# Recent content by bigjoe5263

1. ### Power transformer 60 hz to be tested on 50 hz

thats also what i am thinking Bob S, and if you neglect the Resistance r of the transformer, I(60) = I(50)
2. ### Power transformer 60 hz to be tested on 50 hz

during short circuit test, with the LV side short circuited and voltage will be applied on the HV side and it will be adjusted from zero to a level where the rated current at HV or the LV is expected. The transformer is designed for 60 Hz, however the available supply on the test facility is...
3. ### Power transformer 60 hz to be tested on 50 hz

thanks for your replies.. the technical personnel gave this relation V(60)=V(50)x6/5, these is for the voltage, which can be applied to determine the voltage for the 50hz supply during open circuit test. But during short circuit test, the voltage is to be adjusted from zero upto a level where...
4. ### Power transformer 60 hz to be tested on 50 hz

The two power transformer 69/22.9kV and 230/69kV are both rated 60/80/100MVA designed for 60 Hz operation. However it will be tested on test facility were the available supply is only 50 Hz. During short circuit test at the LV side the 60/80/100MVA rating will be tested for the lowest tap...
5. ### Reliability of substation configuration

msj.. thank you for the info.. regards
6. ### Reliability of substation configuration

hi!. anyone here who have an idea on how to assess the reliability of a ring bus system over an open loop/ radial system? the ring bus is composed of three load bus connected together. thank you
7. ### Closing of an open ring

digoff.. thanks for the figure. assuming there are no generators involve, and circuit breaker A is initially open, are there parameters to be check before circuit breaker is to be closed? what are the things need to be considered? i.e. voltage difference across the open breaker, phase angle...
8. ### Closing of an open ring

dlgoff, that is almost the figure, except that A, B, C are load Bus, i.e. power transformer are connected to them, and also the ring configuration are connected to those bus through the transmission lines between them.
9. ### Closing of an open ring

S--x----------x--A--x----------x--B--x----------x--C--x---------x-->to point A where: S = source A,B,C = interconnection (bus) x = circuit breaker -- = transmission line 69 kV...
10. ### Closing of an open ring

S--x----------x--A--x----------x--B--x----------x--C--- l l x------------------------------------x where: S = source A,B,C = interconnection (bus) x = circuit breaker -- = transmission...
11. ### Closing of an open ring

hi guys, just want to ask, an open loop has three points A,B, C and each point serving a load. there is only one source (a subtransmission 69kV line from a substation), connected at point A. The loop is open at line segment AC (the circuit breaker at point C, connecting the segment AC is...
12. ### A number raise to it self infinitely

hi I have encountered this... . . X X X X = 3 I tried...
13. ### Free Fall

thank you guys for your replies its actually what I thought that g should be negative, and the velocity before it hits the ground is equal to the initial velocity. so using the formula : to calculate for the initial velocity is: -Vo = Vo - gt... and the answer is 49.05 m/s where t...
14. ### Free Fall

I if a body is thrown vertically upward (from ground), and it reaches back to ground in 10 seconds.. then the initial velocity can be calculated by Vf = Vo + gt.. where the final velocity Vf is equal to zero and the maximun height is given by s = Vot + 1/2g(t^2).. Is these correct?
15. ### Game theory

yes it involves cooperative games, the shapely value and the core of an n-person game theory.... Just one question on the prisoners dilemma non constant sum game and non-cooperative...the equilibrium is both of them confess but it confuses me because i think when one of them change the...