Instrument Transformers 600 V Indoor Type Current and Voltage

Transcription

1 Instrument Transformers 0 V Indoor Type and Voltage CONTENTS Schneider Electric Brands Description Page Application and Features Selection Criteria and Selection Charts General Purpose Transformers Torroidal Transformers (Single Ratio) Rectangular Window Transformers (Single Ratio) Split Core Transformers (Single Ratio) Bushing Transformers Auxiliary Transformer Voltage Transformers Glossary of Terms and Abbreviations Appendices Accuracy and Burden Information

2 Application and Features APPLICATION, FEATURES AND SELECTION CRITERIA Square D 0 Volt rated current and voltage transformers are field-proven in well over a million installations where accuracy and longer, more dependable operation are essential. In most cases, the information contained in this catalog should be sufficient for the proper selection of the instrument transformer best suited for your application. However, should you need additional assistance, please feel free to contact your nearest Square D Field Sales Office or contact our Nashville instrument transformers product marketing group. Application Instrument transformers are ideally suited in the following applications: Indoor Switchgear assemblies Motor controllers Over power transformer bushings Over circuit breaker bushings Metering ing sensing NOTE: Transformers listed in this catalog should not be applied to circuits having a phase-to-phase voltage greater than 0 volts, unless adequate additional insulation is applied between the primary and secondary windings. Square D assumes no responsibility for damage of equipment or personal injury caused by the transformers operated on circuits above their published ratings. Features High thermal ratings for short-time use. Most instrument transformers listed in this catalog are UL and CUL Recognized per ification XODW, File No. E570. Manufactured according to rigid Square D quality control standards. Extremely wide range of ratios available. Wide range of window sizes from.3 in ( mm) to.3 in ( mm). Applicable standards are ANSI C57.3 and CSA C3. Models feature strong, molded thermo-plastic cases. Molded plastic core jacket ensures rugged core-to-winding insulation. Low energy loss, grain-oriented silicon steel annealed for optimum magnetic qualities. Most models feature permanent polarity marks molded into the case and large, easy to read ratios are clearly marked on the case. Rugged, corrosion-resistant mounting brackets are available as options. Most ratings are available from stock. Selection Criteria How to Select a Transformer. Determine that the primary range of the current transformer encompasses the application requirement. Lower or specialized ratios may be obtained by adding primary and secondary turns as shown on page 5.. Select the proper window size or slightly larger to fit your primary conductor. Refer to the table below. 3. Determine the usual application of current transformer that best suits the application for which it is intended. Refer to the table below. If the application requirements are not fully defined, refer to Burden and Accuracy Information on page 53.. After selecting a transformer, check its accuracy and burden capabilities by referring to the information page for that transformer. 0 Schneider Electric All Rights Reserved /0

3 Selection Criteria and Selection Charts How to Select a Voltage Transformer Square D offers three models of voltage transformers, each suited for a particular application. Model 50R is designed for applications requiring accurate voltage measurement within the 0.3% accuracy class. Model 50R is ideal for switchboard use with % instrumentation. Model R is designed for voltage indication where accuracy is less critical or where burden requirements are low. Model R is ideally suited for use with transducers and panelboards, and other monitoring applications. Model 70R is designed for extemely accurate voltage measurement where a very low burden is to be used. Examples of such applicatons include the input to PLC modules and other electronic devices with a high input impedance. Transformers Selection Chart Window Diameter IN mm Model Usual Application Metering Metering or Control ing High Output ing Primary Range in Amperes (5 A Secondary) Multi Ratio (MR) UL Recognized Product.3 NR YES NR -0 YES 5R -0 YES R -750 YES R -750 YES 7RL YES 7RT (w/ A secondary) 7R YES 7R YES 7RFT YES.50 3 R -500 YES 0R -0 YES R -0 YES R 0-00 YES.00 R 0-00 YES.5 70R 0-00 YES.50 3R 0-00 MR YES R -0 YES R YES 5.75 R YES.5 59 R YES. 75 5R 0-00 MR YES 5R YES.3 R YES.x.5 5x R -00 YES 3.50x.5 9x YES 3.5x. 90x 70R YES 7.5x3.75 9x95 5R YES Voltage Transformers Selection Chart Application Model Accuracy/Burden and Thermal Rating Primary Voltages ( Volt Secondary) UL Recognized Product YES Product Data on Page No. Large Burden 50R 0.3 W, X, M, Y; 500 VA Thermal to 0 Volts YES Small Burden R 0. W,.X; 50 VA Thermal to 0 Volts YES Small Burden 70R 0.3W,.X; 50 VA Thermal to 0 Volts YES Mounting Brackets Model Bracket Model Bracket Model Bracket Model Bracket Model Bracket NR MB- R MB- R MB-3 70R MB-30 3R Included 5NR MB- 7R MB- R MB-3 R MB-9 R MB-3 7RL MB-7 7R MB- R MB-3 0R Included R Not Available 5R Included X MB- 5R MB-30 R Included 70R Not Available R MB- R MB-3 5R MB-30 R Included 73 Not Available /0 0 Schneider Electric All Rights Reserved 3

4 General Purpose Transformers Models NR, 5NR, 5R, 7RL, and 7RT Model NR Designed for ammeter use, therefore, needs only one panel meter. DESCRIPTION These low cost, compact units offer good electrical performance in a general purpose transformer. UL and CUL Listed per ification XODW. Feature permanent polarity marks molded into the case. All models include two # AWG, " long secondary leads (white polarity X lead). Frequency: 50-0 Hz. Insulation: kv BIL Full Wave (0 Volt class). Applicable Standard: ANSI C57.3. Mounts easily on the conductor. No mounting bracketsnecessary. Optional mounting brackets are available and shipped unassembled. Model 5R features mounting ears molded into the case for easy installation. Model 7RL is are designed for applications used with ammeters, wattmeters, small relays, and cross current compensation. Optional terminals are available. Order as 7RT. Single Ratio Connection Diagram H Model 5NR Designed for ammeter and solid-state transducer applications. X X Excitation curves for Model NR are not available. See the Square D Digest for pricing. Optional Mounting Bracket MB- Mounting bracket MB- is for use with Model 5NR current transformer. The MB- bracket may also be applied to the Model NR, if bracket is required. Removable mounting ears are supplied on Model 5R only. Model 5R Designed for ammeter and solid-state transducer applications. X White No. AWG Leads in. ( mm) Special lead lengths available Black. Diameter Mounting Hole ( Locations) (Model 5R only) A H B E C D. Diameter Mounting Hole ( Locations) T.50 R. 5 S Mounting Bracket R S T IN mm IN mm IN mm Dual inches mm MB MB Model 7RL Designed for ammeter and solid-state transducer applications. Model A B C D E Mounting Bracket IN mm IN mm IN mm IN mm IN mm NR MB- 5NR MB- 5R RL MB-7 7RT MB-7 0 Schneider Electric All Rights Reserved /0

5 General Purpose Transformers Models NR, 5NR, 5R, 7RL, and 7RT Model NR Rating Accuracy Weight VA Hz VA 0 Hz (at Rated ) (Ohms) at 5 C lb kg NR :5.0.0 ±% NR-0 :5.0.0 ±% NR : ±% NR-0 : ±% NR- :5.0.0 ±% NR- : ±% NR-50 5: ±% NR-5 50: ±% NR- 0: ±% NR-5 50: ±% NR : ±% Rating Factor 30 C Ambient Temp. =.0 Model 5NR Rating Accuracy Weight VA Hz VA 0 Hz (at Rated ) (Ohms) at 5 C lb kg 5NR- :5.0.0 ±% NR-5 50: ±% NR- 0: ±% NR-5 50: ±% NR : ±% NR- 0: ±% NR : ±% NR- 0: ±% Rating Factor 30 C Ambient Temp. =.0 Excitation Curves 5NR Secondary Voltage Hz... 0:5 500:5 0:5 300:5 50:5 0:5 50:5 : Secondary Exciting Amperes Hz Model 7RL Rating Accuracy Weight VA Hz VA 0 Hz (at Rated ) (Ohms) at 5 C lb kg 7RL : =% RL- : =% RL-5 50: =% RL- 0: =% RL-5 50: =% RL : =% RL- 0: =% RL : =% RL- 0: =% RL : =% RL- 0: =% RL- 0: =% RL- 0: =% RL-5 500: =% Rating Factor 30 C Ambient Temp. =.5 /0 0 Schneider Electric All Rights Reserved 5

