Sizing of cable tray rev. D.pdf

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/11 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 1 of 11

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

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 2 of 11

CONTENTS

1. SCOPE

2. BASIS & ASSUMPTIONS

3. CABLE TRAY /LADDER SPECIFICATION

4. TRAY SIZING CALCULATION

5. TRAY SIZING VERIFICATION

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 3 of 11

1. SCOPEThis calculation covers the Sizing of Cable Tray with respect to Cable Data consideration required for allequipment 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 belocated in existing LPG-1 substation. Power supply will be from new PMCC to be located in the LPG-1substation.

2. BASIS & ASSUMPTIONS2.1 Electrical Design Basis for New Propane Compressor (Doc. No. section C2.8 of 6867-00-50-50-

DB-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 ElectricalFacilities’ 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 traydesign 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 7098part-1/1988.

3. CABLE TRAY /LADDER SPECIFICATION3.1 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.

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 4 of 11

4. TRAY SIZING CALCULATION:

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)

(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)

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

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 5 of 11

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

(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)

LT Cable size No. Overall Dia. (mm) Total length of Trayrequired (mm)

12P x 1.5mm2 2 29.7 2 x 29.7 = 59.4

6P x 1.5 mm2 8 21.6 8 x 21.6 = 172.8

10C x 2.5mm2 3 21 3 x 21 = 63

6C x 2.5mm2 4 15 4 x 15 =60

3C x 2.5mm2 4 14 4 x 14 = 56

3C x 4 mm2 1 15 1 x 15 = 15

2C x 2.5mm2 2 12 2 x 12 =24

Total: 436.2 mm

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 6 of 11

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

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)

HT Cable size No. Overall Dia. (mm) Total Diameter (mm)

3c x300mm² 1 80.0 1 x 80 = 80.0

Total: 80 mm

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 7 of 11

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

4.2.1 Single core cable

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)

LT Cable size No. Overall Dia. (mm) Total length of Trayrequired (mm)

1C X 300 mm2 12 41 12 x 41 =492

Total: 492 mm

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 8 of 11

4.2.2 Control cable (run through 4’’ GI conduit)

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)

LT Cable size No. Overall Dia. (mm) Total length of Trayrequired (mm)

10C X 2.5 mm2 2 21 2 x 21= 42

Total: 42 mm

LT Cable size No. Overall Dia. (mm) Total length of Trayrequired (mm)

3C X 300 mm2 2 80 2 x 80= 160

Total: 160 mm

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 9 of 11

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 Size - mm2 Overall Diameter (mm) Weight of Cable -

kg/km7 3 4 15 545 X 2.455 4 6 16.5 740 X 1.451 3 70 30 1350 X 0.353 3 95 33 1655 X 1.052 3 185 45 2835 X 0.71 3.5 35 25 910 X 0.351 3.5 50 28 1125 X 0.35

TOTAL 7316

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

Run Core Size - mm2 Overall Diameter (mm) Weight of Cable -kg/km

2 12P 1.5 29.7 945 X 0.78 6P 1.5 21.6 740 X 0.783 10 2.5 21 665 X 1.05

4 6 2.5 15 620 X 1.134 3 2.5 14 435 X 1.071 3 4 15 545 X 0.352 2 2.5 12 385 X 1.25

TOTAL 3775

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 10 of 11

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:

Run Core Size - mm2 Overall Diameter (mm) Weight of Cable -kg/km

1 3 300 80 7140 X 0.35TOTAL 2499

5.2 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 Overall Diameter (mm) Weight of Cable -kg/km

2 3 300 80 7140 X 0.52 10 2.5 21 665 X 0.5

TOTAL 3903

SIZING OF CABLE TRAY

OWNER PMC LSTK

ONGC LIMITED ENGINEERS INDIA LIMITED SAVAIR ENERGY LIMITEDB 25/11/2011 Approval PA PP MD

REV. NO. DATE PURPOSE PREPARED REVIEWED BY APPROVED BY

DOCUMENT NO: 6972-010-50-50-CAL-0020 Page 11 of 11

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