ct sizing calculation of 11kv system-rev0-ver3

THIS SUBMISSION IS DECLARED TO BE STRICTLY IN

ACCORDANCE WITH THE REQUIREMENTS OF THE CONTRACT

SIGNATURE

QATAR POWER TRANSMISSION SYSTEM EXPANSION

PHASE VII (Substations)

CONTRACT NO. GTC/123/2006

SIEMENS CONSORTIUM-GTC/123/2006

SIEMENS AG SIEMENS LIMITED GERMANY INDIA

SUBSTATION NAME / CIRCUIT NAME

Mosemeer, Abu Hamour central, Al Soudan, Ain Khalid South, Al Wadi, MIC-2, MIC-3,QRE,EDS,Khore Community, Al Dhahiya West, Al Jumailyah, Khore Junction, NDQ, Muraikh North, South West Wakrah-1, NBK-2, Abu Thaila Modification, RLF-3, Al Dhahiya, Al Waab Super, MIC Super, Wakrah-2, Lusail Development Super-1,Ain Hamad, Ain Khalid south.

PROJECT DRAWING NUMBER

PH7-3B-10-15-C001

SUBCONTRACTOR / SUPPLIER

0 29-11-2007 FIRST ISSUE R.K. V.H V.A. REV DATE MODIFICATION DRAWN CHECK APPRD

SCALE SIZE DRAWING/DOCUMENT DESCRIPTION DESIGN REPORT FOR CURRENT TRANSFORMER (CT) & VOLTAGE TRANSFORMER (VT) SIZING FOR 11kV SYSTEM

N.A.

A4

TOTAL NO. OF PAGES VER

SIEMENS

Document No.:- GTC123-BN00-AQA-10001

3

91 PAGES

SIEMENS PROJECT:GTC/123/2006 Index

S.No. DESCRIPTION PAGE NUMBER

1 PURPOSE 1

2 DESIGN INPUT 1

3 ASSUMPTIONS 1

4 DESIGN CRITERIA 2

5 CALCULATIONS 2

6 RESULT OF STUDY 3

7 ATTACHMENTS 3

ANNEXURE 1 6-80

ANNEXURE 2 81-82

ANNEXURE 3 83

ANNEXURE 4 84-90

ANNEXURE 5 91

PH7-3B-10-15-C001, Rev 0 of 91

SIEMENS PROJECT:GTC/123/2006 1.0 PURPOSE:

This document is intended to establish the minimum sizes of

- Current transformer in terms of Knee point voltage & Rated burden

- Voltage transformer in terms of Rated burden for various feeders

of 11KV for the following mentioned substations:

Mosemeer

Abu Hamour Central

Al Soudan

Al Wadi

Al Jumailyah

Khore Junction

MIC -2

MIC -3

QRE

EDS

Khore Community

Al Dhahiya West

Muraikah North

South West Wakrah 1

NDQ

NBK -2

RLF-3

MIC Super

Al Dhahiya

Al Waab Super

Lusail Development Super 1

Wakrah 2

Abu Thaila substation modification

Ain Hamad

Ain Khalid south

2.0 DESIGN INPUT : 1. Project contract document

2. Relay catalogue for relay burden

PH7-3B-10-15-C001, Rev 0 of 91

SIEMENS PROJECT:GTC/123/2006

3.0 ASSUMPTIONS : 1. Power Transformer 32/40MVA, 66/11kV, %age impedance at principal

tapping is assumed as 16.33%.

2. Power Transformer 20/25MVA, 66/11kV, %age impedance at principal tapping is assumed as 12.58%..

3. Power Transformer 7.5/10MVA, 33/11kV, %age impedance at principal tapping is assumed as 12%.

4. Power Transformer 25/30MVA, 33/11kV, %age impedance at principal tapping is assumed as 12.58%.

5. 500kVA, 11/0.415kV Earthing Transformer, %age impedance at principal tapping is assumed as 9.60%

6. 1000kVA, 11/0.415kV Earthing Transformer, %age impedance at principal tapping is assumed as 6.00 %

7. 2000kVA, 11/0.415kV Earthing Transformer, %age impedance at principal tapping is assumed as 12.0%

4.0 DESIGN CRITERIA: KNEE POINT VOLTAGE

Apart from rated short time rating of the system, to arrive at minimum knee point voltage, value for steady state through fault current values needs to be determined.

Considering the rated capacity of the bus bars of 11kV, the fault level considered is 31.5kA.

PARAMETERS FOR CABLE BETWEEN CT & RELAY PANEL

Cross section taken is 4 mm2.

Calculation for resistance at 75 deg. C:

Resistance at 20 deg. C = 4.61 ohms / Km Value of Alpha (Temp. coefficient) at 20 deg. C for copper = 0,00393 / deg. C Resistance at 75 deg. C = 4.61 (1 + 0.00393 (75-20)) = 5.61 ohms / kM

Calculation of Loop resistance of the cable between CT & Relay panel:

Taking length of cable between CT & Relay panel as 50 meter Loop resistance = 2 x Length of cable (in kM) X resistance at 75 deg. C (in ohms/kM)

= (2 x 70 x 5.61) / 1000 = 0.785 ohms

Considering 20% safety margin as per contract requirement, (clause 12), = 0.785 * 1.2 = 0.942 ohms

All CT sizing calculations, have been done for a cable length of 50mts. This is the maximum length possible.

PH7-3B-10-15-C001, Rev 0 of 91

SIEMENS PROJECT:GTC/123/2006

RATED BURDEN Rated burden selected for a CT/VT shall be more than the sum of relay/metering burden connected across CT/VT.

5.0 CALCULATIONS: Calculations performed for the CT/VT parameters are enclosed in following annexure:

Annexure # 1: CT Knee point voltage calculations for the 11kV feeders

Annexure # 2: CT burden (in VA) calculations for the 11kV feeders

Annexure # 3: VT burden (in VA) calculations for 11kV the feeders

6.0 RESULT OF STUDY:

Calculation results show that selected parameters for CT/VT are adequate to meet the minimum requirements.

7.0 ATTACHMENTS:

1. Annexure # 1: CT Knee point voltage calculations for 11kV feeders

2. Annexure # 2: CT burden (in VA) calculations for 11kV feeders

3. Annexure # 3: VT burden (in VA) calculations for 11kV feeders

4. Annexure # 4: Relay back-up sheets

5. Annexure #5: LSOH Power Cable Data Sheet

PH7-3B-10-15-C001, Rev 0 of 91

SIEMENS PROJECT:GTC/123/2006ANNEXURE 1

Configuration

Core-1Core-1 Core-2 750/1

66/11KV 50/1 50/1 Class-PX32/40MVA Class-PX Class-5P20 Vk≥250ONAN/ONAF Vk≥100 15VA 11/0.415KV Rct≤6

Rct≤1.2 500KVA Io<25maIo<30ma at Vk 15VA

Core-1750/1

Core-4 Class-5P202500/1 15VAClass-PXVk≥250 Core-2Rct≤9 50/1Io<30ma Class-PX

Vk≥100Rct≤1.2

Core-3 Io<30ma 2500/1Class-PX Core-3Vk≥250 2500/1Rct≤9 Class-PXIo<30ma

Rct≤9Core-2 Io<30ma 2500/1 Class-5P20/1.0Rct≤810VA

Core-12500/1Class-PXVk≥250Rct≤9Io<30ma

Note: - 40 MVA LV side Core-4 is not applicable for NDQ, Muraikh North, South West Wakrah-1, NBK-2

Current Transformer Ration (CTR) = 2500 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on Cable resistance = 5.61x1.2 Ohms/Km

= 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.00

CT knee point voltage calculation for 7SJ61 relay for 11kV Incomer Feeders =A18,=A28 (connected across core-1 )

(Relay will be mounted in Relay panel)

Applicable substations:Mosemeer,Abu Hamour central,Al Wadi,MIC-2,MIC-3,QRE,Khore Community,Al Dhahiya West, NBK-2, Al Soudan, Ain Khalid south

40MVA, 66/11kV transformer,Earthing/auxiliary transformer rating of 500kVA

Vk≥250

Incomer Feeder (Typical bay no: A18,A28) Type:1

66kV side

To partial busbar differential protection(7SJ61)

To Directional Overcurrent & earth fault / Metering(6MD6 & 7SJ62)

To Transformer REF (11kV side) & Main differential protection(7SJ61 & 7UT613)

11kV Bus Feeder =A18, =A28

To Back-up earth fault(7SJ61)

To REF protection for Earthing transformer(7SJ61)

To REF protection for 11kV side(7SJ61)

Cable and trafo differential protection(7SD52)

