|
|
|
|
New Member
|
|
Jul 16, 2008, 05:26 PM
|
|
Current transformer - short time withstand current
Hi,
For ring-type (window-type) CT, do we need to size the CT short time withstand current at the same or above the system short time withstand current (short circuit level)? Any reference/technical explanation?
Thanks!
|
|
|
-
|
|
Jul 16, 2008, 05:54 PM
|
|
Please explain and detail your question a little bit, as it is rather unclear what you exactly mean with it.
Once you have posted details, contact me by private mail (click on my handle and follow instructions) to draw my attention. I will than reply here again.
:)
|
|
|
Uber Member
|
|
Jul 16, 2008, 06:01 PM
|
|
Size it at 1.25 * the expected measured current without regard to peaks. Make sue the CT has an internal clamp.
|
|
|
New Member
|
|
Jul 19, 2008, 08:14 AM
|
|
Hi Credendovidis,
I will install a ring-type/window-type current transformer in a low voltage switchgear.
The system short time current withstand is, say, 80kA/1second. Do we need a current transformer with short time current rating 80kA/1second?
Thanks,
Originally Posted by Credendovidis
Please explain and detail your question a little bit, as it is rather unclear what you exactly mean with it.
Once you have posted details, contact me by private mail (click on my handle and follow instructions) to draw my attention. I will than reply here again.
:)
|
|
|
Junior Member
|
|
Apr 26, 2009, 09:55 AM
|
|
Dear masgagong:
If fact, you are aware that window type cts are not directly connected in the circuit like wp cts. A bar primary conductor is just passed through the window of the ct. Cts are only insulated rated voltage of the system. Hence, there is no requirement of stc rating for window type cts. If the cts are of wp (wound primary) type then, these are directly conneted between current carrying bus bars hence, the are bound to have stc rating. (basically stc rating is meant for current carrying capacity of the conductorof ct) as well as mechanical strength of the cts as this may go under tremendous mechanical stress during fault conditions.
|
|
Question Tools |
Search this Question |
|
|
Add your answer here.
Check out some similar questions!
Short circuit current fault
[ 1 Answers ]
I have quite a simple system. Contains one substation, feeder pillar and 3 houses. I have calculated the short circuit current that the transfromer in the substation can deliver but is there any one that can help me with finding the equations to calculate the short circuit current level supplied by...
Tripping of ac mcb on dc current below its rated current
[ 2 Answers ]
Please let me know why ?
MCB rated for 240/415VAC, 6Amperes trips on 5 Amps DC current at 24VDC voltage level
Ambient operating temperature: 32 ° C
MCB Designed for ambient temperature of 55° C
Why MCB should trip:confused: ?
Current ratio and non current assets
[ 1 Answers ]
How do I know what each makes contains.
current assets 25,000
liabilities 40,000
equity 55,000
non current assets=80,000 ( Is this correct)
non current 60,000
Current capacity of transformer
[ 2 Answers ]
If I have got a 3 phase 750 KVA tranformer of 6.6KV / 380 V , what is the max output current capacity per phase. How is it calculated.
Amperage lost from a current transformer to utility's electric meter(?)
[ 2 Answers ]
I work for an Electric utility.
Have noticed that the actual amperage running through a phase does not match the amperage being sent to the meter with it's proper multiplier from the current transformer (CT)?
Example: phase A is using 83 amps. The X1 tap to the meter from the current...
View more questions
Search
|