11kv kiosk 1kpr.doc

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Reply to Comments on 11KV KIOSK PANEL

Document ID IKE-KPR-KIOSK-RPL-001 Revision 00

Ref. Doc. Email dated 07.06.12 regarding Comments on 11KV

KIOSK PANEL

Sheet 1 of 1

Project: M/s KPR SUGAR MILL LTD. (30MW COGEN PLANT)

Prepared by: Yusuf S Checked By: Kamlakar D Approved By: ABH 03.07.12

1. As per contract kindly indicate the below specifications in drawing:a. Highest System Voltage: 12 kV

IKE REPLY: Noted & the same has been indicated in revised drawings (attached)

b. One minute Power Frequency Withstand voltage : 35 kV(rms)IKE REPLY: Noted & the same has been indicated in revised drawings (attached)

c. 1.2/50 micro second impulse: 95 kV (peak)IKE REPLY: Noted & the same has been indicated in revised drawings (attached)

d. Operating Duty: O-0.3s-CO-3 min-COIKE REPLY: Noted & the same has been indicated in revised drawings (attached)

e. Dynamic Rating: 100 kA

IKE REPLY: Noted & the same has been indicated in revised drawings (attached)

f. Rated short circuit making capacity: 100 kAIKE REPLY: Noted & the same has been indicated in revised drawings (attached)

g. DC current & Decay: 18.1 kA at specified breaker opening time

IKE REPLY: Please refer the Attached type test report for exact value of close/opening and other particulars. Theabove technical values as per type test report, Megawin will not provide dc decay-18.1KA (% of DC componentat contact separation is 37%)

h. Pole Parting Time in ms: Not less than 75 ms, by providing suitable electronic valve in breaker mechanism.

IKE Reply: Pole part time is not applicable and there is no electronic valve in Megawins type tested design. Allparameters are as per type tested design hence Megawin is not able to change the type test parameters.

Closing time less than 5 Cycles Opening time less than 4 cycles

2. Incoming and outgoing busbar size (3150A) shall be mentioned. Kindly revise.IKE Reply: Noted & the same has been indicated in revised drawings (attached)

3. Bill of materials shall be submitted.IKE Reply: Noted & the same has been indicated in revised drawings (attached)

4. Kindly furnish the type test certificates for its temperature rise and short time rating for CT for our review/records.IKE Reply: Noted & the same has been indicated in revised drawings (attached).

5. Please note that all final inspection tests shall be witnessed by the client/consultant. Kindly take care the same in theQAP.IKE Reply: Noted.

(We are also attaching the email received from Megawin for authenticity of above reply)


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Megawin

Switchgear-P-Ltd.

BUS BAR SIZING

CALCULATION FOR

CONTINOUS CURRENT

RATING

Ref. No: MWSG / IKE/GR

Issue No: 01, Dt: 15.05.12

Revision No: R0

Page 1 of 1

CUSTOMER: M/s. IKE ELECTRIC, PUNEPROJECT: KPR SUGARS, KARNATAKA

BUSBAR SIZING CALCULATION FOR AMPERE RATING: 3150A

Specified continuous current rating of the bus bars: 3150A

Max. Permissible current density for Aluminum bus bars:1.0A/Sq.mm

Required area of cross section of Aluminum bus bars for the above: 3150A/1.0

= 3150 Sq.mm

Cross section of the Aluminum bus bar selected for the panel: 120mmX10mmX3 Runs

Area of cross section: 3600 Sq mm

Thus, FLAT type of aluminum bus bar 120mmX10mmX3 Runs is adequate for the continuous current

rating of Main Bus Bar.


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Megawin

Switchgear-P-Ltd.

11KV/40KA/3SEC Short

circuit current Calculation

for single Panel VCB switch

board.

Ref. No: MWSG / IKE/GR

Issue No: 01, Dt: 15.05.12

Revision No: R0

Page 1 of 1

CUSTOMER: M/s. IKE ELECTRIC, PUNEPROJECT: KPR SUGARS, KARNATAKA.CALCULATION FOR SHORT CIRCUIT CURRENT CARRYING CAPACITY FOR BUS BARS

Specified short circuit current rating of the bus bars : 40KA

Specified duration of the short circuit current : 3 second

As per IS 3427 - 1997 we calculate the cross section of bare conductor necessary to withstand thethermal stresses due to short circuit currents with specified duration.

S = (I/)))) (t /))))Where,S is the cross section expressed in Sq.mm.

is expressed in A/mm2 (s / K)

and has the following values:

13 For Copper

8.5 For Aluminum

4.5 For Iron

2.5 For Lead

t is the time, expressed in seconds.

is the temperature rise, expressed in Kelvins (K): for bare conductors, it is normally 180K.Calculation for Main Bus bar

Substitute the values S = (40000 / 8.5) (3/180)Reqd. cross section S = 607.5 Sq.mm

Hence the selected cross section is more than the required cross section of main bus bar, which is

3600 Sq mm


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