Enter The Step-Down Transformer: 3 FAQs

Posted on: 18 July 2016

The step-down transformer is a piece of power equipment used to lower the voltage of electric current flowing through an electric circuit.  There are several reasons why you should think of investing in a step-up down transformer the next time you think of increasing electrical safety around the residential premises.

The question and answer session below explains one of these reasons and it provides a few things you'll need to know about step-down transformers.

Why Should You Buy A Step-Down Transformer?

Your main electricity supplier can make significant losses when distributing electric current over long distances. This type of energy loss often occurs in the form of heat loss. Heat loss is directly proportional to the amount of current being transported/distributed through the grid lines. However, it is indirectly proportional to the voltage of such current. Lower-voltage current translates into greater heater loss during distribution.

Your electricity supplier probably attempts to minimize the described type of energy loss by distributing current at the highest voltage possible.

You need a step-down transformer because the high voltage electricity might not be very safe for residential use. Common incidents/accidents (e.g. electric shocks) may have grave consequences when high voltage electricity is involved. High voltage electricity may also cause damage to electric appliances that have a lower voltage rating (e.g. in case of a power surge).  For example, a freezer with a voltage rating of 110V could easily suffer irreversible damage thanks to a power surge that exposes it to 220 volts of electricity.

Which Step-Down Transformer Should You Buy?

Step-down transformers are differentiated by the type of cooling mechanism that the transformers use. Those that use mineral oil as the cooling mechanism are often referred to as liquid-filled transformers while their counterparts that use air/gases are referred to as dry-type transformers.

Liquid-filled transformers are often considered more efficient than their dry-type equivalent. This is partly attributed to the fact that oil does a better job at cooling hot spot temperatures within the transformer.

For the penny-conscious homeowner, the dry-type transformer is likely to be an attractive option because they're often more affordable than liquid-filled transformers. Thus, your choice of step-down transformer will depend on whether you're more concerned about efficiency or affordability.

Why Would A Dry-Type Transformer Be A Better Choice?

In as much as they may be less efficient, a dry-type transformer might be a better choice for the following reasons:

  • Absence of the fluid cooling medium in a dry-type transformers translates to a less-intensive maintenance schedule required for this electrical device
  • Mineral oil is highly flammable. A dry-type transformer will therefore be less of a fire hazard around your home as compared to one that's fluid-filled.