wire flows from + to -, but we all conventionally talk about it as if it did.

Klaus, in the US you will usually see ground distributed to 240V outlets
even though it is often not used by the equipment that is plugged in.

There will be a ground at any code compliant receptacles for over half
a century or more. And rare to find a piece of equipment that doesn't
use a ground, for obvious reasons.

That is not correct. It was in 1996 that the NEC changed their rules about requiring a separate protective earth. My house built in 1987 has the NEMA 10-30 dryer connector with neutral and no earth. I should look to see if they actually ran an earth wire to the outlet box in which case I can change the connector without running a new wire.

Anyone know if it is permissible to connect a protective earth from one cable to another? If this outlet box has no protective earth, can I simply provide one by other means or does this require a new cable be run? There's a 120 volt outlet with a proper ground right by the 240 volt outlet. Heck, for that matter I could put them both in the same box, right?

--

Rick C.

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

 

[John S]

On 11/3/2019 8:26 PM, Whoey Louie wrote:

On Sunday, November 3, 2019 at 4:40:01 PM UTC-5, John S wrote:
On 11/2/2019 9:55 AM, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C  wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240.  I charge my car at level 2 chargers in lots of
locations and some 90% of them are 208 volts (give or take)
rather than 240.  Instead of getting 7 kW charging rate, I
usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes.  Hotels, hospital parking deck, retail food store,
retirement community parking.  These are the ones I recall off the
top of my head.  I'm sure I've seen 240 volt level 2 charging, but I
don't recall where that would have been.


Even among those commercial operations most of the small ones will only
have 120/240V wiring, two-phase 180 degrees. 208V three-phase is pricey,
needs a special transformer and is typically only used in larger places
or ones with a high electric energy demand.

240/120 is correct because it comes from a 240V center-tapped
transformer. Two phase is not correct. See

https://www.google.com/search?client=firefox-b-1-d&q=two+phase+power

It's not referred to as two phase, but that is what is actually present.
There are two hots that are 180 deg out of phase with each other, which
is what you get from a center tapped transformer. You would model it as
cos(wt), cos(wt+180)

In this thread it has been referred to as two phase. But please see the
link to which I referred that shows two phase as two voltages 90 degrees
apart, not 180 degrees.

Do this: put two appropriately-valued and equal-valued resistors in
series across your single phase outlet (any voltage) and attach your
scope common to the junction of the resistors. Attach your two probes to
the opposite end of the resistors.

You will see two voltages 180 degrees out of phase with each other. So,
have you just created two phase from a single phase source with just a
pair of resistors? I don't think so.

 

[Joerg]

On 2019-11-03 14:29, Klaus Kragelund wrote:

On Saturday, November 2, 2019 at 3:55:41 PM UTC+1, Joerg wrote:
On 2019-10-31 17:10, Rick C wrote:
On Thursday, October 31, 2019 at 7:38:49 PM UTC-4,
klaus.k...@gmail.com wrote:
On Thursday, 31 October 2019 16:27:12 UTC+1, Rick C wrote:
On Thursday, October 31, 2019 at 4:33:20 AM UTC-4,
klaus.k...@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?

A large percentage of commercial installations are 208 volts
rather than 240. I charge my car at level 2 chargers in lots
of locations and some 90% of them are 208 volts (give or
take) rather than 240. Instead of getting 7 kW charging
rate, I usually see 6 or below because of the voltage.


Good info

Commercial, would that be businesses, hotels, or what?

Pretty much yes. Hotels, hospital parking deck, retail food
store, retirement community parking. These are the ones I recall
off the top of my head. I'm sure I've seen 240 volt level 2
charging, but I don't recall where that would have been.


Even among those commercial operations most of the small ones will
only have 120/240V wiring, two-phase 180 degrees. 208V three-phase
is pricey, needs a special transformer and is typically only used
in larger places or ones with a high electric energy demand.

Klaus, in the US you will usually see ground distributed to 240V
outlets even though it is often not used by the equipment that is
plugged in. So there are four connections, 120V phase 1, 120V phase
2, neutral, protective ground. What you need to keep in mind is
that such outlets are generally fused at much more than the usual
15A or 20A. So the cable from the outlet to the fuse in your pump
circuitry must be rated for the highest expected circuit breaker
current rating.

For the US pump, we need to make this funny conduit connection, where
there is a regulatory defined minimum space for the connector, so
that the service tech with his thick fingers, can mount the wires

Reminds me of an episode where our sewer line plugged up. The revision
opening used for the roto-rooter tool is behind a utility room door into
a larger crawl space. The plumber was so fat that he could not squeeze
through so he had to send in his assistant.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/