EARTHING GROUNDING TRANSFORMERS

(ZIGZAG), ZNYN, YND(OPEN), II0]

Grounding Transformers are designed for providing an artificial neutral point for ungrounded three phase power systems. During the line-to-ground faults, grounding transformers provide an easy path to ground faults to limit the fault currents and transient over voltages.

Grounding transformers normally carry short-circuit ground current until the circuit breaker clears the fault. Therefore, they have short time ratings.

The kVA rating of a earthing transformer depends on the normal line to neutral voltage and the fault current value for a specified time, such as seconds to minutes

Test List

Visual & Dimensional Check
Measurement of Voltage Ratio
Measurement of Winding Resistance
Measurement of Zero Sequence Impedance
Measurement of No-Load Loss and Current
Measurement of Short-Circuit Impedance and Load Loss
Dielectric Tests
Separate Source AC Withstand Voltage Test
Induced AC Withstand Voltage Test
Lightning Impulse Test
Temperature Rise Test
Final Check

For special tests, please contact us.