Cable derating for Australian installation ; however general comments/answers are welcome.
1)Is it advisable to design & install a 415VAC cable where cable’s derated ampacity is equal to the circuit’s full load current ? Examples, practical experiences regarding cable failures because of...
With reference to transformer thermal characteristics, power system analysis software ETAP shows a short line & inrush current point(s) in protection co-ordination graphs. The transformer, built to AS60076, is 1000kVA, Dyn11, oil-immersed, Z=6%, temperature class of insulation=A, Winding...
In substations, industrial installations, mine sites etc neutral earthing resistors(NER) are used. However, in many installations, neutral earthing reactors(NEX) are used. I was told that for a couple of projects, NER was deleted from the project drawings and NER was replaced with NEX. Qa)What...
Regarding Jghrist's question "Why are there five terminals? You only mentioned three, the station being analyzed and stations at the ends of the two incoming lines.",terminal 1 & 2 are 2 other earth grids to which station being analyzed is proposed to be bonded,
terminal 3 & 4 are indeed the...
Thanks to all of you who have replied to this post.
A few more questions:
A)Wondering how FCDIST's output shows Total Neutral Current.........: 13000. Amps when no info related to neutral was entered in FCDIST?[13000 is the 11kV earth fault current and there is no neutral conductor...
1)Just to clarify,11kV earth fault value given by client was 27kA. Even though this value is not realistic,did a quick
manual calculation of earth fault current split to earth grid and cable screen.Need help to verify whether the folowing derivation of earth grid fault current of 1700A is...
11/.415kV Distribution substation's(32m long by 15 m wide) propective earth fault current is 27kA but there is limited real estate and the native soil resistivity is very high(~800 ohm-m).There are two incoming 11kV cables to this substation.Running CDEGS software with 13.5kA(assuming 50%...
