Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?

--
*Husband and cat lost -- reward for cat

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
scribeth thus
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?


Yes, they'll cancel out!...


Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..
--
Tony Sayer

On 26/02/2014 17:32, Dave Plowman (News) wrote:

Does it matter if one winding has the connections reversed when they are
in series?


Yes it matters, one will cancel out the other.
The same would happen if the parallel ones were reversed.

On Wed, 26 Feb 2014 17:32:40 +0000 (GMT), Dave Plowman (News) wrote:

The transformer primary has two winding wired in parallel which seem to
be coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will
do it for 240v. Link brown and red and 240 goes between black to orange?

Draws a picture to make sure, yes that is correct. B-)

Does it matter if one winding has the connections reversed when they are
in series?

Yes the fields generated will cancel and it won't work. It may also
get rather hot and go bang.

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

--
Cheers
Dave.

tony sayer wrote:
In , Dave Plowman (News)
scribeth thus
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?


Yes, they'll cancel out!...


Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..

But the fuse will give you a chance!

On Wednesday, 26 February 2014 18:37:51 UTC, dennis@home wrote:
On 26/02/2014 17:32, Dave Plowman (News) wrote:
Does it matter if one winding has the connections reversed when they are
in series?
Yes it matters, one will cancel out the other.
The same would happen if the parallel ones were reversed.

If they do cancel out, the transformer current will depend
on the primary winding resistance, as there will be hardly
any inductance. This means that the transformer will let out
it's magic smoke.

John

On Wed, 26 Feb 2014 18:05:03 +0000, tony sayer wrote:

snip

Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..

I use an incandescent light bulb in series with the mains. Cheap and
cheerful. Keeps the magic smoke in place.

In article o.uk, Dave
Liquorice writes
snip

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

Electrolytic caps are often +50% -20% tolerance so the difference
between 50Hz and 60Hz (17%) is probably not important in this case.

--
Chris Holford

On Wed, 26 Feb 2014 17:32:40 +0000 (GMT), "Dave Plowman (News)"
wrote:

Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?

You can bet your bippy that it does! :-)

If you series the split primary windings in counter-phase, you'll
have created a 'non inductive' wirewound resistor of perhaps circa ten
ohms for something like a 200VA transformer (it all rather depends on
the VA rating of the transformer).

That should blow a 13A plugtop cartridge fuse in about a second or
so. Obviously, a 5A fuse would be a better bet if you're going to
'test and hope' sans any form of continuity testing to identify the
correct pairs to associate with each winding.

The thing is, assuming you make use of the fact that you need to
connect either the red or black to the orange with the remaining
unused wires connected to neutral and on/off switch, you can either
end up shorting one of the split windings in isolation and connect the
other 120v winding across the 230v supply or end up with them wired in
series phase aiding as per requirement.

Now, if you get it wrong, the same 200VA transformer will present a
mere 5 ohms with the shorted out winding effectively making it a
non-inductive resistor with just a small amount of leakage reactance
in series. If you get it right first time by dumb luck, the fuse
doesn't blow and the amp will work just fine.

Provided you're happy to sacrifice a 5A plugtop fuse and you use your
noggin, it's quite possible (if not recommended) to arive at the
correct solution in no more than 2 goes of the "Suck It And See
Method"(tm).

As it happens, in this case, there's no risk of damage to the
rectifier/smooting capacitor pack other than failing to short out the
out of circuit winding when applying 230v across the single 120v
winding.

BTW, closer scrutiny suggest you may have correctly identified which
colours belong to which winding. As I re-read it, you need to either
connect brown to red or else orange to black using the remaining
connections to go to the neutral and switched live terminals.
--
Regards, J B Good

In article o.uk,
Dave Liquorice wrote:
So it looks like I may be lucky and simply altering them to series
will do it for 240v. Link brown and red and 240 goes between black to
orange?

Draws a picture to make sure, yes that is correct. B-)

It's a fairly standard looking transformer with the wires exiting from the
top of the bobbin and on every other ones of this type I've got they go
Winding 1 start finish Winding 2 start finish in a line. So for 240v you
just link the centre two and apply the 240v to the outer two.

Does it matter if one winding has the connections reversed when they are
in series?

Yes the fields generated will cancel and it won't work. It may also
get rather hot and go bang.

