Having followed some of the discussions on cable colors,
I want to share some information regarding the use of cables attached
to the mains supply in IT products, where EN 60950 references
IEC 60227 for PVC wires.
In Europe this IEC standard transforms to
HD 21.1, which in Germany becomes VDE 0281, and for the cable colors
calls up VDE 0293, which corresponds to HD 308 as mentioned below.
I. HD 21.1 S3 (PVC insulated cables) states in Scl. 4. Core Identification:
4.1 General requirements
The cores shall be identified by colors,.....
and in Scl. 4.2
4.2 Colour schemes
4.2.1 Flexible Cables
The core colours, and their rotational position, for flexible cables and
cords
shall be in accordance to HD 308.
II. HD 308 (Identification and use of cores of flexible cables)
2. Identification of cores
2.1 The cores shall be identified by color, except for the cases mentioned
in 2.3 and 2.3.
Table 1 indicates the colours of the cores, according to the number of
cores, as well as
the order of rotation of those colours.
If the number of cores is above 5, cable color (except PE) is black and
numerals are used to identify them.
Table 1
|--------+------------+------------+----------------+----------------|
| Number Colour of cores |
| of |
| cores |
|--------+------------+------------+----------------+----------------|
| | | | |other colours, |
| 1 | green/yello| light blue | |except green and|
| | w | | |yellow and any |
| | | | |bicolour |
| | | | |identification |
| | | | |other than the |
| | | | |combination of |
| | | | |colours green |
| | | | |and yellow. |
|--------+------------+------------+----------------+----------------|
| 2 | light blue | brown | | |
|--------+------------+------------+----------------+----------------|
| 3 | green/yello| brown | | light blue |
| | w | | | |
|--------+------------+------------+----------------+----------------|
| 4 | green/yello| black | light blue | brown |
| | w | | | |
|--------+------------+------------+----------------+----------------|
| 5 | green/yello| black | light blue | brown |
| | w | | | | black |
|--------+------------+------------+----------------+----------------|
2.2 It is not necessary to identify by colour the cores of flat flexible
cables without sheath.
2.3 For the use of single-core sheathed cables, identification by
continuous
coloring of the insulation is not necessary. However, in that case, the
ends
of the cores shall be identified, during installation:
- by the bicolour identification green/yellow for the protective conductor,
- by the color light blue for the neutral conductor.
3. Conditions of use of cores according to their identification by colour
Table 2
|--------------+---------------+--------------------+------------------|
| Colours of |Characteristics| |Conditions for the|
| cores |of the circuit | | cables |
| | | | 1 |
| | | |conductor |
| | | || 2 to 5|
| | | |conductors |
|--------------+---------------+--------------------+------------------|
| |with protective|green/yellow core is|green/yellow core |
| |conductor |used as protective |is used as |
| | |conductor |protective |
| | | |conductor |
|--------------+---------------+--------------------+------------------|
| |without |green/yellow core |green/yellow core |
| |protective |shall not be used |shall not be used |
| green/yellow |conductor | | |
|--------------+---------------+--------------------+------------------|
| |with neutral |Light blue core used|Light blue core |
| |conductor |as neutral conductor|used as neutral |
| | | |conductor |
|--------------+---------------+--------------------+------------------|
| | |Light blue core |Light blue core |
| | |shall not be used as|may be used for |
| | |a protective |other purposes |
| |without neutral|conductor. Countries|except as |
| light blue |conductor |are free to admit or|protective |
| | |preclude the use of |conductor |
| | |the light blue core | |
| | |as a conductor other| |
| | |than the neutral | |
| | |conductor. | |
|--------------+---------------+--------------------+------------------|
| | |Cores may be used |Cores may be used |
| other colors | - |for any purpose, |for any purpose, |
| | |except as protective|except as |
| | |conductor or neutral|protective |
| | |conductor |conductor or |
| | | |neutral conductor |
|--------------+---------------+--------------------+------------------|
According to the above the Neutral wire should be light blue and not have a
core identification by letters.
