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Connect 120 volt circuits to get 240 volts

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Guest

Thu Jan 03, 2019 11:45 pm   



On Thu, 3 Jan 2019 14:09:44 -0600, amdx <nojunk_at_knology.net> wrote:

Quote:
On 12/31/2018 7:13 AM, Lasse Langwadt Christensen wrote:
mandag den 31. december 2018 kl. 14.03.06 UTC+1 skrev upsid...@downunder.com:
On Mon, 31 Dec 2018 00:07:18 +0200, upsidedown_at_downunder.com wrote:


The energy needs for various utility vehicles is of course much
larger, but still city buses can run with a high power charging
station at only at one end of the line. The battery is fully charged
in the time the driver visits the restroom or smokes a cigarette.

??? Where did you get this idea?

There is a charging station about 1 km from where I live and I have
frequently used the bus line in the afternoon returning from the round
trip towards the charging station. The bus accelerates quite strongly
at the end o the leg, so a lot of power must still be available.
Admittedly the total route is less than 10 km long, but this the
second or third winter.

These are Solaris Urbino12 Electric buses. The line round trip
distance is 13 km and according to the schedule, there would be at
most 10 min charging time from the pantograph at the city terminal.
.

yeh they are running some in cities here, 55kWh lithium-titanate battery,
300kW pantograf charger at the end of the line. claims 1kWh/km so only a
few minutes charging needed per trip


I recall seeing a Chinese system that used capacitors and every
bus stop had a connection for a short recharge during the stop.
Found an article.
https://phys.org/news/2009-10-ultracapacitors-city-buses-cheaper-greener.html


A problem for suburban and rural bus lines is how to provide high
peak currents to the bus stops. Taking it from a local weak network
would dim the lights when there is a bus at the stop. Alternatively
running dedicated medium voltage lines along each bus route and using
step-down transformers on each bus stop would be quite expensive.

Arranging MV feeds to the end of the line only would be easierm which
of course requires a bigger battery capacity.

Lasse Langwadt Christense
Guest

Fri Jan 04, 2019 12:45 am   



torsdag den 3. januar 2019 kl. 23.49.09 UTC+1 skrev upsid...@downunder.com:
Quote:
On Thu, 3 Jan 2019 13:34:02 -0800 (PST), edward.ming.lee_at_gmail.com
wrote:


Of course 1500 Vdc at 35 A would give 50 kW, so two hours would fully charge a 100 kWh battery, enough to drive hundreds of kilometers.

Most EV batteries are around 400V. We just need the source to be high enough to avoid the DC booster. There is not much advantage of going kV. There is also higher chance of shock with higher voltage.

The DC booster might not be a bad idea.

On the mains side, you may need some PFC, so that the charger doesn't
generate too much mains harmonics.

Using a DC booster also provides a nice way to have an isolated supply
and in case of ground leakage or short circuit, the output voltage can
be dropped in milliseconds.

480V 100A should be enough.


https://youtu.be/qy9pltNa0rY


Guest

Fri Jan 04, 2019 12:45 am   



On Thu, 3 Jan 2019 13:34:02 -0800 (PST), edward.ming.lee_at_gmail.com
wrote:

Quote:

Of course 1500 Vdc at 35 A would give 50 kW, so two hours would fully charge a 100 kWh battery, enough to drive hundreds of kilometers.

Most EV batteries are around 400V. We just need the source to be high enough to avoid the DC booster. There is not much advantage of going kV. There is also higher chance of shock with higher voltage.


The DC booster might not be a bad idea.

On the mains side, you may need some PFC, so that the charger doesn't
generate too much mains harmonics.

Using a DC booster also provides a nice way to have an isolated supply
and in case of ground leakage or short circuit, the output voltage can
be dropped in milliseconds.

>480V 100A should be enough.

Phil Hobbs
Guest

Fri Jan 04, 2019 1:45 am   



On 1/3/19 11:43 AM, George Herold wrote:
Quote:
On Wednesday, January 2, 2019 at 9:02:20 PM UTC-5, Dave Platt wrote:
In article <f601f50d-f201-44d2-8cb7-a6268090a704_at_googlegroups.com>,
George Herold <gherold_at_teachspin.com> wrote:

I haven't been following along. But when the power fails,
I switch off from the line, and then plug my generator into
my house, and use the fuse/breaker box to run different stuff...
furnace, frig, coffee maker. The frig and furnace are on different
AC lines so I've gotta plug in at different points.
I don't use any switches*, but I do have a double male three prong
plug, that's probably illegal somewhere.