Quite - which is why I was asking. I wondered if the wires were standard
colours in the US. I do have a US transformer here with twin primaries,
and that has a red and a black but purple and yellow.

However, some exhaustive Googling found a pic of the insides of a device
from the same maker 240v connected.

It goes Red and Brown linked. Black to neutral, Orange to Line. Only
other difference (apart from obviously fuse value) is the 240v device has
a DP mains switch, the 110v a single pole one. I won't loose any sleep
over that. ;-)

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

I'll risk that. No big deal to change if it proves a problem. Thanks.

--
*I love cats...they taste just like chicken.

Dave Plowman London SW
To e-mail, change noise into sound.

"tony sayer" wrote in message
news
In article , Dave Plowman (News)
scribeth thus
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?


Yes, they'll cancel out!...


Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..
--

Both voltages are common in the USA. So it will be precisely for this
pupose.
(So there probably exists information somewhere (manufacturer/internet?
Label inside somewhere/users manual) on how to change the voltage
connections.

You commonly see a similar idea on three phase motors too.

In article ,
harryagain wrote:
Both voltages are common in the USA. So it will be precisely for this
pupose.
(So there probably exists information somewhere (manufacturer/internet?
Label inside somewhere/users manual) on how to change the voltage
connections.

Not in the manual or on the maker's site. In common with so many these
days they don't make a schematic available.

--
*Being healthy is merely the slowest possible rate at which one can die.

Dave Plowman London SW
To e-mail, change noise into sound.

On 26/02/2014 17:32, Dave Plowman (News) wrote:
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

That could spell trouble keep a *very* careful eye on it for signs of
overheating. US made kit for their domestic market tends to cut it
extremely fine on the saturation of the transformer and the shift in
frequency from 60Hz down to 50Hz will allow a higher current to flow.
One of my first jobs was to determine why a particular US made colour
monitor died prematurely and sometimes even caught fire in the UK.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?

Yes. Get it wrong and the two windings magnetic fields will cancel each
other out resulting in an almost non inductive load. Check with an LCR
meter to establish which way round produces a 2L load as opposed to an
almost pure resistive one with a tiny inductance.

And really keep an eye on it for overheating. The change from 60 to 50Hz
can saturate the transformer cores on some US kit! Their electronic
designers often can't imagine anywhere outside the USA!

Japanese stuff is always OK anywhere as they have half 50Hz UK and half
USA 60Hz frequency depending on which part of the country you live in!

--
Regards,
Martin Brown

On 26/02/2014 23:10, Chris Holford wrote:
In article o.uk, Dave
Liquorice writes
snip

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

Electrolytic caps are often +50% -20% tolerance so the difference
between 50Hz and 60Hz (17%) is probably not important in this case.

True enough but the tendency of US electronic designers to use cheap and
nasty transformers that are only marginally safe from saturating at 60Hz
is a potentially serious problem for overheating at UK 50Hz.

--
Regards,
Martin Brown

It does matter as it will not work one way around!
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Dave Plowman (News)" wrote in message
...
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?

--
*Husband and cat lost -- reward for cat

Dave Plowman London SW
To e-mail, change noise into sound.

Or put a light bulb into the circuit.

Brown to red and the others to mains via switch, I'd suggest.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"tony sayer" wrote in message
news
In article , Dave Plowman (News)
scribeth thus
Bought a bit of audio gear from the US at a decent price even allowing for
carriage. Guessed it might be 110v - but it is actually marked 120v 60Hz.

Looking inside, it has an analogue power supply - I was rather expecting
an SMPS.

The transformer primary has two winding wired in parallel which seem to be
coil 1 black start brown end, coil 2 red start orange end.

Red and black are paralleled as are brown and orange. Red/Black goes to
neutral, brown/orange to the off/on switch.

So it looks like I may be lucky and simply altering them to series will do
it for 240v. Link brown and red and 240 goes between black to orange?
Does it matter if one winding has the connections reversed when they are
in series?


Yes, they'll cancel out!...


Have you got a VARIAC or similar to test it with before, close switch
and retire to a safe distance?..
--
Tony Sayer

And no there is no wire colour standard. I once bought several transformers
with the same pec but from different places and none had the same colour
ewires, and one just had tags with no visible wires at all.