6 General Purpose Transformers Models NR, 5NR, 5R, 7RL, and 7RT Model 7RT (5 Ampere Ratio) Rating Accuracy Weight VA Hz VA 0 Hz (at Rated ) (Ohms) at 5 C lb kg 7RT : % RT- : % RT-5 50: % RT- 0:5 7RT-5 50:5 7RT :5 7RT- 0:5 7RT :5 7RT- 0:5 7RT :5 7RT- 0:5 7RT- 0:5 7RT- 0:5 7RT-5 500:5 Rating Factor 30 C Ambient Temp. =.5 Excitation Curves Model 7RL and 7RT % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % 3.5. Secondary Voltage Hz.. 0:5 500:5 0:5 300:5 50:5 0:5 50:5 :5 50:5 Secondary Voltage Hz.. 500:5 0:5 0:5 0:5 750: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz 0 Schneider Electric All Rights Reserved /0

7 General Purpose Transformers Models NR, 5NR, 5R, 7RL, and 7RT Model 7RT ( Ampere Ratio) Rating 7RT : 7RT : 7RT : 7RT--00 0: 7RT : 7RT--00 0: 7RT--00 0: 7RT--00 0: 7RT : Rating Factor 30 C Ambient Temp. =.5 VA Hz Excitation Curves Model 7RL and 7RT VA 0 Hz Accuracy (at Rated ) (Ohms) at 5 C Weight lb kg % % % % % % % % % % % % % % % % % % % % % % %.7. Secondary Voltage Hz... 0:5 500:5 0:5 300:5 50:5 0:5 50:5 :5 50:5 Secondary Voltage Hz :5 0:5 0:5 0:5 750: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz Model 5R Rating Accuracy Weight VA Hz VA 0 Hz (at Rated ) (Ohms) at 5 C lb kg 5R- :5.0.0 ±% R-5 50: ±% R- 0: ±% R-5 50: ±% R : ±% R- 0: ±% R : ±% R- 0: ±% Rating Factor 30 C Ambient Temp. =.0 Excitation Curves Model 5R Secondary Voltage Hz... 0:5 500:5 0:5 300:5 50:5 0:5 50:5 : Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 7

8 Torroidal Transformers (Single Ratio) Models R, 7R, and 7RFT DESCRIPTION Model R Designed for metering applications. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Model 7RFT features molded mounting feet. Frequency: 5-0 Hz. Insulation: kv BIL Full Wave (0 Volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model 7R Designed for metering applications. Model 7RFT Designed for metering applications. -3 UNF Female Thread ( Locations) Nameplate H Primary Polarity Mark. Diameter Mounting Hole ( Locations) H F CL H B A G X E C CL Mounting Bracket R S T IN mm IN mm IN mm MB MB X Secondary Polarity Mark..7 B D T x.50 Slot ( Locations) Mounting Bracket MB-. Dia. Mounting Hole ( Locations) T. x.50 Slot ( Locations) Mounting Bracket MB-. Dia. Mounting Hole ( Locations) R R S R S Dual inches mm Model A B C D E F G H Mounting Bracket IN mm IN mm IN mm IN mm IN mm IN mm IN mm IN mm R MB- 7R MB- 7RFT Schneider Electric All Rights Reserved /0

9 Torroidal Transformers (Single Ratio) Models R, 7R, and 7RFT Model RL Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R Secondary Voltage Hz ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- : R-5 50: R- 0: R-5 50: R : R- 0: R : R- 0: R : :5 500:5 0:5 300:5 0:5 0:5 50:5 50:5 : Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 9

10 Torroidal Transformers (Single Ratio) Models R, 7R, and 7RFT Model 7R Rating q ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 7R- 0: R-5 50: R : R- 0: R : R- 0: R : R- 0: R- 0: R- 0: *7R-5 500: Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 * 7R-5 Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Model 7RF Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Models 7R and 7RFT ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 7RFT- 0: RFT-5 50: RFT : RFT- 0: RFT : RFT- 0: RFT-5 50: RFT : RFT- 0: RFT- 0: RFT- 0: Secondary Voltage Hz 0:5 0:5 500:5 50:5 300:5 0:5 Secondary Voltage Hz 500:5 0:5 0:5 750:5 0: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz 0 Schneider Electric All Rights Reserved /0

11 Torroidal Transformers (Single Ratio) Models R, 7R, and 7RFT /0 0 Schneider Electric All Rights Reserved

12 Torroidal Transformers (Single Ratio) Models R and 7R DESCRIPTION Model R Designed for metering and control relaying applications Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz Insulation: kv BIL Full Wave (0 Volt class) Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model 7R Designed for metering and control relaying applications. -3 UNF Female Thread ( Locations) F G X Secondary Polarity Mark.. Dia. Mounting Hole ( Locations).7. 7 Nameplate H Primary Polarity Mark. Diameter Mounting Hole ( Locations) H A CL H B X E CL C B.7 D T R S. x.50 Slot ( Locations) Mounting Bracket MB-. Dia. Mounting Hole ( Locations).7. 7 Mounting Bracket R S T IN mm IN mm IN mm MB MB R T R S. x.50 Slot ( Locations) Mounting Bracket MB- Dual inches mm Model A B C D E F G H Mounting Bracket IN mm IN mm IN mm IN mm IN mm IN mm IN mm IN mm R MB- 7R MB- 0 Schneider Electric All Rights Reserved /0

13 Torroidal Transformers (Single Ratio) Models R and 7R Model R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves ANSI metering Accuracy - Hz Weight Rating Factor B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- : R-5 50: R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R :5 C Secondary Voltage Hz :5 500:5 0:5 300:5 0:5 0:5 50:5 50:5 : Secondary Exciting Amperes Hz Model 7R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 * 7R-5 Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q=ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model 7R ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 7R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C *7R-5 500:5 C Secondary Voltage Hz 0:5 0:5 500:5 50:5 300:5 0:5 Secondary Voltage Hz 500:5 0:5 0:5 750:5 0: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 3

14 Torroidal Transformers (Single Ratio) Models R and R DESCRIPTION Model R Designed for metering and control relaying applications. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X -3 UNF Pan Head Screw ( Locations) Nameplate F G X Secondary Polarity Mark. X Model R Designed for metering and relaying applications. H Primary Polarity Mark.53 Diameter Mounting Hole ( Locations) A H C E B T R S x.3 Slot ( Locations).73 9 C B E D. x.00 Slot ( Locations) Mounting Bracket MB-3 & 3 Dual inches mm Model A B C D E F G Mounting Bracket IN mm IN mm IN mm IN mm IN mm IN mm IN mm R MB-3 R MB-3 Model Mounting Bracket R S T IN mm IN mm IN mm R MB R MB Schneider Electric All Rights Reserved /0

15 Torroidal Transformers (Single Ratio) Models R and R Model R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500:5 C R- 0:5 C R- 00:5 C Secondary Voltage Hz 0:5 0:5 500:5 0:5 0:5 0:5 500:5 300:5 0:5 Secondary Voltage Hz 00:5 0: Secondary Exciting Amperes Hz Model R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R Secondary Exciting Amperes Hz ANSI metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500:5 C R- 0:5 C R- 00:5 C Secondary Voltage Hz 500:5 0:5 0:5 500:5 0:5 0:5 300:5 0:5 Secondary Voltage Hz 00:5 0:5 0: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved Secondary Exciting Amperes Hz 5

16 Torroidal Transformers (Single Ratio) Models R and R DESCRIPTION Model R Designed for metering and control relaying applications. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz. Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model R Designed for metering and relaying applications. H Primary Polarity Mark.53 Diameter Mounting Hole ( Locations) -3 UNF Pan Head Screw ( Locations) Nameplate A H F X G C E B X Secondary Polarity Mark. T R S x.3 Slot ( Locations).73 9 C B E D. x.00 Slot ( Locations) Mounting Bracket MB-3 & 3 Dual inches mm Model A B C D E F G Mounting Bracket IN mm IN mm IN mm IN mm IN mm IN mm IN mm R MB-3 R MB-3 Model R S T Mounting Bracket IN mm IN mm IN mm R MB-3 R MB-3 0 Schneider Electric All Rights Reserved /0

