we all know that in transformer, voltage and current are
inversely related i.e. Vp/Vs= Is/Ip....so in standard
CT..we have a ratio of 200/5...that means our voltage
should increase by ratio of 40..althoug that is not the
case...because that requires high insulation level.and
pratically not feasible......can anybody clarify my
ques.......thanx

Answer Posted / peter b

Current and voltage and still inversely related in a CT.
However, the primary of a CT does not see the full line
Voltage i.e. a CT on a 110kV bus does not have a primary
Voltage of 110kV! The CT's primary is in series with the
main load; the primary voltage of the CT is simply the
induced Voltage due to the AC flowing through the primary.
This Voltage is only a tiny fraction of the full line
Voltage. The only insulation requirement is that the CT as
a whole be insulated from neutral/earth. That's why they
are mounted on long insulators.

Is This Answer Correct ?    0 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

area control error

1293


what is the maximim current drawn by 1 phase and three phase welding machine

1451


How many points does a Circuit can have?

1458


What are the function of different components of servo motor?

1557


draw the block diagram of fire alarm?

4994






What is the feedback in the control system?

632


How to test the Secure Elite 440 Multi function meter working condition.

1614


ASTM D 3455 - Standard Test Methods for Compatibility of Construction Material with Electrical Insulating Oil of Petroleum Origin has been used for Testing Transformer Oils with a product placed in it. Aged Control Oil has a Power Factor of 0.032% at 100°C. Aged Oil with a Test component has a Power Factor of 0.093% at 100°. Is this increase acceptable? If not why? How much increase is acceptable?

1519


and gate circuit diagram,amplifier circuit diagram

1597


List examples of current sources?

620


How to identify the start and end of 3phase 12 lead motor if U1, U2, etc numberings are lost or erased.

1715


Why Transformer Neutral having one earth pit ( more earth electrode resistance) whereas body have many earth pit ( less earth electrode resistance)?

3848


What is the difference between shortcircuit current, rated current of cable & MCB with example? What will be the size of cable required for 5.5 KW motor (Full load current 10 Amps approx.), Starting current with DOL is 120 Amps. Aprrox. Short circuit current with LLLG fault is 2000 Amps Approx.

1589


i have install 750 kva distribution transformer at my site and want to do neutral earthing. what calculations should i follow to determine earthing conductor material and size?

1583


Why GRR starts from 60% of motor speed why not less than 60%?

759