Different Types of Transformers Used Commercially

by Niraj Jayaswal Content Writer

In any commercial electricity supply system, transformers form a crucial part. A variety of transformers is available ranging from low voltage power transformers, step up transformer to many types of dry type transformers. All these transformers for commercial purpose are selecting after evaluating the need of power supply, the type of environment they will be installed into, and the factors of efficiency and cost productivity.

1. Cast-coil transformers

Cast coil transformers are a favorite option when the surroundings of the installation sites have either moisture or airborne contaminants. Every cast-coil transformers provide resistance against these contaminants by the type of structure it has, both the primary and secondary windings are present in a reinforced resin which boosts its efficiency in the overall working.

2. Dry type transformers

These are static devices which do not use the mechanism of cooling any liquid inside the transformers, instead, the air is cooled down. This makes them recommendable by the experts in the field because they show low inflammatory factors and in addition to that, their resistance and structure long lasting. Dry type transformers have varieties of different structures and the cooling mechanism also varies, some of those which are used commercially, they have been listed below:

• Non-ventilated dry type transformers

These transformers are suitable for areas where the atmosphere has contamination. The enclosed structure of non-ventilated dry type transformer provides safeguard against the atmospheric contamination, thereby making them an efficient alternative against ventilated dry type transformer.

• Ventilated dry type transformers

Suitable for indoor electrical system distribution, the ventilated transformer has a huge clearance space for air. Their structural design provides high mechanical protection and offers safe use for indoor distribution.

3. Indoor distribution transformers

All the types of indoor distribution transformers, their effective resistance to the alternating current is always lower in numbers to those transformers which are allocated for substation and related units. These transformers have to be installed with panel boards and each of these are mounted separately to ensure the safety within the vault. High voltage power transformer can also be used because they are based on the pressure type connections for the cables of the major electrical system.

4. Network transformers

The experienced and professional power transformer suppliers always consider the type of environment for which the network transformers are being required. The type of contaminants can vary, altering the suitability of the transformer. Thereby it becomes an important factor to be acknowledged so that both the efficiency and safety of the system is maintained. Whatever type of transformer is used for this purpose, the connections for primary is always delta-connected while the secondary is wye-connected.

4. Oil filled transformers

Even though development has been incorporated in the transformers used for commercial purpose but the conventional oil-filled transformers are still used for various departments. They have a disadvantage of the risk of dielectric breakdown but with testing at regular phases, the rate of efficiency is maintained. Their composition has a mineral oil tank which is tightly closed and the windings encapsulate this structure.

5. Pad mounted transformers

Unlike the indoor distribution transformers, pad mounted transformers are used for substation, primary unit substation, and a secondary unit substation with their tamper-resistant structure, adds an expert of power transformer manufacturers in India. The compartments of primary and secondary connections are separated but placed next to each other, the formers are higher than 600 V while secondary connections are lower than 600 V.

• Substation

The substation transformers have a primary voltage range of 2400 V. Depending upon the phase units, the single phase units are 750-5000 kVA while the range of 750-25000 kVA is for three phase units.

• Primary unit substation

With primary connections maintained with delta system, the primary voltage, in this case, is 6900-138000 V whereas the second voltage lies between 2400-34500 V.

• Secondary unit substation

Their categorization is into three-phase units with 112.5-2500 kVA. The range of secondary voltage is 120-480 V while the primary voltage fluctuates between 2400-34500 V.