Dry type transformers come in all different kinds, some of which are better suited to outdoor installation than others.
Take for example the insulation used on the windings of different dry type transformers: In many cases, VPI – vacuum pressure impregnation – is the method used to insulate the windings of a dry type transformer. This process coats the coils in resin, which is then oven-cured to complete the insulation. If however you want to place your power transformers in an outdoor setting for the long term, you might want to consider cast coils. This method encases the coil in moulded epoxy resin, which is again put into place using a vacuum. Cast coil transformers offer greater robustness and higher dielectric strength, making them particularly well suited to harsh operating environments such as outdoor locations. They can also usually withstand spikes in electrical load, as long as they do not last for too long, without suffering the damage that other dry type transformers might experience. Cast coils also withstand other harsh environments better – including those that are high in dust, moisture, gases or salt. If you have a requirement for outdoor applications, please do not hesitate in contacting us for a design and quotation.