Rudolf

Current
Transformer
Enhanced Quality with a Touch of Style
 New Products
Rudolf launched our new encapsulated current
transformer. Portraying a revolutionary unique

Current design encase using ABS/PC material, we provide

enhance quality with a touch of style.
The various differentiating factors govern the
Transformer manufacturing of Rudolf current transformer lie in both
the choice of world-class raw material and a 100%
testing to complete the supply. We are committed to
Enhanced Quality with a Touch of Style provide our customer with undiscounted quality and
complete assurance of compliance to international
standard.

Basic Features
Correct selection of current transformer is important
as the fundamental usage of CT is:
1) to obtain proportional current in accordance to
specify accuracy and objectives;
2) to insulate control & measuring /
protection from power circuit.

Application
Measuring current transformer is intended to supply
to indicative devices, integrated meter and similar
Company Introduction apparatus.
Bridex Singapore Pte Ltd is founded in 1978 as a They are characterized by their accuracy and for
manufacturer of instruments transformer for the Asian saturating at moderate overcurrent. This effect protects
market. We are the first local electrical switchgear the measuring instruments from possible overcurrent.
components manufacturer that launches our own Asian
Protective current transformer is intended to supply to
identity –
protective relays whereby accuracy of CT need to be
Today we aim to become a knowledge-based, kept especially during overload conditions.
technology driven engineering organization, with
emphasis on providing solution for electrical distribution Construction
and control, in area of instruments, distribution & The high-grade silicon steel core is annealed, varnished
protection and power quality solution in area of power then insulated with polycarbonate core caps. The
quality audit & power quality system and motor secondary winding is toroidally wound by high precision
controller. With our present headquarter in Singapore semi-automatic machinery. For the tape wound ring
and subsidiaries that are located in Australia, Malaysia, type current transformer, the PEW coated windings
Philippines and Vietnam, we are well equipped to are then covered with elephantite paper, varnished and
service both local market and countries in the Asia double-tapped with PVS tapes. For the encapsulated
Pacific. type current transformer, the windings are enclosed in
a compact and heat resistant split cap.
Product Introduction Selection criteria
Rudolf, creating a world class standard in the supply
1) Application – protection or measurement
of current transformer, offers a comprehension range
for both the measuring and protection applications. 2) Information on associated relay or instrument
- nominal current
Ranges available are: - accuracy
• Encapsulated type; - burden
• Tape wound ring type;
3) loss contribute from power loss in power line
• Split core encapsulated type; - distance between transformer & instruments
• Class X tape wound ring type; - diameter of cable use for connection
Designed to meet the highest standards in accordance 4) environmental features
to IEC 60044-1, Rudolf current transformer provides - indoor/ outdoor
you with a world-class product manufactured with our - operating temperature
assurance to comply with international standard. - etc...
 Rudolf Current Transformer

Important of burden
Burden is the impedance of the secondary circuit in ohms and power factor.
For the measurement instrument or protection relay operating via a transformer, in order to operate them,
the primary current has to induce the power required in the secondary current of the instrument or relay.
This induced power must be equal or higher than the losses in the power line + consumption of the measurement
instrument or protection relay.
The burden imposed on a current transformer consist mainly of:
- The impedance of pilot wire between current transformer and instruments/relay
- The impedance of the instrument / relay
- The sum of the above constitute the external burden required

Table illustrating some typical instruments and its typical consumption

Instrument Burden consumed

Moving iron instruments 0.3-15VA

Moving coil instruments 0.5VA
Analogue power meter 0.2-2.5VA
Maximum demand meter 2.5-5.0VA
Digital meter 0.5-1.0VA
Energy meter 1.0-1.5VA
Recording instruments 2.0-5.0VA

Table guide for pilot lead burden

25 1.0
2 0.9
m
1m 2
20 0.8
mm
VA BURDEN ON 5A SEC C.T.

VA BURDEN ON IA SEC C.T.

