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.

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

Answer / guest

secondary winding is s.c

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.

Answer / monojit dutta

IF POLARITY CHANGES, THE DIRECTION OF THE CURRENT FLOW WILL
ALSO CHANGE.

Answer / lokesh

current will flow in the reverse direction.

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.

Answer / s.karthik

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.

Dear Sir, we met a disaster with our 62.5 kva genset, after rewinding we informed by our contract engg that due to return current coming in neutral & impropper earthing this happend. But after all set up & load balance we checked & found again we have about 20 to 32 amp return current on neutral. we have 12 airconditioner + 12 mini fridge on single phase line. Pl suggest any idea to solved this problem

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