17 Torroidal Transformers (Single Ratio) Models R and R Model R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 * R- Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500:5 C R- 0:5 C R- 00:5 C R-5 500:5 C R :5 C *R- 00: Secondary Voltage Hz 0:5 0:5 0:5 0:5 0:5 0:5 500:5 300:5 0: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 7

18 Torroidal Transformers (Single Ratio) Models R and R Model R Rating q ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R : Ground Fault Sensing R- : R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500:5 C R- 00:5 C R-5 500:5 C R :5 C R- 00:5 C *R :5 C *R- 00:5 C Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 * R-50 and R- Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R Secondary Voltage Hz :5 500:5 500:5 0:5 0:5 0:5 0:5 0:5 500:5 :5 50:5 Secondary Voltage Hz :5 00:5 5000:5 00: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz 0 Schneider Electric All Rights Reserved /0

19 Torroidal Transformers (Single Ratio) Models R and R /0 0 Schneider Electric All Rights Reserved 9

20 Torroidal Transformers (Single Ratio) Model 5R Description Model 5R Designed for relaying and other current sensing applications. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz. Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Connections and Connection Diagrams Model 5R- Model 5R- Model 5R- Model 5R-30 Model 5R- 0:5 MR 0:5 MR 00:5 MR 3000:5 MR 00:5 MR Rating (A) 50 X5 X X3 X X Secondary Terminal Connections Rating (A) X5 X X3 X X Secondary Terminal Connections Rating (A) X5 X X3 X X Secondary Terminal Connections Rating (A) X5 X X3 X X Secondary Terminal Connections X5 X X3 X X Rating (A) Secondary Terminal Connections 50:5 X-X3 :5 X-X3 300:5 X3-X 300:5 X3-X 500:5 X-X :5 X-X 0:5 X-X 0:5 X-X 500:5 X-X5 0:5 X3-X 50:5 X-X3 300:5 X-X3 500:5 X-X5 0:5 X3-X5 500:5 X-X3 0:5 X-X5 0:5 X-X5 0:5 X-X3 0:5 X-X 00:5 X-X3 50:5 X3-X 500:5 X3-X :5 X-X 0:5 X-X3 500:5 X-X 300:5 X-X 0:5 X-X 0:5 X-X3 500:5 X-X 3000:5 X-X 0:5 X-X 0:5 X-X 500:5 X-X 00:5 X-X5 3500:5 X-X5 50:5 X3-X5 0:5 X-X5 0:5 X-X5 0:5 X-X3 00:5 X-X5 500:5 X-X5 0:5 X-X5 00:5 X-X5 500:5 X-X 0:5 X-X5 3000:5 X-X5-3 UNF Pan Head Screw (5 Locations) Omitted on Model 5R F G X Secondary Polarity Mark. Dual inches mm Nameplate H Primary Polarity Mark.50 Diameter Mounting Hole ( Locations) H X5 X X3 X X A C B E C E B. D T R S x.3 Slot ( Locations) x.00 Slot ( Locations) Mounting Bracket MB-30 Mounting R S T Bracket IN mm IN mm IN mm MB Model A B C D E F G IN mm IN mm IN mm IN mm IN mm IN mm IN mm 5R Schneider Electric All Rights Reserved /0

21 Torroidal Transformers (Single Ratio) Model 5R Model 5R- Ratingq Accuracy * (Ohms) 5R- 50: : : : : : : : : :5 C0 0.9 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI Standard C57.3 and NEMA Rating SG-. Weight (lb/ kg) lbs kg 3 9 Excitation Curves Model 5R- Secondary Voltage Hz Secondary Exciting Amperes Hz 0:5 500:5 50:5 0:5 300:5 0:5 50:5 50:5 :5 50:5 Model 5R- Ratingq Accuracy * 5R- (Ohms) at 5 C 50: : : : : : : : : :5 C * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI Standard C57.3 and NEMA Rating SG-. Weight (lb/kg) lbs kg 3 9 Excitation Curves Model 5R- Secondary Voltage Hz :5 0:5 900:5 0:5 0:5 0:5 500:5 0:5 :5 300: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved

22 Torroidal Transformers (Single Ratio) Model 5R Model 5R- Ratingq Accuracy * 5R- (Ohms) at 5 C 300: : : : : : : : :5 C0 0.7 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI Standard C57.3 and NEMA Rating SG-. Weight (lb/kg) lbs kg 3 9 Excitation Curves Model 5R- Secondary Voltage Hz :5 0:5 500:5 0:5 :5 0:5 500:5 300:5 0: Secondary Exciting Amperes Hz Model 5R-30 Ratingq Accuracy * 5R-30 (Ohms) at 5 C) 300: :5 0. 0: :5 0. 0: : : : : :5 C0.39 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI Standard C57.3 and NEMA Rating SG-. Weight (lb/kg) lbs kg 3 9 Excitation Curves Model 5R-30 Secondary Voltage Hz :5 0:5 500:5 500:5 00:5 0:5 0:5 0:5 500:5 300: Secondary Exciting Amperes Hz 0 Schneider Electric All Rights Reserved /0

23 Torroidal Transformers (Single Ratio) Model 5R Model 5R- Ratingq Accuracy * (Ohms) 5R- 500: : : : : : : :5 C0.753 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI Standard C57.3 and NEMA Rating SG-. Weight (lb/kg) lbs kg 3 9 Excitation Curves Model 5R- Secondary Voltage Hz :5 3000:5 3500:5 00:5 500:5 500:5 0:5 500: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 3

24 Torroidal Transformers (Single Ratio) Model 5R DESCRIPTION Model 5R Designed for metering, relaying and other current sensing applications. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz. Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X -3 UNF Pan Head Screw (5 Locations) Omitted on Model 5R F G X Secondary Polarity Mark. Dual inches mm Nameplate H Primary Polarity Mark.50 Diameter Mounting Hole ( Locations) H X5 X X3 X X A C B E C E B. D T R S x.00 Slot ( Locations) Mounting Bracket MB x.3 Slot ( Locations) Mounting Bracket R S T IN mm IN mm IN mm MB Model A B C D E F G IN mm IN mm IN mm IN mm IN mm IN mm IN mm 5R Schneider Electric All Rights Reserved /0

25 Torroidal Transformers (Single Ratio) Model 5R Model 5R Ratio q Accuracy Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q For a multi-ratio unit equivalent to Model 5R, refer to Model 5R. Excitation Curves Model 5R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 5R :5 C R- :5 C R-5 50:5 C R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500:5 C R- 0:5 C R- 00:5 C R-5 500:5 C R :5 C R- 00:5 C Secondary Voltage Hz :5 0:5 500:5 0:5 0:5 0:5 0:5 0:5 500:5 50:5 300:5 50:5 0:5 :5 Secondary Voltage Hz :5 500:5 3000: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 5

26 Torroidal Transformers (Single Ratio) Models 70R and R DESCRIPTION Model 70R Designed for metering and control relaying applications. Permanent polarity marks are molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz. Insulation: kv BIL Full Wave (0 volt class) Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model R Designed for metering and light-duty control relaying applications. H Primary Polarity Mark "H" Diameter Mounting Hole ( Locations) -3 UNF Pan Head Screw ( Locations) Nameplate H A C B F X G E C E B X Secondary Polarity Mark. D T x.00 Slot ( Locations). Diameter Mounting Hole ( Locations) 5. R S Mounting Bracket MB x.3 Slot ( Locations) Mounting Bracket R S T IN mm IN mm IN mm MB T. x.50 Slot ( Locations) R S Mounting Bracket MB-9 Dual inches mm MB Model A B C D E F G H Mounting Bracket IN mm IN mm IN mm IN mm IN mm IN mm IN mm IN mm 70R MB-30 R MB-9 0 Schneider Electric All Rights Reserved /0