1.5
0.7

15 0.6
2
m
2.0 m 0.5
2
10 0.4
2.5 mm
2 0.3
4.0 mm
5 6 mm
2
0.2

0.1

0 5 10 15 20 25
APPROX. DISTANCE (DOUBLE WIRE RUN) - C.T. TO RELAY (IN METERS)
Rudolf Current Transformer

Important of accuracy & phase angle

Current error is an error that arises when the current value of the actual transformation ratio is not equal to rated
transformation ratio.

Current error (%) = {(Kn x Is – Ip) x 100}/Ip

Kn = rated transformation ratio

Ip = actual primary current
Is = actual secondary current

Example:
In case of a 2000/5A class 1 5VA current transformer

Kn = 2000/5 = 400 turn

Ip = 2000A
Is = 4.9A

Current error = {(400 x 4.9 – 2000)x100}/2000 = -2%

For protection class current transformer, the accuracy class is designed by the highest permissible percentage
composite error at the accuracy limit primary current prescribed for the accuracy class concerned.
Accuracy class includes: 5P, 10P
Standard accuracy limit factor are: 5, 10, 15, 20, 30

By phase angle
Phase error is the difference in phase between primary & secondary current vectors, the direction of the vectors
to be zero for a perfect transformer.

You will experience a positive phase displacement when secondary current vector lead primary current vector.
Unit of scale expressed in minutes / centiradians.

Circular measure = (unit in radian) is the ratio of the distance measured along the arc to the radius.

Angular measure = (unit in degree) is obtained by dividing the angle subtended at the center of a circle
into 360 deg equal division known as “degrees".

Table – limits of current error and phase displacement for measuring current transformer
(Classes 0.1 To 1)

+/- percentage current +/- Phase displacement at percentage

(ratio) error at of rated current shown below
Accuracy percentage of rated
Class current shown below Minutes Centiradians

5 20 100 120 5 20 100 120 5 20 100 120

0.1 0.40 0.20 0.10 0.10 15 8 5 5 0.45 0.24 0.15 0.15
0.2 0.75 0.35 0.20 0.20 30 15 10 10 0.90 0.45 0.30 0.30
0.5 1.50 0.75 0.50 0.50 90 45 30 30 2.70 1.35 0.90 0.90
1.0 3.00 1.50 1.00 1.00 180 90 60 60 5.40 2.70 1.80 1.80
 Rudolf Current Transformer

Table – limits of current error and phase displacement for measuring current transformer
For special application

+/- percentage current (ratio) +/- Phase displacement at percentage

error at percentage of rated of rated current shown below
Accuracy current shown below
Class Minutes Centiradians
1 5 20 100 120 1 5 20 100 120 1 5 20 100 120
0.2S 0.75 0.35 0.20 0.20 0.20 30 15 10 10 10 0.9 0.45 0.3 0.3 0.3
0.5S 1.50 0.75 0.50 0.50 0.50 90 45 30 30 30 2.7 1.35 0.9 0.9 0.9

Table – limits of current error for measuring current transformers (classes 3 and 5)

+/- Percentage current (ratio) error at

Accuracy percentage of rated current shown below
Class
50 120
3 3 3
5 5 5

Table – limits of error for protection current transformer

Accuracy Current error at Phase displacement at rated primary current Composite error at
Class rated primary rated accuracy limit
current % Minutes Centiradians primary current %

5P +/-1 +/-60 +/-1.8 5

10P +/-3 - - 10

Specifications

Standard : IEC60044-1 2003-02

Rated operational voltage (Un) : 720V
Rated frequency : 50/60Hz
Ambient temperature : -5/40 deg C
Operating humidity : up to 95% relative humidity
Rated short time thermal current (Ith) : 50kA
Rated dynamic current (Idyn) : 2.55 x Ith
Insulation : between primary /secondary conductor >500mΩ
: between toriod core/secondary conductor >200mΩ
Dielectric strength : 2kV 1 minutes
Thermal class of insulation : B
Casing : non-flammable, polycarbonate self extinguishing ABS/PC
Index of protection – casing : IP20
Index of protection – cover : sealable IP20
Accuracy class : Measuring 0.5, 1, 3
: Protection 5P, 10P
Burden : ranging from 3 – 30VA
Rated primary current : ranging from up to 6000A
Rated secondary current : …/5A or …/1A
Rudolf Current Transformer

Class X Current Transformer

Class X current transformer is use in conjunction with high impedance circulating current differential protection
relay, eg restricted earth fault relay. As illustrated in IEC60044-1, the class X current transformer is needed.

