Jsl industries provides jyoti oil cooled voltage transformers, which are suitable for outdoor application. They provide accurate reliable measurement of power and protection of power and protection of distribution system up to 66 kv rating. It is very reliable which is crucial in switchgear. It is comparatively cheap. These are provided with three secondary windings tom meet the needs of metering and protective class. For the prevention of contamination of oil the unit is hermetically sealed type with ss bellows. The company provides dual ration may as per special request. These transformers use best quality cores to achieve maximum accuracy. Lv terminals are easily accessible. Construction of the transformers: voltage transformer is of single pole design and earthing of terminal `n` is a must; vt is supplied with a test tap for measurement of tan delta and capacitance to monitor the insulation property of vt during service; hv and lv windings accommodated in the tank at bottom, which is at earth potential; use of porcelain bushing suitable for heavily polluted atmosphere; oil/paper insulation for better reliability; metal parts treated for corrosion resistance against atmosphere; and all ferrous parts exposed to the atmosphere can be given hot dip galvanisation.