voltage drop calculation

[sesa21615_bridg]

Hello, I have some concerns about the voltage drop calculations: if I made calculations for simply drawings for 180A, 165m and 1 x 240sqm cable, the result is ok, but, if I have the same situation into a much more complicated SLD, the results are completely different and totally unacceptable. The same for 660A, 165m and 3 x240sqm.

If you put circuit breaker - cable-circuit -breakers or circuit breaker-cable-switch disconnector,  and identical data, the results are completely different and I do not understand why!.

I shall post the example and I stay to you disposal for any other necessary explanation. I put on the same page these three examples: the full SLD and, on the right, the simple SLD. Please, check them and see if there is something I am doing wrong!

I need urgently answers as I am working now for a very important hospital project and my customer is a little bit confused about this tool.

Regards, Mihaela Gusa

[Genghiz]

Hello Mihaela

Thanks for reaching the EcoStruxure Power Design – Forum.

We will do the analysis and get back to you on the same.

To proceed further, on this process can you please kindly share with us following information’s.

• The Ecodial project file:
• The software version:

Regards,

Team - Ecodial Expert Support

[Genghiz]

Hello Mihaela,

Thanks for the given project file. 

This has helped the product development team to go for the detailed analysis.

The calculation of voltage drops:

Application is working as expected and there is “no issues” on the voltage drop calculations. This has been proved by the analysis.

Cause:

What are the causes for the “difference in results” at the given circuits?

This is due to the difference in scenarios of these circuits, and their downstream circuits are forced by a new current value, which are different than the working loads.

[sesa21615_bridg]

Hello,

The voltage drop depends on the current and cable impedance; I put manually the same values for the currents, the same cable lengths and sections, so I do not see why the voltage calculation would depend on the downstream loads.

Can you check a little bit more? What formula do you use?

Thanks

Mihaela

[Genghiz · Accepted solution]

Hello Mihaela,

Thanks for your time during the meeting yesterday.

In the given project, the following two feeders are forced by the user defined value of current.The value forced and defined by the user

However, the voltage drop calculation is done based on the ‘value of current calculated – from connected loads.’ This is normal and as expected.

The value of current due to the connected loads

Application Malfunction:

There is a malfunction at the feeder “Protection (QA)_Cable (WD)_Protection (QAbis),” while the value of current is forced by the user at the QAbis.

In this condition, the application is considering the ‘given value of current for the voltage drop calculation,’ and this is not an expected behaviour.

Conclusion:

The product development team has agreed improve/fix the same during the next release of the application.  

[sesa21615_bridg]

Hello,

Thank you! I appreciate. When is it expected the next release happen?

Please, take into consideration the other suggestion - that regarding the possibility to edit the Power or current on the switchboard busbar!

Regards,

Mihaela