TA SeriesMoulded Case Current Transformers

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TA Series Moulded Case Current Transformers

IntroductionThe TA Series is a range of mouldedcase current transformersmanufactured to IEC 60185, theInternational ElectrotechnicalCommission Standard whichspecifies the rating andperformance requirements for CTs tobe used with electrical measuringinstruments and protective devices.

The TA Series includes CTs only foruse with electrical measuringinstruments.

Product Features

Class 3, 1 or 0.5 with 5A and 1Asecondaries as standard

Compact design having aperturesdesigned for standard busbars up to4000A

Choice of bar or foot mounting

Terminal cover and all fixingssupplied with each CT as standard

User Benefits

One range of CTs allows a widevariety of CT applications to beachieved from one supplier

Conforms with industry standarddimensions for copperwork,eliminates mounting problems andreduces the requirement for specialCTs to accommodate the primarycircuit

Adaptable and easily mounted

Full package approach simplifiesordering process

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Cable burden in VA

Copper cross-section Burden (VA/m) of single conductor

(mm2) For 5A secondary CT For 1A secondary CT

0.75 – 0.0471 – 0.034

1.5 0.57 0.0232 0.43 0.017

2.5 0.34 0.0144 0.22 0.00856 0.14 0.0057

10 0.085 0.0034

ApplicationsIn addition to the class accuracy,primary and secondary ratings,when selecting a CT the aperturesize and VA rating must also bedetermined.

Aperture size

The TA series is designed withaperture dimensions that suit thesize of busbar for given primarycurrents.Table 1 shows the copper busbarcurrent ratings for different sizes ofbusbar according to DIN 43761.

Copper busbar ratings

Busbar Current (Amps)

No. of bars

Dimension (mm) 1 2 3 4

20 x 5 320 560 725 –20 x 10 500 925 1320 –25 x 3 280 470 525 –25 x 5 385 660 840 –30 x 3 335 545 590 –30 x 5 445 760 940 –30 x 10 675 1200 1670 –40 x 10 850 1470 2000 258050 x 5 695 1140 1330 201050 x 10 1020 1720 2320 295060 x 5 825 1330 1510 231060 x 10 1180 1960 2610 329080 x 5 1070 1680 1830 283080 x 10 1500 2410 3170 3930

100 x 5 1300 2010 2150 3300100 x 10 1810 2850 3720 4530

VA rating

The VA rating of a CT must begreater than, or equal to, the totalVA burden of all the devices beingfed and the connecting cable. Inorder to select a CT with anappropriate VA rating, refer toTables 2 and 3 which show typicaldevice and cable burdensrespectively.

Table 1

Typical device burden in VA

Moving Iron Instruments 0.4 . . . 1.5Rectified Moving Coil Instruments 0.5Power Instrument 1.0 . . . 2.5Maximum Demand Indicators 2.5 . . . 5.0Digital Indicators 0.5 . . . 1.0kWh Meters 1.0 . . . 5.0Recorders 2.0 . . . 5.0Istat 300 Transducers 0.2 . . . 1.5Static Relays 1.0 . . . 2.5

Table 2

Table 3

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CT Selection TablesAll CTs supplied with full fixing kitand terminal cover as standard.All CTs available with either 1A or5A secondary.

VAPrimary Classcurrent 0.5 1 3150 – 2.5 2.5200 – 2.5 3.75250 1.25 2.5 3.75300 2.5 2.5 3.75400 2.5 3.75 5500 3.75 5 5600 3.75 5 7.5

Type TA30

VAPrimary Classcurrent 0.5 1 3

40 – – 1.2550 – 1.25 1.2560 – 1.25 2.575 – 1.25 2.5

100 – 2.5 3.75125 1.25 3.75 5150 1.25 5 5200 2.5 5 7.5

Type TA20

VAPrimary Classcurrent 0.5 1 3100 2 5 10125 5 7.5 10150 7.5 10 15200 10 15 25250 10 20 30300 10 20 30400 15 30 45500 20 30 45

Type TA100B

Dimensions Ratings

Ø5.5

45

57.6

66.4

Ø17 8.5

58

15.5

20.5

41

30.4

45

29

5.5

Ø5.5

45

57.6

Ø2312.6 11.6

58

2126

41

30.4

45

29

10.6

66.4

31

75

43

5010.5 10.5

11 21 31

M4

S1–k S2–l

40

82

104.5

M5

32

Ø5.55040

P1 K

23

Wound primary CTs for lowerprimary currents are also availableon request.