27 Torroidal Transformers (Single Ratio) Models 70R and R Model 70R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or additional secondary turns. Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or additional secondary turns. Excitation Curves Models 70R and R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 70R- 0: R-5 50: R : R- 0: R : R- 0: R :5 C R- 0:5 C R- 0:5 C R- 0:5 C R-5 500: R- 0: R- 00: R-5 500: Model R Rating q ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- : R-5 50: R- 0: R-5 50: R : R- 0: R : R- 0: R : R- 0: R- 0: R- 0: R-5 500: Secondary Voltage Hz.. 0:5 0:5 0:5 0:5 750:5 0:5 500:5 50:5 300:5 0:5 Secondary Voltage Hz.. 0:5 300:5 50:5 50:5 0:5 :5 Secondary Voltage Hz.. 750:5 500:5 0:5 Secondary Voltage Hz.. 500:5 0:5 0:5 0: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz 70R R R R /0 0 Schneider Electric All Rights Reserved 7

28 Torroidal Transformers (Single Ratio) Models 0R and R DESCRIPTION Model 0R Designed for metering and relaying applications. High-burden capacity design in a choice of small to medium window sizes. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Standard models include a mounting base. If not required, please specify Less Base. Frequency: 5-0 Hz. Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model R Designed for metering and relaying applications -3 UNF Pan Head Screw ( Locations) Nameplate X X Secondary Polarity Mark. H Primary Polarity Mark CL H A CL.5 Diameter ( Locations) Dual inches mm Model Dimension A IN mm 0R.50 3 R R.50 3R Schneider Electric All Rights Reserved /0

29 Torroidal Transformers (Single Ratio) Models 0R and R Model 0R Rating q Rating Factor 30 C Ambient Temp. =.5 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model 0R ANSI Metering Accuracy - Hz Weight DC Resistanace B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 0R- :5 C R-5 50:5 C R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C Secondary Voltage Hz :5 0:5 500:5 50:5 300:5 50:5 0:5 : Secondary Exciting Amperes Hz Model R Rating q Rating Factor 30 C Ambient Temp. =.5 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R ANSI Metering Accuracy - Hz Weight DC Resistanace B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- :5 C R-5 50:5 C R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C Secondary Voltage Hz :5 0:5 750:5 0:5 500:5 50:5 300:5 50:5 0:5 : Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 9

30 Torroidal Transformers (Single Ratio) Models R and 3R DESCRIPTION Model R Designed for metering and control relaying applications. High-burden capacity design in a choice of small to medium window sizes. Permanent polarity marks molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Standard modes include a mounting base. If not required, please specify Less Base. Frequency: 5-0 Hz. Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Single Ratio Connection Diagram H X X Model 3R Designed for metering and relaying applications. -3 UNF Pan Head Screw ( Locations) Nameplate X Secondary Polarity Mark. X H Primary Polarity Mark CL H A CL.5 Diameter ( Locations) Dual inches mm Model Dimension A IN mm R.50 3R Schneider Electric All Rights Reserved /0

31 Torroidal Transformers (Single Ratio) Models R and 3R Model R Rating q Rating Factor 30 C Ambient Temp. =.5 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- :5 C R-5 50:5 C R- 0:5 C R-5 50:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R- 0:5 C Secondary Voltage Hz :5 0:5 750:5 500:5 0:5 0:5 50:5 300:5 50:5 0:5 :5 Secondary Voltage Hz :5 0:5 0:5 0:5 750:5 0:5 500:5 50:5 300:5 0:5 50:5 :5 Secondary Voltage Hz :5 00:5 500:5 500:5 0: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz Model 3R Rating q Rating Factor 30 C Ambient Temp. =.5 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model 3R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 3R- :5 C R- 0:5 C R- 0:5 C R-5 50:5 C R-5 500:5 C R- 0:5 C R- 0:5 C R- 00:5 C R-5 50:5 C R-5 500:5 C R :5 C R :5 C R- 0:5 C R :5 C R- 0:5 C R :5 C R- 0:5 C Secondary Voltage Hz :5 0:5 0:5 0:5 750:5 0:5 500:5 50:5 300:5 0:5 50:5 :5 Secondary Voltage Hz :5 00:5 500:5 500:5 0: Secondary Exciting Amperes Hz Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 3

32 Torroidal Transformers (Single Ratio) Models R DESCRIPTION Secondary terminals are easy-to-install #-3 brass screws. Optional mounting brackets are shipped unassembled. Frequency: 5-0 Hz (Modes R and R). Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Model R Designed for metering and relaying applications. Single Ratio Connection Diagram H X -3 UNF Pan Head Screw ( Locations) Nameplate F X G X Secondary Polarity Mark. T x.00 Slot ( Locations) 5. R S x.3 Slot ( Locations) X Mounting Bracket MB-3 and MB-3 Dual inches mm H Primary Polarity Mark "H" Diameter Mounting Hole ( Locations) H A C E B Mounting Bracket R S T IN mm IN mm IN mm MB C B E D MB Model A B C D E F G H IN mm IN mm IN mm IN mm IN mm IN mm IN mm IN mm R Mounting Bracket MB-3 Model R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 (models R-30 and - =.075 at 55 C) q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- 0: R- 0: R- 00: R-5 500: R : R- 00: Secondary Voltage Hz :5 00:5 500:5 00: Secondary Exciting Amperes Hz 0 Schneider Electric All Rights Reserved /0

33 Torroidal Transformers (Single Ratio) Models R /0 0 Schneider Electric All Rights Reserved 33

34 Torroidal Transformers (Single Ratio) Model 3R DESCRIPTION Model 3R Designed for relaying and other current sensing applications. High-burden capacity design for installation over the ground shield in a current transformer pocket of a high voltage apparatus bushing. Permanent polarity marks are molded into the case. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easier installation. Windings are completely distributed around the core on each tap, resulting in a low reactance on all taps. Mounting holes are provided for bolting the unit around a power transformer or circuit breaker bushing. Frequency: Hz. Insulation: kv BIL full wave (0 volt class) Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Connections and Connection Diagrams Model 3R- Model 3R- Model 3R- Model 3R-30 Model 3R- 0:5 MR 0:5 MR 00:5 MR 3000:5 MR 00:5 MR 50 X5 X X3 X X X5 X X3 X X X5 X X3 X X X5 X X3 X X X5 X X3 X X Rating (A) Secondary Terminal Connections Rating (A) Secondary Terminal Connections Rating (A) Secondary Terminal Connections Rating (A) Secondary Terminal Connections Rating (A) Secondary Terminal Connections 50:5 X-X3 :5 X-X3 300:5 X3-X 300:5 X3-X 500:5 X-X :5 X-X 0:5 X-X 0:5 X-X 500:5 X-X5 0:5 X3-X 50:5 X-X3 300:5 X-X3 500:5 X-X5 0:5 X3-X5 500:5 X-X3 0:5 X-X5 0:5 X-X5 0:5 X-X3 0:5 X-X 00:5 X-X3 50:5 X3-X 500:5 X3-X :5 X-X 0:5 X-X3 500:5 X-X 300:5 X-X 0:5 X-X 0:5 X-X3 500:5 X-X 3000:5 X-X 0:5 X-X 0:5 X-X 500:5 X-X 00:5 X-X5 3500:5 X-X5 50:5 X3-X5 900:5 X3-X5 0:5 X-X5 0:5 X-X3 00:5 X-X5 500:5 X-X5 0:5 X-X5 00:5 X-X5 500:5 X-X 0:5 X-X5 0:5 X-X5 3000:5 X-X5-3 UNF Pan Head Screw (5 Locations) X X X3 X X5. X Secondary Polarity Mark Nameplate H Primary Polarity Mark H Note: Model 3R is supplied with four () mounting holes molded into case. Mounting brackets not required..5 Diameter Mounting Hole ( Locations) Dual inches mm 3 0 Schneider Electric All Rights Reserved /0

