how to calculate knee point voltage of current transformer?

Answer Posted / shakir mehmood

The formula for Knee Point Voltage is:

Vkp = K * If/CTR * (RCT + RL + RR)

in which,

K = Constant, conventionally taken as 2.0

Vkp = The minimum Knee Point Voltage

If = Maximum Fault Current at the location, in Amperes

CTR = CT Ratio

RCT = CT Secondary Winding Resistnace, in Ohms

RL = 2-way Lead Resistance, in Ohms

RR = Relay Burden, in Ohms

Is This Answer Correct ?    31 Yes 5 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

how diside ct mf exmp.200/5 ct

1633


Suppose a 3 phase, 2 pole, 440V induction motor is driving a flywheel of 600mm diameter, 150kg mass. By using v-belt and pulley, the speed is increased to 4500 RPM. What will be the effect on motor current?

932


PLEASE SEND THE PREVIOUS YEARS QUESTION PAPERS OF RRB JUNIOR ENGINEER-ELECTRICAL

1410


How to calculate cable size in HT AND LT

1501


HOW can i REuse the fused MLL LAMPS & GLS LAMPS at our factory

1417






How to detect voltage vector shifting in interconnection protection.

1454


explain safety measures in alternator?

1322


Whar is the KvA rating of 33Kv substation & actual kv rating of power generaating station.

1879


What is measurement?

743


our factory is going under construction mean time transformer 1000 kva 2 nos &load break swithch 12 kv & 4 nos 750 kva 2 nos & 380 kva 2 nos generator to be errcted.how to arrange earth pits &how to earth connect & neutral pit how to calculate in earth bit size.

1654


Is it required to lay 2 runs of GI wires along with armoured cables from one power DB Machines of higher rating?

1554


what is sevice settings for mccb?How can be it setted?

1474


how can service sitting be setted for MCCB?Example for sittings IR (CURRENT RATING),IS(CURRENT STARTING) I O (current operating)?

1734


can mini-curcuit supply MIL-tested transformer !

1613


dear all i am kumara now current working in electrical designing of control and relay panel i want learn some substaion design then any book are available. pls mention name and authour

1504