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VAPrimary Classcurrent 0.5 1 3

50 – – 1.560 – – 1.575 – 1.5 2.5

100 – 3 5125 – 3 5150 – 3 5200 2.5 5 7250 3.75 5 7.5300 5 7.5 10400 5 7.5 10500 5 10 15600 7.5 15 20750 10 15 25800 10 15 25

1000 15 20 30

Type TA200

VAPrimary Classcurrent 0.5 1 3400 10 15 30500 10 15 30600 10 15 30750 10 15 30800 10 15 30

1000 10 15 301200 10 15 301250 10 15 301500 10 15 301600 10 15 302000 10 15 30

Type TA250

VAPrimary Classcurrent 0.5 1 3400 10 15 30500 10 15 30600 10 15 30750 10 15 30800 10 15 30

1000 15 25 301200 20 30 401250 20 30 401500 30 40 501600 30 40 502000 40 50 60

Types TA300/TA380

Dimensions Ratings

25.6

75

43

5010.5 10.5

10.6

M4

S1–k S2–l

40

82

104.5

M5

32

Ø5.55040

P1 K

30.5

30.6

40.6

12.6

20.6

100

61

5010.5 10.5

M4

S1–k S2–l

54

108

130.5

P1

46

M5

32

Ø5.5

55

44

K

10.5

21

12

50.5

43

132

7010.5 10.5

M4

S1–k S2–l

66

132

154.5

P1

52

K

11

43

M5

32

Ø5.56444

32 41 61 81

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VAPrimary Classcurrent 0.5 1 3800 10 15 30

1000 10 15 301200 10 15 301250 10 15 301500 10 15 301600 10 15 302000 10 15 30

VAPrimary Classcurrent 0.5 1 31500 10 15 301600 10 15 302000 10 15 302500 10 15 303000 10 15 304000 10 15 30

VAPrimary Classcurrent 0.5 1 32000 10 15 303000 10 15 304000 10 15 305000 10 15 30

Type TA400

Type TA500

Dimensions Ratings

Type TA600

M4

M5S1–k S2–l

P1 K

187.5 165

82.5

103

95

43

32

40

5923

M4

M5S1–k S2–l

P1 K

202.5 180

90

103

115

43

32

44

6332

12432 60 32

78

193

38

128

27

55

72

4432

62

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Technical Details

Manufactured to IEC 60185: current transformers

Maximum system voltage: 660V

Secondary: 5A or 1A

Voltage isolation: 3kV rms for 60 seconds

Overload: 1.2 In continuously

Thermal current (Ith): 60 x primary current for one second

Dynamic current (Idyn): 2.5 x Ith

Rated current factor: ≤ 5 x primary

Cases: in high impact polycarbonate

Linearity

The error limits are maintained between the following load values:

For CT with VA > 2.5 between 25 and 100% In

For CT with VA ≤ 2.5 between 50 and 100% InAccuracy at other load values is indicated in Table 4 below:

% Accuracy at Phase angle in minutes at

CLASS 0.1In 0.2In 1In 1.2In 0.1In 0.2In 1In 1.2In

0.5 1 0.75 0.5 0.5 60 45 30 301.0 2 1.5 1 1 120 90 60 60

Table 4

How to Order a CTWe require the following information:

1. Model type: to suit busbar size

2. CT ratio

3. Class/VA: to suit the loadingconditions

eg. TA250800/5AClass 0.5, 10VA

To ensure that you order the correct CT, refer to the tables on pages 4, 5 and6 giving VA ratings for each class available. Dimensions are also given toensure that the CT is suitable for the busbar.

St Leonards Works, Stafford, ST17 4LX EnglandTel: 44 (0) 1785 223251 Fax: 44 (0) 1785 212232 Email: enquiries@pcs.alstom.co.uk Internet: www.gecalsthomgpc.co.uk

©1998 ALSTOM T&D Protection & Control Ltd

Our policy is one of continuous development. Accordingly the design of our products may change at any time. Whilst every effort is made to produce up to date literature, this brochure shouldonly be regarded as a guide and is intended for information purposes only. Its contents do not constitute an offer for sale or advice on the application of any product referred to in it.

ALSTOM T&D Protection & Control Ltd cannot be held responsible for any reliance on any decisions taken on its contents without specific advice.

Publication I7-015E 109810 CPS Printed in England.

ALSTOM T&D Protection & Control Ltd