35 Torroidal Transformers (Single Ratio) Model 3R Model 3R- 3R- Ratio q Accuracy * (Ohms) at 5 C 50: : : : : :5 0. 0: : : :5 C 0.09 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.5, Rating Factor 55 C Ambient Temp. =.33 qtaps in accordance with ANSI C57.3 and NEMA SG- Weight lb kg 7.3.Excitation Curves 3R Secondary Voltage Hz 0 0:5 500:5 50:5 0:5 300:5 0:5 50:5 :5 50:5 50: Secondary Exciting Amperes Hz Model 3R- 3R- Ratio q Accuracy (Ohms) at 5 C 300: : :5 0. 0: : : : : :5 C * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.5, Rating Factor 55 C Ambient Temp. =.33 q Taps in accordance with ANSI C57.3 and NEMA SG-. Weight lb kg.7 Excitation Curves Model 3R- Secondary Voltage Hz :5 0:5 900:5 0:5 0:5 0:5 500:5 0:5 :5 300: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 35

36 Torroidal Transformers (Single Ratio) Model 3R Model 3R- 3R- Ratio q Accuracy (Ohms) at 5 C 300: : : :5 0.9 :5 0. 0: : : :5 C * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.5, Rating Factor 55 C Ambient Temp. =.33 q Taps in accordance with ANSI C57.3 and NEMA SG- Weight lb kg 3 5..Excitation Curves Model 3R- Secondary Voltage Hz :5 0:5 500:5 :5 0:5 500:5 300:5 0:5 0: Secondary Exciting Amperes Hz Model 3R-30 3R-30 Ratio q Accuracy (Ohms) at 5 C 300: : : : : : : : : :5 C0.0 * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.5, Rating Factor 55 C Ambient Temp. =.33 q Taps in accordance with ANSI C57.3 and NEMA SG-. Weight lb kg Excitation Curves Model 3R-30 Secondary Voltage Hz :5 500:5 0:5 00:5 500:5 0:5 0:5 0:5 500:5 300: Secondary Exciting Amperes Hz 3 0 Schneider Electric All Rights Reserved /0

37 Torroidal Transformers (Single Ratio) Model 3R Model 3R- 3R- Ratio q Accuracy (Ohms) at 5 C 500:5 0. 0: : : : : : :5 C * Accuracy only applies to the nominal ratio Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 q Taps in accordance with ANSI C57.3 and NEMA SG-. Weight lb kg Excitation Curves Model 3R- Secondary Voltage Hz :5 3000:5 3500:5 00:5 500:5 500:5 0:5 500: Secondary Exciting Amperes Hz /0 0 Schneider Electric All Rights Reserved 37

38 H Rectangular Window Transformers (Single Ratio) Models R and 5R DESCRIPTION Features rectangular window for bus conductor applications with minimum clearance requirements. Large, easy-to-read ratios are clearly marked on the case. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Frequency: 5-0 Hz (Modes R and R). Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Model R Designed for metering applications with minimum clearances. Single Ratio Connection Diagram H X X Model R Nameplate X -3 UNF Pan Head Screw ( Locations) X Secondary Polarity Mark H Primary Polarity Mark (On Back Side) H Primary Polarity Mark H Note: Model R is supplied with four () mounting holes molded in case. Mounting brackets not required... Diameter Mounting Hole ( Locations) Dual inches mm 3 Model R Rating q ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg R- : R-5 50: R- 0: R : R- 0: R- 0: R- 0: R- 0: R- 0: R- 00: R-5 500: R : R- 00: Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 Models R-5, -30, and - Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. 0 Schneider Electric All Rights Reserved /0

39 Model 5R Rectangular Window Transformers (Single Ratio) Models R and 5R 5.09 X Secondary Polarity mark X Nameplate Model 5R Designed for metering applications H Primary Polarit y Mark (H Primary Polarity mark on back) Diameter Mounting Hole ( Locations) Dual inches mm Model 5R Rating q ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 5R- 0: R : R- 0: R : R- 0: R- 0: R- 0: R-5 500: R- 0: R- 00: R-5 500: R : R-3 30: R- 00: R : Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 Models R-5, -30, and - Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. /0 0 Schneider Electric All Rights Reserved 39

40 Split Core Transformers (Single Ratio) Models 70R and 73 DESCRIPTION Model 70R features a split core design for easy installation over an existing bus or cable conductor. Window length or width may be increased or decreased as an option. Large, easy-to-read ratios are clearly marked on the case. Model 70R Split core design for load surveying, ground fault relaying and metering applications. Secondary terminals are #-3 brass screws and include flat washers and bronze lockwashers for easy installation. Mounting brackets provided with transformer. Frequency: Hz (Model 70R and 73). Insulation: kv BIL full wave (0 volt class). Applicable Standard ANSI C57.3. UL and CUL recognized per ification XODW. Screws and Core Section Removable for Installation Diameter Mounting Hole ( Locations) Screws and Core Sections Removable for Installation Model 73 Designed for load surveying and current measurement on non-revenue metering and energy management applications.. H H Polarity Mark H X 0.3 () Mounting Holes H Primary Polarity Mark.3. X Polarity Mark 7 X Primary Polarity Terminal X X X X N/P Note: Model 70R is supplied with four () mounting holes in frame. Mounting brackets not required. Model 73 Dual inches mm Model 70R 0 Schneider Electric All Rights Reserved /0

41 Split Core Transformers (Single Ratio) Models 7R and 75R (Single Ratio) Model 70R Rating q Rating Factor 30 C Ambient Temp. =.33, Rating Factor 55 C Ambient Temp. =.0 Models 70R--30, -, and -50 Rating Factor 30 C Ambient Temp. =.0, Rating Factor 55 C Ambient Temp. = 0.75 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. 73-0: : : : : : : : : : : : : : Rating Factor 30 C Ambient Temp. =.33 Models 73R--30 and - Rating Factor 30 C Ambient Temp. =.0 q Ratios are based on one primary turn, with user-applied primary conductor. Refer to page 5 for other ratios using multiple primary turns or secondary turns. Excitation Curves Model 70R and 73R ANSI Metering Accuracy - Hz Weight B0. B0. B0.5 B0.9 B. (Ohms) at 5 C lb kg 70R- 0: R : R- 0: R- 0: R- 0: R- 0: R-5 500: R- 0: R- 00: R-5 500: R : R- 00: R : Model 73R Ratio q B0..5 VA ANSI Metering Accuracy - Hz B0. 5 VA B0.5.5 VA B0.9.5 Va B. 5 VA (Ohms) at 5 C Secondary Voltage Hz :5 00:5 00:5 500:5 0:5 0:5 0:5 0:5 0:5 0:5 500:5 Secondary Voltage Hz :5 3000:5 00:5 00:5 500:5 500:5 0:5 0:5 0:5 0:5 0:5 0:5 500: Secondary Exciting Amperes Hz Model 70R Secondary Exciting Amperes Hz Model 73R /0 0 Schneider Electric All Rights Reserved

42 Bushing Transformers, 50 0Hz Models 7R and 75R (Single Ratio) Model 7R Window Size.5 in. (5 mm) Rating (A) ANSI Accuracy ification - Hz Metering B-0. B-0. B-0.5 B-0.9 B-. 7R500 50:5 7R750 75:5 C.. 7R :5 C.. 7R5 50:5 C 0.. 7R 0:5 C R5 50:5 C R30 300:5 C R 0:5 C R50 500:5 C R 0:5 C R75 750:5 C R 0:5 C R 0:5 C R 0:5 C R5 500:5 C R 0:5 C R 00:5 C R5 500:5 C R :5 C R 00:5 C Rating Factor 30 C Ambient Temp. =.0, Model 7R Rating Factor 30 C Ambient Temp. =.5 Model 75 Window Size.5 in. (5 mm) Rating (A) ANSI Accuracy ification - Hz Metering B-0. B-0. B-0.5 B-0.9 B-. Rating Factor 30 C Ambient 75R500 50:5 C R750 75:5 C R :5 C R5 50:5 C R 0:5 C R5 50:5 C R30 300:5 C R 0:5 C R50 500:5 C R 0:5 C R75 750:5 C R 0:5 C R 0:5 C R 0:5 C R5 500:5 C R 0:5 C R 00:5 C R5 500:5 C R :5 C R 00:5 C Rating Factor 30 C Ambient Temp. =.0, Model 75R Rating Factor 30 C Ambient Temp. =.5 0 Schneider Electric All Rights Reserved /0

