user manual and technical documentation - itr

Low Power Current Transformer IEC 61869-1, IEC 61869-6, IEC 61869-10

User manual and technical documentation

Document version: 02i02

Update: 2019-01-08

Safety information

National and local electrical safety regulations must always be followed.

Improper operation of the transformer or its application to purposes different from the intended use may pose hazards to operators and /or may lead to the equipment damage.

Exploration of damaged device can result in malfunction of protected object and result in threat to life and health.

Reliable and defect-free operation of the device needs appropriate transportation, handling, storage, installation and commissioning as well as correct operation and maintenance.

Whenever changes are made in the device, measures should be taken to avoid inadvertent tripping.

Comments

We reserve the right to modify the device.

Concepts conversion factor and sensivity used herein are synonymous and they determine the proportion of current flowing in the primary circuit to the output voltage of the secondary circuit.

CR and CRR current transformers are used for supervision and control in industrial facilities.

Remaining user documentation can be downloaded from energetyka.itr.org.pl.

http://www.energetyka.itr.org.pl/

IU_CR_CRR_MANUAL_02i02_ENG 3 / 15

Contents: 1. Introduction 4

Symbols ........................................................................................................................................... 4 2. Designated use and operation manual 5 3. Place of installation 6 4. Additional information 9

Measurement accuracy .................................................................................................................. 9 Characteristics ................................................................................................................................ 9

5. Technical parameters 12 Input/output circuit ...................................................................................................................... 12 Connectors .................................................................................................................................... 12 Environmental conditions ............................................................................................................. 12 Protection level ............................................................................................................................. 12 Mechanical tests ........................................................................................................................... 12 Electrical parameters .................................................................................................................... 13

6. Remarks of manufacturer 14 Maintenance, inspections, repairs ................................................................................................ 14 Storage and transport ................................................................................................................... 14 Disposal ......................................................................................................................................... 14 Service and guarantee .................................................................................................................. 14

7. Contact 15

4 / 15 IU_CR_CRR_MANUAL_02i02_ENG

1. Introduction

Symbols

Electrical warning symbol indicates the presence of hazardous energy circuits or electric shock hazards.

The warning symbol indicates the important information related to the threat to life and health.

The information symbol indicates the clarification of relevant features and parameters of the device.


2. Designated use and operation manual

Developed in the ITR CR and CRR low power current transformers are working on the basis of a

Rogowski coil.

They are made in PCB technology (Printed Circuit Board) thereby resulted very high precision geometry of transformers and hence high repeatability of electrical parameters. They are characterized by constant conversion factor (sensivity) in the entire measuring range. Conversion factor is defined as the quotient of the RMS value of the output voltage of the transformer and the RMS value of sinusoidal current at a 50 Hz frequency flowing in the primary circuit of transformer In a grid with a 60 Hz nominal frequency, conversion factor is defined as the quotient of the RMS value of the output voltage of the transformer and the RMS value of sinusoidal current at a 60 Hz frequency flowing in the primary circuit of transformer. The transformer with conversion factor equal to 1xS at 50Hz will be characterized by conversion factor equal to 1.2 x S at 60 Hz. Due to their very good electrical parameters, low weight and small size, transformers can replace the traditional transformers. They are offered in two mounting versions: the releasable and non-releasable and in three accuracy classes: 0.5 / 0.2 / 0.1.

Fig. 2.1. The view of CR and CRR series current transformers

CR and CRR current transformers cooperate with measuring or protection devices, equipped with a low voltage inputs.

CR and CRR current transformers are suited for industrial environments installation. They can be installed on isolated cables or bushings. They are used to measure, analyze power quality and security in electricity grids of low, medium and high voltage with a frequency of 50 Hz or 60 Hz.

CR and CRR transformers may be disconnected and connected during operation without the need short-circuit the output terminals.

CR and CRR current transformers do not require any additional actions after installing and running the switchboard.


3. Place of installation

Current transformers CR series are designed for installation during the realization of installing in the switchgear. Split transformers from the CRR series can be installed at any time, which allows mounting in upgraded or already completed switchboards. The transformers should be fixed in a permanent basis and without backlash on the bushing or cable in the switch bay. They can be fastened to the bracket with screws M4 placed in the holes on the outside of the housing or to the cable with wedges or clasps. The connection cables should be made of shielded twisted-pair. Shield should be attached to the EP only from the side of the measuring or protection device (bay controller). The order of wires (S1,S2) of the twisted pair between the transformer and the bay controller should be the same for all transmitters, as shown in Fig. 3.1.

