Fault Level At 11Kv

[luckierPhil]

Hi.  I'm working on an old 11kV system with a mixture of old padmounts and ground mounted tx's.  I need to know the fault current at one of the sites to enable a design of the earthing grid to proceed.  I can get the fault level at the LV board using Fluke 1653.  Do I just use the impedance of the TX (and obviously the turns ratio) to work out the HV fault level or is there another method?

 

[ProDave]

f you are working on an 11KV distribution network, then your employer should have trained you, or ensured you were adequately trained before they employed you.

If you don't know how to work out something so vital, you should not be asking on a forum, but asking your employer for guidance as they should know their network parameters, or another more experienced member of staff will.

This is an electricians forum and most of us on here only ever deal with LV installations.

Or is this a wind up and I have fallen hook line and sinker?

 

[Andy™]

as above. but your probably best asking on an Aussie forum than here

 

[Sidewinder]

I think in Aus, sparks get to do more HV work.

I know a mate of mine, we we apprentices together used to work with the "DNO" when they had problems to get the power to the mine back on.

That was out in the northern Territories.

Welcome to the forum luckierPhil, but we are. UK based forum centred around BS7671.

 

[Manator]

Welcome to the forum, we are UK based as stated above, however calculating the fault levels are the same. Each Tx will have a nameplate with the impedance stamped upon it as a % you need all this data to calculate the overall fault levels. Hand written calculations are hard and laborious often flawed because of all the conversions required.

A simple method is the MVA method of calculating, its far too detailed to go into over a forum but I am sure if you do a web search you will find all kinds of methods to achieve what you require.

 

[kerching]

35/40 years ago I could have told you

Now I cannot remember what I had for breakfast, if indeed I had any!

Sorry!

Welcome anyway