The following illustrates the method to size a class X current transformer.

Step 1: calculating knee point voltage Vkp

Vkp = {2 x Ift (Rct+Rw)}/ k

Vkp = required CT knee point voltage

Ift = max transformer through fault in ampere
Rct = CT secondary winding resistance in ohms
Rw = loop impedance of pilot wire between CT and the
K = CT transformation ratio

Step 2: calculate Transformer through fault Ift

Ift = (KVA x 1000)/(1.732 x V x Impedance)

KVA = transformer rating in kVA

V = transformer secondary voltage
Impedance = transformer impedance

Step 3: How to obtain Rct

To measure when CT is produce

Step 4: How to obtain Rw

This is the resistance of the pilot wire used to connect the 5th class X CT at the transformer star point to the relay
in the LV switchboard. Please obtain this data from the Electrical contractor or consultant. We provide a table to
serve as a general guide on cable resistance.

Example:
Transformer Capacity : 2500kVA
Transformer impedance : 6%
Voltage system : 22kV / 415V 3phase 4 wire

Current transformer ratio : 4000/5A

Current transformer type : Class X PR10
Current transformer Vkp : 185V
Current transformer Rct : 1.02Ω (measured)

Pilot wire resistance Rw : 25 meters using

6.0mm sq cable
= 2 x 25 x 0.0032
= 0.16Ω

Ift = (kVA x 1000) / (1.732 x V x impedance)

= (2500 x 1000) / (1.732 x 415 x 0.06)
= 57,968 round up 58,000A

Vkp = {2 x Ift (Rct+Rw) } / k

= {2 x 58000 (1.02+0.16) } / 800
= 171.1Ω
Rudolf Class X CT with knee point voltage of 185V is suitable to be use in this application.
 Rudolf Current Transformer

Encapsulated Current Transformer

Selection Guide
Ratio Standard burden (VA)

Accuracy class 3 Accuracy class 1 Accuracy class 0.5

60/5A 3 - - - - - - - - - - - - - - - - - - -
100/5A 3 5 - - - - - 3 5 - - - - - - - - - - -
120/5A 3 5 - - - - - 3 5 - - - - - - - - - - -
100/5A 3 5 - - - - - 3 5 - - - - - - - - - - -
150/5A 3 5 7.5 10 - - - 3 5 - - - - - - - - - - -
200/5A 3 5 7.5 10 15 20 - 3 5 7.5 - - - 3 - - - - - -
250/5A 3 5 7.5 10 15 20 - 3 5 7.5 10 - - 3 5 - - - - -
300/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 3 5 7.5 10 15 - -
200/5A 3 5 7.5 10 - - - 3 5 7.5 - - - 3 - - - - - -
250/5A 3 5 7.5 10 15 - - 3 5 7.5 10 - - 3 5 - - - - -
300/5A 3 5 7.5 10 15 20 - 3 5 7.5 10 15 - 3 5 7.5 - - - -
400/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 3 5 7.5 10 - - -
500/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 -
600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
400/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 - - 3 5 7.5 10 - - -
500/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 - 3 5 7.5 10 15 - -
600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 -
800/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1200/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
800/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1200/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
2000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1200/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
2000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
2500/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
1600/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
2000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
2500/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
3000/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
3200/5A 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30 3 5 7.5 10 15 20 30
Subjected to change without prior notice
E
F

Dimension Drawing
E
F

G
G D
Dimension
D Case
type
A B C D E F G H

RE01 88 106 98 43 70 52 68 18
H RE11 88 106 98 43 70 52 68 27
E
F
C

H RE31 92 110 102 43 70 52 72 43

C

RE51 117 135 127 43 70 52 97 63

G
RE61
D
131 149 141 43 70 52 111 77
RE71 142 160 152 43 70 52 95 86
A
A RE81 170 193 185 43 70 52 95 111

H
C

B
 Rudolf Current Transformer

Tape Wound Ring Type (measuring current transformer)