As I understand it, in order for a "generator to home wiring" setup to
be legal, you need to use a real transfer switch - one which makes it
physically impossible to have both the generator, and the incoming
mains feed, hooked up to the house wiring simultaneously.

The way you're (apparently) doing it, it would be possible for you to
accidentally try to back-power the mains... if you fail to open some
of the breakers (individual-circuit or the main disconnect) or if
somebody inadvertently tries to "reset a tripped breaker" under these
conditions. A cross-connect of that sort could easily kill someone.

At the very least, if you're going to do this, I'd think it a good
idea for you to have a "lockout padlock" that you use to close the
breaker box after you open the main disconnect and the individual
circuit breakers. That would, at least, prevent some "helpful"
individual from reconnecting the line while the generator is powered
up.

Right all 'helpful' individuals are informed that there is no power,
the generator is running and not to go outside and energize the AC
cut-off switch. It only happens once every few years, and I don't
worry about it.

But people always complain when I describe what I do.

George H.


AFAIK the usual safe way to do this is what I have--an aluminum plate
with slots cut in it, bolted to the front of the panel so that the
"generator in" breaker can only be closed when the main breaker is open.

It's a cheap and very slick solution to the transfer switch problem.

We tend to lose power about once a year, usually for less than a day.
Late last winter we were out for 8 days. I got on the Con Edison outage
page, and by extrapolating their progress during Day 1, I figured it
would be about that long. There were no generators to be had by then,
so I got one online, and had the electricians in to do the transfer
switch and feed cable. (The generator goes outside, chained to a large
Metasequoia.) I was up and running by Day 4, total cost $400 for a 4.4
kW generator and $1k for the electricians.

Cheers

Phil Hobbs

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

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


Guest

Fri Jan 04, 2019 1:45 am   



>"How can you plug one extension cord into two outlets??? "

It is two, god damn you gotta tell some people everything.

Steve Wilson
Guest

Fri Jan 04, 2019 2:45 am   



George Herold <gherold_at_teachspin.com> wrote:

Quote:
If I told you there was a padlock on the disconnect box would you feel
better?


Only if you use it.

You never mentioned this earlier. If the box is locked, how can anyone turn
on the electricity while you are working on it?

Quote:
It's very hard to forget that the generator is on, the new one is quieter
than the old one, but still makes a racket.


So the noise tells you electricity is available.

> George H.

amdx
Guest

Fri Jan 04, 2019 4:45 am   



On 1/3/2019 4:19 PM, upsidedown_at_downunder.com wrote:
Quote:
On Thu, 3 Jan 2019 14:09:44 -0600, amdx <nojunk_at_knology.net> wrote:

On 12/31/2018 7:13 AM, Lasse Langwadt Christensen wrote:
mandag den 31. december 2018 kl. 14.03.06 UTC+1 skrev upsid...@downunder.com:
On Mon, 31 Dec 2018 00:07:18 +0200, upsidedown_at_downunder.com wrote:


The energy needs for various utility vehicles is of course much
larger, but still city buses can run with a high power charging
station at only at one end of the line. The battery is fully charged
in the time the driver visits the restroom or smokes a cigarette.

??? Where did you get this idea?

There is a charging station about 1 km from where I live and I have
frequently used the bus line in the afternoon returning from the round
trip towards the charging station. The bus accelerates quite strongly
at the end o the leg, so a lot of power must still be available.
Admittedly the total route is less than 10 km long, but this the
second or third winter.

These are Solaris Urbino12 Electric buses. The line round trip
distance is 13 km and according to the schedule, there would be at
most 10 min charging time from the pantograph at the city terminal.
.

yeh they are running some in cities here, 55kWh lithium-titanate battery,
300kW pantograf charger at the end of the line. claims 1kWh/km so only a
few minutes charging needed per trip


I recall seeing a Chinese system that used capacitors and every
bus stop had a connection for a short recharge during the stop.
Found an article.
https://phys.org/news/2009-10-ultracapacitors-city-buses-cheaper-greener.html

A problem for suburban and rural bus lines is how to provide high
peak currents to the bus stops. Taking it from a local weak network
would dim the lights when there is a bus at the stop. Alternatively
running dedicated medium voltage lines along each bus route and using
step-down transformers on each bus stop would be quite expensive.

Arranging MV feeds to the end of the line only would be easierm which
of course requires a bigger battery capacity.