mit freundlichen Gruessen/ best regards
Volker Gasse
IBM Germany, Technical Relations/Product Safety,
Tel: +49-7031-16-6796, Fax: -6916, e-mail: ga...@de.ibm.com
Mail: D3114/7103-91, D-70548 Stuttgart, Germany
---------------------- Forwarded by Volker Gasse/Germany/IBM on 22.04.99
14:39 ---------------------------
"Crabb, John" <jo...@exchange.scotland.ncr.com> on 22.04.99 11:04:09
Please respond to "Crabb, John" <jo...@exchange.scotland.ncr.com>
To: "'Crane, Lauren'" <lcr...@bev.etn.com>, "'discussion group'"
<emc-p...@ieee.org>
cc: (bcc: Volker Gasse/Germany/IBM)
Subject: RE: What color is neutral.
I would tend to agree with your interpretation that " light
blue is only required WHERE A CIRCUIT INCLUDES A NEUTRAL
IDENTIFIED BY COLOR. If another acceptable means of identification
is used, such as marking, then light blue is not required."
(I am mystified why they have chosen to specify the neutral
conductor colour
but have left the line conductor requirements as "preferred"
colours).
You could always ask IEC TC16 for a formal "interpretation" of this
requirement.
I do not know if they have a formal process for such requests.
For IEC 60950, there is the IEC/TC 74 Chairmans Advisory Panel
which answers such requests.
Another couple of points.
I would imagine that the very definite requirement for protective
conductors
to be green/ellow is there because this is the most critical
conductor, and
we do not want any other (confusing) method of identification other
than
colour.
Surely you have to concern yourself with the requirements in the
appropriate
product standard which applies to your particular product. IEC 60446
is not a
product standard.
Is there an EN 60446 ? It is not mentioned in the 1998/99 BSI
Catalogue.
You quote from EN 60446 ed3, but given IEC 60446 was dated February
1999,
I would not have expected the equivalent EN to be available so
quickly.
Regards,
John Crabb, Development Excellence (Product Safety) ,
NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2
3XX
E-Mail :john.cr...@scotland.ncr.com
Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus
6-341-2289.
> -----Original Message-----
> From: Crane, Lauren [SMTP:lcr...@bev.etn.com]
> Sent: 21 April 1999 16:18
> To: 'Crabb, John'; 'discussion group'
> Subject: RE: What color is neutral.
>
> Mr. Crabb,
>
> I appreciate your spending 2c (or is that 2p!) on this issue.
> As the 'thread' initiator, I hope I can trouble you with a follow-up.
>
> As you and Mr. John Woodgate (often read in the s.e.e.c newsgroup)
> suggested, I have attempted to contact the ANSI-listed members of the US
> TC44 committee regarding this issue. I still am waiting for their
replies.
>
>
> Since you are so close to the standards development process.....
>
> Regarding 602446, I did get a copy of the recent (third) edition. Its
> terminology is substantially the same as EN 60204-1 1997.
>
> This is the point where I would be very interested in your comments.
>
> The standard reads (quoting from EN 60446 ed3 section 3.2.2)
> "Where a circuit includes a neutral or mid-point conductor identified by
> colour, the colour used for this purpose shall be blue. In order to avoid
> confusion with other colours it is recommended to use an unsaturated
> colour
> blue, called here 'light blue'....."
>
> My thesis (that has been supported by some notified/competent bodies but
> rejected by many peers in the industry) is that, as the section says,
> light
> blue is only required WHERE A CIRCUIT INCLUDES A NEUTRAL IDENTIFIED BY
> COLOR. If another acceptable means of identification is used, such as
> marking, then light blue is not required.
>
> This language in this section on neutrals is substantially different from
> other sections, such as the protective conductor (3.3.2) which allows no
> discretion on identifying the conductor. That is to say "The bi-colour
> combination green-and-yellow shall be used for identifying the protective
> conductor....."
>
> This is much more exact than what is said for the neutral.
>
> Am I missing something here???
>
> Thanks for any comments.
>
> PS - the equipment we make is hard wired into the customers facility
> (rather
> than plug & cord connected) so it frequently comes under the scrutiny of
> electrical inspectors.
>
> Lauren Crane
> Eaton Corporation
> lcr...@bev.etn.com
>
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