43 Bushing Transformers, 50 0 Hz Models 7R and 75R (Single Ratio) Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) :5 ANSI Accuracy ification Hz Metering (Ohms) at 5 C B-0. B-0. B-0.5 B-0.9 B : :5 0. 0: :5 0.7 C :5 0. 0: : : : Rating Factor 30 C Ambient.0 Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) 300:5 ANSI Accuracy ification Hz Metering (Ohms) at 5 C B-0. B-0. B-0.5 B-0.9 B : : :5 0. :5 C : : : : Rating Factor 30 C Ambient.0 Model 7R-30 Window Size.5 in. (5 mm) 7R30 Rating (A) 300:5 Model 7R-, -, -30, - Rating Factor 30 C Ambient Temp. =.0 Model 7R- Rating Factor 30 C Ambient Temp. =.5 ANSI Accuracy ification Hz Metering (Ohms) at 5 C B-0. B-0. B-0.5 B-0.9 B : :5 0. 0:5 0. 0:5 C : : : :5 0.7 Rating Factor 30 C Ambient.0 Excitation Curves Models7R-, 7R-, and 7R-30 (left to right) SECONDARY VOLTAGE - Hz :5 0:5 900:5 0:5 0:5 500:5 0:5 300:5 0:5 : SECONDARY EXCITING CURRENT - AMPERES - Hz Secondary Voltage Hz :5 0:5 500:5 0:5 :5 0:5 500: Secondary Exciting Amperes Hz 0:5 300:5 SECONDARY VOLTAGE - Hz :5 500:5 0:5 00:5 500:5 0:5 0:5 0:5 500: SECONDARY EXCITING CURRENT - AMPERES - Hz Model 7R- Model 7R- Model 7R :5 /0 0 Schneider Electric All Rights Reserved 3

44 Bushing Transformers Models 7R and 7R (Multi Ratio) Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) 500:5 ANSI Accuracy ification Hz Metering (Ohms) at 5 C B-0. B-0. B-0.5 B-0.9 B : : : C : : : :5.570 Rating Factor 30 C Ambient.5 Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) 50:5 ANSI Accuracy ification Hz Metering (Ohms) at 5 C B-0. B-0. B-0.5 B-0.9 B : : : :5 0.0 C :5 0. 0: : : :5 0. Rating Factor 30 C Ambient.0 Model 7R-, -, -30, - Rating Factor 30 C Ambient Temp. =.0 Model 7R- Rating Factor 30 C Ambient Temp. =.5 Excitation Curves Models 7R- and 7R SECONDARY VOLTAGE - Hz :5 3500:5 3000:5 500:5 00:5 500:5 0:5 500:5 SECONDARY VOLTAGE - Hz 0 0 0:5 500:5 50:5 0:5 300:5 50:5 0:5 50:5 :5 50: SECONDARY EXCITING CURRENT - AMPERES - Hz SECONDARY EXCITING CURRENT - AMPERES - Hz Model 7R- Model 7R- 0 Schneider Electric All Rights Reserved /0

45 Bushing Transformers Models 7R and 7R (Multi Ratio) Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) Rating Factor 30 C Ambient Temp. =.0 Model 7R- Window Size.5 in. (5 mm) 7R Rating Factor 30 C Ambient Temp. =.0 Model 7R-30 Window Size.5 in. (5 mm) 7R30 Rating Factor 30 C Ambient Temp. =.0 ANSI Accuracy ification Hz Metering B-0. B-0. B-0.5 B-0.9 B-. Excitation Curves Models 7R-, 7R-, and 7R-30 (Ohms) at 5 C : : :5 0. 0: : C : : : :5 0. 0: Rating (A) ANSI Accuracy ification Hz Metering B-0. B-0. B-0.5 B-0.9 B-. (Ohms) at 5 C 300: : :5 0. 0:5 0.3 :5 C : : : :5.003 Rating (A) ANSI Accuracy ification Hz Metering B-0. B-0. B-0.5 B-0.9 B-. (Ohms) at 5 C 300: :5 0. 0: : :5 0.5 C : : : : :5.550 SECONDARY VOLTAGE - Hz :5 0:5 900:5 0:5 0:5 500:5 0:5 300:5 0:5 :5 Secondary Voltage Hz :5 0:5 500:5 0:5 :5 0:5 500:5 0:5 300:5 SECONDARY VOLTAGE - Hz :5 500:5 0:5 00:5 500:5 0:5 0:5 0:5 500:5 300: Secondary Exciting Amperes Hz SECONDARY EXCITING CURRENT - AMPERES - Hz SECONDARY EXCITING CURRENT - AMPERES - Hz Model 7R- Model 7R- Model 7R-30 /0 0 Schneider Electric All Rights Reserved 5

46 Bushing Transformers Models 7R and 7R (Multi Ratio) Model 7R- Window Size.5 in. (5 mm) 7R Rating (A) Rating Factor 30 C Ambient Temp. =.5 Model 7R- Window Size.5 in. (5 mm) 7R Rating Factor 30 C Ambient Temp. =.0 Excitation Curves Models7R- and 7R- ANSI Accuracy ification Hz Metering B-0. B-0. B-0.5 B-0.9 B-. (Ohms) at 5 C 500: : : :5.5 C : : :5.3 00:5.70 Rating (A) ANSI Accuracy ification Hz Metering B-0. B-0. B-0.5 B-0.9 B-. (Ohms) at 5 C :5 :5 0:5 0:5 300:5 300:5 0:5 0:5 500:5 500:5 C :5 0:5 0:5 0:5 900:5 900:5 0:5 0:5 0:5 0:5 SECONDARY VOLTAGE - Hz :5 3500:5 3000:5 500:5 00:5 500:5 0:5 500:5 SECONDARY VOLTAGE - Hz :5 500:5 50:5 0:5 300:5 50:5 0:5 50:5 :5 50: SECONDARY EXCITING CURRENT - AMPERES - Hz SECONDARY EXCITING CURRENT - AMPERES - Hz Model 7R- Model 7R T Model T in (mm) 7R 3.3 (3) 7R 3.3 (3) 75R.75 (7) H Ø.5 5. H R.75 (7) 0 Schneider Electric All Rights Reserved /0

47 Auxiliary Transformer Model X Model X Auxiliary Transformer Auxiliary Transformer ANSI Accuracy ification - Hz Metering Ratio (without brackets) B-0. B-0. B-0.5 X : X : X : X : X : X00500 : X : X : Rating Factor 30 C Ambient Temp. =.5-3 Studs /0 0 Schneider Electric All Rights Reserved 7

48 Voltage Transformers Models 50R, R, and 70R DESCRIPTION These voltage transformers are designed for line-to-line or line-to-ground connection on the primary voltage indicated. See the table below to determine the applicable configuration for proper system voltage indication. Model 50R is designed for switchboard use. This model features high accuracy and burden capacity for excellent performance in metering and indication. Model R is a compact, lightweight design, providing exceptional performance in electrical indicating and recording instrumentation. Model 70R is designed for extremely accurate voltage measurement where low burden is to be used. Permanent polarity marks are molded into the case. Large, easy-to-read ratios are clearly marked on the case. Primary and secondary terminals are fully insulated #-3 threaded studs, complete with nuts and washers. Terminal covers and mounting base are also supplied. Frequency: Hz. Insulation: kv BIL full wave (0 volt class) Applicable Standard ANSI C57.3. UL recognized per ification XODW. Model 50R Designed for a wide range of electrical indicating, recording instruments and protective relays in power systems. Model 50R Primary Voltage Rating (Volts) Secondary Voltage Rating (Volts) Voltage Ratio 50R- : System Transformer Connections Y Ø - Ground Ø - Ø 50R- : Y Ø - Ground Ø - Ø 50R-.: Y Ø - Ground 50R : 5Y Ø - Ground 50R- : 50R-0 0 5: Y 0Y 0 Ø - Ø Ø - Ø Ø - Ø Ø - Ø Accuracy and Burden Rating Thermal Burden Rating (VA) 30 C Ambient 55 C Ambient Weight lb kg 0.3Y,.Z k a Use on 77/ wye systems. Use V delta systems. Model R Designed for use with voltmeters, transducers and other types of electrical indicating and recording instrumentation. Model R k a Primary Voltage Rating (Volts) Use on 77/ wye systems. Use V delta systems. Secondary Voltage Rating (Volts) Voltage Ratio R- : System Transformer Connections Y Ø - Ground Ø - Ø R- : Y Ø - Ground Ø - Ø R-.: Y Ø - Ground R : 5Y Ø - Ground R- : R-0 0 5: Y 0Y 0 Ø - Ø Ø - Ø Ø - Ø Ø - Ø Accuracy and Burden Rating Thermal Burden Rating (VA) 30 C Ambient 55 C Ambient Weight lb kg 0.Y,.X Schneider Electric All Rights Reserved /0

