what is the difference between 5P20 class CT , PS Class CT
and 5P10 class CT??
- 5 Answers
- 145255 Views
- I also Faced
- E-Mail Answers
Answer Posted / amit_er1981
CT's are categorized as Protection CT, Special Protection
CT and Measuring CT. Based on this, the CT's are
classified. Here is the meaning of the CT classes:
Class 5P20:
The letter 'P' indicates it is a protection CT.
The number 5 indicates the accuracy of the CT. Most common
accuracy numbers are 5 and 10.
The number 20 (called accuracy limit factor) indicates that
the CT will sense the current with the specified accuracy
even with 20 times of its secondary current flows in the
secondary. This is required for protection CT, because the
fault current is high and the CT should be able to sense
the high fault current accurately to protect the system.
The common numbers are 10, 15, 20 and 30.
Class PS:
PS is for 'Protection Special'. This class of CT's are used
for special protection such as differential protection,
distance protection etc.
Class 1M:
The letter 'M' indicates it is a measuring CT.
The number 1 indicated the accuracy of the CT. The
measuring CT's should be more accurate than the protection
CT. The most common accuracy numbers are 0.5 and 1.
Measuring CT's are intended to work in normal and it
doesn't require working with accuracy beyond the CT
secondary current rating, so the accuracy limit factor is
not mentioned here.
| Is This Answer Correct ? | 295 Yes | 18 No |
Post New Answer View All Answers
How line capacitance & line inductance varies with increase in height tower.
How to run a three phase motor into single phase........
why actual valve timing diagram is different than ideal valve timing digram of a 4 stroke engine?
What is the application of Dyn1 and Dyn11 vector group of transformer?
Why human body feel electric shock?
what is the difference between interconnection and intraconnections in the circuit diagrams
How to arrange a hous hold earthing system to keep minimum earth resistance( below 7ohms).
What are the transformer losses?
a 100mva,400/200v transformer has leakage impdce of 10% draws a steady state line currentof---------------
Both generator parallel condition shared load equally but one genrator taking ampere more than the other what are all the causes to make like this
I need the recommended size for a 3 phase transformer at 13.8 KV Primary and connected loads of 3000 kVA at 4200 volts and 2375 kVA @ 480 volts AC.
what is meant by vector group of a transformer? How can it be derived?
What difference between ref protection and differential protection ?
we have two generators different capacity on 15 MW and other 6MW at 11 KV , 15 MW gen. bus short level current 40KA,and 6MW short level current 25KA,, length of cable 100MTR between 6 MW from 15MW gen. for bus coupling . kindly tell any one can we use both NGR OR one NGR from any GEN. BOTH NGR has diff. rating. Tariq pakistan
following are the questions asked in interviews: 1) Considering the short circuit fault, which switchgear is preferable, SFU OR MCCB? Which operates faster? whicg one is popular in Indian Market and why? 2)Define SCPD. What is type2 coodination? 3)Why the contactor rating is higher for the fuseless selection than for fuse selection? whether the ratinf of SFU or MCCB remains the same in both the cases? 4)If the HP rating is known then can you calculate the ratings of L.V Switchgear(SFU/MCCB, contactor, OLR) without using the selection chart?
