ETA EMGlNEERlNG PRIVATE LIMITED 503-504, Prakash Deep Building, 7, Tolstoy Marg, New Delhi - 110001 Ph. : 01 1-26451115/6/7/8,43743800, 41520840/43 Fax : 011-43743866,41520844 Ernail : etametro@vsnl.net

Ref: ETA/ICML/9MW/BC/SClKW035 Date: July 26, 201 1

DGM - BUSINESS DEVELOPMENT (POWER) MIS CESC Limited CESC House Chowringhee Square Kolkata - 700 0022 West Bengal.

KIND ATTN: MR ADRlT PALCHOUDHURY

SUB: ICML 9MW SOLAR POWER PROJECT AT PRATAPGARH, DlST KUTCH, GUJARAT - CLARIFICATION TO DSLP CQACULATIONS AND SWITCH YARD LIGHTING PROTECTION LAYOUT

REF: (1) ICML REF: LII GEOE 11 055-E-11-12-015 DT 5171201 1

Dear Sir,

Further to your queries vide your mail referred (1) above regarding SCADA System, we are pleased to attach herewith point-wise clarifications with respect to the above system for your kind perusal.

We hope the above is in line with your requirements and would request you to kindly let us have your approval to enable us to proceed further.

Thanking you and assuring you of our best services at all times.

Yours faithfully For ETA ENGINEERING PVT LTD

SAURABH CHAUHAN GENERAL MANAGER

Encl: as above

.............................

Regd. Office : 5, Moores Road, Chennai - 600 006 Tamil Nadu, India

Branches (Tel.) - Bangalore : 41802300, Chennai : 28297626, Hyderabad : 27763529130, Mumbai : 67742700, Pune : 26051310, Kolkata : 24864329

subject to incorporation of Commentslmodificatlons as noted. Resubmit revised drgs.ldocs after Incorporating the comments

DOCUMENT No.: ETA/ICML/SOLAR/GUJ/ELECT/ERTH/OS9-A

Lightning Protection Calculation for 66/11 kV SIS Control Room

CONTROL ROOM BUILDING

For design of lightning protection we have analysed the tallest part of the building. i.e. Top terrace level area of the control room.

Annual thunderstrom days = 30 days

Estimation of exposure of risk ( Ref CI.No.8.1.2 of IS 2309)

Control Room Area : Length L - - 20 m W~dth W = 11.6 m

- Height H - 4.2 m

Collection Area Ac = [ LXW + 2[U(H] + 2[WXH] + P X H Ac . = 552.86488 m2

TOTAL COLLECTION AREA: Ac = 552.86488 m2

~ i g h t n i n ~ flashes per km2 per year 'Ng' for thunderstrom dayslyear as per Ref. Clause no. 8.1.2 of IS 2309.

Ng = 1.9

Probable number of strikes ( risk) to the structure per.year is

P =ACXN~XIO" P = 1.05E-03

Weighting factor ( Ref CI.No. 8.1.5 of IS 2309) A 1 .O from table-IA,for use of structure. B 0.4 from table-1 B,for type of construction. C 1 .O from table-1 C,for content or consequential effects. D 1 .O from table-I D,for degree of isolation. E 0.3 from table-I E,for type of company.

The overall weighting factor = A*B*C*D*E = 0.12

After applying the weighting factor, Probable risk factor

P = 1.05E-03 x 0.12

Probable risk factor : P = 1.26E-04 per year

As per cl.no:8.1.3 of IS 2309 suggested acceptable risk figure = per year. (Protection is not required)

II Now from the above calculation i t has been found that probable risk factor P is more than the acceptable risk factor.Hence protection is necessary.

One down conductor is required for each 30m of perimeter of the structures protected as per 18-2309 CI.No.12.2.3 (B)

Total Perimeter to be protected - - 63.2 m

Hence, from IS 2309 CI. No. 12.2.3 (b) minimum Three down conductors are required.As shown in layout we are providing four down conductors.

SCHEDULE OF EQUIPMENT -66kV

IS. NO. I DESCRIPTION I Qlv. I SYMBOL 1 I I I

72.5KV.B30&31.WA FOR 3% SF6 aRculT BREWER. 01 NO.. -

1 1 72.WV.630AJl.SKA FOR Sac , ENTER BREAK ISOUmR THREE PHASE WTH EARTH SmTM I OZ 1-1 I PHASE 7ZWV WlDM)R PT (3 SCONObRY)

P/P/PIypu 03 NO..

SURGE ARRESTOR . ZINC OXIDE . 8CUV.lWA 08 N h

I 6 I SlRlNG INSULATOR IAS PER BW( - I 12.5 MVhll/BBKV. 3Ph. DYnll O N A N / ~ S m m a m a or NO.. 2 . 1

CLEARANCE TABLE

m A s m PHASE (PP)

PHASE TD EARTH (PE)

scncu CLE*RANCE (SC)

CROVNO CLEARANCE I 4 2 M

TO THE NEbREST PART NOT AT EARTH 2440 P o m n A L w AN I N ~ A T W

A. HIMEST SlSTDl WLTADE 72.5 kV

B. UMlNINC IMPVLSE WLTAGE

C TIPES OF SISTDl EARTHING SWOLY EARTHED

0. SISrm FRECUENCY

NOTES: 1. AU DIMENSIONS ARE IN MM. UNLESS D T H W S E SPECIFIED. 2. CREEPAGE DISTANCE- 25mm/kV, MINIMUM CREEPAG: 1825mm.

NO.^ DISC INSULATORS: BNOS (TENSION) 5NOS (SUSPENSION)

3. CONDUCTOR SIZE/DElAILS. - W N BUS : ACSR SINGLE ZEBRA - EOUIPMENTS IWER CONNECTION. WAF0 BAY & UNE BAYS : ACSR SINGLE ZEBRk

4. CONDUCTOR TENSION - W N BUS : 1000 ko/CONWCTOR/PHASE. - OMER BUS : 1000 &/PwE.

'

- SHIELD WIRE : 500 kg. 5. PUNTH HEIGHT OF AU. EOUIPMENT FOUNOATlON WIU BE +300MM PlUlrm

MCEPT CB FROM M E FINISHED COUND L M L (F.C.L). GRAVEL TOP LEML WlLL BE +150MM FROM THE F.G.L

6. DETAILS OF CABLE TRMCH W l U BE SHWM IN OUTDOOR, INDOOR TRENCH LAYOUT. 7. DElAILS OF CULVERT TYPE TRENCH AND CABLE ENTRY INSIDE CONTROL R W M

WlLL BE SHOWN IN TRENCH MYOUT.

8 REFER PRESENT DRAWlNC FOR LAYOUT PURPOSE ONLY

01 W

S.K

m - - ANL

BY

nrrr

nnmi 2 4 . ~ 1 1

D A T I

>L O ~ ~ I I

HXI APPROVU F I N APPROVAL

OtSCRIPTION

BTA-KIm I h ~ P , " . " , m ~ ~ ~ ~ ~ f i ~ ~ ~ ~ I fit I Y n

ISIUDBY

ypBByY PRIP.BY

CiSW1BY

XU[

N A N A m -- nBlnn Am

M I A

A S S I M 1 1

INTEGRATED COAL htMNG m D ~P((OIIFIACT(R ~?'-PRIVA~~UMIIPD -- - - - - - = = - - - - '.-- -----,- ? = = - I I . I - U Y I * - i IU*M, - . ..

I-ul.#-n-

PROECT

9 1 ~ ~ S O W W ~ K i O E T A T K l l N l ~ A I U T

br* ntlt

SWITCHYARD LAYOUT PLAN

h v . lahn