Fault current Definition and 9 Threads

Hi, I was having a discussion with a colleague today now I'm second guessing myself. My understanding of nameplate kVA is that it is based on 'ambient temperature, temperature rise, heat transfer, thermal mass, thermal time constant, materials used, and expected transformer life'. However...

I'm trying to resolve an issue I'm experiencing with some overhead power distribution lines, was wondering if anyone can help me out. Here is the scenario: three phase, 4 wire, wye connected 13.4kV power distribution system. 556.5kcmil bare ACRS wire is mounted on a crossarm 24" apart over a...

Any idea how can we decide on the fault current time 1, 3 or 5 sec. for grounding cable sizing? Also, what is the related temperature to the selected timing?

Hello all! I am carrying out the theoretical (that is, by calculation means) unsymmetrical fault calculations for three winding transformer. It is to my understanding that for the zero sequence impedance for a three winding transformer depends on the winding connections of the generator and...

i have a TT earthing system and to decrease the resistance of the system I'm connecting the rods in parallel. i have the earthing conductor connected but as a mean of security, I'm thinking of connecting a second earthing conductor from the rod to the main Earth bar. Does this cause a any...

so calculating FC on an infinite bus is easy but how do you calculate it by hand for a finite bus? here is the concept i am having an issue understanding: let say i have a transformer that is 225KVA with 5%z and 3 phase 480 to 208. with infinite bus i have 12491A available on the...

hi could someone please explain the attached circuit to me in detail. From what i understand: the open circuit caused by the opened switch in series with the resistance causes a fault current in the system. This higher than normal current across the 200 ohm resistor causes a high...

Last time I was talking about Isolated Voltage, and some of you people were really helping me about, but I posted (did) something stupid and got the thread deleted. I am sorry for that. Now, I want to talk about my confusion in a different (safe) way. The above figure shows a...

Six, 6.6kV ,3phase, alternators are connected to a common set of bus bars. Each has positive negative and zero sequence reactances of 0.90 ohm, 0.72 ohm, 0.30 ohms respectively . An Earth fault occurs on one bus bar . Determine the value of fault current if all alternator neutrals are solidly...