What happens when the polarity changes in CT? Explain
briefly?
Answers were Sorted based on User's Feedback
Answer / m s venkateswara rao
polarity of the CT secondary is depend up on the polarity of CT primary. For example current flow in primary of a CT is considered from P1 to P2 current flow in secondary will be from S1 to S2. If the CT is used for multi function meter to measure the Active power, apparent power will show negative readings if polarity is changed. If is used for protection and the type of protection is considered is non directional over current/ earth fault there is no difference in CT polarity change. If it is directional over current/earth fault relay will not operate because it will never seance positive value as the protection type is directional.So by changing the polarity of CT, protection for which we opted will defeated.
| Is This Answer Correct ? | 32 Yes | 1 No |
Answer / digvijay
My question regarding worng connection in any phase of ct,
Is there any effect on power factor of that phase which is wrongly connected
| Is This Answer Correct ? | 6 Yes | 0 No |
Answer / sanjiv c keshari
CT means current transformer are used for earth fault protection and current showing.If polaraty has changed so CT will not work proper it is showing wrong reading.
| Is This Answer Correct ? | 4 Yes | 9 No |
Answer / monojit dutta
IF POLARITY CHANGES, THE DIRECTION OF THE CURRENT FLOW WILL
ALSO CHANGE.
| Is This Answer Correct ? | 4 Yes | 9 No |
Answer / guna
CT - current transformer, other name is instrument transformers, which are used to measure high currents. By depending upon winding ratio (Ex,20:5) it gives the current value at the user end. if we change the polarity means (5:20) either it will show high current nor it can get short circuited due to abnormal current flow on the LT side.
| Is This Answer Correct ? | 2 Yes | 15 No |
consider the example of CT with the ratio 50:5.
it means if 50amps is flowing in the primary,it will show
only 5 amps in the secondary.Now when the polarity is
changed,50 amps will flow in the secondary which is
comparatively high,and the windings are designed to carry
only 5 amps and hence as a result the windings will burn due
to the volumenous amount of current flowing throught he circuit.
| Is This Answer Correct ? | 4 Yes | 41 No |
super position theorem is applicable to
how to find 5 kilo meter long under ground 33 kv cable fault location if IR VALUE shows 0.05 M ohm @5000 volt.and cable fault locator shows some time fault distance 3 kilo meter ,3.7 kilo meter and some time 1 kilo meter? now how to find the fault location that where is leakage. note--it is tested with 5000 kv megger and insulation resistance is 0.05 M ohm. and some time 0.03 M ohm comes.
WHY DG are rated in KVA or MVA ???., but ALL power plants are rated in KW or MW.,,?
what happens if power factor is maintained at 0.9?give me the answer in technicall way rather than telling the penality n all
which of the following elements is not present in stainless steel
How to connect a Restricted earth fault relay for 2000KVA,11/0.433 KV Distribution Transformer and What is the neutral CT ratio should be selelcted for 2000 MVA Transformer for estabilishing the Restricted earth fault relay
In a generator (Synchronous) does the rotor speed (frequency) corresponds to the speed of the water (in hydro). does the torque on the turbine relate to the flow of water?
how to calculate induction motor rating (HP) if name plate is missing from motor at site condition ?
6 Answers ABB, apatel, Bhel, Spatel, Voltas,
What is the difference between Zero Current Transformer and Core Balance CT ?
What is the general power consumption rating of CPU CRT type and Flat type, Monitor,Printer, projector, Scanner?
What's the difference between a generator using 50Hz and 60Hz? When do we need to use a generator 50Hz and 60Hz?
PLEASE SEND THE PREVIOUS YEARS QUESTION PAPERS OF RRB JUNIOR ENGINEER-ELECTRICAL
Civil Engineering (5086)
Mechanical Engineering (4456)
Electrical Engineering (16639)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)