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AC Power Line Color Conventions

C

Chris Carlen

Jan 1, 1970
0
Hi:

I see a US 120V chassis wired:

AC line hot BLACK --> switched AC hot BROWN
AC line neutral WHITE (1) --> switched neutral LIGHT BLUE

I think I've seen the same arrangement in universal 120-240VAC equipment.

I'm wondering if it would be considered bad form to substitute gray for
the lt. blue for switched neutral, since lt. blue is harder to get, and
gray is mentioned in NEC as an acceptable "grounded conductor" (ie.,
neutral) color.

The trouble is that in USA neutral is expected to be at 0V, while in
Euro and other 220VAC areas, what is the lt. blue conductor?

Are euro and other countries with 220VAC a single phase w/ respect to
ground (one hot and a grounded neutral)? Or are they two 110VAC w/
respect to ground but antiphase w/ respect to each other as in USA?

But things get more complicated then with 240VAC in the USA which is
usually black and red hot conductors. What then would be a good pair of
colors for the switched 240VAC hots? Just stick with brown and blue?

There is a problem creating consistency here if the 220VAC wiring in
Euro and 220VAC regions is different from USA with it's anti-phase setup.


(1) or BLACK + WHITE stripe








--
Good day!

________________________________________
Christopher R. Carlen
Principal Laser&Electronics Technologist
Sandia National Laboratories CA USA
[email protected]
NOTE, delete texts: "RemoveThis" and
"BOGUS" from email address to reply.
 
P

Phil Allison

Jan 1, 1970
0
"Chris Carlen"
I see a US 120V chassis wired:

AC line hot BLACK --> switched AC hot BROWN
AC line neutral WHITE (1) --> switched neutral LIGHT BLUE

I think I've seen the same arrangement in universal 120-240VAC equipment.

I'm wondering if it would be considered bad form to substitute gray for
the lt. blue for switched neutral, since lt. blue is harder to get, and
gray is mentioned in NEC as an acceptable "grounded conductor" (ie.,
neutral) color.

The trouble is that in USA neutral is expected to be at 0V, while in Euro
and other 220VAC areas, what is the lt. blue conductor?

Are euro and other countries with 220VAC a single phase w/ respect to
ground (one hot and a grounded neutral)? Or are they two 110VAC w/
respect to ground but antiphase w/ respect to each other as in USA?

But things get more complicated then with 240VAC in the USA which is
usually black and red hot conductors. What then would be a good pair of
colors for the switched 240VAC hots? Just stick with brown and blue?

There is a problem creating consistency here if the 220VAC wiring in Euro
and 220VAC regions is different from USA with it's anti-phase setup.



** There is no real distinction ( in terms of electrical safety) between
Active & Neutral wires when dealing with the INSIDES of portable
appliances. All wires which attached to the incoming AC supply must be
treated as potentially LIVE and dangerous - whether nominally Neutral
conductors or not.

NEVER get the damn silly idea in your head that the Neutral colour wires
inside an appliance are different from the Active ones and hence safe to
handle.

It would be CRIMINAL to suggest that same idea to another.





........ Phil
 
D

DJ Delorie

Jan 1, 1970
0
Chris Carlen said:
I'm wondering if it would be considered bad form to substitute gray
for the lt. blue for switched neutral, since lt. blue is harder to
get, and gray is mentioned in NEC as an acceptable "grounded
conductor" (ie., neutral) color.

Be careful about the distinction between "grounded conductor" and
"grounding conductor". The latter is usually green or bare.
 
S

Stanislaw Flatto

Jan 1, 1970
0
Chris said:
Hi:

I see a US 120V chassis wired:

AC line hot BLACK --> switched AC hot BROWN
AC line neutral WHITE (1) --> switched neutral LIGHT BLUE

I think I've seen the same arrangement in universal 120-240VAC equipment.

I'm wondering if it would be considered bad form to substitute gray for
the lt. blue for switched neutral, since lt. blue is harder to get, and
gray is mentioned in NEC as an acceptable "grounded conductor" (ie.,
neutral) color.

The trouble is that in USA neutral is expected to be at 0V, while in
Euro and other 220VAC areas, what is the lt. blue conductor?

Are euro and other countries with 220VAC a single phase w/ respect to
ground (one hot and a grounded neutral)? Or are they two 110VAC w/
respect to ground but antiphase w/ respect to each other as in USA?

But things get more complicated then with 240VAC in the USA which is
usually black and red hot conductors. What then would be a good pair of
colors for the switched 240VAC hots? Just stick with brown and blue?
Here you are talking about wiring pre-~1970 when for years the "old
good" tradition was implemented partly to get rid of manufactured wires
stock.
There is a problem creating consistency here if the 220VAC wiring in
Euro and 220VAC regions is different from USA with it's anti-phase setup.


(1) or BLACK + WHITE stripe

Are your chromosomes XY? If yes then you are part of the human male
population which includes 40% of 'color blind' (partially/totally)
members. The 'old' AC wiring was line-red, neutral-black, ground-white.
So a color-blind person (like a B/W film) was perceiving the black AND
red in the same way. So mistakes happened till the standards
organisation issued a new coloring scheme which is recognised by
differences on the gray scale so the three wires can be connected by
anyone. Brown- line, light blue- neutral and green(with or without
yellow stripe)- ground.

