Understanding Electrical Phase, Neutral and Grounding

Understanding Electrical Phase, Neutral and Grounding

It's a common dilemma to find yourself at home with a tangled maze of wires of various colors, without the slightest idea how to recognize them. In reality, there is a method to the chaos. Look at electrical cables through the lens of their sheath colors. If the electrical system has been installed according to legal standards, each color indicates a specific role of the cable.

Identify the Colors and Functions of Electrical Wires

Let there be order and clarity in the world of wires and cables. To do this, let's focus on the wires coming out of the meter: the Phase and the Neutral. Let's explore what their colors are and, more importantly, what are the "tasks" that these wires perform within your electrical system.

The Phase in the Electrical System

The phase is the key element in the electrical system that has the task of carrying the current through the circuit. The phase cable is generally marked with three colors: black, brown and sometimes, gray.

Identify the Phase at Home

The phase cable is what brings the current into the house. For a clearer understanding, this is the wire that, if accidentally touched, emits electric current. It is strongly recommended that you do not try to touch it. Although the color of the sheath can help you recognize it, for greater safety, you should always use a voltage tester to test it. A phase tester acts like a small screwdriver that has a lamp inside, which lights up when it touches the phase.

Electrical Safety Precautions

The phase is very dangerous and to ensure safety, it is always best to leave these matters to the experts. The shock of current that may be received during careless handling of the phase can have very serious and in many cases, life-threatening consequences.

The color of neutral in compliant systems

In compliance with the regulations in force, the neutral in electrical systems must be blue or light blue.

Neutral cable operation

The cable at rest does not carry current unless it is crossed by the return current of the electrical circuit. In simple words, the phase cable carries the current that enters our user, for example a light bulb. The current flowing through the bulb then exits the system through the neutral, closing the circuit.

The single-phase system

This mechanism occurs in the single-phase system.

The three-phase system

In the three-phase system, however, the neutral takes on a different function, that of balancing the phases. In certain cases, such as in the three-phase four-wire system, the neutral does not exist. Let's see it in detail.

Earthing: Rules and Conventions

Earthing is an element that cannot be missing in any correct electrical system. It must always be yellow-green in colour, a rather well-known rule which reduces the risk of errors. However, there are those who, despite the rules, are tempted to reinvent the conventions, using different colors inappropriately.

Beware of Common Mistakes

Be wary of those who do not follow the specifications dictated by the legislation. Some pseudo electricians, in fact, use pieces of the yellow-green cable, used for earthing, to create jumpers also on the phase. An error that should not be underestimated.

Functions and Importance of Earthing

Earthing is the wire that can potentially save your life, and this is why it is often associated with lifesaving. The latter, in fact, without an earthing system created in accordance with standards, would have no reason to exist. The earth cable has the fundamental function of discharging any electrical leaks present in the system to the ground, guaranteeing safety and protection.

Returns and Cable Colors

The cables used as "returns" can be of various colors including white, red, purple, orange and turquoise.

Lamp Return Function

The lamp return plays a fundamental role in the circuit of an electrical system. This cable connects a "pole" of the lamp to the switch and allows you to close the phase-neutral circuit through the switch itself.

Phase Neutral Circuit Mechanics

In practice, the phase goes towards the switch while the neutral goes towards the "pole" of the lamp. To close the circuit from the switch to the lamp, a wire of a different color is used, called a “lamp return”.