Short circuit level

[Denan]

Hi,

I would like to discuss the following statement:

"It is better to have short circuit level at 440V that is 80-90kA, than at 690V with 50-60kA"

What would you say is correct, and why?

PS! Regarding generator on a ship.

Thanks,
Denan

 

[7anoter4]

If it is the Incident Energy Exposure during an electrical arc event the 440V/90 KA is better than 690V/60 KA. The problem is if the switchgear could withstand 90 KA .The x"d of 4.5% for a 3 MVA generator is also a problem for both 440V and 690 V, I suppose.

 

[Denan]

Thanks 7anoter4!

Could you please explain this regarding Incident Energy Exposure some more?

 

[7anoter4]

I think you'll find more if you'll see this link:

http://www.arcadvisor.com/arcflash/afa_v1p1_calculation_example.html

Regards

 

[Denan]

Thanks again, I will see it.