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used

The required K'SSC = I High set point = 20 atleast IN

Relay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA

b) Knee point voltage :The calculated value of knee point voltage is

=

1.3 x Ipn

Knee Point voltage required =

= 154.49 volts

20% margin on Vk value = 185.39

(For determining the Voltage developed across CT, a current of 1.5 times of the maximum possible throughfault current has been considered)Vk > 2 x 1.5 x If x (Rct + 2RL )

%age impedance at 40 MVA = 0.1633Taking a negative tolerance of 15% = 0.1388

If =

If = 15.1262 kA

Vk >

> 180.46 volts

To establish that CT rated knee point volatge is atleast 2 times that voltage developed across the CT in case of through fault condition with one of the CT saturated, the formula used is :

Considering infinite source,the maximum through fault current on 40 MVA transformer would be:

401.732 x 11 x 0.1388

Ihigh set point x I2N x (Ri+RBC)

The minimum CT knee point Voltage shall be selected more than above

1.320 x (9+1.042) x 1

Where If is magnitude of through fault current

Stability check for REF protection for through fault condition


1.5x15126.2x(9+0.942 )x22500

a) Effective symmetrical short-circuit current factor (K' SSC):

I2N = Relay Normal Current

Value 20 will be selected for calculations

RBC = Connected Burden across CT in VARi = Internal CT burden in VA

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used

For transformer, ktd = 3

The required K'SSC = I SCC x ktd

IPN

Where:

%age impedance at 40 MVA = 0.1633Taking negative tolerance of 15% = 0.1388

ISSC =

ISSC = 15.1262 kA

K'SSC = 15126.2 x 32500

K'SSC to be considered for calculations = 18.15

Where


c) Knee point voltage :The calculated value of knee point voltage is

=

Knee Point voltage required =1.3

Knee Point voltage required = 140.20 volts20% margin on Vk value = 168.24 volts

ISSC = symmetrical short-circuit current

a) Transient dimensioning factor (ktd):

CT Knee point voltage calculation for 7UT613 relay for 11kV Incomer Feeders =A18,=A28 (connected across core-1 )


1.732 x 11 x 0.1388

IPN = CT rated primary current


(1.042 + 9) x 1 x 18.15

40

b) Effective symmetrical short-circuit current factor (K' SSC):

ISN = CT rated secondary current

(RBC+ Ri ) X ISN X K'SSC

1.3

Considering infinite source at 11 kV ,the maximum through fault current on 40 MVA transformer would be:

PH7-3B-10-15-C001, Rev 0 of 91


The required K'SSC = 20 atleast

Also K'SSC =

Where

Ri = Internal CT burden in VA = 8.0 VARBN = Nominal Burden of CT in VA = 10 VARelay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) = 1.042 VA

K'SSC =(1.042+8)

Calculated Value for K'SSC = 39.81 > 20

(10+8) x20

RBC = Connected Burden across CT in VA

Since the selected K'SSC is more than Minimum required K'SSC (20), Hence selected CT is OK

Adequacy checking calculations for 7SJ62 and 6MD6 relay for 11kV Incomer Feeders =A18,=A28 (connected across core-2 )


RBN+ Ri x KSSC

RBC + Ri

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Used



b) Knee point voltage :

The calculated value of knee point voltage is

=1.3 x Ipn

Knee Point voltage required = 20 x (1.042+9) x 11.3

= 154.49 volts20% margin on Vk value = 185.39 volts

Ri = Internal CT burden in VAI2N = Relay Normal Current






Feeders =A18,=A28 (connected across core-3 )CT Knee point voltage calculation for 7SJ61 type used for Partial Bus bar protection

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000

For line differential protection ktd = 1.20


IPN

Where:


ISSC = 40

ISSC = 15.1262 kA

K'SSC = 15126.2x1.22500

K'SSC to be considered for calculations = 7.26Where

Relay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VAc) Knee point voltage :


=

Knee Point voltage required = (1.042+9) x1x7.261.3

Knee Point voltage required = 56.08 volts20% margin on Vk value = 67.30



1.3


Ri = Internal CT burden in VA

Considering infinite source at 11kV, the maximum through fault current on 40 MVA trafo would be :

IPN = CT rated primary currentISSC = symmetrical short-circuit current

Formula Used


1.732 x 11 x 0.1388


a) Transformer dimensioning factor (k td):


CT Knee point voltage calculation for 7SD5 relay for 11kV incoming feeders =A18, =A28(connected across Core-4)

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 5.61x1.2

= 6.732 Ohms/Km

Loop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.00

Formula Used



b) Knee point voltage :The calculated value of knee point =

1.3 x Ipn


= 154.49 volts20% margin on Vk value = 185.39



If =

If = 15.1262 kA

Vk >

> 180.46 volts





1.732 x 11 x 0.138840


20 x (9+1.042) x 1


25001.5x15126.2x(9+0.942 )x2


(As per contract document)






CT calculation for 7SJ61 relay for 11kV Incomer Feeders =A18,=A28 (connected across 11kV Neutral side CTs of 500KVA)

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 50 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732Loop Resistance ( 2RL ) = 0.942 Ohms

Loop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 1.20 OhmsCT Internal Burden in VA = (I)² x 1.2 = 1.2

Formula Used


Where


b) Knee point voltage :The calculated value of knee point = 1.3 x Ipn


= 34.49 volts20% margin on vk value = 41.39

Vk > 1.5(If x (Rct + 2RL ) x 2)

= 0.0960 = 0.0816

If =

If = 321.6172 A

Vk >

> 96.39 volts

50

As the through fault current could be ground fault current which can be max 750A, the stablility is being checked for this max value.

1.5 x 750 x (1.2 + 0.942 ) x 2


%age impedance at 500 KVAOverall Impedance ( taking 15% negative tolerance)

5001.732 x 11 x 0.0816


1.2 x (1.2+1.042) x 1

Considering infinite source,the maximum through fault current on 500 KVA transformer would be:





CT calculation for 7SJ61 type used for REF protection of 11kV side of Earthing transformer (Applicable for Phase and Neutral side CTs)





PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 750 amp.Relay Normal Current (IN) = 1 amp.


Also K'SSC =

Where

Ri = Internal CT burden in VA = 6.0 VARBN = Nominal Burden of CT in VA = 15 VARelay Burden = 0.05 = 0.050 VARBC = (Loop Burden+ Relay Burden) = 0.992 VA

K'SSC =6+0.992


CT calculation for 7SJ61 type used for REF protection of 11kV side of Earthing transformer (Applicable for 500 KVA HV Neutral side CTs)



RBN+ Ri x KSSC

RBC + Ri


(15+6) x20

PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =1.2+0.992


Adequecy check for 7SJ61 type used for O/C protection of 11kV side of Earthing transformer


RBN+ Ri x KSSC

RBC + Ri


(15+1.2) x20


PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 750 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 Ohms

Loop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 6.00 OhmsCT Internal Burden in VA = (I)² x 6 = 6.000Formula Used


Where






= 0.0960 = 0.0816

If =

If = 8.5248 kA

Vk >

> 236.72 volts

CT Knee point voltage calculation for 7SJ61 type used for REF protection of 433 V side of Earthing transformer (Applicable for Neutral side CTs)

5001.732 x 0.415 x 0.0816

1.5x8524.8x(6+0.942 )x2

Overall Impedance ( taking 15% negative tolerance)%age impedance at 500 KVA





20 x (6+1.042) x 1

Considering infinite source, the maximum through fault current on 500 KVA transformer would be:








750

PH7-3B-10-15-C001, Rev 0 of 91


Configuration


66/11KV 50/1 50/1 Class-PX20/25MVA Class-PX Class-5P20 Vk≥250ONAN/ONAF Vk≥100 15VA 11/0.415KV Rct≤6

Rct≤1.2 500KVA Io<25maIo<30ma at Vk 15VA

Core-1750/1

Core-4 Class-5P202500/1 15VAClass-PXVk≥250 Core-2Rct≤9 50/1Io<30ma Class-PX

Vk≥100Rct≤1.2






Vk≥250




Applicable substations:Al Jumailyah, Khore Junction


66kV side








Cable and trafo differential protection(7SD52)

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used




=

1.3 x Ipn


= 154.49 volts




If =

If = 12.2750 kA

Vk >

> 146.45 volts






20 x (9+1.042) x 11.3






251.732 x 11 x 0.1069

1.5x12275x(9+0.942 )x22500


PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 12.2750 kA

K'SSC = 12275 x 32500


Where



=






ISSC = symmetrical short-circuit currentIPN = CT rated primary currentISN = CT rated secondary current


251.732 x 11 x 0.1069



1.3

(1.042 + 9) x 1 x 14.73


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


K'SSC =(1.042+8)




RBN+ Ri x KSSC

RBC + Ri


(10+8) x20


PH7-3B-10-15-C001, Rev 0 of 91














CT Knee point voltage calculation for 7SJ61 type used for Partial Bus bar protection Feeders =A18,=A28 (connected across core-3 )

