Transformer with rating 5MVA and above 33kV voltage class is normally known as Power Transformers and is installed in Substations with various protective devices. The accreditation from the national accreditation board for testing and calibration laboratories (NABL) for the VADODARA (ERDA)test laboratory is in accordance with ISO/IEC 17025:2005 for electrical parameters in line with national and international standards
Certification : ISO9001 : 2008,ISO14001 : 2004,OHSAS18001 : 2007Request a Quote
Smaller ratings upto 5 MVA and Voltage range upto 33 KV. Normally connected to Power Transformer Grid lines to distribute to load centers. Very small rating upto 100 KVA, 11 KV are mounted on pole to supply lighting and other domestic load. Above 160 KVA to 2000 KVA are normally for Catering to Industrial load or large Town ship / Mall load.
These are basically distribution transformers. Dry type transformers are preferred to oil cooled transformer, in place where there is fire hazards e.g. thickly dense area like Big-Store, Multistory Building, theatres etc. Since these are located near load centers, long line connection and transmission losses are reduced. The higher cost is partly compensated by lower transmission loss, smaller length of conductors and lower losses. Great care must be exerted since live parts are accessible.Request a Quote
The magnetic core of the transformers is manufactured from a high grade, cold rolled grain oriented silicon steel. The stacking of the laminations is either butt lap or step lap type. The magnetic core is generally of a multi-layer, circular cross section type, where the slitting and cutting of the magnetic core is done by automatic machines. In order to reduce the sound level of the transformer to a minimum, the magnetic core and its framework are carefully sized to minimize the vibrations and in particular, the magnetostriction effects which constitute the main sources of sound in distribution transformers. In addition, in order to reduce the no load losses and / or the no load current ofthe transformer, the quality of the magnetic steel and the induction together with the design of the magnetic core are carefully chosen to meet the requirements.
One of our major quality commitment is to provide high-quality surface protection. The coating (painting) type is chosen in accordance with the environmental conditions, considering the degree of pollution, humidity, etc. Zinc Spray / Hot dip galvanized tank, HV/LV cover and conservator may also be provided.
Tap changers allow voltage adjustment for a variation of the supply network voltages on the primary side of the transformer, or for increasing or decreasing the secondary voltage. Tappings are provided on the primary winding and connected to an off-circuit tap changer. The operating handle for the hand-operated, off-circuit tap changer is mounted outside. The standard tapping range is ±2x2.5%. However we can provide tapping range as per customer requirement. For adjustment operations, the transformer needs to be de-energized. However, on request for special applications, an on load tap changer can be provided.
The high voltage winding material is either copper or aluminum: the choice depends on the load losses and on the rated power. The shape of the conductor is either of a round or rectangular type. To obtain a controlled temperature gradient, cooling ducts are added in the coil. High voltage coils are in long layers or of disc type. Due to recent developments in the winding process, interlayer insulation and wire insulation have allowed the automation of the winding process.