Class 3.0 Class 1.0 Class 0.5 Approx. Wt. In
Type Kg Per 10mm
Ratio ID OD VA 3 5 15 3 5 7.5 10 15 20 30 5 7.5 10 15 20 30 C.T. Thickness

60/5A 30 70 40 - - - - - - - - - - - - - - - 0.100

Thickness in mm
100/5A 30 70 35 40 - 40 - - - - - - - - - - - - 0.103

SR 1
120/5A 30 70 35 40 - 40 40 - - - - - - - - - - - 0.104
150/5A 30 70 30 35 - 35 40 - - - - - - - - - - - 0.105
200/5A 28 70 30 30 - 30 35 40 - - - - 40 - - - - - 0.106

150/5A 40 80 40 40 - 40 - - - - - - - - - - - - 0.122

Thickness in mm
200/5A 40 80 30 30 - 30 40 40 - - - - - - - - - - 0.123
SR 2

250/5A 40 80 30 30 40 30 35 40 - - - - 40 - - - - - 0.124
300/5A 40 80 30 30 40 30 30 35 40 40 - - 30 40 40 - - - 0.125
400/5A 40 80 30 30 35 30 30 30 35 35 40 - 30 35 40 40 - - 0.127

Thickness in mm
200/5A 45 85 35 40 - 40 40 - - - - - - - - - - - 0.128
SR 3

250/5A 45 85 30 35 40 30 35 40 - - - - 40 - - - - - 0.129
300/5A 45 85 30 30 40 30 30 35 40 - - - 35 40 40 - - - 0.130
400/5A 45 85 30 30 35 30 30 30 35 35 40 - 35 35 40 40 - - 0.132
Thickness in mm

400/5A 58 95 30 30 40 30 30 30 35 40 40 - 30 35 40 40 - - 0.153
SR 4

500/5A 58 95 30 30 35 30 30 30 30 35 40 - 30 35 35 40 - - 0.154
600/5A 57 95 30 30 35 30 30 30 30 35 40 40 30 30 35 40 40 - 0.155
800/5A 55 98 30 30 30 30 30 30 30 30 35 40 30 30 30 35 40 40 0.160
Thickness in mm

600/5A 70 109 30 30 40 30 30 30 35 40 - - 30 35 35 40 - - 0.162

SR 5

800/5A 70 109 30 30 30 30 30 30 30 30 35 40 30 30 30 35 40 - 0.164

1000/5A 68 110 30 30 30 30 30 30 30 30 35 40 30 30 30 35 40 40 0.168
1200/5A 67 112 30 30 30 30 30 30 30 30 30 35 30 30 30 30 35 40 0.182
Thickness in mm

800/5A 85 122 30 30 30 30 30 30 30 30 35 40 30 30 30 35 40 - 0.220

SR 6

1000/5A 83 122 30 30 30 30 30 30 30 30 35 40 30 30 30 35 40 40 0.230

1200/5A 83 125 30 30 30 30 30 30 30 30 30 35 30 30 30 30 35 40 0.240
1600/5A 82 126 30 30 30 30 30 30 30 30 30 35 30 30 30 30 35 40 0.260
Thickness in mm

1200/5A 110 147 30 30 35 30 30 30 30 40 40 40 30 30 30 40 40 40 0.334

SR 7

1600/5A 110 150 30 30 30 30 30 30 30 30 35 40 30 30 30 30 35 40 0.342

2000/5A 108 150 30 30 30 30 30 30 30 30 35 35 30 30 30 30 35 35 0.350
2500/5A 106 154 30 30 30 30 30 30 30 30 35 35 30 30 30 30 35 35 0.410
Thickness in mm

1600/5A 120 157 30 30 30 30 30 30 30 35 40 40 30 30 35 35 40 40 0.402

SR 8

2000/5A 120 160 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.420

2500/5A 118 162 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.460
3000/5A 116 164 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.502
Thickness in mm