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000

For line differential protection ktd = 1.20


IPN

Where:


ISSC = 25

ISSC = 12.2750 kA

K'SSC = 12275x1.22500

K'SSC to be considered for calculations = 5.89Where

Relay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VAc) Knee point voltage :


=

Knee Point voltage required = (1.042+9) x1x5.891.3

Knee Point voltage required = 45.50 volts20% margin on Vk value = 54.60


Formula Useda) Transformer dimensioning factor (k td):


CT Knee point voltage calculation for 7SD5 relay for 11kV incoming feeders =A18, =A28(connected across Core-4)


1.3


1.732 x 11 x 0.1069



Considering infinite source at 11kV, the maximum through fault current on 25 MVA trafo would be :

PH7-3B-10-15-C001, Rev 0 of 91



= 6.732 Ohms/Km


Formula Used




1.3 x Ipn





If =

If = 12.2750 kA

Vk >

> 146.45 volts






RBC = Connected Burden across CT in VARi = Internal CT burden in VAI2N = Relay Normal Current


20 x (9+1.042) x 1


Stability check for REF protection for through fault conditionTo establish that CT rated knee point volatge is atleast 2 times that voltage developed across the CT in case of through fault condition with one of the CT saturated, the formula used is :



251.732 x 11 x 0.1069

1.5x12275x(9+0.942 )x22500


PH7-3B-10-15-C001, Rev 0 of 91




Formula Used


Where





Vk > If x (Rct + 2RL ) x 2

= 0.0960 = 0.0816

If =

If = 321.6172 A

Vk >

> 64.26 volts







1.2 x (1.2+1.042) x 1






500

50


1.732 x 11 x 0.0816


750 x (1.2 + 0.942 ) x 2

PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =6+0.992


Adequecy check for 7SJ61 type used for REF protection of 11kV side of Earthing transformer (Applicable for 500 KVA HV Neutral side CTs)


RBN+ Ri x KSSC

RBC + Ri


(15+6) x20


PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =1.2+0.992


(15+1.2) x20




RBN+ Ri x KSSC

RBC + Ri


PH7-3B-10-15-C001, Rev 0 of 91



Loop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 6.00 OhmsCT Internal Burden in VA = (I)² x 6 = 6.000Formula Used


Where






= 0.0960 = 0.0816

If =

If = 8.5248 kA

Vk >

> 236.72 volts







20 x (6+1.042) x 1


%age impedance at 500 KVA




750

Overall Impedance ( taking 15% negative tolerance)

5001.732 x 0.415 x 0.0816

1.5x8524.8x(6+0.942 )x2



PH7-3B-10-15-C001, Rev 0 of 91


Configuration


66/11KV 100/1 100/1 Class-PX32/40MVA Class-5P20 Class-PX Vk≥500ONAN/ONAF 15VA Vk≥100 11/0.415KV Rct≤7.5

Rct≤0.4 1000KVA Io<25maIo<30ma at Vk/2

Core-3400/1 Core-1

Class-PX 750/1Vk≥250 Class-5P20

Rct≤9 15VAIo<30ma at Vk

Core-2100/1Class-PXVk≥100Rct≤0.4

Core-3 Io<30ma at Vk/2

2500/1Class-PX Core-3Vk≥250 2500/1Rct≤9 Class-PXIo<30ma






Applicable substations : NDQ, Murraikh North, South west wakrah,Lusail Development Super 1


Vk≥250



66kV side








PH7-3B-10-15-C001, Rev 0 of 91


Formula Used




=

1.3 x Ipn


= 154.49 volts




If =

If = 15.1262 kA

Vk >

> 180.46 volts





1.5x15126.2x(9+0.942 )x22500




1.320 x (9+1.042) x 1





401.732 x 11 x 0.1388

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 15.1262 kA

K'SSC = 15126.2 x 32500


Where



=





1.3





(1.042 + 9) x 1 x 18.15

1.732 x 11 x 0.1388

IPN = CT rated primary currentISSC = symmetrical short-circuit current



40


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


K'SSC =(1.042+8)




RBN+ Ri x KSSC

RBC + Ri


(10+8) x20


PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meter#REF! = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Used



b) Knee point voltage :


=1.3 x Ipn



CT Knee point voltage calculation for 7SJ61 type used for Partial Bus bar protection






Feeders =A18,=A28 (connected across core-3 )


PH7-3B-10-15-C001, Rev 0 of 91



= 6.732 Ohms/Km

Loop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 Ohms

CT Internal Burden in VA = (I)² x 9 = 9.00

Formula Used




1.3 x Ipn





If =

If = 15.1262 kA

Vk >

> 180.46 volts












25001.5x15126.2x(9+0.942 )x2



1.732 x 11 x 0.138840


20 x (9+1.042) x 1

PH7-3B-10-15-C001, Rev 0 of 91




Formula Used


Where





Vk > 1.5(If x (Rct + 2RL ) x 2)

= 0.0600 = 0.0510

If =

If = 1029.1751 A

Vk >

> 30.20 volts








20 x (0.4+1.042) x 1





1.5 x 750 x (0.4 + 0.942 ) x 2


100


10001.732 x 11 x 0.051


PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =6+0.992




(15+6) x20


RBN+ Ri x KSSC

RBC + Ri

(Applicable for 1000 KVA HV Neutral side CTs)Adequacy check for 7SJ61 type used for REF protection of 11kV side of Earthing transformer

PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =1.2+0.992



RBN+ Ri x KSSC

RBC + Ri


(15+1.2) x20



PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPNWhere:


ISSC =

ISSC = 1.0292 kA

K'SSC =400

= 7.72K'SSC to be considered for calculations = 7.72

Where



=




1

(1.042 + 9) x 1 x 7.72

1.732 x 11 x 0.051

1029.17505444336 x 3








1.3


CT Knee point voltage calculation for 7UT613 relay for 11kV Incomer Feeders to 1000 KVA EAT-(connected across core-3 )


PH7-3B-10-15-C001, Rev 0 of 91



Loop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 7.50 OhmsCT Internal Burden in VA = (I)² x 7.5 = 7.500Formula Used


Where






= 0.0600 = 0.0510

If =

If = 27.2793 kA

Vk >

> 460.58 volts

1500









20 x (7.5+1.042) x 1



Overall Impedance ( taking 15% negative tolerance)%age impedance at 1000 KVA


10001.732 x 0.415 x 0.051

1.5x27279.3x(7.5+0.942 )x2


PH7-3B-10-15-C001, Rev 0 of 91


Configuration


66/11KV 100/1 400/1 Class-PX20/25MVA Class-5P20 Class-PX Vk≥500ONAN/ONAF 15VA Vk≥250 11/0.415KV Rct≤7.5

Rct≤9 1000KVA Io<25maIo<30ma

Core-1 Core-1100/1 750/1

Class-PX Class-5P20Vk≥100 15VARct≤0.4

Io<30ma Core-2100/1Class-PXVk≥100Rct≤0.4







Applicable substations:Abu Thaila Substation Modification


Vk≥250



66kV side








PH7-3B-10-15-C001, Rev 0 of 91


Formula Used




=

1.3 x Ipn


= 154.49 volts




If =

If = 12.2750 kA

Vk >

> 146.45 volts

2500


251.732 x 11 x 0.1069

1.5x12275x(9+0.942 )x2




1.3





20 x (9+1.042) x 1




PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 12.2750 kA

K'SSC = 12275 x 32500


Where



=



(1.042 + 9) x 1 x 14.73




1.3



251.732 x 11 x 0.1069



ISSC = symmetrical short-circuit currentIPN = CT rated primary current


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


K'SSC =(1.042+8)


(10+8) x20



RBN+ Ri x KSSC

RBC + Ri



PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meter#REF! = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Used






Feeders =A18,=A28 (connected across core-3 )


CT Knee point voltage calculation for 7SJ61 type used for Partial Bus bar protection





PH7-3B-10-15-C001, Rev 0 of 91



= 6.732 Ohms/Km


Formula Used




1.3 x Ipn





If =

If = 12.2750 kA

Vk >

> 146.45 volts


1.732 x 11 x 0.1069

1.5x12275x(9+0.942 )x22500



25





20 x (9+1.042) x 1







PH7-3B-10-15-C001, Rev 0 of 91




Formula Used


Where





Vk > If x (Rct + 2RL ) x 2

= 0.0600 = 0.0510

If =

If = 1029.1751 A

Vk >

> 20.13 volts


1.732 x 11 x 0.051





750 x (0.4 + 0.942 ) x 2


1000

100




0.4 x (0.4+1.042) x 1







PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =6+0.992



RBN+ Ri x KSSC

RBC + Ri


(15+6) x20


Adequecy check for 7SJ61 type used for REF protection of 11kV side of Earthing transformer (Applicable for 1000 KVA HV Neutral side CTs)

PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =1.2+0.992






RBN+ Ri x KSSC

RBC + Ri

(15+1.2) x20

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPNWhere:


ISSC =

ISSC = 1.0292 kA

K'SSC =400


Where


c) Knee point voltage :The calculated value of knee point =



1029.17505444336 x 3





(1.042 + 9) x 1 x 7.72



11.732 x 11 x 0.051






PH7-3B-10-15-C001, Rev 0 of 91



Loop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 7.50 OhmsCT Internal Burden in VA = (I)² x 7.5 = 7.500Formula Used


Where






= 0.0600 = 0.0510

If =

If = 27.2793 kA

Vk >

> 460.58 volts


1.732 x 0.415 x 0.051

1.5x27279.3x(7.5+0.942 )x21500



1000






20 x (7.5+1.042) x 1






PH7-3B-10-15-C001, Rev 0 of 91


Configuration


66/11KV 200/1 400/1 Class-PX32/40MVA Class-5P20 Class-PX Vk≥450ONAN/ONAF 15VA Vk≥100 11/0.415KV Rct≤15

Rct≤9 2000KVA Io<25maIo<30ma at Vk/2

Core-1200/1 Core-1

Class-PX 750/1Vk≥100 Class-5P20Rct≤0.6 15VA

Io<30ma at Vk/2Core-2200/1Class-PXVk≥100Rct≤0.6








Applicable substations:MIC Super , Al Dhahiya,Al Waab Super, Wakrah 2, EDS


Vk≥250


66kV side








PH7-3B-10-15-C001, Rev 0 of 91


Formula Used




=

1.3 x Ipn


= 154.49 volts




If =

If = 15.1262 kA

Vk >

> 180.46 volts





20 x (9+1.042) x 1


1.3






401.732 x 11 x 0.1388

1.5x15126.2x(9+0.942 )x22500


PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 15.1262 kA

K'SSC = 15126.2 x 32500


Where



=








401.732 x 11 x 0.1388



1.3

(1.042 + 9) x 1 x 18.15


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


K'SSC =(1.042+8)




RBN+ Ri x KSSC

RBC + Ri


(10+8) x20


PH7-3B-10-15-C001, Rev 0 of 91















PH7-3B-10-15-C001, Rev 0 of 91



= 6.732 Ohms/Km


Formula Used




1.3 x Ipn





If =

If = 15.1262 kA

Vk >

> 180.46 volts








20 x (9+1.042) x 1





401.732 x 11 x 0.1388

1.5x15126.2x(9+0.942 )x22500


PH7-3B-10-15-C001, Rev 0 of 91




Formula Used


Where





Vk >1.5( If x (Rct + 2RL ) x 2)

= 0.1200 = 0.1020

If =

If = 1029.1751 A

Vk >

> 17.34 volts







20 x (0.6+1.042) x 1






20001.732 x 11 x 0.102


750 x (0.6 +, 0.942 ) x 2x1.5200


PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =Where


K'SSC =6+0.992


(15+6) x20



Adequacy check for 7SJ61 type used for REF protection of 11kV side of Earthing transformer (Applicable for 2000 KVA HV Neutral side CTs)


RBN+ Ri x KSSC

PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =Where


K'SSC =1.2+0.992




(15+1.2) x20



RBN+ Ri x KSSC

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 1.0292 kA

K'SSC =400


Where



=







Considering infinite source at 11 kV ,the maximum through fault 40 current on 2 MVA transformer would be:

21.732 x 11 x 0.102


1029.17505444336 x 3



1.3

(1.042 + 9) x 1 x 7.72


PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 3000 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 15.00 OhmsCT Internal Burden in VA = (I)² x 15 = 15.000Formula Used


Where






= 0.1200 = 0.1020

If =

If = 27.2793 kA

Vk >

> 434.89 volts







20 x (15+1.042) x 1







3000


1.5x27279.3x(15+0.942 )x2


20001.732 x 0.415 x 0.102

PH7-3B-10-15-C001, Rev 0 of 91


Configuration:

33 KV SIDE Core-2 Core-1750/1 600-300/1Class - 5P20 Class - PX15 VA Vk≥ -

33/11 KV Rct≤9 - 4.57.5/10MVA Io=30mA at Vk/2ONAN/ONAF

Core-3800/1Class - PXVk≥250Rct≤9Io=30mA at Vk/2

Core-2600-300/1Class - 5P20/1.020 - 10 VA

Core-1600-300/1Class - PXVk≥600 - 300 Rct≤9 - 4.5

Io=30mA at Vk/2

Current Transformer Ration (CTR) = 600 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meter#REF! = 5.610 Ohms/Km20% margin on Cable resistance = 5.61x1.2 Ohms/Km




10MVA, 33/11kV transformer

Applicable substations:Ain Hamad


Partial Bus Bar protection(7SJ61)




11kV side REF Protection(7SJ61)

Backup earth fault(7SJ61)

8.47ohm750A, 30sNER

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used


Relay Burden = 2*0.05 = 0.1 VARBC = (Loop Burden+ Relay Burden) = (0.942 + 0.1) 1.042 VA


=

1.3 x Ipn


= 154.49 volts 85.26 volts

20% margin on Vk value = 185.39 102.31



If =

If = 5.146 kA

Ratio 600/1 Ratio 300/1

Vk > 1.5 x 5146 x (9 + 0.942 ) x 2 1.5 x 5146 x (4.5 + 0.942 ) x 2600 300

> 255.81 volts 280.05 volts




20 x (9 + 1.042) x 11.3





Ratio 600/1 Ratio 300/120 x (4.5 + 1.042) x 1


101.732 x 11 x 0.102





PH7-3B-10-15-C001, Rev 0 of 91


Formula Used

For transformer, ktd = 3.00


IPN

Where:


ISSC =

ISSC = 5.146 kA


K'SSC = 5146 x 3 5146 x 3600 300

K'SSC to be considered for calculations = 25.73 51.46

Where



=

Ratio 600/1

Knee Point voltage required = (1.042 + 9) x 1 x 25.73 (1.042 + 4.5) x 1 x 51.461.3 1.3

Knee Point voltage required = 198.75 volts 219.38 volts20% margin on Vk value = 238.51 volts 263.25 volts



CT knee point voltage calculation for 7UT613 relay for 11kV Incomer Feeders =A18,=A28 (connected across core-1 )



10.001.732 x 11 x 0.102



1.3

Ratio 300/1


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


Ratio 600/1 Ratio 300/1K'SSC = (20 + 8) x 20 (10 + 4) x 20

(1.042 + 8) (1.042 + 4)

Calculated Value for K'SSC = 61.93 55.53

> 20 20

RBN = Nominal Burden of CT in VA





RBN+ Ri x KSSC

RBC + Ri

PH7-3B-10-15-C001, Rev 0 of 91














PH7-3B-10-15-C001, Rev 0 of 91


Formula Used

The required K'SSC = I High set point = 20 IN atleast

Relay Burden =0.05VA 0.05 VARBC = (Loop Burden+ Relay Burden) = (0.942 + 0.05) 0.992 VA


Knee Point voltage required = (0.992 + 9) x 1 x 20 (0.992 + 4.5) x 1 x 201.3 1.3

Knee Point voltage required = 153.72 84.4920% margin on Vk value = 184.47 101.39(As per contract document)



If =

If = 5.146 kA


Vk >600 300

> 255.81 280.05


CT Knee point voltage calculation for REF protection with 7SJ61 relay (connected across LV neutral core-1)







101.732 x 11 x 0.102

1.5 x 5146 x (9 + 0.942 ) x 2 1.5 x 5146 x (4.5 + 0.942 ) x 2



PH7-3B-10-15-C001, Rev 0 of 91




Also K'SSC =

Where


K'SSC =

2.2+0.992



RBN+ Ri x KSSC

RBC + Ri


(15+2.2) x20

Adequecy check for 7SJ61 type used for O/C protection of 11kV side of Earthing transformer -Core-2


PH7-3B-10-15-C001, Rev 0 of 91


Configuration

33/11KV25/30MVAONAN/ONAF

Core-175/1

Class-PXVk≥250Rct≤0.4

Io<30ma at Vk


Core-22500/1Class-5P20/1.0Rct≤810VA

Core-12500/1Class-PXVk≥ 250Rct≤9Io<30ma




Applicable substations:RLF-3




33kV side



To Transformer Main differential protection( 7UT613)


NER

PH7-3B-10-15-C001, Rev 0 of 91


Formula Used




=

1.3 x Ipn


= 154.49 volts




If =

If = 14.7300 kA

Vk >

> 175.73 volts

a) Effective symmetrical short-circuit current factor (K'SSC):





