Ive just run a calculation for a distribution board with the following inputs
1000KVA transformer @ 4.75% showing a fault current as 28.7KA EFLI at 0.0089.
On this transformer there is a bolt on protection
The cable from this cable is to be a 25mm 4 core run on tray on it own for 5m before it terminates in a Distribution board.
My problem is at the Main Panel the fault level is 28.7KA (from supply page), But my calc (short circuit fault summary) at the DB (only 5m away is coming out as 7,233A (b). I would expect it to be in the 20's range.
Am i missing something
I was expecting a fault level issue due to the proximity of the board to the supply?
Ian S Langley
We would need the project in question to investigate this matter for you - could you please log a Service Request here and attach the project? Many thanks.
Shane Regan | Principle Building Performance Support Engineer
Was a reply ever given? I've experienced this previous also.
This was from some time back however from searching my records here I don't believe we ever received the project in question.