49 Voltage Transformers Models 50R, R, and 70R Model 70R Ideal for applications such as input to PLC modules and other electronic devices with high input impedance. Model 70R k a Primary Voltage Rating (Volts) Use on 77/ wye systems. Use V delta systems. Secondary Voltage Rating (Volts) Voltage Ratio System Transformer Connections 70R : Y Ø - Ground 70R- : 70R-.73: 70R- : Y D 3Y Y Ø - Ground Ø - Ø Ø - Ground Ø - Ø Ø - Ground Ø - Ø 70R-.: Y k Ø - Ground 70R : 5Y Ø - Ground 70R-3 3.7: 70R- : 70R-0 0 5: 3Y 3 Y a 0Y 0 Ø - Ø Ø - Ø Ø - Ø Ø - Ø Ø - Ø Ø - Ø Accuracy and Burden Rating Thermal Burden Rating (VA) 30 C Ambient 55 C Ambient Weight lb kg 0.3W Polarity Mark.. Diameter Mounting Holes ( Locations) Nameplate Nameplate H H X X X SECONDARY X PRIMARY H H Dia Dual inches mm /0 0 Schneider Electric All Rights Reserved 9

50 Voltage Transformers Models 50R, R, and 70R VOLTAGE TRANSFORMER CIRCLE DIAGRAMS Circle Diagram Accuracy Determination Voltage Transformers (VT) Circle Diagrams are provided as an easy method for determining accuracy at any burden and power factor. The radial lines represent different power factors for the burdens and the concentric circles represent burden amount in Volt-Amperes. VT accuracy at a specific burden may be determined by choosing the appropriate power factor line that represents the power factor of the actual burden, then extending outward in the radial direction to the appropriate volt-ampere level. Note that the concentric circles represent proportional Volt-Amperes that increase in value as you extend outward. The Ratio Correction Factor and Phase Angle error for this Burden may be taken from the ordinate and abscissa of the circle diagram. Example: Burden Volt-Amperes = VA Burden Power Factor =.95 The Model R circle diagram provides an accuracy of operation: Ratio Correction Factor =.007 Phase Angle = +.3 minutes Standard Burdens for Voltage Transformers Burden VA Power Factor W.5 0. X M Y Z Model 50 Model Ratio Correction Factor PF 0. PF 75.0 VA 0. PF 35.0 VA 5.0 VA.5 VA 0. PF 0.7 PF 0.3 Accuracy Phase Angle (Minutes) Ratio Correction Factor PF 5.0 VA.5 VA 0.95 PF Typical 0.5 PF 0. Accuracy 0.7 PF 0. PF 0. PF 0. PF 0. PF 0 PF Phase Angle (Minutes) Model 70.0 PF 0.95 PF Typical 0.5 PF 0.7 PF PF Ratio Correction Factor VA 0. PF 0. PF 0. PF 0 PF Accuracy Phase Angle (Minutes) 50 0 Schneider Electric All Rights Reserved /0

51 Glossary of Terms and Abbreviations Term or Abbreviation Accuracy ing accuracy of current transformers Accuracy ratings of voltage transformers AMB ANSI B.I.L. Burden Compensated VA Rating Factor of window type transformers Rating Hz Insulation of Instrument Transformer kv Polarity Definition Metering accuracy of current transformers. The accuracy class followed by a standard burden for which the accuracy class applies. The accuracy rating applies only over the specified current or voltage range and at the stated frequency. The burden of current transformers may be expressed in two ways: in voltamperes (VA) or in ohms impedance, for example B-. means a burden of. ohms at a specific power factor (See page 53). To convert, use formula: VA = I Z. A relaying accuracy class is designated by two symbols which effectively describe the capability of the transformer as follows: C means the transformer ratio can be calculated, i.e. a window type current transformer with uniformly distributed windings. The C rating refers to a low-reactance design. The secondary terminal voltage rating is the voltage which the transformer will deliver to a standard burden at times normal secondary current without exceeding % ratio error. Furthermore, the ratio error must be limited to % at any current from to times rated current at any lesser burden. For example, relay accuracy class C means that the ratio can be calculated and that the ratio error will not exceed % at any current if the burden does not exceed.0 ohms ( ohm x 5 amperes X times normal current = volts). Note: Previous standards used the term L in place of C, such as L, L0, etc. CSA Standard C3 used the term L in place of C. Accuracy classes are based on the requirement that the transformer correction factor (TCF) is within specified limits when the power factor of the metered load has any value from 0. lag to.0, from zero burden to the specified standard burden (See page 5), and at any voltage from 90% to % of the rated transformer voltage. Ambient American National Standard Institute (Successor to USASI, United States of America Standards Institute) Basic insulation level, which is the withstand of a. x 50 full wave impulse of specified kv crest value. Burden of an instrument transformer is equivalent to the term load as applied to a power transformer. Transformer is compensated to provide maximum accuracy at that burden. The factor by which the nominal rated secondary current (usually 5 amperes) can be multiplied to obtain the maximum secondary current that can be carried continuously without exceeding the allowable temperature rise above a specified ambient temperature. The factor will also apply to the primary current if the primary conductor is of sufficient size to carry the current without exceeding the allowable temperature rise The ratio of the rated primary value to the rated secondary value as stated on the nameplate. Hertz = cycles per second. Denotes the maximum (Line-to-Line) voltage of the circuit on which it should be used. (NOTE: Voltage transformers may be limited by their primary voltage ratings to use at a lower voltage than that of their insulation class.) Conformity to the class means that the transformer is capable of withstanding low frequency insulation tests, and basic insulation level (BIL) tests as prescribed in ANSI C57.3. Kilovolt or 0 volts. The relative instantaneous polarity of the leads or terminals is indicated by permanent marking, i.e. H and X are of the same polarity. They are identified by white dots, white wires, or the actual terminal designations. PRI. Primary. SEC. Ratio VA Secondary. Ratio of transformer, primary: secondary. Volt-amperes. X, X Secondary Terminals (See Polarity ). /0 0 Schneider Electric All Rights Reserved 5

52 Appendices APPENDIX A ADJUSTING CURRENT TRANSFORMER RATIO Use the equations provided in this section to obtain special ratios from standard ratings. Window type current transformers (CT) are rated on the basis of a single primary turn. Other ratios are obtainable by the use of multiple turns. Any window type current transformer listed herein may have its nominal ratio adjusted to a nonstandard ratio by the use of primary and secondary turns as follows: Applying Turns to Adjust Ratio Primary Turns To provide a coarse adjustment to the ratio, the required number of primary turns should be applied as shown in Figure. An electrical turn is defined as one pass through the window. Nameplate Primary Amps = New Primary Amps of Turns Example: For :5 Ampere CT with primary turns = 5 Primary Thus the new ratio is 5:5. X Secondary Turns For finer adjustment to the ratio, secondary turns may be added or subtracted by routing the X lead in the proper direction. To subtract turns, take the X lead and pass it through the window from H to H (see Subtracting Turns at top left). To add turns, the X lead is passed through the window in the reverse direction (see Adding Turns at bottom left). [Nameplate Primary Amperes ± (Extra secondary turns x 5 Amperes/turn)]:5 = New Ratio. H Subtracting Turns: 3 primary turns with secondary turns subtracted Example: For :5 Amperes CT with secondary turns added. + ( x 5) = :5 Amperes Ratio For 50:5 Amperes CT with 3 secondary turns subtracted (3 x 5) = 35:5 Ampere Ratio H X Primary and Secondary Turns The relationship of ratio to primary and secondary turns is expressed in the following formula: Ka = Kn ± Nsa Np Where: Ka = actual transformation ratio obtained = Adding Turns: primary turn with secondary turn added Desired Primary Amperes Secondary Amperes Kn = nameplate transformation ratio = Primary Amperes Secondary Amperes Nsa = of secondary turns added or subtracted. Np = of primary turns. Example: For :5 Amperes CT with primary turns added, how many secondary turns are required to make a 30:5 CT ratio? Ka = = ± Nsa Nsa = + turns (added) 5 0 Schneider Electric All Rights Reserved /0