20 x (9+1.042) x 11.3






301.732 x 11 x 0.1069

1.5x14730x(9+0.942 )x22500


PH7-3B-10-15-C001, Rev 0 of 91


Formula Used



IPN

Where:


ISSC =

ISSC = 14.7300 kA

K'SSC = 14730 x 32500


Where



=





b) Effective symmetrical short-circuit current factor (K'SSC):



301.732 x 11 x 0.1069



1.3

(1.042 + 9) x 1 x 17.68


PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


K'SSC =(1.042+8)



a) Effective symmetrical short-circuit current factor (K'SSC):

RBN+ Ri x KSSC

RBC + Ri


(10+8) x20


PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 2500Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meter (Relay will be Cable Resistance for mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Useda) Effective symmetrical short-circuit The required K'SSC = I High set point = 20 atleast

IN

RBC = Connected Burden across CT in Ri = Internal CT burden in VAI2N = Relay Normal CurrentRelay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA

b) Knee point voltage : Ihigh set point x I2N x The calculated value of knee point = 1.3 x Ipn



The minimum CT knee point Voltage


PH7-3B-10-15-C001, Rev 0 of 91


Core-1400-300/1Class-PXVk≥250-300Rct≤1.75-1.25Io<30ma

Core-2400-300/1Class-5P20/1.0Rct≤3-2VA Burden -10 VA

Current Transformer Ration (CTR) = 300 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 5.61 x 1.2

= 6.732 Ohms/KmLoop Resistance (2RL ) = 0.942 Ohms

Loop burden in VA; (I)2 x 2RL = 0.942 VACurrent Transformer resistance (Rct) = 1.25 Ohms

Short time rating of 11kV system (I sc) = 31.50 kA

Formula UsedKnee point voltage requirement Vk >

If = Primary current under maximum steady state through fault cnditions.

RL = Lead resistance of single lead from relay to current transformerRct = Secondary resistance Lead resistance of single lead from relay to current transformer If = Maximum through fault current = 50 x In 50Guard relay burden per element (RG) = 0.05 ohm

Knee point voltage requirement Vk >

Required parameters for CTs Ratio 300/1 Ratio 400/1

> 50/1+50/1 x (1.25+0.942+2x0.05) 50/1+50/1 x (1.75+0.942+2x0.05)

> 164.60 189.60

20% margin on Vk value > 197.52 227.52

Outgoing Feeder (Typical bay no: A10,A20) Type:1

Applicable substations:All substations with 11kV switchgear except Ain Hamad

CT Knee point voltage calculation for SOLKOR type relay used for Pilot wire protection Applicable for 11kV Outgoing Feeders


50 / In + If / In * (Rct + 2Rl)Where:In = Rated current, amps. = 1A

N = CT ratio = 400-300/1A

50 / In + If / In * (Rct + 2R L + 2RG)


11kV Bus

To Feeder Overcurrent & earth fault protection / metering(7SJ61 + 6MD6)

To Pilot wire differential, Cable overload protection(SOLKOR)

PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where

RBN = Nominal Burden of CT in VA Ri = Internal CT burden in VARelay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VARequired parameters for CTs Ratio 300/1 Ratio 400/1

K'SSC = (10+2) x20 (+3) x20(1.042+2) (1.042+3)

Calculated Value for K'SSC = 78.90 14.84

> 20 20


Adequacy checking calculation for 7SJ61 & 6MD6 relay for 11kV Cable feeders (connected across core-2)


RBN+ Ri x KSSC

RBC + Ri

Since the calculated K'SSC is more than Minimum required K'SSC (20), Hence selected CT is OK

PH7-3B-10-15-C001, Rev 0 of 91


Outgoing Feeder (A30,A40) Type:2

Core-1100/1Class - 5P1010VA

Core-2100/1Class - 1.0 Core-110VA 750/1

Class - PXVk≥Rct≤6

11/0.415 kV Io<25mA500 KVAONAN/ONAF

Core-1750/1Class - PXVk≥Rct≤6Io<25mA

Current Transformer Ration (CTR) = 100 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meter

Cable Resistance for 4.0mm2 at 750C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 1.500 OhmsCT Internal Burden in VA = (I)² x 1.5 = 1.50


Also K'SSC =

Where


K'SSC =(1.042 + 1.5)

Calculated Value for K'SSC = 90.48 > 20.00


Adequacy checking calculations for 7SJ61 relay for 11kV Incomer Feeders (connected across core-1)

RBN+ Ri x KSSC

RBC + Ri


RBC = Connected Burden across CT in VARi = Internal CT burden in VA RBN = Nominal Burden of CT in VA

(10 + 1.5) x 20


11kV Bus

To Over current / Earth fault (7SJ61)

415V side REF Protection(7SJ61)

415V side REF Protection(7SJ61)

Metering

PH7-3B-10-15-C001, Rev 0 of 91


Current Transformer Ration (CTR) = 750 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4.0mm2 at 750C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 6.000 OhmsCT Internal Burden in VA = (I)² x 6 = 6.000Formula Used

The required K'SSC = IHigh set point = 20 atleast IN

Where

Relay Burden = .1 VA 0.1 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA





= 0.0960 = 0.082

If =

If = 8.525 kA

Vk >

> 236.72 volts


500


(1.732 x415 x 0.0816)

1.5 x 8525 x (6 +0.942) x 2750







1.3



20 x (6 + 1.042) x 1




CT knee point voltage calculations for 7SJ61 type used for REF protection of 415 V side of 315kVA transformer (Applicable for Phase and Neutral side CTs)

PH7-3B-10-15-C001, Rev 0 of 91


Core-1 Core-22500/1 2500/1Class-PX Class-PXVk≥250 Vk≥250Rct≤9 Rct≤9Io<30ma Io<30ma

Core-12500/1Class-5P20/1.0Rct≤8.510 VA

Current Transformer Ration (CTR) = 2500 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4 mm²at 75°C = 5.610 Ohms/Km20% margin on cable resistance = 6.732 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Used




Knee Point voltage required = 20 x (9+1.042) x 11.3


Applicable substations: All substations with 11kV switchgear except Ain Hamad

Bus Coupler (Typical bay no.A12) Type:1




CT Knee point voltage calculation for 7SJ61 type used for Partial Bus bar differential protection



Applicable for I/C and B/C



11kV Bus-1 11kV Bus-2



To Overcurrent/Earth fault and Metering(6MD6 + 7SJ61)

PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where


RBN = Nominal Burden of CT in VA Relay Burden = 2*0.05 = 0.100 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA

K'SSC =(1.042+8.5)



Adequacy checking calculation for 7SJ61 & 6MD6 relay (connected across core-2 )


RBN+ Ri x KSSC

RBC + Ri


(10+8.5) x20

PH7-3B-10-15-C001, Rev 0 of 91


Core-2Core-1 800/1800/1 Class-PXClass-PX Vk≥250Vk≥250 Rct≤9Rct≤9 Io<30mA at Vk/2Io<30mA at Vk/2

Core-1800/1Class-5P20/1.0Rct≤8.515 VA

Current Transformer Ration (CTR) = 800 /1Relay Normal Current (IN) = 1 amp.Length of cable between CT and Relay = 70 meterCable Resistance for 4.0mm2 at 750C = 5.610 Ohms/Km20% margin on cable resistance = 6.730 Ohms/KmLoop Resistance ( 2RL ) = 0.942 OhmsLoop Burden in VA = (I)² x 0.942 = 0.942Current Transformer resistance (Rct) = 9.00 OhmsCT Internal Burden in VA = (I)² x 9 = 9.000Formula Used


Relay Burden = 0.1 VA 0.1 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA







20 x (9+1.042) x 1



CT knee point voltage calculations for 7SJ61 type used for Partial Bus bar differential protectionApplicable for I/C and B/C

Bus Coupler (A12) Type:2


11kV Bus-1 11kV Bus-2



To Overcurrent/Earth fault and Metering(6MD6 + 7SJ61)

PH7-3B-10-15-C001, Rev 0 of 91



Also K'SSC =

Where

Relay Burden = 2*0.05 = 0.10VA 0.1 VARBC = (Loop Burden+ Relay Burden) = (0.942+0.1) 1.042 VA

K'SSC =(1.042+8.5)


RBN = Nominal Burden of CT in VA

(15+8.5) x20


RBN+ Ri x KSSC

RBC + Ri


Adequacy checking calculation for 7SJ61 & 6MD6 relay (connected across core-1 )


PH7-3B-10-15-C001, Rev 0 of 91


Sr. No.

