Afternoon all
I hope someone can shed some light on what i think is a problem with hevacomp connect, i am currently working on a large project and at the transformer, we have a fault current of 24kA but 10m upstream we have a fault current of 7.9kA so losing 17kA through 3 no. 185mm2 SWA cables.
I thought this may have simply been an error on this project due to entering something incorrectly but a colleague checked a calc they produced and the same happens, it seems the board downstream will let nothing more than 3kA through.
I have tried changing the protective device and this changes nothing on the fault current which remains at 7.9kA.
Any ideas / help would be greatly appreciated.
Andy
Happy to have helped.
Duncan Brown
Wow, thank you very much Duncan, i was dubious about using the likes of a forum to answer this simply due to never having used 1 before. I am sold, you have been excellent, thank you.
a colleague did say could the device be limiting the current.
Honestly, thank you. I will relay this back and may be back with more questions once i have spoken to colleagues
Andy - you have used current limiting devices in the circuit (Schneider Compact NSX MCCB + Micrologic 2) - Under fault conditions, the current is limited. This document contains a little more information.In the example circuit, for example, the device on MSB/SA way 3 is an NSX400 N 2.3 50kA. If you examine the device data, you can see that the let through energy is going to be between (I haven't interpolated the figure exactly) 6 and 7kA.
Answer Verified By: Duncan Brown
It is the fault current up to Block 3 End feed unit - BB/01-SA/B3/EF01 is the final value i need, handballing the calc we arrive at around 6kA. if we go from the transformer to MSB/SA we are going from 24kA to 6.4kA through 3 No. 185mm2 armoured cables.
Does that help?
Andy - can you let me know what you are examining upstream? Is it a particular way?Thanks,