Differential Relays

Siemens LSA 2.2.6 . March 1995 1

Overview

Application Comment Climaticrequirementsaccording toformerDIN 40 040

Features

Matching currenttransformer

Multi–tap aux. current transformer to match different current transformer ratios.4AM51 70–7AA: Standard version, primarily for transformer overall differential

protection.4AM52 72–2AA: Version with double thermal withstand capability, e.g. when

connecting to wide–range current transformer (continuous rating2 x �N).

4AM52 72–3AA: Version with higher saturation factor (mainly for the busbardifferential protection).Greater overcurrent factor because of higher voltages

HKG

HKG

HKG

Numerous ratios can beselected using terminalconnections (see page2/31)fN = 45 to 60 Hz

Aux. C.T. for C.T.powered trippingcircuits

Auxiliary current transformer for C.T. powered trip coils in stations where no batterysupply can be made available.4AM50 65–2CB: For 1 A C.T.s4AM50 70–8AB: For 5 A C.T.sSuitable for tripping coils with �N � 0.5 A or 1 A, VN � 40 V or 20 V, P � 20 VA.

HKDHKD

Unlike transducers, nodefined rated power orclass accuracy required.fN = 45 to 60 Hz

Input and matchingcurrent transformer

Input and matching current transformer for phase selective busbar differential pro-tection.4AM51 20–1DA: For 1 A C.T.s4AM51 20–2DA: For 5 A C.T.s1)

HKGHKG

fN = 45 to 60 Hzwith varistor

3–phase summationinput C.T.

Input 3–phase summation current transformer for busbar differential protection.4AM51 20–3DA: For 1 A C.T.s4AM51 20–4DA: For 5 A C.T.s

HKGHKG

fN = 45 to 60 Hzwith varistor

Isolating transformer Isolating transformer for pilot–wire differential protection. Provides galvanic isolationbetween pilot wires and relays.7XR9 500: For differential protection relays 7SD10, 7SD74 and 7SD503

(for use with 3 wires of control cables or protection cables)7XR9 513: For pilot–wires differential relays 7SD24, 7SD76 and 7SD502

(for use with 1 pair of telephone wires).

HKG

HKG

7 kV insulation

20 kV insulation

Climatic requirements: HKG = –25 �C to +125 �Crelative humidity max. 75 %annual average <65 %on 60 days of the year up to 85 %(equally distributed over the year) condensation not permissible

HKD = –25 �C to +125 �Crelative humidity max. 90 %annual average <80 %on 30 days of the year up to 100%(equally distributed over the year) condensation permissible

1) If increased thermal withstand is required type 4AM51 20–4DA is recommended.

Auxiliary current transformers 4AM50, 4AM51, 4AM52 and isolating transformers 7XR95

Fig. 1

7XR9 5004AM5...–. with varistor fitted4AM5.

Siemens AG 1995�

Differential Relays

Siemens LSA 2.2.6 . March 19952

Order No. Windings of auxiliary current transformers Weight, approx.

Number of windings(in relation to each other)

