Answer / prashant soni

HT Cable size dependson fault level to be withstood and its duration..

If you take XLPE, HT Cable of ALU conductor,
condiering 350MVA for 1 sec *(18.37kA), min. C/A will be found out by Area(A) = (Short ckt current (kA)*Square root of Time)/k
k is constant = 0.094 for XLPE ALu conductor.

This will give you min. size required for HT system (11/22/33/6.6/3.3kV)

Choose nearest standard higher size for HT Cable..
primary 3*240 sqmm AL cable

Answer / ahmed

how many cable shoul be connected for 2000kva transformer of 11kv.

primary 3*240 sqmm AL cable


Secondry 4*630 sqmm AL / single phase (L1,L2,L3 & L4)
(u1,u2,u3 & u4) R-Phase
(v1,v2,v3 & v4) Y-Phase
(w1,w2,w3 & w4) B-Phase

(N1,N2,N3 & N4) Neutral

Answer / upen

250sqmm

I have a question, I visit 01 site and face a problem, there is 2.5 ton Air Con working, when air con compressor is running at that time rectifier voltages are increasing upto 290-295 v and rectifier is giving main high alarm (rectifier is APC single phase), before starting compressor rectifier voltages was 230v. when air con is going off rectifier voltages are decreasing smoothly at its actual voltages 230v. Load on Genset phases is this: Red-13.5 amp AC (Air Con load), Yellow-1.7 amp AC (BTS lights etc.) and Blew-4 amp AC (telecom system load), Genset phase to phase and neutral to phase voltages are also ok. These are 10 sites having same system and same rectifier APC brand at every site 02 genset are working but the problem is same at all these 10 sites. What will be the reason behind???

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Dear all, i completed M.E(Power Electronics & Drives) 2011 passed out having 78% so i need job in core side but i don't know how can i receive the calls from electrical companies and i uploaded my CV in naukri, times jobs etc.. In that iam not recieved any mails from good companies so give me best procedure plzzzzzzzzzzzzzzzzzzzzzzzz..... Thanks, K.Linga Reddy Email-id:-lingareddykmthm@gmail.com Ph no:-08015402078

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