Nachiketa Technology

Gangyal, Jammu, Jammu & Kashmir

DISTRIBUTION TRANSFORMERS.

Nachiketa Manufacturesa wide range of distribution and power transformers ranging from 10 KVA to 5000 KVA. These transformers can be free breathing or hermetically sealed. Conventional transformers are fitted with a conservator with breather for free breathing while hermetically sealed are without breathing with bolted cover. Hermetically sealed transformers are totally maintenance free and are particularly suited for use in exposed outdoor environments such as moisture, salt or dust laden atmospheres. They are used extensively in chemical plants, oil and gas terminals where poor accessibility makes regular maintenance undesirable.

Transformers immersed in synthetic coolants are suitable for use indoors, with adequate ventilation, or near to the load centre where oil would not be considered environmentally acceptable. The liquid filled transformers can be supplied with cooling either by corrugations on the side of the tank or Pressed steel radiators mounted on tank body. Transformers can be filled with either oil or one of several low flammability synthetic fluids such as midel. Both types can be supplied with HV and LV Switchgear incorporated into substations. can supply conventional/hermetically sealed/bolted type, indoor/outdoor type, pole/platform mounted 3 phase, 50/60 Hz, oil immersed, ONAN/ONAF/ OFWF cooled, step up/step down, double wound with Al/Cu conductor, Continuous duty transformers from 5 KVA to 20 MVA upto 33 KV Class with A Class Insulation and designed to withstand Short Circuit, & Impulse Test in accordance to IEC / BS / ANSI / IS / NEEMA.

The term"Variac"(from "vary AC") has become generic, and commonly refers to any continuously variable autotransformer. Variac is a trade name, and has changed ownership several times since early 1930s when the device was first produced. Other trade names include Powerstat and Dimmerstat, and I'm sure there are many others. Some manufacturers simply call their versions "variable voltage transformers". The trade name Variac has been owned or licensed by Warburton Franki (in Australia), General Radio (Genrad), Claude Lyons, Statco and probably a few others as well. I shall use the term Variac (small "v") in its generic form - this does not imply that variable transformers with the Variac branding are more desirable than others, only that I'm used to the term having used it all my working life.

The Variac is a special type of transformer, generally having a single winding and a single layer. The top section of the winding is flattened and machined to remove the insulation and provide a smooth surface for the sliding brush that's used to select the voltage needed. Some variations use a roller instead of a brush, but there seems to be no specific advantage. I still have my first Variac (branded as such) that I bought sometime around 1960, and it's been dismantled for service once in all that time - see Figure 1a. Figure 1b is a Matsunaga 1kVA Variac - made in Japan especially for use in Australia. It is described as a "Deluxe Slide Regulator" (sic).