Sounds like a P ioneer piece of kit, but I'm going back a lot of years now..
Leans on old walking stick.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Dave Plowman (News)" wrote in message
...
In article o.uk,
Dave Liquorice wrote:
So it looks like I may be lucky and simply altering them to series
will do it for 240v. Link brown and red and 240 goes between black to
orange?

Draws a picture to make sure, yes that is correct. B-)

It's a fairly standard looking transformer with the wires exiting from the
top of the bobbin and on every other ones of this type I've got they go
Winding 1 start finish Winding 2 start finish in a line. So for 240v you
just link the centre two and apply the 240v to the outer two.

Does it matter if one winding has the connections reversed when they
are
in series?

Yes the fields generated will cancel and it won't work. It may also
get rather hot and go bang.

Quite - which is why I was asking. I wondered if the wires were standard
colours in the US. I do have a US transformer here with twin primaries,
and that has a red and a black but purple and yellow.

However, some exhaustive Googling found a pic of the insides of a device
from the same maker 240v connected.

It goes Red and Brown linked. Black to neutral, Orange to Line. Only
other difference (apart from obviously fuse value) is the 240v device has
a DP mains switch, the 110v a single pole one. I won't loose any sleep
over that. ;-)

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

I'll risk that. No big deal to change if it proves a problem. Thanks.

--
*I love cats...they taste just like chicken.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Martin Brown wrote:
Japanese stuff is always OK anywhere as they have half 50Hz UK and half
USA 60Hz frequency depending on which part of the country you live in!


This was made in China.

What is interesting is the legend on the rear panel also shows 100v 60 Hz
and 230v 50 Hz as choices - presumably with a different transformer(s)?

But this one was marked 120v 60 Hz and I can't see why they'd make the
transformer for that with two windings in parallel if couldn't be altered
to 240v.

--
*Warning: Dates in Calendar are closer than they appear.

Dave Plowman London SW
To e-mail, change noise into sound.

On 27/02/2014 10:07, Dave Plowman (News) wrote:
In article ,
Martin Brown wrote:

Japanese stuff is always OK anywhere as they have half 50Hz UK and half
USA 60Hz frequency depending on which part of the country you live in!

This was made in China.

What is interesting is the legend on the rear panel also shows 100v 60 Hz
and 230v 50 Hz as choices - presumably with a different transformer(s)?

Possibly. Maybe the same one and a different internal setting.

But this one was marked 120v 60 Hz and I can't see why they'd make the
transformer for that with two windings in parallel if couldn't be altered
to 240v.

The thing to watch out for is that it might only be safe under full load
when on 240v and 60Hz (the transformer needs ~20% less metal).

Monitor it very closely for signs of overheating after conversion.

--
Regards,
Martin Brown

On 27/02/2014 07:52, harryagain wrote:


Both voltages are common in the USA. So it will be precisely for this
pupose.

Unlikely, me thinks. 240V in the states would be used for high power
items that would otherwise draw too much current at 110/120V. This class
of item wouldn't fall into that use category, 240V wouldn't necessarily
be plumbed in at the environment of use (studio, lounge etc...).

More than likely the choice of transformer is commonly in international
use. However the designer might not have sized the device for 50Hz use,
even though the provided windings are configurable. And then there's
other components. Ratings of capacitors, rectifiers, EMI filters and
insulation / creepage distance.

So all that needs checking to be safe. You are right about consulting
documentation.

--
Adrian C

Adrian C wrote:
On 27/02/2014 07:52, harryagain wrote:


Both voltages are common in the USA. So it will be precisely for this
pupose.

Unlikely, me thinks. 240V in the states would be used for high power
items that would otherwise draw too much current at 110/120V. This class
of item wouldn't fall into that use category, 240V wouldn't necessarily
be plumbed in at the environment of use (studio, lounge etc...).

More than likely the choice of transformer is commonly in international
use. However the designer might not have sized the device for 50Hz use,
even though the provided windings are configurable. And then there's
other components. Ratings of capacitors, rectifiers, EMI filters and
insulation / creepage distance.

So all that needs checking to be safe. You are right about consulting
documentation.


As the product is described as 50/60Hz. It is very unlikely that two
different transformer cores will be used. Also, 110/120V products have
to withstand up to about 150V in operation because of the US
distribution system of very long lines and the resulting poor
regulation. I can't recall the exact voltage ranges we designed for in
120V PSUs, but I reckon it was 80 to 160V. My experience is that I've
yet to see a US consumer transformer fail due to core saturaton at 50Hz.
I generally buy US ceiling fans for summer use and none of these have
yet shown any signs of overheating.

