How to generate a neutral in a two-phase network using single-phase transformers

In electrical installations, having a neutral is essential for the correct operation of certain equipment and systems.

According to ICT-BT-08, the standardised connection schemes (TT, IT and TN) define the way in which the transformer secondary is grounded, which influences the availability and use of the neutral.

The TT scheme is the most commonly used, as it is mandatory for any receiving installation connected to a public low-voltage distribution network. In this type of network, the neutral is grounded by regulation, which highlights its importance within the electrical system.

However, in some network configurations, such as in two-phase installations, the need for generation may arise.

In this article, we will explain how to generate a neutral in a two-phase network using transformers and present the most suitable solutions for this purpose.

What is neutral?

The neutral conductor is the wire that provides a return path for the electric current in an alternating current (AC) system. Its main function is to balance the loads in the system and ensure a stable flow of electricity.

Why is the neutral important?

As we can see, the importance of the neutral is fundamental in this type of installation and proof of this is the obligatory nature required by the SAT of the different equipment currently installed, such as air conditioners, boilers, biomass equipment, some brands of electric vehicle chargers, etc.

How to switch from a two-phase network (PH+PH) to a single-phase network (PH+N)

This need arises mostly because a machine (air conditioning, boiler, etc.) whose control board needs an isolated neutral must be powered.

To carry out this procedure, we will use a single-phase transformer with the appropriate power, which we will connect in the primary with the two phases and at the output, we will make a bridge between one of the phases of the output and earth. From now on, this line will act as neutral.

Single-phase transformers recommended for generating a neutral

POLYLUX has a range of single-phase transformers designed to provide a reliable solution to the problem of the absence of neutral in electrical installations. Some options include:

These last two series are perfect for situations where higher rating levels are required, such as energy power supply for air conditioning systems, electric vehicle chargers, etc.

Do you want to know how to make connections and bridges in each series?