what is the differnce between high impedance relay and low
impedance relay

Answer Posted / chander, ak

High impedance principle means that protective relay has a
such a large series impedance that even the largest through
fault current occuring during transient condition does not
start an un-necessary relay operation.High impedance relay
is one in which all CTs must have the same ratios. it is
employed in The differential protection of generators, bus
bars, motors and reactors.
Low impedance relays do not have any additional series
impedances and are usually employed for transformers
differential protection.

Is This Answer Correct ?    12 Yes 8 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

full form of flry b

3616


could anybody able 2 send me jindal steels previous papers fr electrical steam....pls send 2 my id if possible....sirisha.shaik@gmail.com

1590


what is the method of earthing of a transformer using electrodes?

1729


The power supplied to a 33microF capacitor from a 120V, 60Hz source will be

1651


hi i will D.E.E.E.is completed pls send rrb diploma old qustion papaer sent in my e mail. i.d.

1863






1.what is difference between ATS & STS main use. 2.what is difference between ACB& VCB With symobles,and main partes, manimum range. 3.How many types of relays and main function.

5612


What is inrush current?

645


if field breaker of generator is closed prior to its rated speed on a power generating unit. what will be the effect on generator, unit transformer and starting transformer.

1300


How to calculate loses in transformer of 160 KVA ?

1236


Why do you have to use Protecion relay with the function MTB ( Mechanical Trip Button ) for electrical system.

1708


how can we determine size of a cable by knowing the kw or current rating of a load?how can we calculate the resistance box of a slip ring motor?

1334


Can anybody tell abt concrete encased earthing or grounding?

1620


what is the size of cable for 15kw motor and 85 meter cable length using with vfd

1964


What is difference between Harmonic and Non harmonic Capacitor Bank?

2399


This is urgent!! What is a Thyristor-based 3-ways selector switch with Zero crossing control? how does it operate and where is it mostly found in a system?

1581