2000/5A 130 168 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.468

SR 9

2500/5A 130 170 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.500

3000/5A 128 172 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.530
3500/5A 126 174 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.570
Thickness in mm

2500/5A 140 178 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.532

SR 10

3000/5A 140 180 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.562

3500/5A 138 182 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.580
4000/5A 136 184 30 30 30 30 30 30 30 30 35 40 30 30 30 35 35 40 0.605

TAPE WOUND RING TYPE (Measuring Current Transformer) - extended range

Class 3.0 1.0 0.5 Approx. Wt. In
Type Kg Per 10mm
Ratio ID OD VA 5 7.5 10 15 20 3 5 7.5 10 15 20 30 5 7.5 10 15 C.T. Thickness

60/5A 30 85 40 70 90 - - 60 70 - - - - - - - - - 0.401
Thickness in mm
SR 1S

100/5A 30 85 35 40 50 70 - 35 40 50 70 90 - - 90 - - - 0.403
120/5A 30 85 30 40 50 60 - 35 40 50 70 80 - - 70 - - - 0.410
150/5A 30 85 30 30 35 40 - 30 30 35 40 50 - - 40 40 - - 0.410
Thickness in mm

150/5A 40 85 30 35 40 50 - 30 35 40 50 60 - - 50 60 - - 0.284
SR 2S

200/5A 40 85 30 30 35 40 50 30 30 35 40 50 50 - 40 40 50 50 0.290
250/5A 40 85 30 30 30 35 40 30 30 30 35 40 40 - 30 35 40 50 0.294
300/5A 40 85 30 30 30 30 35 30 30 30 30 35 40 - 30 35 35 40 0.295
Thickness in mm

200/5A 45 85 30 30 35 40 50 30 30 35 40 50 60 - 40 40 50 60 0.278
SR 3S

250/5A 45 85 30 30 30 35 40 30 30 30 35 40 50 - 35 35 40 50 0.284
300/5A 45 85 30 30 30 30 40 30 30 30 30 35 40 - 30 35 35 40 0.286

Subjected to change without prior notice

• All dimensions are in mm. 1A secondary on request

 Rudolf Current Transformer

Tape wound ring type (protection current transformer)

Class/ALF 5P5 5P10 5P15 Approx. Wt. In

Type Kg Per 10mm
Ratio ID OD VA 5 7.5 10 15 20 30 5 7.5 10 15 20 5 7.5 10 15 C.T. Thickness

100/5A 30 95 50 65 80 100 130 - 85 100 - - - - - - - 0.403

Thickness in mm
120/5A 30 95 50 60 70 100 120 - 80 100 - - - - - - -
PR 1
0.406

150/5A 30 95 40 50 60 80 110 - 70 90 110 - - - - - - 0.410

200/5A 28 95 40 40 40 55 65 - 50 65 75 - - - - - - 0.415

150/5A 40 100 50 60 70 85 105 - 80 100 110 120 - - - - - 0.330

Thickness in mm
200/5A 40 100 40 40 50 65 75 110 55 70 85 115 - - - - - 0.333
PR 2

