Reducing Fault Through Level on Transformer primary
Reducing Fault Through Level on Transformer primary
(OP)
Beside using a current limiting fuse in series with standard E type fuse( K type can't be used) on primary side of a transformer ( 10MVA, 28KV), is there any other solution to limit the fault through current?
Thanks
Thanks






RE: Reducing Fault Through Level on Transformer primary
Although I am curious as to why do you need to limit the fault current on the primary side? It will have very little effect, if any on the secondary side.
Rafiq Bulsara
http://www.srengineersct.com
RE: Reducing Fault Through Level on Transformer primary
RE: Reducing Fault Through Level on Transformer primary
David Castor
www.cvoes.com
RE: Reducing Fault Through Level on Transformer primary
I think you need to work closely with your senior engineers and use their guidance.
Rafiq Bulsara
http://www.srengineersct.com
RE: Reducing Fault Through Level on Transformer primary
RE: Reducing Fault Through Level on Transformer primary
"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla
RE: Reducing Fault Through Level on Transformer primary
RE: Reducing Fault Through Level on Transformer primary
As you can see from the diagram and as you have noted, a through fault is cleared by the 250E fuse and the CL fuse doesn't get into the current limiting range anyway, so there is no limiting of the through fault.
That doesn't mean that you never need a CL fuse on the primary of a transformer. Often CL fuses are used on distribution transformers to limit the energy in a high side transformer fault to prevent catastrophic failure.
This isn't normally done on power transformers. As noted by VTer, this size transformer usually has a primary breaker and differential protection because it acts faster than fuses and can limit damage from a fault. Smaller transformers are cheaper and often do not justify the cost of a breaker.