NEMA EI 21.2-1991 (R1997, R2002)
Withdrawn
A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.
INSTRUMENT TRANSFORMERS FOR REVENUE METERING (125 KV BIL THROUGH 350 KV BIL)
10-05-2014
12-06-2012
FOREWORD
SCOPE
Section 1 CURRENT TRANSFORMERS
General Requirements
Definitions
Standard Ratings
Nameplate
Polarity Marking of Terminals
Primary Current Identification
Test Card
Terminals
Space for User Identification Number
Mechanical Construction
Small-Size Outdoor Current Transformers
125 kV BIL through 200 kV BIL
Large Size Outdoor Current Transformers
150 kV BIL through 350 kV BIL
Section 2 VOLTAGE TRANSFORMERS
General Requirements
Definitions
Standard Ratings
Nameplate
Polarity Marking of Terminals
Primary Voltage Identification
Test Card
Terminals
Space for User Identification Number
Small-Size Outdoor Voltage Transformers
125 kV BIL through 200 kV BIL
Large-Size Outdoor Voltage Transformers
150 kV BIL through 350 kV BIL
APPENDIX A Circle Method for Determination of Voltage
Transformer Accuracy
FIGURES
1.1 0.3 Accuracy Class Limits for Current Transformers
1.2 Small-Size Outdoor Current Transformers 125 kV
BILL through 200 kV BIL
1.3 Large-Size Outdoor Current Transformers 150 kV
BILL through 350 kV BIL
1.4 Primary Terminal Dimensions for Large Size Outdoor
Current Transformers, 150 kV BIL through 350 kV BIL
2.1 0.3 Accuracy Class Limits for Voltage Transformers
2.2 Small-Size Outdoor Voltage Transformers 150 kV
BILL through 200 kV BIL, One Bushing Type 10
2.3 Small-Size Outdoor Voltage Transformers 125 kV BIL
through 200 kV BIL, Two Bushing Type
2.4 Large-Size Outdoor Voltage Transformers, 150 kV BIL
through 350 kV BIL, One Bushing Type
2.5 Large-Size Outdoor Voltage Transformers, 150 kV BIL
through 350 kV BIL, Two Bushing Type
A-1 Circle Method for Determination of Voltage
Transformer Accuracy
A.2 Sample of Graph Paper Specifically Scaled for
Voltage Transformer
TABLES
1.1 Standard Metering Burdens for Current Transformers
with 5 Ampere Secondaries
1.2 Standard Accuracy Class for Current Transformers
2.1 Standard Burdens for Voltage Transformers
2.2 Standard Accuracy Class for Voltage Transformers
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