Maximum Zs values.

RE: Maximum Zs values.

Shane Regan — Wed, 11 Mar 2020 08:42:14 GMT

Hi Stuart,

We have been reviewing this in light of your request. Hevacomp calculates impedance in order to arrive at a fault current. That fault current is used with the time current curve of the device to ascertain the disconnect time. That disconnect time is checked against Regulation 411 to gauge pass or fail. All manufacturer data is checked an verified by the manufacturer before it is published. At present we do not hold Max Zs values in the manufacturers data but this is something we will review for future releases as an alternate to our current method.

RE: Maximum Zs values.

StuartO — Tue, 10 Mar 2020 15:36:01 GMT

Can I have a response please

RE: Maximum Zs values.

StuartO — Tue, 25 Feb 2020 17:13:23 GMT

Can Bentley please provide the response to the wider forum please.

I have recently attended a training course and the IET and NICEIC are of the opinion that the Zs calculation 411.4.4 should not exceed the values indicated in table 41.3 where the manufacturer data is the same as table 41.3. All Schneider and Eaton values for MCB's are provided in accordance with table 41.3.

RE: Maximum Zs values.

Duncan Brown — Tue, 13 Jun 2017 10:18:42 GMT

Hi Ian - I responded to this query in service ticket 7000642313 for Steve Wherry.

Regards,