EARTHING OR 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.