53 Appendices APPENDIX B APPENDIX C PARALLELING CURRENT TRANSFORMERS To parallel CT secondaries to combine currents from two or more feeders from the same phase, follow guidelines 7 below. All transformers, which have their secondaries paralleled, must be connected in the same phase of the primary circuit. All transformers must have the same nominal ratio regardless of the circuits in which they are connected. The secondaries must be paralleled at the meter, not at the CT. Use only one common ground point for all the secondaries of all transformers. This should be at their common point at the meter. Each CT must be capable of supporting n times the burden within the desired accuracy class, where n = number of CTs in parallel, (0.3 accuracy class for switchboard use). A common potential must be available for the meter. The meter must have sufficient current capacity to carry the sum of the currents from all the transformers to which it is connected. BURDEN AND ACCURACY INFORMATION In applying the burden and accuracy limits of instrument transformers, it is important to keep in mind that accuracy and burden are interdependent, the same as load and regulation are in power transformer terminology. Power Transformer Instrument Transformer Load = Burden Regulation = Accuracy All instrument transformers will have some small error. The metering accuracy classes are defined in the table below: Accuracy Transformer Max. Error At Secondary Amps 5.0 Amp 0.5 Amp Accuracy Determination Voltage Transformer Max. Error 90-% Volts 0.3 ±0.3% ±0.% ±0.3% 0. ±0.% ±.% ±0.%. ±.% ±.% ±.% Recommended accuracy classes for metering and control relaying uses are shown below. Switchboard instruments are normally % rated meters, and panel meters are % or 3% rated. Accuracy of Meter % % 3% Accuracy of CT or VT 0.3% 0.%.% Accuracy of CT or VT for Wattmeters, Watt-hourmeters, Varmeters, Transducers, etc. 0.3% Accuracy of CT or VT for Control use..% The standard burden limits defined by ANSI C57.3 for current and voltage transformers are as follows: Burden Transformers Impedance Ohms Volt Amperes Power Factor Voltage Transformers Burden Volt-Amperes Power Factor B W.5 0. B X B M B Y B Z ZZ /0 0 Schneider Electric All Rights Reserved 53

54 Appendices Burden Determination The Burden consists of the sum total of the wiring and all connected devices. Determine the burden of the connected devices by referring to the nameplate or catalog data. If the burden is expressed in voltamperes, add this directly for the Voltage Transformer, or convert to ohms impedance for the Transformer, using Nomogram No Nomogram No. Relationship Between Volt-Amperes (VA), Amperes (I) and Impedance (Z): If two values are known, the third can be found. Place a straightedge on the two known quantities and read the third. Example: Amperes and. Ohms of Resistance = 3. VA. (Based on the formula: VA = I Z) VA Schneider Electric All Rights Reserved /0

55 Appendices Determining Burden Measure the length of the wire run between the current transformer and the burden (typically a meter, relay, transducer, etc.). Refer to Nomogram No. and determine the resistance, in ohms, of the wires that connect the secondary of the current transformer to the devices. The Nomogram makes allowances for the return wire. Add this resistance from Nomogram No. to the impedance of the connected burdens..0 ' 5' ' 5' Nomogram No. Resistance of Copper Wire Place a straight edge between Wire Size and Length of Wire Run and read the Ohms of Resistance in the circuit on the center scale. Example: # wire and ' of Wire Run =.0 Ohms of Resistance. # # # ' ' 50' ' 70' ' 90' ' 50' 0' 50' 300' 0' # Excitation Data Calculating CT Metering Accuracy from Excitation Curves The accuracies shown in the Data Sheets for each CT are for standardized burdens and provide a quick approximation of the accuracy for most purposes. However, if a more precise value of accuracy is needed to refer to the Excitation Curves where the exciting current, Ie, is plotted against secondary voltage, Vs. The transformer ratio error expressed as a percentage becomes: Where: Is = Secondary % (RE) Ie x Is To use the curves to determine Ie, first calculate Vs. H Ip H Rs Vs X X] Is Burden Typical CT Circuit Diagram By referring to a typical CT circuit as shown at left, it shows that the voltage Vs must force the secondary current Is through the entire circuit consisting of the secondary winding and the burden, including the interconnecting leads. The resistance of the secondary winding Rs is listed in this catalog for a given CT under the heading of DC R ohms. Z is commonly referred to as Burden and must be obtained from the catalog information of the connected devices added to the resistance of the interconnection leads and Rs. Ohm s Law gives us Vs = IsZ. We may now refer to the Excitation Curve for the CT in question and determine Ie, the exciting current. /0 0 Schneider Electric All Rights Reserved 55

56 Appendices Calculating Accuracy For example, a 300:5 ratio CT with a total burden of Z =.5 ohm. With amperes in the primary, the secondary current will be: Is = x 5 = Amps 300 Vs = IsZ = Amps x.5 ohms = Volts Referring to Figure, we see that at secondary volts, the exciting current, Ie, is equal to.0 amperes. Thus, the percent error of the CT would be: % (Ratio Error) = Ie x =.0 x = % Is Secondary Voltage Volts Hz... 0:5 500:5 0:5 300:5 50:5 0:5 50: Secondary Exciting Amperes Hz Typical Excitation Curves Figure ing CT Accuracy ANSI C57.3 defines relay accuracy in terms of the secondary terminal voltage that a current transformer will supply, with a standard burden connected and times secondary current flowing, while not exceeding percent ratio error. The excitation curves have as their ordinate, secondary voltage, which includes the CT internal voltage drop. In order to determine if the CT is adequate for a particular relay accuracy level, from the excitation curve, the total secondary voltage Vs must be calculated, which will include the internal voltage drop. Since the CT will operate at an elevated temperature over Ambient of 30 C, we must take into consideration the maximum temperature rise of 55 C. Rc = Secondary winding resistance corrected to 5 C (30 C + 55 C) =.555 x Rs (secondary resistance). Zt = Total Impedance of burden circuit = R c =.5Z b +.Z b Where: Xb =. Zb Rb =.5 Zb Z t =.555R s + R b +.Z b Obtain Rs from specific CT and ratio used, and determine Zt, using the standard relay burden data indicated below. 5 0 Schneider Electric All Rights Reserved /0

57 Appendices ANSI Standard Burdens Accuracy Rb (Ohms) Zb (Ohms) Accuracy Rb (Ohms) Zb (Ohms) C C0.0.0 C C0.0.0 C C0.0.0 C The formula to determine the secondary voltage, required from the current transformer, to maintain a certain relay accuracy is: Vs = Is x Zt Is = x 5 amperes = amperes for Fault considerations. Vs = amperes x Zt Vs = Minimum voltage required to meet the relay accuracy. Vsc = Secondary voltage at ampere exciting current on CT curve. The relay accuracy rating defines that the CT must not exceed % error at the Vs level. The % error level is represented by the ampere excitation current line (based on ampere total secondary current) on the CT excitation curve. Extending up the ampere line to the ratio used, find Vsc. If Vsc is greater than, or equal to Vs calculated, then the CT is adequate for the relay accuracy. /0 0 Schneider Electric All Rights Reserved 57

58 5 0 Schneider Electric All Rights Reserved /0

59 /0 0 Schneider Electric All Rights Reserved 59

60 Square D Company Airpark Center Drive Nashville, TN SquareD ( ) Schneider Canada Inc. 9 Waterman Avenue, MB Y Toronto, Ontario No. CT970R/0 June 0 0 Schneider Electric All Rights Reserved