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Default Electrical Question. US 220v vs UK 240v

Both of the systems are basically the same. The only thing that
differs
is the frequency. US is 60Hz, UK is 50Hz.


The second part, the frequency, correct. The first part, incorrect.
The US and UK systems are quite different. In the US the transformer
secondary winding is centre-tapped, giving 120-0-120V. Connecting to
one live (hot) conductor and the neutral gives 120V. Connection to the
two live conductors gives 240V

In the British system the distribution system is almost always three
phase. The transformer is normally in a local substation, serving a
much larger area than the small pole mounted ones common in the US. The
secondary windings are connected in star (wye), with the neutral
conductor connected to the central point which is earthed (grounded).
Until recently the nominal Voltages were 415V between live conductors,
and 240V between any single live conductor and neutral. In both cases
+/- 6%. A few years ago this was changed to 400/230V +10/-6%. Nothing
really changed, except on paper, it was to standardise the Voltage in
Britain (415/240V) with that in the rest of Europe (380/220V) We
should now refer to it as 400/230V, but most people still call it
415/240V; it is usually closer to the latter figure.

Domestic installations are normally single phase. Each house will be
fed one of the three live conductors, and the neutral. Typically each
phase will be used in every third house along a street, i.e. if you are
on the red phase your neighbour on one side will be on yellow, while
that on the other side will be on blue. The earth and neutral
conductors are always different, but, at least at the substation, the
neutral will be at earth potential, and should be very close to it
elsewhere. There is no second live conductor, no centre tap on the
transformer, and no 120V anywhere. The only place in Britain, but not
in the rest of Europe, that you will find a centre-tapped system like
in the US is on building sites, and a few other places such as stations
on the London Underground, where portable tools ure used on a 110V
system which is centre-tapped to earth (55-0-55V) which is fed from a
local isolating transformer. Note that this can only be used for 110V
equipment; connecting to just one side to get 55V is not permitted.

There are three and four prong plugs and jacks, the three prong

model
uses the two hot, plus a neutral. The four prong uses two hot,
neutral, and
ground. They're both basically the same except the four prong runs

an earth
ground for failsafe. Just be sure your tools can run on 60Hz.


Correct in the US, quite different in the UK. Our plugs have three
pins, live, neutral and earth. Except for a special one used on
shavers and toothbrushes we have no two pin plugs now; we did in the
past, but they have not been made for many decades. You will not find
a plug with two live pins here. We do have both 4 and 5 pin plugs for
industrial use. These have three live and one earth pin. The 5 pin
ones also have a neutral pin. We do not have normal mains plugs with
two live pins.

For most equipment the frequency difference will not matter.

European flexible cables are colour coded:-

Brown - Live
Blue - Neutral
Green and yellow striped - Earth

The colours can be different for British equipment more than about 30
years old, and the situation becomes complicated with installed cabling
in buildings, and all types of three phase cables, due to changes which
have taken place in the past, and further changes which are taking
place now, to harmonise colours throughout Europe. If you have to deal
with anything like this consult an electrician who is familiar with
European standards.

British mains plugs have the earth pin, the large one, at the top.
when looking into a socket the live pin is on the right, and the
neutral pin on the left. Of course, when looking onto the pins of the
plug this will be reversed, as you are looking in the opposite
direction.

European equipment which has a three core cable should not be connected
to a 2 pin American socket, nor should the earth conductor ever be
connected to either the live or neutral conductors. You should never
find European equipment where earth and neutral are conected
internally, nor where the neutral is connected to the case (unless the
equipment has a serious fault, in which case it should not be used
anyway) Assuming that it is connected corrected correctly, European
220/230/240V equipment
should operate from a US 240V supply, with the live conductor connected
to one 'hot' leg, and the neutral conductor to the other. A possible
complication is that European equipment will be likely to have single
pole switches and circuit breakers which when tripped would leave what
is normally the neutral conductor, but which in the US would be
connected to one of the 'hot' legs connected, and therefore live at
120V. What US electrical regulations would have to say about this I've
no idea.

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MaKiNeRo d\(Ò_ó\)b
 
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Default

Hello

European flexible cables are colour coded:-

Brown - Live
Blue - Neutral
Green and yellow striped - Earth


The live conductor, also colored in blak or gray

Frequently use blak-blue-green/yellow

only Spain, two phase lines (2 wire - 220 Volt), used phase-phase colours or
phase-neutral colours.



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