Fig. 3.1. Wiring diagram of CR transformer

Internal contacts (ZZ) connectors should be combine by short, single cable when CRR transformers are used. Connecting cables should be lead out to the measuring device from the extreme (S1,S2) contacts connectors. The method of connection is shown in Fig. 3.2.

Fig. 3.2. Wiring diagram of CRR transformer You must keep the same position (the orientation) of all transformers in relations to current cables (Fig. 3.3). The transformers may be shifted to each other, as shown in Fig. 3.4. You must keep the same position (the orientation) of all transformers in relations to each other, as shown in Fig. 3.5.


Fig. 3.3. The correct positioning of the current transformers in relations to each other.

Fig. 3.4. The correct shift positioning of the current transformers in relations to each other

Fig. 3.5. The incorrect positioning of the current transformers in relations to each other.

Current cable or current conductor rail doesn't have to be put centrically in the mouth of the transformer, as shown in Fig. 3.6. If current conductor is placing with the shift, it does not affect on the quality of work of the transformer.


Fig. 3.6. The correct centric and non-centric positioning of the current cable

Current conductor weaved through mouth of the transformer can’t have a shield, or the shield should be weaved through back. Figure 3.7. describes how to intersperse the screen leaded from the current shielded cable. Lead of the screen should be interleaved by the transformer in the direction opposite to the screen of the cable, so that the magnetic fields generated by current flowing in the screens abolished each other.

Fig. 3.7. Method of installation the transformer on the shielded cable.

The cable should be secured against movement by using attachment elements or cable ties.

The parameters required for the connecting cable, depending on its length, are specified in the table:

Transmission system for low power transformers

Long-term electric strength Voltage impulse electric

strength

Lenght of connecting cable <10 m 820 V 1,5 kV 1,2/50 µs

Lenght of connecting cable ≥ 10 m 3 kV 5 kV 1,2/50 µs

The recommended type of connecting cable that meets the above requirements - Belden 9501.


4. Additional information

Measurement accuracy

Transformer, as a source of the measuring signal, represents the voltage source and its load resistance is equal to the self-resistance Rc. Transformer, as a source of the measuring signal, represents the voltage source and its load resistance is equal to the self-resistance Rc. Self-resistance together with the load resistance of transformer (Ro is input resistance of the measuring system) creates a voltage divider. The voltage measured by the measuring device is equal to the voltage of unloaded transformer reduced according to the formula Ro/( Ro + Rc). If decrease of output signal of transformer must be limited, transformer should be connected to the input circuit of device, which has resistance at least an order of magnitude greater than self-resistance of transformer. In order to improve the accuracy of the entire measuring system, must be determined the conversion factor in the measurement system (Sp), according to the following formula:

𝐒p = 𝐒 𝐑o

𝐑o + 𝐑𝐜

where:

Sp - conversion factor of the measuring system S - conversion factor of unladed CR or CRR current transformer Ro - load resistance (input resistance of the measuring system) Rc - self-resistance of transformer

Example CR 1-55 transformer, cooperating with the input system with input resistance 33 kOhm, will have a conversion factor : Sp = 1,018.mV / A (1,046 mV / A x 33kΩ / (33kΩ + 0.9 kohm) - for 50Hz) Sp = 1,222.mV / A (1.255 mV / A x 33kΩ / (33kΩ + 0.9 kohm) - for 60Hz)

Characteristics

Fig. 4.1 The characteristics of the output U voltage related to I current; 50 Hz.


Fig. 4.2 The characteristics of the output U voltage related to I current; 60 Hz.

Fig. 4.3 The characteristics of the S conversion factor (sensivity) related to f current frequency.


Fig. 4.4 The characteristics of the Rc resistance related to T temperature.

0

2000

4000

6000

8000

10000

12000

-60 -40 -20 0 20 40 60 80 100

Rc

[Ω]

T [°C]

CR 6-55

CR 3-55, CRR 3-50

CR 2-78

CR 1-120

CR 2-55

CR 1-78

CR 2-25

CR 1-55, CRR 1-50

CR 1-25

CR 05-55


5. Technical parameters

Input/output circuit

Maximum continuous voltage at the device terminals ~24 V

Maximum temporary voltage at the device terminals ~150 V

Maximum unique voltage at the device terminals 250 V

Test voltage of electrical strength ~2 kV

Rated frequency 50 / 60 Hz

Work frequencies 1 Hz … 20 kHz

Accuracy class (3 versions) 0.5/0.2/0.1

The transformer’s operating conditions (current, conversion factor) should be selected so that the transformer's output voltage does not exceed the safe voltage of ~ 24 V during normal operation.

