ABB REF 543 and SKM software

[AMBMI]

I'm evaluating the overcurrent settings of an ABB REF 543 relay.
I'm using the SKM software.
The 51 element has been set with an extremely inverse characteristic and, looking at the time current diagram, at high currents it should be faster than the 50 element. The SKM software doesn't show that and the trip characteristic remains flat (so the relay seems to trip "using" the 50 element). It could be acceptable if the 50 element would block the 51 element but I didn't find any info in the relay manual about the expected behavior.
Is there anybody who knows how the REF 543 is working?
I don't have the REF 543 to test it directly...
Thanks in advance.

 

[slavag]

Hi.
No problem, its possible.
It internal locgic issue, build by CAP505.
please see an example.
Good Luck