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Thank you everybody for your great technical support. Now everything is clear. Best regards Daniel

Just a couple of things WAROSS(ELECTRICAL) If my understanding is correct, after setting all timers to maximum and starting up the motor, I have to watch out the moment in which the line current stabilizes (nominal value?). This will give the value of t1 Then, I have to re-start the motor with...

Dear gentlemen Thank you for your valuable responses.I appreciate all the experience you have shared with me. Best Regards Daniel

Dear Gentelmen: I am the going to take part of a start up of a big Wound Rotor Motor and this is my first time with 700HP motor). I will appreciate so much if anybody of you can give me some values according to a similar experience and application. What I really need is the time of every timer...

Dear Alehman Thank you for you reply however I have read GE Paper GER3979 (Dimensioning of Current Transformer for protection application). There they include a factor "Ks" (Saturation or Transient Factor) that has to do with other factors (TPX or TPY CT design, Instantaneous operating time "ts"...

Dear Gentlemen Can anyone please help me. I have an electrical system with the next data: X/R: 15.3; If=14500A; Vsys=10kV The installation will include a MV Switchgear I'm thinking of using a Feeder Protection Relay with the next: -CT rating/Maximum Transient: 80xInom=400A for 1sec -CT...

Dear gentlemen: I'd appreciate if Can anyone please tell me Since how many KVA OR MVA worth selecting in Protective relays the function 32 for Power Generator's applications Thanks in advance

Thanks to you gentlemen for your useful answers.

Probably I didn't explain you very well, but this is my case.Most minning companies in my country use Cutler Hammer Switchgears, when the customer need an Overcurrent protection and measurement the switchgears mostly has one CTs per phase. On the other hand I've seen some utilities that have ABB...

Dear sirs Most of american switchgears has as standard one CT per phase (Total:3) in order to use it for protective and measurement, while most of european switchgears have 02 CTs per phase (total:6)for the same use (protective &measurement). ¿What is the technical advantage to use one one CT...

For most Oil Inmersed Transformers Temperature of reference is 75°C. The impedance (%Z)is get it by the next expession: Z%=sqrt((R%)^2+(X%)^2)=Vcc(%) Where R%=Ohmic part involved copper loss and X(%)=Inductive part involved leakage inductance (Dimension of the coil and distances beetwen HV and...

IEC 76 rules European transformers. According this 60°C: Top oil temperature rise (measured by thermometer) And 40°C: Maximum ambient temperature So, with these values maximum temperature for oil is 100°C, but as Gordonl said is common to be conservator to extend life of the transformer. Why...