Cart (0)
- No items in cart.
Total
$0
There is a technical issue about last added item. You can click "Report to us" button to let us know and we resolve the issue and return back to you or you can continue without last item via click to continue button.
Not a subscriber? Register for a trial account.
Already a subscriber? 
MADCAD.com Free Trial
Sign up for a 3 day free trial to explore the MADCAD.com interface, PLUS access the
2009 International Building Code to see how it all works.
If you like to setup a quick demo, let us know at support@madcad.com
or +1 800.798.9296 and we will be happy to schedule a webinar for you.
| Email * | |
| Password * | |
| Confirm * | |
| First Name * | |
| Last Name * | |
| Title | |
| Company Name * | |
| Company Size * | |
| Industry * | |
| Address * | |
| Address 2 | |
| City * | |
| State * |
Zip *
|
| Country * | |
| Phone * | |
| How did you hear about MADCAD.com? * |
|
Reset password
Enter your personal account email address to request
a password reset:
a password reset:
Reset password
Enter your account email address to request
a password reset:
a password reset:
Security check
Please login to your authorized staff account to use this feature.
Are you sure you want to empty the cart?
Report To Us
Contact us for a custom quote
⨯To continue with accurate pricing,
please select your company type below:
⨯We need your input!
Are you a code official in a jurisdiction with less than 300,000 population?
⨯ We need your input!
⨯We need your input!
Are you an existing Madcad user?
If so, please login to continue with the free items in your cart.
⨯We need your input!
This bundle includes subscribed items.
Download File
eLibrary >
ANSI NEMA C12.1-2024 American National Standard for Electric Meters-Code for Electricity Metering >
Expand All
TOC Search:
ANSI NEMA C12.1-2024 American National Standard for Electric Meters-Code for Electricity Metering, 2024
- Section 1 Scope and references [Go to Page]
- 1.1 Scope
- 1.2 References
- Section 2 Definitions
- Section 3 Standards and standardizing equipment [Go to Page]
- 3.1 General
- 3.2 Traceability paths to the International System of Units, SI [Go to Page]
- 3.2.1 Direct transfer [Go to Page]
- 3.2.1.1 Independent laboratory
- 3.2.1.2 Meter laboratory transport standard comparison to an NMI
- 3.2.1.3 Indirect transfer
- 3.3 Meter laboratory [Go to Page]
- 3.3.1 Laboratory conditions
- 3.3.2 Reference temperature and humidity
- 3.3.3 Laboratory power sources
- 3.4 Meter shop
- 3.5 Laboratory standards [Go to Page]
- 3.5.1 Basic reference standards
- 3.5.2 Transport standards
- 3.6 Periodic verification of reference standards
- 3.7 Portable/field/working standard watthour meters
- 3.8 Performance records
- 3.9 Performance requirements for standard watthour meters [Go to Page]
- 3.9.1 General test conditions [Go to Page]
- 3.9.1.1 Test voltage
- 3.9.1.2 Test current
- 3.9.1.3 Test phase angle
- 3.9.1.4 Test frequency
- 3.9.1.5 Waveform distortion
- 3.9.1.6 Ambient temperature
- 3.9.1.7 External magnetic field
- 3.9.2 Tests for portable and reference standards [Go to Page]
- 3.9.2.1 Insulation
- 3.9.2.2 Accuracy specification for the effect of variation of voltage and current [Go to Page]
- 3.9.2.2.1 Reference conditions
- 3.9.2.2.2 Performance requirements
- 3.9.2.2.3 Effect of variation of voltage and current
- 3.9.2.2.4 Effect of variation of ambient temperature
- Section 4 Acceptable performance of new types of electricity meters and associated equipment [Go to Page]
- 4.1 General [Go to Page]
- 4.1.1 Acceptable meters
- 4.1.2 Adequacy of testing laboratory
- 4.1.3 Retesting of new meter type
- 4.1.4 Test documentation
- 4.1.5 Test device
- 4.1.6 Tests performed as a group
- 4.1.7 Handling of failed device
- 4.1.8 Restart testing
- 4.1.9 Reporting of test meters
- 4.2 Types of meters [Go to Page]
- 4.2.1 Basic type
- 4.2.2 Variations within the basic type
- 4.2.3 Type designation
- 4.2.4 Form designation