250/5A 40 95 40 40 50 60 75 - 50 70 85 110 - 75 100 - - 0.292

300/5A 40 95 35 40 40 60 65 90 50 60 70 100 - 70 85 110 - 0.295

200/5A 45 95 40 55 65 80 110 115 75 95 115 - - - - - - 0.278

Thickness in mm

250/5A 45 95 40 50 60 70 85 110 60 85 90 115 - 85 110 - - 0.284

PR 3

300/5A 45 95 35 40 40 60 70 95 50 65 85 100 - 70 95 - - 0.286

400/5A 45 95 35 40 40 60 60 85 60 60 70 90 - 65 80 100 - 0.292

400/5A 58 100 35 40 50 60 70 95 60 70 80 105 - 75 95 115 - 0.231

Thickness in mm

500/5A 58 100 35 40 40 60 60 80 50 60 70 90 110 70 85 100 - 0.251

PR 4

600/5A 57 100 30 35 40 50 60 70 50 55 60 80 95 65 75 90 110 0.261

800/5A 55 104 30 30 35 40 50 60 40 50 55 65 80 55 65 75 95 0.271

600/5A 70 114 35 35 40 50 55 70 50 55 65 80 100 70 80 90 115 0.283

Thickness in mm

800/5A 70 114 35 35 35 40 45 55 40 50 50 60 75 50 60 70 85 0.294

PR 5

1000/5A 68 116 35 35 35 35 40 50 40 40 50 55 65 50 60 70 80 0.360

1200/5A 67 117 35 35 35 35 40 40 35 40 40 50 60 40 50 60 70 0.326

800/5A 85 125 35 35 35 40 50 60 40 50 55 65 85 60 70 80 95 0.316

Thickness in mm

1000/5A 83 127 35 35 40 40 40 60 40 50 50 65 75 50 60 70 85 0.333

PR 6

1200/5A 83 128 35 35 35 35 40 40 35 35 40 45 60 40 50 60 65 0.351

1600/5A 82 130 35 35 35 35 35 40 35 35 35 40 50 40 50 50 65 0.378

1200/5A 110 152 35 35 35 35 40 50 40 40 50 45 65 50 60 65 80 0.421

Thickness in mm

1600/5A 110 155 35 35 35 35 35 40 35 35 40 40 50 35 50 50 60 0.434

PR 7

2000/5A 108 158 30 30 30 30 30 40 35 35 35 40 40 35 40 50 50 0.443

2500/5A 106 162 30 30 30 30 30 35 35 35 35 40 40 35 40 40 50 0.462

1600/5A 120 165 35 35 35 35 40 40 35 40 40 45 60 50 50 60 70 0.491

Thickness in mm

2000/5A 120 165 35 35 35 35 35 40 35 35 40 40 45 40 40 50 55 0.502

PR 8

2500/5A 118 168 35 35 35 35 35 40 35 35 35 40 40 35 40 50 50 0.528

3000/5A 116 170 35 35 35 35 35 40 35 35 35 40 40 35 40 40 50 0.562

2000/5A 130 175 35 35 35 35 35 40 35 35 40 40 50 40 50 50 60 0.538

Thickness in mm

2500/5A 130 175 35 35 35 35 35 40 35 35 40 40 40 40 40 50 55 0.564

PR 9

3000/5A 128 178 35 35 35 35 35 40 35 35 35 40 40 35 40 40 50 0.602

3500/5A 126 180 35 35 35 35 35 40 35 35 35 40 40 35 40 40 40 0.624

2500/5A 140 185 35 35 35 40 40 40 35 35 40 40 50 40 40 55 60 0.630

Thickness in mm

3000/5A 140 185 35 35 35 35 35 40 35 35 35 40 40 35 40 40 50 0.656

PR 10

3500/5A 138 188 35 35 35 35 35 40 35 35 35 40 40 35 40 40 40 0.684

4000/5A 136 190 35 35 35 35 35 40 35 35 35 40 40 35 35 40 40 0.712

Subjected to change without prior notice

• All dimensions are in mm. 1A secondary on request
 Rudolf Current Transformer

Tape wound ring type (protection current transformer)

Class/ALF 10P5 10P10 10P15 Approx. Wt. In
Type Kg Per 10mm
Ratio ID OD VA 5 7.5 10 15 20 30 5 7.5 10 15 20 5 7.5 10 15 C.T. Thickness

