Recent content by GadreP

Dear Friends, I have a step-up transformer of 415/11000V, 160kVA. Can anybody provide me information on civil details? I basically need the height of foundation from FGL & how much clearance is required on all the 4 sides of transformer. Also I need to install a DG set (160kVA, 415V) in...

Hi Raghun, thanks for your reply. Bus fault level & breaker fault levels are matching. I will definitely take a note of LSIG protection but is assumption of 125% margin is correct? In that case transformer upto 175kVA can work on this breaker.

Dear Friends, I have a question regarding sizing of the breaker for primary side of transformer. I have 160kVA, 415 to 11kV, Z=4.5%, ONAN transformer. Its full load current is 223A. What should be the size of the feeder. I referred to NEC & it says 125% of FLC of transformer. I have chosen...

dpc: For relay setting & feeder sizing 12 times of primary full load current is ok, but please tell me whether I am saying is correct or not? When I am charging a transformer on no-load, inrush should be 10-12 times of its No-Load Amps..?

Dear All, thanks for your replies. But please confirm one thing: 1) If we are charging a transformer on No-Load then 10-12 times what we say should be 10-12 times of No-Load current which is 5-6% of Full load current (FLA). 2) If we charge a transformer on loaded condition then that 10-12...

Cuky2000, I am unable to download this file; windows is giving an error. Can u please upload in some other format or provide a patha of the website?

Guys, I have a step-up transformer 100 kVA, 415/11000V. The impdance is 5%. What is a value of inrush current? I read some articles but everybody has different views which is really confusing me. Some people say 10-12 times rated primary current & some people say 10-12 time secondary rated...

Hi guys, I just want your opinion about a system: I have a turbing generator star connected. The supplier is suggesting a 3 Pole ACB with neutral contactor. The ACB rating is 630A, 415V. What will happen if I use 4 Pole ACB without neutral contactor? Please suggest whether a system will work...

One method for OH single phase system is Sending end voltage= receiving end V + IZ. If the system is single phase two wire, we multiply this equation by 2. But what do we do for 3 phase 4 wire. Do we need to multiply by root 3? (1.732) or is it something else? Pls help me out to solve this..

For U/G cables we consider Vd= 1.732*I*(R cos (phi)+ X sin (phi))/1000* No. of runs. I just wanted to know what formula do we consider while estimating voltage drop for overhead transmission line. Do we calculate by same formula or it will change considering 1 conductor?

I guess Booster transformer at receiving end panel seems to be better option..

Ok.. so capacitor bank KVAr rating (25 KVAr) calculated from formula KVAr=1.732*V*I*Sin(phi)will be correct? I will assume PF as 0.85 or 0.9 at receiving end & 0.8 at generating end. I hope by using capacitor bank of 25 KVAr at receiving end panel will compensate my 160V voltage drop. To...

Guys, in the above case, it is absolutely not possible to go to the higher voltage. Power will be generated at 415V only. Is the method of calculating voltage drop is correct? (I will use ACSR's data sheet once I get it) The primary use of Capacitor bank is to improve PF but can it be used for...

So, based on above formula voltage drop comes around 160V. So on 415V bus, I will be getting 255V considering 2KM distance. I need to maintain voltage at 415V level.

Hi Magoo.. I used Vd=I*1.732*(R*cos(phi)+X*sin(phi))*length/(1000*No. of runs). Is this formula correct? The maximum current demand is 150 Amp,P.F at generating point is 0.8 lag & load side KW rating is 80 KW. As the design is at primary stage I don't have motor details like at what PF the...