Connectors

crimp connection SPTA1/2-3,5

screw connection M3

Cable type shielded twisted-pair 2 x 0,2...1,5mm2 e.g. Belden 9501

Environmental conditions

Operating temperature -40˚C … +85 ˚C

Storage temperature -55˚C … +90 ˚C

Maximum relative humidity no condensation, frost, ice

Insulation class after installing 1

Installation category III

Electrical environment B

Pollution degree 2

Protection level

Degrees of protection provided by enclosures (IP Code)

Case IP 68

screw connection IP 00

crimp connection IP 40

Mechanical tests

Sinusoidal vibration PN-EN 60255-21-1:1999 1 class

Single and multiple shocks and bumps PN-EN 60255-21-2:2000 1 class


Electrical parameters

The table shows the basic electrical parameters of current transformers. Transformers are presented in the order resulting from the conversion factor.

Tab. 5.2.1. Electrical parameters of current transformers CR / CRR

Type

S Measuring range ID Ith Rc Ro

[ mV/A ] [ kA ] [ kA ] [ Ω ] [ kΩ ]

50 Hz 60 Hz min … max

0,520 0,624 0,2 A … 200 kA 50 300 450 ≥ 20

1,081 1,298 0,1 A … 100 kA 20 100 530 ≥ 20

1,046 1,255 0,1 A … 150 kA 35 150 900 ≥ 30

1,039 1,249 0,1 A … 150 kA 35 150 1150 ≥ 30

1,146 1,375 0,1 A … 150 kA 65 150 1900 ≥ 40

2,165 2,598 50 mA … 50 kA 15 50 1070 ≥ 30

2,098 2,596 50 mA … 75 kA 25 75 1800 ≥ 40

2,082 2,498 50 mA … 75 kA 25 75 2300 ≥ 40

3,182 3,818 30 mA … 50 kA 30 50 4000 ≥ 40

6.340 7,608 15 mA … 25 kA 20 25 8000 ≥ 40

Przetworniki rozłączalne

1,046 1,255 0,1 A … 150 kA 35 150 900 ≥ 30

3,182 3,818 30 mA … 50 kA 25 50 4000 ≥ 40

S – conversion factor (sensivity) for grids 50Hz or 60Hz Measuring range – transformer accuracy class is ≤0,5% within this range ID – maximum continuous current Ith - maximum instantaneous current (≤1 s) Rc – self-resistance of transformer Ro – recommended load resistance


6. Remarks of manufacturer

Maintenance, inspections, repairs

The manufacturer recommends that correctness of device operation is verified: a) each time - during commissioning, b) at least once a year - in mine face installations, c) at least once every 5 years - in installations other than front face.

Also inspections resulting from branch regulations should be undertaken.

Storage and transport

Current transformers are packed in transport packages and secured against damage during transport and storage. Devices should be stored in transport packages, indoors, in places free from vibrations and direct effects of weather conditions, dry, well ventilated, free from harmful vapors and gases. Ambient air temperature should be between –55°C and +90°C, and relative humidity should not exceed 90%.

Disposal

Products are made mostly from recyclable materials, or materials that can be processed again or disposed of in environmentally sound manner. Decommissioned devices can be collected for recycling, provided that their condition is that of normal wear and tear. All components that are not recyclable shall be disposed of in environmentally sound manner.

Service and guarantee

Regular guarantee period is 36-month. Had the sale been preceded by execution of an Agreement between the Buyer and the Seller, provisions of such Agreement shall apply. Guarantee covers remedying of defects, free of charge, provided that instructions specified in the Warranty Card are adhered to. Detailed guarantee conditions may be found at energetyka.itr.org.pl in the w „Sale Regulations”.

• The guarantee period is counted from the date of sale.

• The warranty is extended by a period of residence of the product in the repair.

• Unauthorized tampering with the product will void the warranty.

• Warranty does not cover damage resulting from improper use of the product.

http://www.itr.org.pl/


7. Contact

Tele- and Radio Research Institute ICT and Electronics Centre

03-450 Warsaw, ul. Ratuszowa 11

tel.: + 48 22 590 73 91 e-mail: [email protected] www: energetyka.org.pl

mailto:[email protected]

http://energetyka.org.pl/

user manual and technical documentation - itr

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