100/5A 30 95 50 60 75 100 130 - 85 100 - - - - - - - 0.403

Thickness in mm
120/5A 30 95 50 60 70 95 120 - 80 105 - - - - - - -
PR 1
0.406

150/5A 30 95 40 50 60 80 110 - 65 90 110 - - - - - - 0.410

200/5A 28 95 40 40 40 55 65 - 50 60 70 - - - - - - 0.415

150/5A 40 100 50 55 65 85 100 - 75 100 110 120 - - - - - 0.330

Thickness in mm
200/5A 40 100 40 40 50 60 70 - 55 70 85 110 - - - - - 0.333
PR 2

250/5A 40 95 40 40 50 60 70 - 50 70 85 110 - 75 95 - - 0.292

300/5A 40 95 35 40 40 60 65 85 50 60 70 95 - 70 85 105 - 0.295

200/5A 45 95 40 50 60 80 100 115 75 95 110 - - - - - - 0.278

Thickness in mm

250/5A 45 95 40 50 60 70 85 110 60 75 90 115 - 85 110 - - 0.284

PR 3

300/5A 45 95 35 40 40 60 70 95 50 65 80 100 - 70 90 - - 0.286

400/5A 45 95 35 40 40 60 60 85 50 55 65 85 - 65 80 95 - 0.292

400/5A 58 100 35 40 40 60 70 90 60 65 80 100 - 75 95 110 - 0.231

Thickness in mm

500/5A 58 100 35 40 40 60 60 80 50 60 70 85 110 70 80 95 - 0.251

PR 4

600/5A 57 100 35 35 40 50 50 70 50 50 60 80 90 60 75 85 110 0.261

800/5A 55 104 35 35 35 40 50 60 40 50 50 60 80 55 65 75 90 0.271

600/5A 70 114 35 35 40 50 50 70 50 55 60 80 95 70 80 90 110 0.283

Thickness in mm

800/5A 70 114 35 35 35 40 40 55 40 40 50 60 70 50 60 70 85 0.294

PR 5

1000/5A 68 116 35 35 35 35 40 50 35 40 50 55 65 50 55 65 80 0.360

1200/5A 67 117 35 35 35 35 35 40 35 40 40 50 60 40 50 55 65 0.326

800/5A 85 125 35 35 35 40 50 60 40 50 55 65 80 60 65 75 95 0.316

Thickness in mm

1000/5A 83 127 35 35 40 40 40 60 40 40 50 60 75 50 60 70 80 0.333

PR 6

1200/5A 83 128 35 35 35 35 40 40 35 35 40 45 60 40 50 60 65 0.351

1600/5A 82 130 35 35 35 35 35 40 35 35 35 40 50 40 50 50 65 0.378

1200/5A 110 152 35 35 35 35 40 50 40 40 50 45 65 50 60 65 80 0.421

Thickness in mm

1600/5A 110 155 35 35 35 35 35 40 35 35 35 40 50 35 50 50 60 0.434

PR 7

2000/5A 108 158 30 30 30 30 30 30 35 35 35 40 40 35 40 50 50 0.443

2500/5A 106 162 30 30 30 30 30 30 35 35 35 35 40 35 40 40 50 0.462

1600/5A 120 165 30 30 30 35 35 40 35 40 40 45 60 50 50 55 65 0.491

Thickness in mm

2000/5A 120 165 30 30 30 35 35 40 35 35 35 40 50 40 40 50 50 0.502

PR 8

2500/5A 118 168 30 30 30 35 35 35 35 35 35 40 40 35 40 40 50 0.528

3000/5A 116 170 30 30 30 35 35 35 35 35 35 40 40 35 40 40 50 0.562

2000/5A 130 175 30 30 30 35 35 40 35 35 40 40 50 40 50 50 60 0.538

Thickness in mm

2500/5A 130 175 30 30 30 35 35 40 35 35 35 40 40 35 40 40 50 0.564

PR 9

3000/5A 128 178 30 30 30 35 35 35 35 35 35 40 40 35 40 40 50 0.602

3500/5A 126 180 30 30 30 35 35 35 35 35 35 40 40 35 40 40 40 0.624

2500/5A 140 185 35 35 35 35 40 40 35 35 40 40 50 35 40 50 60 0.630

Thickness in mm

3000/5A 140 185 35 35 35 35 35 40 35 35 35 40 40 35 40 40 50 0.656

PR 10

3500/5A 138 188 35 35 35 35 35 35 35 35 35 40 40 35 35 40 40 0.684

4000/5A 136 190 35 35 35 35 35 35 35 35 35 40 40 35 35 40 40 0.712

Subjected to change without prior notice

• All dimensions are in mm. 1A secondary on request

 Rudolf Current Transformer

Split Core Type

The connection of a current transformer is done in series with the feeder wires, which must be interrupted. The subsequent
