No, we manufacture low and medium voltage dry transformers up to class 36.2kV.

We do work with such transformers, but for indoor use only;

For current transformers, we sell “window”, “bar” and “wound primary” type.

For low-voltage, we supply up to 0,6 kV, and for medium voltage, up to 25 kV.

A self-transformer has only one winding wound over a laminated core. An isolating transformer has two separated windings, being primary and secondary circuits.

On an isolating transformer, the input windings (primary circuit) have no physical contact with the output windings (secondary circuit). An isolating transformer is an equipment intended for power transmission from one circuit to another, causing the induction of voltages and currents.

A self-transformer is a power machine capable of inducing power to a circuit and change voltage and current. Differently from an isolating transformer, it uses only one winding. According to the transformation required at a given part of the winding, a tap is placed at that point, which values will be different from those of the self-transformer’s input.

The differentiated constitution of the autotransformer guarantees it certain advantages, a better performance is found in the autotransformer and there will be a lower voltage drop in these models. Another great advantage is a reduced price compared to conventional transformers.

The purpose of voltage regulation is to evaluate the voltage variation, relating the behavior of the voltage under load and without load in relation to a reference (usually the voltage under load).

It is a device used to change the taps of a winding, and this operation must be performed with the transformer de-energized. The tap variation makes it possible to raise or reduce the transformed voltage by varying the transformer ratio.

TAMURA dry transformers require little maintenance. However, it is necessary to carry out constant monitoring to avoid problems such as accumulation of dirt (which can cause loss of cooling capacity and consequent loss of power), deformation of its structure and also check the connections, among others.

Maintenance items:
1) Visual inspection of the place;
2) Cleaning as specified below in item 5.2, checking of air inlets and outlets;

3) Check that there was no overheating at the connection terminals;
4) Check the operation of the thermal protection set;
5) Check pressure at terminal contacts, switchgear panel.

The installation and maintenance manual is available for download on this website for more information.

All Routine tests are carried out as per standard NBR 5356-11 in its latest revision.