color coding for plc wiring

I was wondering if there is a standards chart that shows the color codes for inputs,outputs,AC voltage and DC voltage,etc....

I don't know if it is a standard or code, but I like to use the following:

power wiring hot==black
power wiring neutral==white
inputs and outputs==red
dc positive==brown
dc negative==blue
ground==green or green with a yellow stripe

Thanks for the info

This is a link to NFPA 79: Electrical Standards for Industrial Machinery http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=79&cookie%5Ftest=1

If you scroll down you will see a link that will let you view the book.

Chapter 13 will provdie information on wire identification (color).
Green or green with yellow stripe is Ground but there are exceptions (multi-conductor cable) that will allow solid green to be used as a non-grounded conductor. Personally I probably would not use green for anything but ground.

Orange is used for AC connductors that may be energized when cabinet (panel) power is OFF. Again, there are exceptions.
White with Orange stripe for AC grounded conductors that may be energized when cabinet (panel) power is OFF.
NOTE: In the past I was use to this being yellow but since yellow was used for 3 phase it got changed somewhere along the line.

AC grounded conductor (neutal) is white, gray, or 3 continuous white stripes on another color NOT Green, Blue, or Orange.

White with Blue stripe for DC grounded current carrying cunductors.

Black for ungrounded (HOT) AC or DC power conductors.
Red for ungrounded AC control conductors.
Blue for ungrounded DC control conductors.
There are exceptions.

That said I am use to seeing +24vdc use Brown and DC common use Blue, started seeing it over 25 years ago on European built equipment.

I have usually seen:
AC power is black/white, or black/red/white. Green or green/yellow stripe is always ground.
Unswitched/separate source AC is yellow.
DC 0V is blue, sometime I have seen the DC common as blue with white stripe.
DC +ve is brown; I have seen it blue.
The IO is usually blue if DC, red if AC, although I would prefer to see them different colour than the DC power.

I believe there are some guidlines as pointed out, but generally the standard is down to the local company.

If they don't specify then the panel builder would use what he thinks is correct.

Companies should have their site standard and ensure suppliers adhere to it, nothing worse than a colour meaning low power in one panel and high in the next.

Some pretty common ones I've seen are:

Orange - Interlocking/Interface wiring (can be live when panel isolated)

Blue - 24VDC +ve and -ve

Red - 110VAC Live
White - 110VAC Neutral

Black - 415VAC (Power)

Having said that, I've seen purple, grey and all sorts in different panels over the years.

Thanks to everyone for the info!!