IEC 60909 VS IEC61363
IEC 60909 VS IEC61363
(OP)
Hi
We are performing an IEC Fault calculation on the off shore installation. The switchboard rating is at offshore is 25kA for 1 sec which i assume is Ib(IEC60909).the calculation i am doing is IEC 61363. The result I am getting form the software is T0,T1,T2,T3 and T4 AC,DC and total. Now how I define (IEC61363) these results to the short circuit value stated at the nameplate of switchboard.
Thanks
We are performing an IEC Fault calculation on the off shore installation. The switchboard rating is at offshore is 25kA for 1 sec which i assume is Ib(IEC60909).the calculation i am doing is IEC 61363. The result I am getting form the software is T0,T1,T2,T3 and T4 AC,DC and total. Now how I define (IEC61363) these results to the short circuit value stated at the nameplate of switchboard.
Thanks






RE: IEC 60909 VS IEC61363
There is a lot of such software. For instance:
http://www.digsilent.de/tl_files/digsilent/files/n...
These are not symbols used in IEC61363-1 [at least not in BS edition which I have] and there is not the usually output.
It is possible To...T4 are the location points where the short-circuit current is calculated as at transformer terminals, at generators terminals or at switchgear [breaker] terminals. Also AC could be the Iac(t) component and DC Idc(t) component.
However in ch.9 of the standard [nevertheless it is for low-voltage equipment] it is stated:
“The circuit-breaker’s rated short-circuit breaking capacity shall not be less than the calculated
prospective short-circuit breaking current. This value shall be obtained by calculating the a.c.
component of the short-circuit current Iac(t) at its point of installation on the system at the time
at which the circuit breaker’s contacts separate."
I think this time could be 100 msec [0.1 sec].
The short-circuit current withstand of 25 kA for 1 second it is referred to the thermal stability of the breaker [See IEC 60865-1 Short-circuit currents –Calculation of effects –ch.3.2.4.1]