In article ,
Martin Brown wrote:
On 27/02/2014 10:07, Dave Plowman (News) wrote:
In article ,
Martin Brown wrote:

Japanese stuff is always OK anywhere as they have half 50Hz UK and
half USA 60Hz frequency depending on which part of the country you
live in!

This was made in China.

What is interesting is the legend on the rear panel also shows 100v 60
Hz and 230v 50 Hz as choices - presumably with a different
transformer(s)?

Possibly. Maybe the same one and a different internal setting.

Not quite sure what you mean? On an analogue power supply, the mains input
is always set by tappings on the transformer.

But this one was marked 120v 60 Hz and I can't see why they'd make the
transformer for that with two windings in parallel if couldn't be
altered to 240v.

The thing to watch out for is that it might only be safe under full load
when on 240v and 60Hz (the transformer needs ~20% less metal).

If they were cutting costs to the last fraction of a penny on components,
why use a dual winding transformer? Be cheaper to have a different one for
each and every voltage? And make assembly easier?

Monitor it very closely for signs of overheating after conversion.

Bit difficult, that one.

--
*The beatings will continue until morale improves *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Capitol wrote:
As the product is described as 50/60Hz. It is very unlikely that two
different transformer cores will be used. Also, 110/120V products have
to withstand up to about 150V in operation because of the US
distribution system of very long lines and the resulting poor
regulation. I can't recall the exact voltage ranges we designed for in
120V PSUs, but I reckon it was 80 to 160V. My experience is that I've
yet to see a US consumer transformer fail due to core saturaton at 50Hz.
I generally buy US ceiling fans for summer use and none of these have
yet shown any signs of overheating.

It's pretty easy to get a 110v transformer to run US equipment here. If it
really were a problem with transformer design on the average low power
device I'd have thought it would be known.

--
*No sentence fragments *

Dave Plowman London SW
To e-mail, change noise into sound.

On 27/02/2014 14:17, Dave Plowman (News) wrote:
In article ,
Martin Brown wrote:
On 27/02/2014 10:07, Dave Plowman (News) wrote:
In article ,
Martin Brown wrote:

Japanese stuff is always OK anywhere as they have half 50Hz UK and
half USA 60Hz frequency depending on which part of the country you
live in!

This was made in China.

What is interesting is the legend on the rear panel also shows 100v 60
Hz and 230v 50 Hz as choices - presumably with a different
transformer(s)?

Possibly. Maybe the same one and a different internal setting.

Not quite sure what you mean? On an analogue power supply, the mains input
is always set by tappings on the transformer.

There may be jumpers that can switch it from a series to parallel
winding configuration if that is what the maker intended. A lot of US
stuff tends to be cheapskate though and only work on local US mains.

Ronson electric shavers spring to mind as an example of a horrible
design that depended on a 60Hz mechanical resonance to work properly and
was useless in the UK. They pushed them very hard as Xmas presents.

No idea if their modern ones still have this problem but they did in the
1970's.

But this one was marked 120v 60 Hz and I can't see why they'd make the
transformer for that with two windings in parallel if couldn't be
altered to 240v.

The thing to watch out for is that it might only be safe under full load
when on 240v and 60Hz (the transformer needs ~20% less metal).

If they were cutting costs to the last fraction of a penny on components,
why use a dual winding transformer? Be cheaper to have a different one for
each and every voltage? And make assembly easier?

Depends how they cost their inventory.

Monitor it very closely for signs of overheating after conversion.

Bit difficult, that one.

LCD thermochromic label and check after a few hours use.

--
Regards,
Martin Brown

In article ,
Martin Brown wrote:
Not quite sure what you mean? On an analogue power supply, the mains
input is always set by tappings on the transformer.

There may be jumpers that can switch it from a series to parallel
winding configuration if that is what the maker intended. A lot of US
stuff tends to be cheapskate though and only work on local US mains.

I'd suggest you read my first post.

--
*If God had wanted me to touch my toes, he would have put them on my knees

Dave Plowman London SW
To e-mail, change noise into sound.

Got it done and all working. Transformer only slightly warm after running
an hour or so.

