what is the use of neutral displacement relay

Answer Posted / loboreliance2003

The relay comprises an attracted armature element fed via a
rectifier and series resistor. It can be provided with
either a fixed
setting, or variable settings using a plug bridge. It has a
minimum
withstand of rated voltage continuously.
Operation of Neutral Voltage Displacement Relays
The zero sequence current that flows for an earth-fault on
an un-earthed network is determined by the capacitance of
the cable to earth. This flow of current leads to a rise in
the voltage of the neutral point of the incoming supply
(the star-point of either the generator or transformer). It
is this rise that is detected by a neutral voltage
displacement relay. If the network is quite small (i.e.
short cables), then the zero-sequence voltage will be
unstable. This is why an instantaneous relay is only
generally used to provide an alarm. In the event of a
fault, neutral voltage protection cannot detect the
location of a fault, so all sources of supply should be
disconnected.

Is This Answer Correct ?    10 Yes 9 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

In TNC switch, is there any 1NO+1NC block ? and if we move over closing position, is ther any affect on trip position or vice versa?

1875


When we need up only in o/p 440v, so why we use directly in 11kva in input?

1371


How to calculate the electrical load for a standard telecom BTS shelter and choose the DG set capacity for the same load?

2775


What is a differential amplifier?

738


Why there are some equipment(i.e:TV) that using 2-pin plug instead of three? What happen if there is current leakage? Are we going to get electric shock??

1825






my UPS suddenly goes off and all panel light also blow off.This happens even main electric supply is not interrupted.After some time it automatically starts functioning normally.Batteries are new.

1678


hello everybody. what does an abnormal stator winding impedance or dc resistance show? thanx

1559


What is the need for a controller?

762


Where burned of electricity,when,who, & why.

1601


What is the difference between alternator and generator?

836


Tell me about ur past electrical maintanence job

1529


What are the different types of controllers?

743


what is the minimum voltage require to injure our body?

5921


How servo stabilizer works.

1733


placing earthing pit in pathway is correct or wrong??. placing earthing wireGI1/18 inside walls is correct or wrong?. explain!!!

1792