Wires color code

[Toni Jesus]

Hi everyone!

I have got confused by all the wires color (Voltage code) in existing automation installation and explanations I had from others. Can someone explain the wires colors (Voltage code) used in automation (Europe) for cabling panels and devices (plc's, contactors, relays, etc), for p.ex:
- 24V AC,
- 24V DC,
- 48V AC,
- 110V AC,
- What violet color stand for?
- Is there a color for wires used to connect safety circuits?

Thanks in advance
Toni

 

[RussB]

The only color that is really important is the "copper" color under the insulation, everything else is arbitrary and you are free to create your own color code. Electrons do not care so long as there is enough "copper" color to share.
Anyway one should not rely on a color code, that is a good way to get hurt.
HTH

 

[Tom Jenkins]

I don't know about the EU other than ground. This must be green/yellow stripe.

In the US the only code requirements are white or grey for neutral, green or green/yellow stripe for ground, and any other color for voltage above ground.

By convention, not code, most use blue for DC, red for control, black for 120 VAC power, and yellow for foriegn voltage (foreign voltage means it is powered from outside the panel, not a voltage used in the EU!).

 

[gravedigger02]

In our plant we have machines from europe and the color coding is the same as Tom Jenkins mentioned.

 

[MikeW]

Use the "Search Feature" on this site, there have been quite a few threads over the years of standard "wire color codes". The bottom line is it varies a lot and you need to verify with the customer that they meet their "internal code" as many place have unofficial standards they observe. Like Russ said, only the internal conductor matters, I used to have a color blind panel wiring technician that relied on the label on the spool for what the color was.

 

[rootboy]

The only color that is really important is the "copper" color under the insulation, everything else is arbitrary and you are free to create your own color code.

Well, no. At least not from the standpoint of the NEC. Which carries the weight of law in most states (if not all).

Anyway one should not rely on a color code, that is a good way to get hurt.
HTH

Now, I can agree with that.

 

[Toni Jesus]

Hey!

Of course the the most importante is the wire sizing regarding the intensity...



You mean that there is no standart (IEC,...) in use? or convention?

But stil, I have seen some kind of homogeneity in many installations (makes me wonder about standart)as;


24V AC - White for 0V and Red for 24V
24V DC - White for 0V and Red or blue for 24V, or
Black for - and Red for + (Only for Battery?)

If you know what I mean...

 

[MikeW]

24V DC - White for 0V and Red or blue for 24V, or
Black for - and Red for + (Only for Battery?)

If you know what I mean...

Don't remember from which "standard" it comes from (do not have my work PC home this weekend) but Red & Black for 24VDC ungrounded systems, Blue & Blue w/ White stripe for 24VDC where the common is grounded. We standardized internally at our plant with White w/ Blue Stripe as it's easier to see/ trace in a panel.

 

[Toni Jesus]

Got some answers from the standard IEC 60204-1 but still not complete...I share in case anybody else ask;

Where colour-coding is used for identification of conductors, it is recommended that they be
colour-coded as follows:
– BLACK: AC and DC power circuits;
– RED: AC control circuits;
– BLUE: DC control circuits;
– ORANGE: excepted circuits in accordance with 5.3.5.​

Exceptions:

​

​

to the above are permitted where:​

– insulation is used that is not available in the colours recommended; or​

​

​

– multiconductor cable is used, but not the bicolour combination GREEN-AND-YELLOW.​