Page 6 - Energize June 2022

COVER STORY

Cast resin transformers:

The path to a greener future

by Paddy Padayachee Pr. Eng, MSAIEE, Revive Electrical Transformers

Distribution cast resin dry-type transformers (CRT) have been around for the last 30 years in Europe and have been
used for various types of applications and installations. As distribution transformers, cast resin types are relatively
new in Southern Africa. As a result, not much information about CRTs is freely available locally. This article will inform
the general engineering community and assist engineers, project leaders, buyers and contractors to understand why
cast resin transformers offer a path to a greener future in South African electrical installations.

ince we are familiar with good the extreme conditions that they are exposed to in Southern Africa. However, we have
old oil-filled transformers, we all experienced oil leaking transformers, oil samples, oil changes or degeneration of
Sare aware of all the benefits and insulation, faulty protection (Bucholz, PRV, OTI) and fire, explosions and more. Most of the
typical issues associated with them. We above mentioned can be avoided by choosing CRTs instead of oil-filled transformers.
have been using oil-filled transformers Distribution CRTs (100 kVA to 5 MVA, and up to 33 kV) contain the same basic
successfully for many years and we know components as oil-filled transformers: they have a magnetic core, an LV winding and a
that oil-filled transformers can withstand MV winding. The only difference is that resin and air is used instead of oil as the main