what is the CT of protection and CT of metering ? what is
class 5P10 & 5P20 and class PS ?

Answer Posted / pin baloo

Standard accuracy classes:
At rated frequency and with rated burden connected, the amplitude error and phase error and composite error of a CT shall not exceed the values given in the following:
Accuracy class//Amplitude error at rated primary current(%)//Phase displacement at rated primary current(°)//
Composite error eC at rated accuracy limit primary current(%):

5P // ±1% // ±1° // 5%
10P // ±%3 // - // 10%
Marking: The accuracy class of a CT is written after the rated power. E.g. 10 VA 5P10, 15 VA 10P10, 30 VA 5P20
Accuracy limit current IAL:
Current transformers for protection must retain a reasonable accuracy up to the largest relevant fault current. Rated accuracy limit current is the value of primary current up to which the CT will comply with the requirements for composite error eC.
Accuracy limit factor kALF:
The ratio of the accuracy limit current to the rated primary current.
kALF = IAL/IN. (eq. 2)
The standard accuracy limit factors are 5, 10, 15, 20 and 30.
Marking: Accuracy limit factor is written after the accuracy class. E.g. 10 VA 5P10, 15 VA 10P10, 30 VA 5P20.

Is This Answer Correct ?    26 Yes 8 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is conductor constant of raccun conductor

1777


What is the instrument to check the rotating diode fuse of alternator in running conditions?

2006


please anybody help me to find out the BHEL trainee Exam previous year questions papers . if u ve pls. send it to surekhared@gmail.com

1506


What determines the thickness of the lamination or stamping?

1171


aternator every parts and its working

1174






what is the difference between the voltage of 5 volts capacitor and and 5volts battery?

1453


What is Primary And Secondary Injection Test of Relay and Other Electrical Devices. How IT is carried out.

3015


can any tell me why slope 40% and 80% is calculated in differential protection?

1432


'documenˁ

1515


what is the meaning of the symbol << >> put in transformer drawing

1449


How to calculate the fuel consumption for 600kva DG genset which connecting with 25%load?

1696


I have motor of 3 H.P. How i found the rating of capacitor use in it in single phase motor..???

2129


can we make a electric generator,which can not use any type of fuel,air,solar,gas,thermal,coal,petrol,etc and able to produce electrical energy (or self electricity generating generator)

1496


what is the function of bearing in dc mchine" and where it is placed

2072


if the armature current in a dc generator is ac ( sinusoidal ) why doesnt the sjhape af armature mmf a sinusoidal (ni) ? armature mmf in case of a dc machine is triangular.

1506