P3L30 Calculation

[Hendra393652]

Dear All,

I need help for the explain example case in the attachment file this below.

Best regards,

Hendra Kusumah

[Hendra393652]

our relays had been tripped on customer site and we need to give clarification to them.

we found on the fault log & disturbance recorder that the magnitude and phase of the currents are quite similar (attachment slide 2). but we don't know why the relays indicate that the differential protection 1-2-3 operated (attachment slide 1).

kindly please advise.

the setting of both relays are available on attachment slide 3.

thank you.

[Pete_Vivers]

Hello, These sorts of issues should be managed by using BFO. If not already done so please raise a BFO issue to ensure that it is tracked and has priority

[hugoNP]

Hi team,

Hendra and me have tried to understand the sample case provided in the manual book, but it seems miss some details and have many typos.

We try to come up with the calculation excel (with what we understand), as attached. Hopefully the formulas are correct and it could be helpful to all of you.

Thank you.

[Chunmei_Yang]

Hello:

 Nominal primary setting is intended to accommodate possible transformer on line, however for cable It must be the same on both ends.

I notice the settings for nominal current is different :

Propose to check the power system if a transformer included, then configure the correct nominal primary current.

Chunmei