Feeder Description CT Ratio used CT Knee Point Voltage (V)

CT Resistance (ohms)

VA burden due to Secondary

leads

Total VA burden

Remarks Applicable substations

1 Bay =A18,=A28 (Incomer feeder)

Core-1, Cl. PX 2500/1 250 9 7SJ61 7UT613 0.050 0.050 0.942 1.042Core-2, 5P20/1.0 2500/1 6MD6 7SJ62 0.050 0.050 0.942 1.292 Rated Burden selected= 10 VA

Ammeter 0.250

Core-3, Cl. PX 2500/1 250 9 7SJ61 0.050 0.942 0.992

Core-4, Cl. PX 2500/1 250 9 7SD52 0.050 0.942 0.992 Mosemeer,Abu Hamour central,Al Wadi,MIC-2,MIC-3,QRE,Khore Community,Al Dhahiya West, NBK-2, Al Soudan, Ain Khalid south,Al Jumailyah, Khore Junction

2 Earthing transformer (500KVA)

Core-1, Cl. PX 50/1 100 1.20 7SJ61 0.050 0.942 0.992Core-2, 5P20/1.0 50/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VA

Trafo Neutral, Cl. PX (11kV side) 2500/1 250 9.0 7SJ61 0.050 0.942 0.992Trafo Neutral, Cl. PX (11kV side) 50/1 100 1.20 7SJ61 0.050 0.942 0.992

Trafo Neutral, 5P20/1.0 (11kV side) 750/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VATrafo Neutral, Cl. PX (415 V side) 750/1 250 6 7SJ61 0.050 0.942 0.992

3 Earthing transformer (1000KVA)

Core-1, Cl. PX 100/1 100 0.40 7SJ61 0.050 0.942 0.992Core-2, 5P20/1.0 100/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VA


Trafo Neutral, 5P20/1.0 (11kV side) 750/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VATrafo Neutral, Cl. PX (415 V side) 1500/1 500 7.50 7SJ61 0.050 0.942 0.992

4 Earthing transformer (2000KVA)Core-1, Cl. PX 200/1 100 0.60 7SJ61 0.050 0.942 0.992

Core-2, 5P20/1.0 200/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VACore-3, Cl. PX 400/1 100 9.00 7UT613 0.050 0.942 0.992


Trafo Neutral, 5P20/1.0 (11kV side) 750/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 15 VATrafo Neutral, Cl. PX (415 V side) 3000/1 450 15.00 7SJ61 0.050 0.942 0.992

6 Bay =A12 (Bus sectionalizer)T1, Core-1, 5P20/1.0 2500/1 7SJ61 6MD6 0.050 0.050 0.942 1.292 Rated Burden selected= 10 VA

Ammeter 0.250

T1, Core-2, Cl. PX 2500/1 9 7SJ61 0.050 0.942 0.992

T2, Core-1, Cl. PX 2500/1 9 7SJ61 0.050 0.942 0.992

Mosemeer,Abu Hamour central,Al Wadi,MIC-2,MIC-3,QRE,Khore Community,Al Dhahiya West, NBK-2, Al Soudan, Ain Khalid south,Al Jumailyah, Khore Junction

Common for all substations with 11kV switchgear except Ain Hamad

MIC Super , Al Dhahiya,Al Waab Super, Wakrah 2, EDS

Relays connected Relay Burden (in VA)

Al Jumailyah, Khore Junction,Mosemeer,Abu Hamour central,Al Wadi,MIC-2,MIC-3,QRE,Khore Community,Al Dhahiya West, NBK-2, Al Soudan, Ain Khalid south,Abu

Thaila Substation Modification,NDQ, Murraikh North, South west wakrah,Lusail Development Super 1,MIC

Super , Al Dhahiya,Al Waab Super, Wakrah 2, EDS,RLF-3

NDQ, Murraikh North, South west wakrah,Lusail Development Super 1,Abu Thaila Substation

Modification.

PH7-3B-10-15-C001, Rev 0 of 91


Sr. No.

Feeder Description CT Ratio used CT Knee Point Voltage (V)

CT Resistance (ohms)

VA burden due to Secondary

leads

Total VA burden

Remarks Applicable substationsRelays connected Relay Burden (in VA)

7 Outgoing Feeders =Typ. A10,A20T1, Core-1, Cl. PX 400-300/1 1.75-1.25 SOLKOR 3.500 0.942 4.442

T2, Core-1, 5P20/1.0 400-300/1 7SJ61 6MD6 0.050 0.050 0.942 1.292 Rated Burden selected= 15 VAAmmeter 0.250

8 Bay =A18,=A28 (Incomer feeder)Core-1, Cl. PX 600-300/1 600-300 9-4.5 7SJ61 7UT613 0.050 0.050 0.942 1.042

Core-2, 5P20/1.0 600-300/1 6MD6 7SJ62 0.050 0.050 0.942 1.292 Rated Burden selected= 10 VAAmmeter 0.250

Core-3, Cl. PX 800/1 250 9 7SJ61 0.050 0.942 0.992

9 Bay =A18 & =A28 (LV neutral)Core-1, Cl. PX 600-300/1 9-4.5 7SJ61 0.050 0.942 0.992Core-2, 5P20 750/1 Rated Burden selected= 15 VA

10 Bay =A30 & =A40 (315kVA transformer feeders)

Core-1, 5P10/1.0 100/1 7SJ61 0.050 0.942 0.992 Rated Burden selected= 10 VACore-2, Cl. 1.0 100/1 Rated Burden selected= 10 VA

Cl. PX (415V side) 750/1 6.00 7SJ61 0.050 0.942 0.992

11 Bay =A12,=A22 (Bus sectionalizer)T1, Core-1, CL5P20/1.0 800/1 8.5 7SJ61 6MD6 0.050 0.050 0.942 1.092 Rated Burden selected= 15 VA

T1, Core-2, Cl. PX 800/1 250 9 7SJ61 0.050 0.942 0.992T2, Core-1, Cl. PX 800/1 250 9 7SJ61 0.050 0.942 0.992

12 Outgoing Feeders =A90, =A70, =A50, =A10,= A20, =A60, =A80, =A100,

T1, Core-1, Cl. PX 400-300/1 300-250 1.25-1.75 SOLKOR 3.500 0.942 4.442T2, Core-2, 5P20/1.0 400-300/1 7SJ61 6MD6 0.050 0.050 0.942 1.292 Rated Burden selected= 15 VA

Ammeter 0.250

Ain Hamad

Ain Hamad

Ain Hamad

Common for all substations with 11kV switchgear except Ain Hamad

Ain Hamad

Ain Hamad

PH7-3B-10-15-C001, Rev 0 of 91


Sr. No.

Feeder Description VT Ratio used Total VA burden

Remarks

1 Bay =A14 -T15Winding-1, 1.0/3P 11/ √3 : 0.11/√3 6MD6 0.050 1.450 Rated Burden selected= 30 VA

Voltmeter 1.400

2 Bay =A24 -T16Winding-1, 1.0/3P 11/ √3 : 0.11/√3 6MD6 0.050 1.450 Rated Burden selected= 30 VA

Voltmeter 1.400.

3 Bay =A18, =A28 (Incomer feeder)Winding-1, 1.0/3P 11/ √3 : 0.11/√3 6MD6 7SJ62 0.050 0.050 2.500 Rated Burden selected= 30 VA

Voltmeter 1.400AVR 1.000

4 Outgoing Feeders (Typ.) =A10,A20Winding-1, 1.0/3P 11/ √3 : 0.11/√3 6MD6 0.050 0.050 1.500 Rated Burden selected= 30 VA

Voltmeter 1.400

Relays connected Relay Burden (in VA)

PH7-3B-10-15-C001, Rev 0 of 91

Siemens SIP · 2006

2 Overview

2

2/53

CT design according to BS 3938/IEC 60044-1 (2000)

The design values according to IEC 60044 can beapproximately transfered into the BS standarddefinition by following formula:

CT dimensioning formulae

K'ssc = Kssc · R R

R Rct b

ct b

++ '

(effective)

with K'ssc W Ktd ·I

ISCC max

pn

(required)

The effective symmetrical short-circuit currentfactor K'ssc can be calculated as shown in the tableabove.

The rated transient dimensioning factor Ktd de-pends on the type of relay and the primary DCtime constant. For relays with a required satura-tion free time from w 0.4 cycle, the primary (DC)time constant TP has only little influence.

