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
how wecalculate breaking capcity of acb mcb mccb .explain with example
3Cx240 & 3Cx300 sqmm Al. cable from lv side. What is the calculation for this cable??
Why dry type cast resin transformers tap link blast in HV side while power shut down times on load?
Explain the working of any one cutting machine
How harmonic block test are conducted on relays ( Siemens,Areva ect )power transformer using omicron kit?
What is a slack bus?
how to calculate regulation constants for over head lines? and what are the regulation constant for raccoon conductor at different voltage level and different P.F?
HOW MANY TYPES OF FUSE?
Electromagnetic torque developed by the motor is compared to shaft torque. A less B same C depends on motor design D more
How does a transformer contribute towards the widespread popularity of ac system over dc?
what is the star delta connetion and how can do it a three phase motor with control witing with picture
why there using acb enclosure in big buildings
What is the Resposiblity of Electrical Utility Engineer
What is power in wattage of 8.5 TR AC
what will happen if the prime mover on the field excitation of the on-coming generator fails?Explain.