what is the CT of protection and CT of metering ? what is
class 5P10 & 5P20 and class PS ?
- 16 Answers
- 125301 Views
- JEE Main, ONGC, VRA, I also Faced
- E-Mail Answers
Answer Posted / sindhu sl
There are three types of core basically used in Current Transformers
they are
1)Metering
2)Protection
3)PS core or Protection Special
Basically CT are the one which is used to measure the current in the lower value as Ammeters and other measuring meters are rated at a lower value.Thus CTs step down the current and this is used for metering or protection purpose.
1)METERING:
Metering cores are used only for measurement.for a 500/1 A CT the core should essentially saturate after 120% of the rated current then only it will give accurate measurements.So saturation must be very much higher for metering core.
it is identified as 0.1S,0.2S,0.5S.These are the accuracy class explained by Indian Standars. 0.1S is more accurate than 0.2 and 0.5.
2)Protection Core:
Protection cores are used when a high surge current enters or in the case of any abnormal current.So the core should not saturate when the primary experiences high current.
it is designated as 5P10,5P20 etc
here 5 denotes the percentage of error
P-Protection
10-Accuracy Limit Factor(ratio of accuracy limit Primary current/Rated Primary Current)
If ALF is high then the Class of protection is also high.
3)Protection Special or PS Core:
This is also used for special type of protection in case of heavy faults particularly differential faults. It is determined by Knee Point voltage or Short time current
| Is This Answer Correct ? | 7 Yes | 1 No |
Post New Answer View All Answers
how a.c. genarator control power factor when its conected to grid supply by incrising or decresing excitation voltage.
during installation time of transformer and alternator which points we have to observed?
from generating station If 400v LT line length is 1000m how much voltage is drop and how do i calculate it? which cable will be use for this line?
can we start slipring motor on star delta like we start induction motor ? if yes where will we connect ?
What are the advantages of skewing of cage rotor conductors?
There are a trformer and an induction machine. Those two have the same supply. For which device the load current will be maximum? And why?
What is creepage distance..... what will be the value for different voltage level
What are motor generator sets and explain the different ways the motor generator set can be used ?
What is the difference between relays and contactor construction wise?
WHAT IS THE DIFFERENE IN ACTION OF MCB,MCCB,RCCB
use of PIR in ehv breaker
WHAT WOULD BE THE FORMULA OF WIRE GAUGE FOR A FULL LOAD CURRENT
how many electricity poles are there and what are the names and their sizes.
how are reversing the direction of dc motor
why are installed water leakage detection system data centers & server rooms
