Answer / raj

Voltage is applied through open delta PT only.

Answer / ekanadam patlavath

dc 110 voltage used for relay operating. for reverse power
operetion

Answer / nur.asidik

to make polarisation

Answer / rajesh bodduna

Open delta voltage is used to check the direction of fault,
i.e secondary voltages are connected in delta fashion with
open at one end . . The directional earth fault relay will
get volatge from open delta and currents from CT's as inputs.

Answer / hamed

Directional Earth fault relay requires to Inputs line
Current and line voltage.
So in case of Current there are standard output of any CT
(either 1A or 5A).And for Voltage Inputs there is a
Standard Potential transformers witch give 110/(sqr.root of
3).

sometimes, eventhough the HV side of the transformer is opened there is a voltage in LV side .How is it possible?

4 Answers  

What will hapen if we connect more capacitors than required for powerfactor control? Exactly what will be the effect on power system?

2 Answers   Mandovi Pellets,

why we somewhere use ryb phase sequance, somewhere use uvw, and somewhere abc??

4 Answers  

What is ERD used in Elevators??

1 Answers   Emerson,

What is mason's gain formula?

0 Answers  

What are the causes of electrical faults?

1 Answers  

3ph motor running with unequal kw and different pf what are the reasons

0 Answers   UltraTech,

What is meant by class of CT&PT?

1 Answers  

what is the preventive maintence for ht panels and busbars and vcb abd acb's.

0 Answers   Future Group,

Difference between On Line capacitor and Station Type capacitor.

0 Answers  

when we conduct high voltage testing why milli amp. is required?

2 Answers  

what is difrent between earthing and ground

4 Answers