Table 2/1 CT requirements

Relay type Transient dimensioning factor Ktd Min. required sym. short-circuit current factor K’ssc

Min. required kneepoint voltage VK

Overcurrent-time protection7SJ511, 512, 5317SJ45, 46, 607SJ61, 62, 63, 64

– K'ssc =I

I

High set point

pn

at least: 20

VK =I

I

High set point

pn13. •· (Rct + R'b) · Isn

at least:20

13.· (Rct + R'b) · Isn

Line differential protection(pilot wire)7SD600

– K'ssc = I

Iscc max (ext. fault)

pn

and:

3

4

4

3=

••

=( )

( )

K'

K'

ssc pn end1

ssc pn end2

I

I

VK = I


pn13. •· (Rct + R'b) · Isn

and:

3

4

4

3=

••

=( / )

( / )

V

V

K pn sn end1

K pn sn end2

I I

I I

Line differential protection(without distance function)7SD52x, 53x, 610 (50 Hz)7SD52x, 53x, 610 (60 Hz)

Transformer1.21.6

Busbar /Line1.21.6

Gen. /Motor1.21.6

K'ssc =

Ktd ·I


pn

and (only for 7SS):

K'ssc = 100 (measuring range)

VK =

Ktd ·I


pn13. •· (Rct + R'b) · Isn

and (only for 7SS):

VK = 100

13.· (Rct + R'b) · Isn (measuring range)

Transformer / Generatordifferential protection7UT6127UT613, 633, 6357UM62

Transformer434

Busbar /Line43–

Gen. /Motor555

Busbar protection7SS5, 7SS600

for stabilizing factors k = 0.50.5

Distance protection7SA522, 7SA6, 7SD5xx*)*) with distance function

primary DC time constant TP [ms] K'ssc =Ktd (a) ·

I

Iscc max (close -in fault)

pn

and:

Ktd (b) ·I

Iscc max (zone 1- end fault)

pn

VK =Ktd (a) ·

I

Iscc max (close -in fault)

pn13. •· (Rct + R'b) · Isn

and:

Ktd (b) ·I

Iscc max (zone 1-end fault)

pn13. •· (Rct + R'b) · Isn

Ktd (a)Ktd (b)

= 30 = 50 = 100 = 200

14

25

45

45

VK =( )R R Ib ct sn sscK+ • •

13.

Example:IEC60044:

600/1, 5P10, 15 VA, Rct = 4 .

IEC PX or BS:( )

VK1.3

V V=+ • •

=15 4 1 10

146

Rct = 4 .

For CT design according to ANSI/IEEE C 57.13please refer to page 2/56

A

PH7-3B-10-15-C001, Rev 0 of 91

2 Overview

Protection Coordination

Siemens SIP · 2006

2

2/56

Example 2:Stability-verification of the numerical busbarprotection relay 7SS52

I

ISCC.max.

pn

=30 000

60050

, A

A=

According to table 2/1 on page 2/53 Ktd = ½)

K'ssc = 1

250 25• =

Rb =15

15VA

1 A 2= .

Rrelay = 0.1 .

Rlead =2 0 0175 50

60 3

• • =.. .

R'b = Rl + Rrelay = 0.3 . + 0.1 . = 0.4 .

K'ssc =R R

R Rct b

ct bsscK

++

• = ++

• =' .

.4 15

4 0 410 43 2

. .. .

Result:

The effective K'ssc is 43.2, the required K'ssc is25. Therefore the stability criterion is fulfilled.

Relay burden

The CT burdens of the numerical relays ofSiemens are below 0.1 VA and can therefore beneglected for a practical estimation. Exceptionsare the busbar protection 7SS60 and the pilot-wirerelays 7SD600.

Intermediate CTs are normally no longer neces-sary as the ratio adaptation for busbar and trans-former protection is numerically performed in therelay.

Analog static relays in general have burdens belowabout 1 VA.

Mechanical relays, however, have a much higherburden, up to the order of 10 VA.

This has to be considered when older relays areconnected to the same CT circuit.

In any case, the relevant relay manuals should al-ways be consulted for the actual burden values.

Burden of the connection leads

The resistance of the current loop from the CT tothe relay has to be considered:

Rlead =2 • •. l

A

l = single conductor length from the CTto the relay in m.

Specific resistance:

. = 0.0175. • mm

m

2(copper wires) at 20 °C

A = conductor cross-section in mm2

Fig. 2/93

CT design according to ANSI/IEEE C 57.13

Class C of this standard defines the CT by ist sec-ondary terminal voltage at 20 times rated current,for which the ratio error shall not exceed10 %. Standard classes are C100, C200, C400 andC800 for 5 A rated secondary current.

This terminal voltage can be approximately calcu-lated from the IEC data as follows:

Vs.t.max = 20 •5 A •Rb •Kssc

20

withRb =

P

II Ab

sn

Nsnand we get2

5= ,

Vs.t.max =Pb sscK

A

•5

Example:IEC60044:

600/5, 5P20, 25 VA

ANSIC57.13: Vs.t.max =

( )25 20

5

VA

A

•= 100 V, acc. to class C100

ANSI CT definition

A

PH7-3B-10-15-C001, Rev 0 of 91

4 Technical Data

268 7SJ61 Manual

C53000-G1140-C118-7

4.1 General Device Data

4.1.1 Analog Inputs

Current Inputs

1) only in models with input for sensitive ground fault detection (see ordering data in Appendix

A.1)

4.1.2 Auxiliary Voltage

DC Voltage

Nominal Frequency fNom 50 Hz or 60 Hz (adjustable)

Nominal Current INom 1 A or 5 A

Ground Current, Sensitive INs = linear range 1.6 A 1)

Burden per Phase and Ground Path

- at INom = 1 A

- at INom = 5 A

- for sensitive ground fault detection at 1 A

Approx. 0.05 VA

Approx. 0.3 VA

Approx. 0.05 VA

Current overload capability

- Thermal (rms)

- Dynamic (peak value)

100· INom for 1 s

30· INom for 10 s

4· INom continuous

250· INom (half-cycle)

Current overload capability for high-sensitivity input INs 1)

- Thermal (rms)

- Dynamic (peak value)

300 A for 1 s

100 A for 10 s

15 A continuous

750 A (half-cycle)

Voltage supply using integrated converter

Rated auxiliary DC VAux 24/48 VDC 60/110/125 VDC

Permissible Voltage Ranges 19 to 58 VDC 48 to 150 VDC

Rated auxiliary DC VAux 110/125/220/250 VDC

Permissible Voltage Ranges 88 to 300 VDC

Permissible AC ripple voltage,

Peak to Peak, IEC 60 255-1115 % of the auxiliary voltage

Power Input Quiescent Approx. 3 W

Energized Approx. 7 W

Bridging Time for Failure/Short Circuit,

IEC 60255–11

(in not energized operation)

= 50 ms at V = 110 VDC

= 20 ms at V = 24 VDC

A

- at INom = 1 A Approx. 0.05 VA

Current Inputs

PH7-3B-10-15-C001, Rev 0 of 91

4.1 General

5197SD5 Manual

C53000-G1176-C169-1

4.1 General

4.1.1 Analog Inputs

Current Inputs

Requirements for current transformers

Voltage inputs

Nominal frequency fN 50 Hz or 60 Hz (adjustable)

Nominal current IN 1 A or 5 A

Power Consumption per Phase and Earth Path

- at IN = 1 A Approx. 0.05 VA


- for sensitive earth fault detection at 1A Approx. 0.05 VA

Current Overload Capability per Current Input

- thermal (rms) 100 · IN for 1 s

30 · IN for 10 s

4 · IN continuous

- dynamic (pulse current) 250 · IN (half-cycle)

Current Overload Capability for Sensitive Earth Current Input

- thermal (rms) 300 A for 1 s

100 A for 10 s

15 A continuous

- dynamic (pulse current) 750 A (half-cycle)

1st Condition:

For a maximum fault current the current transformers must not be

saturated under steady-stateconditions

2nd Condition:

The operational accuracy limit factor n' must be at least 30 or a non-

saturated period of t'AL of at least 1/4 AC cycle after fault inception

must be ensured

n' = 30

or

t'AL = 1/4cycle

3 rd Condition:

Maximum ratio between primary currents of current transformers at

the ends of the protected object

Nominal voltage UN 80 V to 125 V (adjustable)

Measuring range 0 V to 218.5 V (rms)

Power consumption At 100 V = 0.1 VA

Voltage overload capability per phase

- thermal (rms) 230 V continuous

A


Current Inputs

Voltage inputs

Power consumption = 0.1 VA

PH7-3B-10-15-C001, Rev 0 of 91

4

Page 10 of 10

A

PH7-3B-10-15-C001, Rev 0 of 91

A

PH7-3B-10-15-C001, Rev 0 of 91

AVR TECHNICAL DATA SHEETAVR TECHNICAL DATA SHEETA

PH7-3B-10-15-C001, Rev 0 of 91

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BS

6724

1.4

Rated

Voltag

eV

600/1

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600/1

000

600/1

000

1.5

Test V

oltag

e (1 m

in)

VA

C/m

in4000

4000/m

in3500 (5

min

)

1.6

Conducto

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1) C

ross sectio

nal area (N

om

inal)

mm

²4

610

16

25

50

120

150

240

120

95

410

616

25

35

46

10

16

35

10

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2) M

aterial Copper

Cu

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

Copper

3) D

esign (S

tranded

, sectoral ect)

Stran

ded

Stan

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/Circu

larnded

/Circ

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/Circ

randed

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randed

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randed

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4) O

verall d

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ppro

x)

mm

2.5

23.1

24.0

2N

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N.A

.N

.A.

