OIL-IMMERSED EARTHING TRANSFORMERS

APPLICATION:

Earthing transformers are used to obtain a neutral point in compensated or resistor grounded networks. These are the three-phase transformers which in normal working conditions,
while no ground fault occurs, provide power supply to unit auxiliaries. The coil windings are made in the ZNyn11 arrangement, which enables the division of the current between phases and reduces the current on the line which has been exposed to ground fault or short circuiting. The secondary
winding can permanently operate at rated conditions, even if the primary winding is loaded with compensated current. In the event that the network is grounded using a resistor, the neutral point of these devices is connected to an earthing resistor used to input the active component. In compensated networks it is usually combined with an arc-suppression reactor which is used to ensure the appropriate reactance for clearing the arc and earth fault currents.

Hermetically sealed (without conservator) or with conservator
Core– grain-oriented electrical steel sheets
assembled into core using the “Step-Lap” method
Winding – electrolytic aluminium or copper wire, enamelled round or profiled in paper isolation,
Tank – corrugated or with radiators,
made of steel, painted or hot dip galvanized
Standard colour is RAL7030 or other colours on requestej