Understood. How about charging a capacitor bank at each stop between
bus charges and use the charged capacitors to charge the bus. That would
reduce peak demand.
Mikek

Tim Watts
Guest

Fri Jan 04, 2019 5:45 pm   



On 04/01/2019 16:20, George Herold wrote:
Quote:
On Thursday, January 3, 2019 at 6:52:37 PM UTC-5, Phil Hobbs wrote:
On 1/3/19 11:43 AM, George Herold wrote:
On Wednesday, January 2, 2019 at 9:02:20 PM UTC-5, Dave Platt wrote:
In article <f601f50d-f201-44d2-8cb7-a6268090a704_at_googlegroups.com>,
George Herold <gherold_at_teachspin.com> wrote:

I haven't been following along. But when the power fails,
I switch off from the line, and then plug my generator into
my house, and use the fuse/breaker box to run different stuff...
furnace, frig, coffee maker. The frig and furnace are on different
AC lines so I've gotta plug in at different points.
I don't use any switches*, but I do have a double male three prong
plug, that's probably illegal somewhere.

As I understand it, in order for a "generator to home wiring" setup to
be legal, you need to use a real transfer switch - one which makes it
physically impossible to have both the generator, and the incoming
mains feed, hooked up to the house wiring simultaneously.

The way you're (apparently) doing it, it would be possible for you to
accidentally try to back-power the mains... if you fail to open some
of the breakers (individual-circuit or the main disconnect) or if
somebody inadvertently tries to "reset a tripped breaker" under these
conditions. A cross-connect of that sort could easily kill someone.

At the very least, if you're going to do this, I'd think it a good
idea for you to have a "lockout padlock" that you use to close the
breaker box after you open the main disconnect and the individual
circuit breakers. That would, at least, prevent some "helpful"
individual from reconnecting the line while the generator is powered
up.

Right all 'helpful' individuals are informed that there is no power,
the generator is running and not to go outside and energize the AC
cut-off switch. It only happens once every few years, and I don't
worry about it.

But people always complain when I describe what I do.

George H.


AFAIK the usual safe way to do this is what I have--an aluminum plate
with slots cut in it, bolted to the front of the panel so that the
"generator in" breaker can only be closed when the main breaker is open.

It's a cheap and very slick solution to the transfer switch problem.

We tend to lose power about once a year, usually for less than a day.
Late last winter we were out for 8 days. I got on the Con Edison outage
page, and by extrapolating their progress during Day 1, I figured it
would be about that long. There were no generators to be had by then,
so I got one online, and had the electricians in to do the transfer
switch and feed cable. (The generator goes outside, chained to a large
Metasequoia.) I was up and running by Day 4, total cost $400 for a 4.4
kW generator and $1k for the electricians.

Right, I'm a cheapskate and wanted to avoid the ~$1k for transfer
switch and electrician. Well the first time I did this I wasn't thinking
about safety, just getting the furnace running to stay warm.


The British cheapskate way to do this (as in it meets the regs) is to
simply plug your boiler in to a standard outlet mounted specifically for
that purpose.

Then you can have a second outlet on a completely isolated circuit which
is powered by the generator - or for super cheapskate, run an extension
in when required.

Unplug boiler. Plug into temporary supply. Job done, safe, cheap,
foolproof[1]

I can't see why that would fall too far foul of other jurisdictions - at
least it is basically safe, idiot proof and easy.

[1] Apart from the slight matter of earthing/grounding which is going to
be jurisdiction specific.

Quote:
George H.

(Side note: after making my own double male three pronged plug I found
that the previous owner had made one too. (found in the back of a drawer
with other electronics bits.) I've always figured he did the same trick.)


You made a Jesus Cord?

--
Email does not work

Tim Watts
Guest

Fri Jan 04, 2019 5:45 pm   



On 04/01/2019 16:21, Lasse Langwadt Christensen wrote:

Quote:
unless they were all disconnected and then the risk is that you energize
a line someone is working on


Which is exactly why generator transfer switches exist :)


--
Email does not work

Lasse Langwadt Christense
Guest

Fri Jan 04, 2019 5:45 pm   



fredag den 4. januar 2019 kl. 17.06.55 UTC+1 skrev George Herold:
Quote:
On Thursday, January 3, 2019 at 7:51:04 PM UTC-5, Steve Wilson wrote:
George Herold <gherold_at_teachspin.com> wrote:

If I told you there was a padlock on the disconnect box would you feel
better?

Only if you use it.
Well the disconnect box is outside on the side of my house.
There is a pad lock on it, but the lock is old, rusty and
doesn't close anymore.
It's mainly there for looks... it sorta looks locked.

You never mentioned this earlier. If the box is locked, how can anyone turn
on the electricity while you are working on it?