N.A

.N

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18.4

13

11.4

2.5

24.0

23.1

24.8

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2.5

23.1

24.0

24.8

N.A

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23.1

2

5) N

o. o

f cores

44

44

44

44

11

12

22

22

23

33

33

55

1.7

Insu

lation

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

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XL

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PE

XL

PE

XL

PE

XL

PE

XL

PE

XL

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XL

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XL

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XL

PE

XL

PE

1.8

Fillers

Material - P

oly

pro

pylen

eP

oly

pro

pylen

e fillers - Wherev

er necessary

Poly

pro

pylen

e fillers - Wherev

er necessary

1.9

Arm

our b

eddin

g

Type

Poly

meric L

SO

H P

oly

meric L

SO

H

Nom

inal T

hick

ness

mm

0.8

0.8

0.8

0.8

11

1.4

1.4

11

0.8

0.8

0.8

0.8

0.8

0.8

10.8

0.8

0.8

0.8

10.8

0.8

1.1

0A

rmour

Type o

f wire

Galv

anized

Steel W

ire Arm

our

AW

A G

alvan

ised S

teel Wire

Num

ber o

f wires

No.

27

30

35

37

36

44

44

48

44

31

28

23

29

25

33

32

30

22

24

32

36

34

39

33

Diam

eter of w

ires - Nom

inal

mm

1.2

5*

1.2

51.2

51.2

51.6

1.6

2.5

2.5

1.6

1.6

*1.6

*1.2

5*

1.2

5*

1.2

5*

1.2

51.2

51.6

1.2

5*

1.2

5*

1.2

51.2

51.6

1.2

51.2

5

* W

ire size hig

her th

an sp

ecified in

BS

6724

1.1

1O

uter co

verin

gL

SO

HL

SO

H T

ype L

TS

-1 L

SO

H T

ype L

TS

1

Material

LS

OH

Type L

TS

-1 L

SO

H T

ype L

TS

1

Nom

inal T

hick

ness

mm

1.4

1.5

1.5

1.6

1.7

1.9

2.3

2.4

1.8

1.6

1.6

1.4

1.5

1.4

1.5

1.6

1.7

1.4

1.4

1.5

1.6

1.8

1.6

1.5

Min

. thick

ness

mm

0.9

21.0

01.0

01.0

81.1

61.3

21.6

41.7

21.2

41.0

81.0

80.9

21.0

00.9

21.0

01.0

81.1

60.9

20.9

21.0

01.0

81.2

41.0

81.0

0

1.1

2C

om

pleted

cable

Overall d

iameter - A

ppro

xm

m16.4

18.7

21.1

21.3

26.1

32.0

47.1

51.4

32.8

32.8

22.3

14.7

18

15.9

20.4

20.4

23.3

15.3

16.6

19.5

21.6

25.7

22.9

20

Weig

ht p

er meter - A

ppro

xkg

600

750

960

1195

1850

2860

6900

8190

2740

1460

1210

460

715

550

905

985

1395

515

625

840

1025

1830

1130

860

Max

imum

dru

m len

gth

m1000

1000

1000

1000

1000

1000

500

500

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1000

1.1

3C

able d

rum

s

Overall d

iameter - A

ppro

xm

1000

1200

1200

1200

1400

1600

1800

2000

1600

1800

1200

1000

1200

1000

1200

1200

1200

1000

1000

1200

1200

1400

1200

1200

Wid

th - A

ppro

xm

710

740

1040

1040

1040

1070

1130

1135

1070

1130

1040

700

740

700

1040

1040

1040

710

710

740

1040

1040

1040

1040

Weig

ht lo

aded

- Appro

xkg

690

880

1110

1345

2030

3150

3710

4395

3030

1720

1360

560

845

650

1055

1135

1545

615

725

970

1175

2010

1280

1010

1.1

4C

ontin

uous cu

rrent carry

ing cap

acity

based

on th

e conditio

ns

Laid

in th

e gro

und (T

ouch

ing each

oth

er)

a) One circu

itA

47

59

79

102

131

187

312

349

480

332

292

56

94

70

121

157

188

47

59

79

102

157

79

59

b) T

wo circu

itsA

38.0

747.7

963.9

982.6

2106.1

1151.4

7252.7

2282.6

9388.8

0268.9

2236.5

245.3

676.1

456.7

098.0

1127.1

7152.2

838.0

747.7

963.9

982

.62

127.1

763.9

947.7

9

c) Three circu

itsA

32.9

041.3

055.3

071.4

091.7

0130.9

0218.4

0244.3

0336.0

0232.4

0204.4

039.2

065.8

049.0

084.7

0109.9

0131.6

032.9

041.3

055.3

07

1.4

0109.9

055.3

041.3

0

Draw

n in

to d

ucts

a) One circu

itA

39

48

65

83

107

152

258

291

421

315

281

46

77

58

99

127

153

39

48

65

83

128

65

48

b) T

wo circu

itsA

31.2

038.4

052.0

066.4

085.6

0121.6

0206.4

0232.8

0336.8

0252.0

0224.8

036.8

061.6

046.4

079.2

0101.6

0122.4

031.2

038.4

052.0

066.4

0102.4

052.0

038.4

0

c) Three circu

itsA

27.3

033.6

045.5

058.1

074.9

0106.4

0180.6

0203.7

0294.7

0220.5

0196.7

032.2

053.9

040.6

069.3

088.9

0107.1

027.3

033.6

045.5

058

.10

89.6

045.5

033.6

0

In air

One circu

it at 50 °C

A37

46

64

83

109

163

293

335

510

328

282

43

74

55

98

128

158

37

46

64

83

134

64

46

1.1

5M

ax co

nducto

r temp

°C90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

90

1.1

6C

onducto

r short circu

it curren

t

carryin

g cap

acity fo

r 1 sec.

Cab

le loded

as above p

rior to

kA

0.5

70.8

61.4

32.2

93.5

87.1

517.1

621.4

534.3

217.1

613.5

90.5

71.4

30.8

62.2

93.5

85.0

10.5

70.8

61.4

32.2

95.0

11.4

30.8

6

short ck

t & fin

al conducto

r temp o

f°C

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

250

1.1

7M

in rad

ius o

f ben

d aro

und w

hich

cable can

be laid

a) Laid

direct

m6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

6 x

OD

6 x

OD

b) In

ducts

m6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

6 x

OD

6 x

OD

c) In air

m6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

8 x

OD

6 x

OD

6 x

OD

6 x

OD

6 x

OD

8 x

OD

6 x

OD

6 x

OD

1.1

8D

ucts

Nom

inal in

ternal d

iameter o

f pip

es or

mm

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

100

ducts th

rough w

hich

cable can

be p

ulled

1.1

9M

axim

um

dc resistan

ce

per k

m o

f cable at 2

0 °C

of co

nducto

rohm

/Km

4.6

13.0

81.8

31.1

50.7

27

0.3

87

0.1

53

0.1

24

0.0

754

0.1

53

0.1

93

4.6

11.8

33.0

81.1

50.7

27

0.5

24

4.6

13.0

81.8

31.1

50.5

24

1.8

33.0

8

1.2

0M

axim

um

ac resistance

of co

nducto

r per k

m o

f cable at m

ax.

ohm

/Km

5.8

83.9

32.3

31.4

70.9

27

0.4

94

0.1

97

0.1

60.0

968

0.1

97

0.2

47

5.8

82.3

33.9

31.4

70.9

27

0.6

68

5.8

83.9

32.3

31.4

70.6

68

2.3

33.9

3

conducto

r temp - 9

0 °C

1.2

1in

sulatio

n resistan

ce

per k

m o

f cable p

er core

Mohm

Will b

e calculated

form

the in

sulatio

n resistan

ce constan

t at 90 °C

I.e. 3.6

7 m

egao

hm

.km

Will b

e calculated

form

the in

sulatio

n resistan

ce constan

t at 90 °C

I.e. 3.6

7 m

egao

hm

.km

1.2

2M

anufactu

rer quality

assuran

ce accord

ing

CO

MP

LY

CO

MP

LY

to IS

O 9

000, 9

001, 9

003 &

9004

1.2

3T

ype test certificate to

be issu

ed b

y

CO

MP

LY

CO

MP

LY

indep

enden

t laborato

ry

A

PH7-3B-10-15-C001, Rev 0 of 91

ct sizing calculation of 11kv system-rev0-ver3

Documents

transient

effective

ihigh set

abu hamour

px vk100 rct1

rct 2rl

knee point

ain khalid