The Basics of Electrical Tape
Electrical tape is a versatile and necessary part of any electrical contractor’s kit. In its simplest form, electrical tape provides an easy way to insulate wires carrying electricity. Yet there is another key use for electrical tape—marking.
Electrical tape comes in many standard colors, and sometimes those colors can be used to differentiate wires on the jobsite. To get the full use out of electrical tape as marking, you need to understand what each color means. Each standard color of electrical tape has a specific significance, and to learn those meanings we must first understand phasing.
What is Phasing?
Not all electricity supplied by power systems is created equal. Most people know the difference between AC and DC—Alternating Current and Direct Current—but phases are a little more complex.
Electrical systems can be 1 Phase, 3 Phase or in rarer circumstances, 2 Phase. Essentially, a system’s Phase indicates how many unique peaks and valleys of power it carries. All AC power has natural peaks and valleys, and so using more phases allows for a higher total quantity of power to be delivered, since the system is more often near a peak.
3 Phase systems are generally considered optimal because they deliver the best ratio between a high amount of power and a low number of conductors. They are powerful and cost-effective solutions to many power needs.
1 Phase systems are generally found in residential applications and deliver simple, efficient, reliable power at a lower voltage. Motors generally cannot run on single-phase power without the addition of a motor starter because the single-phase power does not provide enough initial torque. 2 Phase systems are an obsolete technology and are only found in outdated installations.
Why does this Matter for Wire and Tape Color?
Wires are frequently color-coded, which helps the professionals who work on them determine what each wire’s role is, in addition to keeping a system manageable. A huge tangle of black wires would be incomprehensible—using color-coding helps prevent this. Most wires come with a standard black insulation and must be marked with colored electrical tape to show their purpose. The meanings of the different colors are as follows:
Green wires always indicate the system’s ground. The ground wire is physically connected to the earth and keeps the electrical system as close as possible to the ground potential while providing a safe path for ground-fault currents to flow.
White wires are typically used to indicate the neutral (or grounded) conductor. The neutral acts as the center point between different phases. Grey-marked wires typically indicate the neutral wire in a high-voltage system, taking the place of a White.
Black, Red and Blue are all used as different phase wires. In 3 Phase systems all three will be used—in 1 Phase systems, only the Black and Red. These wires typically have 240 V between each other, and 120 V to the neutral or ground.
Brown, Orange and Yellow serve the same purpose as Black, Red and Blue, only instead of representing a normal 3 Phase 240 V system, they indicate a higher voltage system—most often, 480 V between each hot wire, with 277 V between each hot and the ground or neutral. High voltage systems carry far more electrical current and should only be handled by an experienced electrician.
You may find an older 3 Phase system with Black, Red and Orange wires for the three phases. In these cases, the orange wire typically has 208 V to ground, instead of the 120 V of a typical wire in a 3 Phase system. This is dangerous because any circuits connected to the Orange phase will be carrying this higher voltage, which can easily fry home electronics!
In some systems, including those outside the US, ballast or lighting control circuits, the colors of wires may mean different things that this standard. Always check available wiring diagrams or do research on your local standards before working with electricity! Staying up to date on local codes and proper application techniques helps keep you (and your installations) safe.
Wrapping Up
The typical way to indicate a wire’s phase and voltage is to wrap a ring of tape around both terminations, to make the purpose clear. WarriorWrap, the premier brand of vinyl electrical tape from NSI, is available in the full line of 11 colors to handle any labeling needs.
Electrical tape is an effective insulator for electrical current and choosing the right color of tape for the job helps keep the jobsite clear and safe. When you need electrical tape, choose WarriorWrap—next-generation professional tape with a comprehensive lineup to get the job done right the first time, every time.