Dear all,
Can anybody tell me that how to choose CT for a specific
load? I have a 200kw induction motor, which ratio CT should
be installed? Is there a formula or calculation that
determines the CT ratio for a load?
Regards.
Answers were Sorted based on User's Feedback
Answer / guest
I dont know of any formula to answer your question, but I
follow a trial method which worked out well for ME.First
know your full load current and the expected running
amperes which would be below your full load amperes.Now
choose your ampere meter which will show your running /full
load amperes at about 75% of the chosen amp meter scale.Now
you can select your CT .
In this case a 200 KW motor full load current is about 370
amps and for 75% scale reading would be 500 amps.So your CT
rating would be 500/5 and the amp meter also of the same
rating.
Is This Answer Correct ? | 6 Yes | 1 No |
Answer / k.prakashchandra
Another method.Divide KW by 0.75 (lowest pf expected) to get
KVA. Calculate current which is about 380 A at 400 V line
voltage.You can choose a CT 0f either 400 or 500 A as
primary current.The secondary current of CT is decided by
meter and relays.This is generally either 1 or 5 A .
Is This Answer Correct ? | 1 Yes | 1 No |
difference b/w current and voltage relay?
how to test and calculat the head and discharge in borewell compressor
Formulae for calculating the transmission line losses for different voltage levels
what is the acceptable limit value for Desolve Gas Analysis/
what is single turn and multiturn encoder ? Can single turn encoder be used to show rpm of a motor(on shaft) ? Plz explain in brief .abanirout@gmail.com
Why converter duty transformer neutrals are not earthed...i am still not sure if this question is also correct...Please email at ranjan120482@gmail.com
what is thermal setting and magnetical setting?
Ceiling Fan and Storage type water heater. Discuss
what is the function of AVR in generator? how the generator maintain the frequency while varies the load?
Please clarify, 1. Is it required to lay two runs of GI wire along with Armoured LT cable if it is laid between one big mains (63Amps TPN SDF) to small main (32A TPN SDF) with proper glanding termination? 2. If the armoured cable with proper glanding is laid from DB to CNC machine, is it required to run two runs of body earthing to the Machine from DB? 3.If the armoured cable with proper glanding is laid from Substation to Hangar, distance is approx. 100 mtrs, is it required to do earthing at shop area though the primary termination at substation is earthed through gland.
what is DG A,B,C,D check?
What is meant rectifiers..