It's very hard to forget that the generator is on, the new one is quieter
than the old one, but still makes a racket.

So the noise tells you electricity is available.
Huh, no it tells me the generator is on. You seemed to suggest that
I would forget it was on and then go blindly out and re-energize the AC.

Say If I did reconnect to to local AC power line would my generator then
be trying to power the entire neighborhood? That would cause it to bog
down quickly.


unless they were all disconnected and then the risk is that you energize
a line someone is working on

George Herold
Guest

Fri Jan 04, 2019 5:45 pm   



On Thursday, January 3, 2019 at 6:52:37 PM UTC-5, Phil Hobbs wrote:
Quote:
On 1/3/19 11:43 AM, George Herold wrote:
On Wednesday, January 2, 2019 at 9:02:20 PM UTC-5, Dave Platt wrote:
In article <f601f50d-f201-44d2-8cb7-a6268090a704_at_googlegroups.com>,
George Herold <gherold_at_teachspin.com> wrote:

I haven't been following along. But when the power fails,
I switch off from the line, and then plug my generator into
my house, and use the fuse/breaker box to run different stuff...
furnace, frig, coffee maker. The frig and furnace are on different
AC lines so I've gotta plug in at different points.
I don't use any switches*, but I do have a double male three prong
plug, that's probably illegal somewhere.

As I understand it, in order for a "generator to home wiring" setup to
be legal, you need to use a real transfer switch - one which makes it
physically impossible to have both the generator, and the incoming
mains feed, hooked up to the house wiring simultaneously.

The way you're (apparently) doing it, it would be possible for you to
accidentally try to back-power the mains... if you fail to open some
of the breakers (individual-circuit or the main disconnect) or if
somebody inadvertently tries to "reset a tripped breaker" under these
conditions. A cross-connect of that sort could easily kill someone.

At the very least, if you're going to do this, I'd think it a good
idea for you to have a "lockout padlock" that you use to close the
breaker box after you open the main disconnect and the individual
circuit breakers. That would, at least, prevent some "helpful"
individual from reconnecting the line while the generator is powered
up.

Right all 'helpful' individuals are informed that there is no power,
the generator is running and not to go outside and energize the AC
cut-off switch. It only happens once every few years, and I don't
worry about it.

But people always complain when I describe what I do.

George H.


AFAIK the usual safe way to do this is what I have--an aluminum plate
with slots cut in it, bolted to the front of the panel so that the
"generator in" breaker can only be closed when the main breaker is open.

It's a cheap and very slick solution to the transfer switch problem.

We tend to lose power about once a year, usually for less than a day.
Late last winter we were out for 8 days. I got on the Con Edison outage
page, and by extrapolating their progress during Day 1, I figured it
would be about that long. There were no generators to be had by then,
so I got one online, and had the electricians in to do the transfer
switch and feed cable. (The generator goes outside, chained to a large
Metasequoia.) I was up and running by Day 4, total cost $400 for a 4.4
kW generator and $1k for the electricians.


Right, I'm a cheapskate and wanted to avoid the ~$1k for transfer
switch and electrician. Well the first time I did this I wasn't thinking
about safety, just getting the furnace running to stay warm.

George H.

(Side note: after making my own double male three pronged plug I found
that the previous owner had made one too. (found in the back of a drawer
with other electronics bits.) I've always figured he did the same trick.)


Quote:

Cheers

Phil Hobbs

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

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


George Herold
Guest

Fri Jan 04, 2019 5:45 pm   



On Thursday, January 3, 2019 at 7:51:04 PM UTC-5, Steve Wilson wrote:
Quote:
George Herold <gherold_at_teachspin.com> wrote:

If I told you there was a padlock on the disconnect box would you feel
better?

Only if you use it.

Well the disconnect box is outside on the side of my house.
There is a pad lock on it, but the lock is old, rusty and
doesn't close anymore.
It's mainly there for looks... it sorta looks locked.
Quote:

You never mentioned this earlier. If the box is locked, how can anyone turn
on the electricity while you are working on it?

It's very hard to forget that the generator is on, the new one is quieter
than the old one, but still makes a racket.

So the noise tells you electricity is available.

Huh, no it tells me the generator is on. You seemed to suggest that
I would forget it was on and then go blindly out and re-energize the AC.

Say If I did reconnect to to local AC power line would my generator then
be trying to power the entire neighborhood? That would cause it to bog
down quickly.

George H.
Quote:

George H.



Guest

Fri Jan 04, 2019 5:45 pm   



So, if we hang a diode on each of the 480V 3 phase. We get 240V x (1 + .75 + .75) = 576V. Right? I think their design max out at 700V. Parts get more expensive beyond 700V.

