Hello,
We currently have an engineer on site in Egypt commissioning two GE Multilin SR489 Generator Protection relays. He has experienced problems communicating with the relays from his laptop through the front RS232 port.
We have contacted GE helplines and checked everything they suggested...
To jhrist:
Yes, but the MiCOM P633 manual states that all Iref currents must be calculated using the same Sref and they recomend also to use as Sref the highest value, in this case 48MVA. Therefore the Iref current on LV side are higher. It's strange for me but this is exactley what the manual...
I'll give you all details:
The power transformer is: 220/6.6/6.6Kv, 48/28/28MVA, Yny0yo vector group.
CT HV side: 150/5
CT both MV side: 3000/5
The user's guide states: the relay itself calculates Idiff and Irestrain, based on Iref.
I ref, is calculated by the relay using the formula:
Iref...
To jhrist:
That's true: the relay is a numerical one, P633 manufactured by Alstom (MiCOM range) with the capability to compensate a possible wrong connection on CTs by settings. The protected transformer has an Yny0yo vector group and even 'inside' of the relay is not neccesary to compensate...
Hello,
First of all, excuse my English. I'm a young commisioning engineer and I have a situation on site related to transformer differential protection. The question is reffering to CTs star point connection (both set of CTs). Is that true if the primary position of CTs on HV side is P1 -...