B1

A D2

C F7

E H16

G K1

I M2

L O7

N Q16

P

4AM51 70–7AA Rated current �N1) A

Max. voltage V52

54

514

132

52

54

514

132

3.4 kg

4AM52 72–2AA Rated current �N1) A

Max. voltage V102

104

1014

232

102

104

1014

232

5 kg

4AM52 72–3AA Rated current �N1) A

Max. voltage V54

58

528

164

54

58

528

164

5 kg

4AM50 65–2CB Rated current �N1) A 1 1 1 1 2.4 kg

Number of windings 110

Ka

110

Kb LbLa Kc Lc Kd Ld110 110 Primary windings

Number of windings 88laka

88lbkb

Secondary windings

Rated current �N1) A 1.25 1.25

4AM50 70–8AB Rated current �N1) A 5 5 5 5 2.4 kg

Number of windings 22Ka

22Kb LbLa Kc Lc Kd Ld

22 22 Primary windings

Number of windings 88laka

88lbkb

Secondary windings

Rated current �N1) A 1.25 1.25

Number of windingsB

1A C

2E

4D F

8H

16G I

32500

ZY

4AM51 20–1DA Max. current, continuously AMax. voltage V

6.80.4 0.8

6.81.6 3.2

6.86.4 12.5

0.85200

3.5 kg

4AM51 20–2DA Max. current, continuously AMax. voltage V

260.4 0.8

261.6 3.2

notfitted

0.85200

3.5 kg

4AM51 20–3DA Number of windingsB

3A D

6C F

9E H

18G K

24I M

36L O

90N

500

ZY

3.5 kg

Max. current, continuously AMax. voltage V

41.2

42.4

43.6

47.2

49.6

414.4

236

0.85200

4AM51 20–4DA Number of windingsB

1A D

2C F

3E H

4G K

6I M

8L O

12N

500

ZY

3.5 kg

Max. current, continuously AMax. voltage V

17.50.4

17.50.8

17.51.2

17.51.6

17.52.4

17.53.2

84.8

0.85200

7XR9 500 Isolating transformer for differential protection with threepilot–wires

a10a9 a8

b10 b8b9

Isolating transformer 1 : 1for voltages up to 4,2 kVtest voltage 7 kV

approx. 15 kg

7XR9 513 Isolating transformer for differential protection with two pilot–wires

M1K1 L1

M2 L2K2

Isolating transformer 1 : 1, max. 550 V0,4 A continously, 3 A 10 s, 10 A 1 stest voltage 20 kV, 50 Hz, 1 min

approx. 5 kg

1) Thermal withstand with simultaneous loading of all the windings:1.2 x �N/continuously; 10 x �N/10 s; 25 x �N/1 s.

Auxiliary current transformers 4AM50, 4AM51, 4AM52 and isolating transformers 7XR95

Fig. 2Connection of windings

A B C D E F G H KaLaKbLb ka la

J K L M N O P Q

A B C D E F

G H J Y Z

A B C D E F

Y Z

A B C D E F G H

J K L M N O Y ZKcLcKdLd kb lb

4AM51 70–7AA4AM52 72–2AA4AM52 72–3AA

4AM50 70–8AB4AM50 65–2CB

4AM51 20–1DA 4AM51 20–2DA 4AM51 20–3DA4AM51 20–4DA

Differential Relays

Siemens LSA 2.2.6 . March 1995 3

Isolation transformer 7XR95

Dimension drawings in mm

Fig. 3Auxiliary current transformers 4AM50, 4AM51, 4AM52 without varistor

Type

4AM50

4AM51

4AM52

a

84

84

90

b

96

96

120

c

102

116

110

d

70

84

83

e

88

103

102

f

106

106

123ed

c

f

5.8

ba

g

Fig. 4Auxiliary current transformer 4AM51 with varistor

84

106

7258

11

102.5

5.8

399684

Fig. 5Isolation transformer 7XR9513

100 86

292

220

204

181.

5ca

.55

122

8.5

∅ 6.5

Fig. 6Isolation transformer 7XR9500

143

77

8 220

90

40172

108

162

108

Differential Relays

Siemens LSA 2.2.6 . March 19954

Conditions of Sale and Delivery

Subject to theGeneral Conditions of Supply and Deliveryfor Products and Services of theElectrical and Electronic Industryand to any other conditions agreed uponwith the recipients of catalogs.

�

The technical data, dimensions and weights are subject to change unlessotherwise stated on the individual pagesof this catalog.

The illustrations are for reference only.

We reserve the right to adjust the pricesand shall charge the price applying onthe date of delivery.

Export Regulations

In accordance with present German andUS export regulations export licences (da-ted 02.95) are not required for the prod-ucts listed in this catalog.Export and re–export are therefore

permissible without the approval of therelevant authorities except where currentGerman export regulations contain coun-try–specific restrictions.

Subject to change.Relevant are the criteria stated in the delivery note and in the invoice.An export licence may be required due to country–specific application of theproduct.

Trademarks

All product designations used are trade-marks or product names of Siemens AGor of suppliers.

Dimensions

All dimensions in this catalog are given inmm

Responsible for

Technical contents: Norbert Schuster,Siemens AG, EV S T11, Nürnberg

General editing: Claudia Kühn–Sutiono,Siemens AG, EV MK 2, Erlangen

Conditions of Sale and Delivery � Export Regulations � Trademarks � Dimensions

A 9.91 a

Siemens Aktiengesellschaft

BereichEnergieübertragung und -verteilungGeschäftsgebietZähler, Sekundär- und NetzleittechnikP. O. Box 48 06D-90026 Nürnberg

Order No.: E50001-K5722–A161–A1–7600Printed in the Federal Republic of Germany

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