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...
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%...
