There are several color-coding schemes for control cables. Get quick links to them here…
The most common control cable insulation color schemes are from ICEA standard S-73-532. It contains several different methods for marking the insulation. ICEA Method 1 consists of two different color code tables.
The most common coloring schemes are ICEA Method 1, tables E-1 and E-2, and Method 4.
OmniCable has posted handy color tables at the following links:
Method 1 uses different colors. Method 4 prints the conductor number on the insulation.
Click here for a more comprehensive description of the various schemes presented in the ICEA standard.
ICEA Method 1, Table E-1 conflicts with the National Electric Code (NFPA 70) conductor color requirements. The NEC reserves white and green insulation for neutral and equipment grounding conductors.
Table E-1 uses white and green for the insulation and striping, but Table E-2 omits both completely. So, for any NEC application, you must use ICEA Method 1, Table E-2.
Or rather, you must not use Table E-1.
NFPA 79, “Electrical Standard for Industrial Machinery,” also specifies certain wiring colors to denote particular functions that are generally consistent with the NEC. There are exceptions, but some examples from Article 13 are as follows:
- Equipment grounding conductor: Green insulation, with or without one or more yellow stripes
- Grounded AC circuit conductor (i.e., the neutral wire): White, gray, or three continuous white stripes on insulation that is not green, blue, or orange
- Grounded DC circuit conductor: white with blue stripe
- Grounded AC circuit conductor that remains energized when the circuit disconnect is in the OFF position: white with orange stripe
- Ungrounded conductors that remain energized when the circuit disconnect is in the OFF position: orange
Conductor insulation colors in multi-conductor control cables are varied to improve safety and reduce rework.
A short bulletin by a cable distributor explains: “Color codes decrease potentially hazardous confusion by ensuring cables are in compliance with applicable codes and providing a quick visual assurance that cables are connected correctly.”
Sometimes you will need to include not only a conductor name or number on a wiring diagram or schematic, but also the conductor insulation color. The different colors provide helps to the installers that make it easier to identify the conductors during installation.
This reduces the likelihood of making a wiring error, and this can save time during testing by eliminating the need to troubleshoot or rewire a circuit.
To know how to label the colors, you need to know which insulation color scheme the cable is manufactured to. This can be another item to add to your design checklist.