--
*If you don't like the news, go out and make some.

Dave Plowman London SW
To e-mail, change noise into sound.

On Thu, 27 Feb 2014 09:41:24 +0000
Tim Streater wrote:

In article , harryagain
wrote:

Both voltages are common in the USA.

Yes, my house had both voltages (240 to run the washing machine/dryer)
and a whole variety of different sockets.


We lived in many houses in the US, and 240 volts was only ever provided
for dryers or cookers. We never had any sockets (receptacles in
American) wired for 240v except for those specific devices.

--
Davey.

On Fri, 28 Feb 2014 15:04:33 +0000
Tim Streater wrote:

In article , Davey
wrote:

On Thu, 27 Feb 2014 09:41:24 +0000
Tim Streater wrote:

In article , harryagain
wrote:

Both voltages are common in the USA.

Yes, my house had both voltages (240 to run the washing
machine/dryer) and a whole variety of different sockets.


We lived in many houses in the US, and 240 volts was only ever
provided for dryers or cookers. We never had any sockets
(receptacles in American) wired for 240v except for those specific
devices.

Sorry, my post was incomplete. I meant to say: " ... and a whole
variety of different 120V sockets."


Understood.

I had 2-pin, 2-pin-polarised, 3-pin, and I'm sure there must have been
others. The US 3-pin socket and its flimsy accompanying plug is a PoS,
given that for a given activity, twice the current is passing, hence
four times the heat generated at the socket. The cable for anything
using a lot of power, such as a fan heater, is huge.


Totally agreed. And why they haven't caught on to the idea of putting a
fuse in the plug, I have no idea. Most plugs there now are moulded onto
the end of the cable.

--
Davey.

In article ,
Davey wrote:
Totally agreed. And why they haven't caught on to the idea of putting a
fuse in the plug, I have no idea. Most plugs there now are moulded onto
the end of the cable.

In theory, each US socket is on its own radial with its own circuit
breaker.

UK fuse in the plug is to protect the flex (maximum 13 amp) as the circuit
is capable of 30 amps or so.

--
*A clear conscience is the sign of a fuzzy memory.

Dave Plowman London SW
To e-mail, change noise into sound.

Davey wrote:
On Fri, 28 Feb 2014 15:04:33 +0000
Tim wrote:

In ,
wrote:

On Thu, 27 Feb 2014 09:41:24 +0000
Tim wrote:

In , harryagain
wrote:

Both voltages are common in the USA.

Yes, my house had both voltages (240 to run the washing
machine/dryer) and a whole variety of different sockets.


We lived in many houses in the US, and 240 volts was only ever
provided for dryers or cookers. We never had any sockets
(receptacles in American) wired for 240v except for those specific
devices.

Sorry, my post was incomplete. I meant to say: " ... and a whole
variety of different 120V sockets."


Understood.

I had 2-pin, 2-pin-polarised, 3-pin, and I'm sure there must have been
others. The US 3-pin socket and its flimsy accompanying plug is a PoS,
given that for a given activity, twice the current is passing, hence
four times the heat generated at the socket. The cable for anything
using a lot of power, such as a fan heater, is huge.


Totally agreed. And why they haven't caught on to the idea of putting a
fuse in the plug, I have no idea. Most plugs there now are moulded onto
the end of the cable.


US Xmas lights have fused plugs.

On 2/28/2014 10:55 AM, Dave Plowman (News) wrote:

In theory, each US socket is on its own radial with its own circuit
breaker.

Really? Each socket on its own radial? Radials, yes. Circuit breakers,
yes. But apart from things like freezers, cookers, etc, quite a few
sockets per radial.

On Fri, 28 Feb 2014 11:11:27 -0500
S Viemeister wrote:

On 2/28/2014 10:55 AM, Dave Plowman (News) wrote:

In theory, each US socket is on its own radial with its own circuit
breaker.

Really? Each socket on its own radial? Radials, yes. Circuit
breakers, yes. But apart from things like freezers, cookers, etc,
quite a few sockets per radial.



Agreed. When we had some additional wiring done, it was because the
existing CB couldn't handle both the microwave oven and the 'fridge
together, and that circuit supplied the whole kitchen except for the
240v oven.
There was one CB for each end of the house on each floor, making 4 CBs,
including one for the single room upstairs.

--
Davey.