Sizing of cable tray rev. D.pdf

SIZING OF CABLE TRAY

LPG - I UNIT FOR

NEW PROPANE GAS COMPRESSOR

ONGC CONTRACT NO. MR/MM/LSTK/AB/OTP/PGC(R)/2009/Y15BC09001/PC-6039 OF

OIL AND NATURAL GAS CORPORATION LIMITED MUMBAI, INDIA

CONSULTANT

ENGINEERS INDIA LIMITED, VADODARA

OWNER

ONGC LIMITED B 25/11/11 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 1 of 11

SIZING OF CABLE TRAY CONTENTS

1. SCOPE 2. BASIS & ASSUMPTIONS 3. CABLE TRAY /LADDER SPECIFICATION 4. TRAY SIZING CALCULATION 5. TRAY SIZING VERIFICATION

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 2 of 11

SIZING OF CABLE TRAY 1.

SCOPE This calculation covers the Sizing of Cable Tray with respect to Cable Data consideration required for all equipment of “New Propane gas compressor” project at LPG-1 plant, Uran complex of Oil & Natural Gas Corporation limited (ONGCL). The panels for all the equipment are considered to be located in existing LPG-1 substation. Power supply will be from new PMCC to be located in the LPG-1 substation.

2.

3.

BASIS & ASSUMPTIONS 2.1

Electrical Design Basis for New Propane Compressor (Doc. No. section C2.8 of 6867-00-50-50DB-01 rev. B, clause no.7.2 & 14.2 “Cable laying philosophy”).

2.2

Cable Data as per Cable Schedule doc. no. 6972-010-50-50-CSH-0021.

2.3

Cables are considered to be laid in single layer.

2.4

Spare capacity of 10 % is considered for cable trays (as per ‘Design Philosophy for Electrical Facilities’ clause no. 7.2.5 of cabling system).

2.5

Refer ‘Design Philosophy for Electrical Facilities’ Cl.no: 7.2.8 of cabling system – for cable tray design related to loading.

2.6

Cable data for sizing of cable trays have been selected based on the Standard chart of “Polycab” make Copper & aluminium conductor, XLPE insulated, armoured cable conforming to IS 7098 part-1/1988.

CABLE TRAY /LADDER SPECIFICATION 3.1

Refer Standard Specification no. 6-51-0082 rev. 2, Clause no.3.1 & 4.1 of “Cable Trays & Laying”.

3.2

Cable ladders are recommended for sizes above 300mm.

3.3

Cable trays shall comply with the requirements specified in EIL installation standard (7-51-0333).

3.4

HT Power, LT Power and control cables shall be laid in separate trays wherever trays are used.

3.5

Refer to NEC table 318-9 for the maximum fill area for multicore cables.

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 3 of 11

SIZING OF CABLE TRAY TRAY SIZING CALCULATION:

4.

4.1

CABLES FROM LPG-1 S/S TO NEW PROPANE GAS COMPRESSOR 4.1.1 Cable tray from LPG-I to New Propane gas compressor shed (New Propane gas Compressor) LT Cable size

No.

Overall Dia. (mm)

Total length of Tray required (mm)

3c x 4 mm²

7

15.0

7 x 15 = 105.0

4c x 6 mm²

5

18.0

5 x 18 = 90.0

3c x 70 mm²

1

30.0

1 x 30 = 30.0

3c x 95mm²

3

33.0

3 x 33 = 99

3c x 185 mm²

2

45.0

2 x 45 = 90

3.5c x 35 mm²

1

26.0

1 x 26 = 26

3.5c x 50 mm²

1

29.0

1 x 29 = 28 Total: 468 mm

(Copper conductor up-to 16 mm2). Sum of total Diameter for LT Power cables = 468 mm. With spare capacity of 10%, size required = 516 mm Recommended tray size for single layer of LT cables: Select from the Standard Cable tray sizes available = 1no. X 600 mm. Cables are touching to each other.

For cable tray drawing refer annexure II (b)

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 4 of 11

SIZING OF CABLE TRAY 4.1.2

Cable tray from LPG-I to New Propane gas compressor shed (New Propane gas Compressor)

LT Cable size

No.

Overall Dia. (mm)

12P x 1.5mm2

2

29.7

2 x 29.7 = 59.4

2

8

21.6

8 x 21.6 = 172.8

2

10C x 2.5mm

3

21

3 x 21 = 63

6C x 2.5mm2

4

15

4 x 15 =60

2

3C x 2.5mm

4

14

4 x 14 = 56

3C x 4 mm2

1

15

1 x 15 = 15

2

12

2 x 12 =24

6P x 1.5 mm

2

2C x 2.5mm

Total length of Tray required (mm)

Total: 436.2 mm (Copper conductor up to 16 mm2). Sum of total Diameter for LT Power cables = 436.2 mm. With spare capacity of 10%, size required = 480 mm Recommended tray size for single layer of LT cables: Select from the Standard Cable tray sizes available = 2no. X 300 mm. Cables are touching to each other.