connecting up of current transformers in already existing units or distributor or main boxes involves problems which are
widely known and can cause a great deal of extra wage costs and time. Our TP transformer with separated core can
solve this problem in a simple manner in the following way:
• It is a simple application, as the current circuit to be measured must not be interrupted. The separate measuring core
of the transformer enables it to be subsequently moulded at any time. This constructive design enables the transformer
to be applied universally.
• Its shape and the generous dimensions of the through channel facilitate the insertion of large cables and bars.
• It is fully isolated with self-extinguishing ABS casing UL94 V-O. Its secondary connections can be capped with a
bridge facility, thereby protecting the current transformer when the secondary circuits is open.
There are 5 different dimensions and current strengths from 100A to 5000A and with the outputs .../5A, ...1A ,
and ...A/1.5 V. Other outputs in voltage and current may be obtained on request.

Burden (VA) Dimension of case unit (mm)

Ratio Weight
(Kg)
Class 0.5 Class 1.0 Class 3.0 a b c d e f g h i

100/5A - - 1.5
150/5A - - 2
TP 23

200/5A - 1.5 2.5 20 30 51 89 110 34 47 40 32 0.75

250/5A - 2 4
300/5A 1.5 4 6
400/5A 2.5 6 10

250/5A 1 2 4
300/5A 1.5 3 6
400/5A 1.5 3 10
TP 58

500/5A 2.5 5 15
600/5A 2.5 5 17.5 50 80 78 114 145 32 32 32 33 0.90
700/5A 3 6 18
800/5A 3 7 18
1000/5A 5 10 20

250/5A 1 2 4
300/5A 1.5 3 6
Split Core Series 400/5A 1.5 3 10
TP 88

500/5A 2.5 5 15
600/5A 2.5 5 17.5 80 80 108 144 145 32 32 32 33 1.00
750/5A 3 6 18
800/5A 3 7 18
1000/5A 5 10 20

500/5A - 4 12
600/5A - 5 14
750/5A 3 6 17
TP 812

800/5A 3 7 18 80 120 108 144 185 32 32 32 33 1.20

1000/5A 5 9 20
1200/5A 6 11 24
1250/5A 7 15 28
1500/5A 8 17 30

1000/5A 10 15 20
1500/5A 15 20 25
TP 816

2000/5A 15 20 25
2500/5A 15 20 25 80 160 120 184 245 52 47 52 38 3.50
3000/5A 20 25 30
4000/5A 20 25 30
5000/5A 20 25 30

Subjected to change without prior notice

 Rudolf Current Transformer

Ordering Information
B = cw bracket
NRE - 3Z0 - 3Z0 - 0060 - 1B 1 = /1A
B1 = cw bracket & /1A

Type
for tape wound for encapsulated
1 = SR/PR1 A = SR/PR10 0 = RE01
2 = SR/PR2 C = SR/PR11 1 = RE11
3 = SR/PR3 D = SR/PR12 3 = RE31
4 = SR/PR4 E = SR/PR13 5 = RE51
5 = SR/PR5 F = SR/PR14 6 = RE61
6 = SR/PR6 G = SR/PR15 7 = RE71
7 = SR/PR7 H = SR/PR16 8 = RE81
8 = SR/PR8
9 = SR/PR9

Primary ratio
0060 = 60/5A

Burden/Rs for class X secondary resistance

3Z0 = 3VA
5Z0 = 5VA
7Z5 = 7.5VA
010 = 10VA
015 = 15VA
020 = 20VA

Accuracy/Kpv for class X knee point Volt

metering protection
3Z0 = class 3 S05 = 5P5
1Z0 = class 1 S10 = 5P10
0Z5 = class 0.5 T05 = 10P5
0Z2 = class 0.2 T10 = 10P10
T20 = 10P20

Application
NRE = metering encapsulated
NRM = metering tape wound
NRP = protection tape wound
NRX = class X
R-0EDCI-000CT-C0-1205

Bridex Singapore Pte Ltd

15 Senoko Avenue, Singapore 758305
Tel : 6756 0833 Fax : 6756 2007
Website : http://www.bridex.com.sg E-mail : sales@bridex.com.sg