Tim Watts
Guest

Fri Jan 04, 2019 5:45 pm   



On 04/01/2019 16:35, Tim Watts wrote:
Quote:
The British cheapskate way to do this (as in it meets the regs) is to
simply plug your boiler in to a standard outlet mounted specifically for
that purpose.


I forgot to add - this is actually near zero extra cost for a new wiring
job.

We require a double pole isolator to any boiler supply. A 13A unswitched
socket meets the requirements. So the plug and socket replaces a double
pole fused isolator of similar cost. Same backbox in wall etc :)



--
Email does not work

George Herold
Guest

Fri Jan 04, 2019 6:45 pm   



On Friday, January 4, 2019 at 11:35:36 AM UTC-5, Tim Watts wrote:
Quote:
On 04/01/2019 16:20, George Herold wrote:
On Thursday, January 3, 2019 at 6:52:37 PM UTC-5, Phil Hobbs wrote:
On 1/3/19 11:43 AM, George Herold wrote:
On Wednesday, January 2, 2019 at 9:02:20 PM UTC-5, Dave Platt wrote:
In article <f601f50d-f201-44d2-8cb7-a6268090a704_at_googlegroups.com>,
George Herold <gherold_at_teachspin.com> wrote:

I haven't been following along. But when the power fails,
I switch off from the line, and then plug my generator into
my house, and use the fuse/breaker box to run different stuff...
furnace, frig, coffee maker. The frig and furnace are on different
AC lines so I've gotta plug in at different points.
I don't use any switches*, but I do have a double male three prong
plug, that's probably illegal somewhere.

As I understand it, in order for a "generator to home wiring" setup to
be legal, you need to use a real transfer switch - one which makes it
physically impossible to have both the generator, and the incoming
mains feed, hooked up to the house wiring simultaneously.

The way you're (apparently) doing it, it would be possible for you to
accidentally try to back-power the mains... if you fail to open some
of the breakers (individual-circuit or the main disconnect) or if
somebody inadvertently tries to "reset a tripped breaker" under these
conditions. A cross-connect of that sort could easily kill someone.

At the very least, if you're going to do this, I'd think it a good
idea for you to have a "lockout padlock" that you use to close the
breaker box after you open the main disconnect and the individual
circuit breakers. That would, at least, prevent some "helpful"
individual from reconnecting the line while the generator is powered
up.

Right all 'helpful' individuals are informed that there is no power,
the generator is running and not to go outside and energize the AC
cut-off switch. It only happens once every few years, and I don't
worry about it.

But people always complain when I describe what I do.

George H.


AFAIK the usual safe way to do this is what I have--an aluminum plate
with slots cut in it, bolted to the front of the panel so that the
"generator in" breaker can only be closed when the main breaker is open.

It's a cheap and very slick solution to the transfer switch problem.

We tend to lose power about once a year, usually for less than a day.
Late last winter we were out for 8 days. I got on the Con Edison outage
page, and by extrapolating their progress during Day 1, I figured it
would be about that long. There were no generators to be had by then,
so I got one online, and had the electricians in to do the transfer
switch and feed cable. (The generator goes outside, chained to a large
Metasequoia.) I was up and running by Day 4, total cost $400 for a 4.4
kW generator and $1k for the electricians.

Right, I'm a cheapskate and wanted to avoid the ~$1k for transfer
switch and electrician. Well the first time I did this I wasn't thinking
about safety, just getting the furnace running to stay warm.

The British cheapskate way to do this (as in it meets the regs) is to
simply plug your boiler in to a standard outlet mounted specifically for
that purpose.

Then you can have a second outlet on a completely isolated circuit which
is powered by the generator - or for super cheapskate, run an extension
in when required.

Unplug boiler. Plug into temporary supply. Job done, safe, cheap,
foolproof[1]

I can't see why that would fall too far foul of other jurisdictions - at
least it is basically safe, idiot proof and easy.

[1] Apart from the slight matter of earthing/grounding which is going to
be jurisdiction specific.

George H.

(Side note: after making my own double male three pronged plug I found
that the previous owner had made one too. (found in the back of a drawer
with other electronics bits.) I've always figured he did the same trick.)


You made a Jesus Cord?

OK.
I've got what I call my 'suicide' plug in my drawer. AC blades on one side,
banana jacks (at standard 3/4" separation) on other. That's much scarier
to me than the double male plug. (It gets used more often too.)

George H.
Quote:

--
Email does not work


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