For cable tray drawing refer annexure II (c)

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 5 of 11

SIZING OF CABLE TRAY 4.1.3

Cable tray from Panel no. 19 in LPG-I to New Propane compressor 6.6kV HT motor

HT Cable size 3c x300mm²

No.

Overall Dia. (mm)

Total Diameter (mm)

1

80.0

1 x 80 = 80.0 Total: 80 mm

Sum of total Diameter for HT Power cables = 80 mm. With spare capacity of 10%, size required = 88 mm Select from the Standard Cable tray sizes available = 1no. X 300 mm.

For cable tray drawing refer annexure II (a)

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 6 of 11

SIZING OF CABLE TRAY 4.2

CABLE TRAY FROM LPG-1 S/S TO LPG-2 S/S 4.2.1

Single core cable

LT Cable size 1C X 300 mm2

No.

Overall Dia. (mm)

12

41

Total length of Tray required (mm) 12 x 41 =492 Total: 492 mm

Sum of total Diameter for HT Power cables = 492 mm. With spare capacity of 10%, size required = 542 mm Select from the Standard Cable tray sizes available = 1no. X 600 mm. Spacing between cables is 80 mm after trefoil connection

For cable tray drawing refer annexure I (a)

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 7 of 11

SIZING OF CABLE TRAY 4.2.2

Control cable (run through 4’’ GI conduit)

LT Cable size 10C X 2.5 mm2

No.

Overall Dia. (mm)

2

21

Total length of Tray required (mm) 2 x 21= 42 Total: 42 mm

LT Cable size 3C X 300 mm2

No.

Overall Dia. (mm)

2

80

Total length of Tray required (mm) 2 x 80= 160 Total: 160 mm

Sum of total diameter for control cables = 42 mm. Sum of total diameter for HT Cables =160 mm. Total diameter of control and power cables is 202 mm (42 + 160). With spare capacity of 10%, size required = 223 mm. Select from the Standard Cable tray sizes available = 1no. X 300 mm

For cable tray drawing refer annexure I (b)

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 8 of 11

SIZING OF CABLE TRAY 5. TRAY SIZING VERIFICATION:

5.1

CABLES FROM LPG-1 S/S TO NEW PROPANE GAS COMPRESSOR

5.1.1 Cable tray from New PMCC to Field Equipment (New Propane gas Compressor)

5.1.1.1 LT Cables laid on 600mm tray are as follows: Run

Core

7 5 1 3 2 1 1

3 4 3 3 3 3.5 3.5

Size - mm2

Overall Diameter (mm)

4 6 70 95 185 35 50

Weight of Cable kg/km 545 X 2.45 740 X 1.45 1350 X 0.35 1655 X 1.05 2835 X 0.7 910 X 0.35 1125 X 0.35

15 16.5 30 33 45 25 28 TOTAL

7316

5.1.1.2 LT Cables laid on 2 NOS. 300 mm tray are as follows Size - mm2

Run

Core

Overall Diameter (mm)

2

12P

1.5

29.7

8

6P

1.5

21.6

740 X 0.78

3

10

2.5

21

665 X 1.05

4 4

6

2.5

15

620 X 1.13

3

2.5

14

435 X 1.07

1

3

4

15

545 X 0.35

2

2

2.5

12

385 X 1.25

TOTAL OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

Weight of Cable kg/km 945 X 0.7

3775

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 9 of 11

SIZING OF CABLE TRAY

5.1.2 Cable tray from Panel no. 19 to New Propane compressor 6.6kV HT motor

HT Cables laid on 1no. 300 mm tray are as follows:

5.2

Run

Core

Size - mm2

Overall Diameter (mm)

Weight of Cable kg/km

1

3

300

80 TOTAL

7140 X 0.35 2499

CABLE TRAY FROM LPG-1 S/S TO LPG-2 S/S

5.2.1 HT Cables laid on 600 mm tray are as follows:

Run

Core

Size - mm2

Overall Diameter (mm)

Weight of Cable kg/km

12

1

300

41

1840 X 3

TOTAL

5520

5.2.2 Control Cables along with HT Cables laid on 300 mm tray are as follows: Run

Core

Size - mm2

2

3

300

80

2

10

2.5

21

665 X 0.5

TOTAL

3903

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

Overall Diameter (mm)

Weight of Cable kg/km 7140 X 0.5

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 10 of 11

SIZING OF CABLE TRAY Conclusion:

Thus the Cable tray size selection meets all the requirements of:a) Spare Capacity (10%) b) Allowable fill area (as per NEC table) c) Cable load (as per Design Philosophy for Electrical Facilities – Cl. no: 7.2.8

OWNER

ONGC LIMITED B 25/11/2011 REV. NO. DATE

PMC

LSTK

ENGINEERS INDIA LIMITED Approval PA PURPOSE PREPARED

SAVAIR ENERGY LIMITED PP MD REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020

Page 11 of 11