Ideal ground is considered zero, neutral is only cirquit completion
connection to the source and its voltage to ground can be anything.
The 220-240AC are single phase 'active-neutral', no ground involved.

HTH

Stanislaw
Slack user from Ulladulla.
 
E

Eeyore

Jan 1, 1970
0
Chris said:
Hi:

I see a US 120V chassis wired:

AC line hot BLACK --> switched AC hot BROWN
AC line neutral WHITE (1) --> switched neutral LIGHT BLUE

I think I've seen the same arrangement in universal 120-240VAC equipment.

I'm wondering if it would be considered bad form to substitute gray for
the lt. blue for switched neutral, since lt. blue is harder to get, and
gray is mentioned in NEC as an acceptable "grounded conductor" (ie.,
neutral) color.

The trouble is that in USA neutral is expected to be at 0V, while in
Euro and other 220VAC areas, what is the lt. blue conductor?

230V actually.

Blue ( light blue ) is neutral. However many European countries have unpolarised
plugs that allow appliances to be 'reverse connected'.

Are euro and other countries with 220VAC
230V

a single phase w/ respect to
ground (one hot and a grounded neutral)?
Yes.

Or are they two 110VAC w/
respect to ground but antiphase w/ respect to each other as in USA?
No.

But things get more complicated then with 240VAC in the USA which is
usually black and red hot conductors. What then would be a good pair of
colors for the switched 240VAC hots? Just stick with brown and blue?

I would.

There is a problem creating consistency here if the 220VAC
230V

wiring in
Euro and 220VAC regions is different from USA with it's anti-phase setup.

We don't have '2 phase' here.

Graham
 
E

Eeyore

Jan 1, 1970
0
Phil said:
"Chris Carlen"

** There is no real distinction ( in terms of electrical safety) between
Active & Neutral wires when dealing with the INSIDES of portable
appliances. All wires which attached to the incoming AC supply must be
treated as potentially LIVE and dangerous - whether nominally Neutral
conductors or not.

NEVER get the damn silly idea in your head that the Neutral colour wires
inside an appliance are different from the Active ones and hence safe to
handle.

It would be CRIMINAL to suggest that same idea to another.

It would indeed.

Only Ground ( green/yellow ) is 'safe'.

However it's far from unknown to find outlets with no ground in some parts of
Europe AIUI. In which case, adopt design as for Class II equipment ( double
insulated ).

Graham
 
E

Eeyore

Jan 1, 1970
0
DJ said:
Be careful about the distinction between "grounded conductor" and
"grounding conductor". The latter is usually green or bare.

Not green any more ( for a long time actually ). Green with a yellow stripe.

Graham
 
B

Ben Jackson

Jan 1, 1970
0
The trouble is that in USA neutral is expected to be at 0V, while in
Euro and other 220VAC areas, what is the lt. blue conductor?

I know you mean 0V vs 120V or so, but remember that neutral must
only be bonded to ground at the panel. In an appliance, there may
be a small potential between neutral and ground. Or if there's a
loose neutral in the panel, a LARGE potential...
 
D

DJ Delorie

Jan 1, 1970
0
Stanislaw Flatto said:
So a color-blind person (like a B/W film) was perceiving the black
AND red in the same way.

Er, no. I know a couple of color blind people, and used to work on
accessibility testing for color blindness in software.

What color blind people can't tell the difference between is various
shades of (for example) red and green. Bold colors can usually be
discriminated (by brightness, or by weak color reception), and
certainly they can tell colors from black and white.

To simulate red-green color blindness, modify your color palette so
that all red and green channels are replaced with a yellow of similar
brightness (leave blue alone). This gives you black, white, blue,
yellow, and blends.

One of my subjects joked that he was going to paint his house pink and
cyan, because *he* couldn't tell the difference.

They also have trouble with red and green street lights at night; not
enough visual clues to tell which light is on.
 
P

Phil Allison

Jan 1, 1970
0
"Ben Jackson"
I know you mean 0V vs 120V or so, but remember that neutral must
only be bonded to ground at the panel. In an appliance, there may
be a small potential between neutral and ground. Or if there's a
loose neutral in the panel, a LARGE potential...


** This is VERY dangerous crapology.

In a portable appliance, nominal neutral conductors must be assumed to beat
LIVE at *full line voltage* - anytime.

The legal requirements for insulation type and thickness, clearances and
creepage distances are the SAME for all AC supply current carrying
conductors.






....... Phil
 
E

Eeyore

Jan 1, 1970
0
Phil said:
"Ben Jackson"

** This is VERY dangerous crapology.

In a portable appliance, nominal neutral conductors must be assumed to beat
LIVE at *full line voltage* - anytime.

The legal requirements for insulation type and thickness, clearances and
creepage distances are the SAME for all AC supply current carrying
conductors.

See also the IEC requirements for 'double insulated' AC conductors in equipment.

Graham
 
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