- 4.2.5 Acceptance of basic types in whole or part
- 4.2.6 Minor variations
- 4.2.7 Special types
- 4.3 Specifications for design and construction [Go to Page]
- 4.3.1 Sealing
- 4.3.2 Enclosures
- 4.3.3 Terminals and markings
- 4.3.4 Construction and workmanship
- 4.3.5 Provision for adjustment
- 4.4 Selection of meters for approval tests [Go to Page]
- 4.4.1 Samples to be representative of the basic type
- 4.4.2 Number to be tested
- 4.5 Conditions of test [Go to Page]
- 4.5.1 Tests to be applied
- 4.5.2 Configuration
- 4.5.3 Meters for measurements other than watthours
- 4.5.4 Meters of non-standard classes
- 4.5.5 Meters with wide-voltage range
- 4.5.6 Meters equipped with an auxiliary communications device (ACD) [Go to Page]
- 4.5.6.1 Reference conditions
- 4.5.6.2 Test mode
- 4.5.6.3 Test time
- 4.5.6.4 Antennas
- 4.5.6.5 Multiple ACDs
- 4.5.6.6 ACD states
- 4.5.6.7 Tests with dormant ACD condition
- 4.5.7 Mounting
- 4.5.8 Voltage and frequency
- 4.5.9 Current classes and test amperes
- 4.5.10 Form designations
- 4.5.11 Displays [Go to Page]
- 4.5.11.1 Viewing requirements
- 4.5.11.2 Size of digits
- 4.5.11.3 Direction of energy flow
- 4.5.12 Provisions for testing of calibration [Go to Page]
- 4.5.12.1 Requirement for test outputs
- 4.5.12.2 Physical implementation of test pulse output [Go to Page]
- 4.5.12.2.1 Optical test output port (OTOP)
- 4.5.12.2.2 Type A, Use of ANSI type 2 optical port
- 4.5.13 Nameplate
- 4.6 Rules governing the acceptance of types [Go to Page]
- 4.6.1 Tolerances
- 4.6.2 Determination of failure and rejection [Go to Page]
- 4.6.2.1 Failure
- 4.6.2.2 Meter type certification rejection criteria
- 4.7 Performance requirements [Go to Page]
- 4.7.1 Test conditions [Go to Page]
- 4.7.1.1 Loading for accuracy tests
- 4.7.1.2 List of type tests
- 4.7.2 Accuracy tests, internal influences [Go to Page]
- 4.7.2.1 Test No. 1: No load
- 4.7.2.2 Test No. 2: Starting load
- 4.7.2.3 Test No. 3: Load performance [Go to Page]
- 4.7.2.3.1 Meters equipped with an ACD (influence of ACD on load performance)
- 4.7.2.4 Test No. 4: Effect of variation of power factor
- 4.7.2.5 Test No. 5: Effect of variation of voltage [Go to Page]
- 4.7.2.5.1 Test No. 5a: Effect of variation of voltage on the solid state auxiliary device
- 4.7.2.6 Test No. 6: Effect of variation of frequency
- 4.7.2.7 Test No. 7: Equality of current circuits
- 4.7.2.8 Test No. 8: Meter losses [Go to Page]
- 4.7.2.8.1 Test No. 8a: Meter losses with ACD present
- 4.7.2.9 Test No. 9: Temperature rise [Go to Page]
- 4.7.2.9.1 Test on current class 10, 20, 100, 200, and 320 meters
- 4.7.2.10 Test No. 10: Effect of register friction
- 4.7.2.11 Test No. 11: Effect of internal heating
- 4.7.2.12 Test No. 12: Effect of tilt
- 4.7.2.13 Test No. 13: Stability of performance
- 4.7.2.14 Test No. 14: Effect of phase sequence reversal
- 4.7.3 Performance tests, external influences [Go to Page]
- 4.7.3.0 Performance verification [Go to Page]
- 4.7.3.0.1 Accuracy performance verification
- 4.7.3.0.2 Auxiliary communications device performance verification
- 4.7.3.1 Test No. 15: Insulation
- 4.7.3.2 Test No. 16: Voltage interruptions test
- 4.7.3.3 Test No. 17: Effect of high-voltage line surges [Go to Page]
- 4.7.3.3.1 100 kHz ring wave
- 4.7.3.3.2 1.2/50 microsecond – 8/20 microsecond combination wave
- 4.7.3.4 Test No. 18: Effect of external magnetic field
- 4.7.3.5 Test No. 19: Effect of variation of ambient temperature [Go to Page]
- 4.7.3.5.1 Test No. 19a: Effect of variation of ambient temperature on the solid state auxiliary device, except ACDs
- 4.7.3.6 Test No. 20: Effect of temporary overloads [Go to Page]
- 4.7.3.6.1 Effect on accuracy
- 4.7.3.6.2 Effect on magnetic bearing
- 4.7.3.6.3 Effect on mechanical structure and insulation
- 4.7.3.7 Test No. 21: Effect of current surges in ground conductors
- 4.7.3.8 Test No. 22: Effect of superimposed signals
- 4.7.3.9 Test No. 23: Effect of voltage variation—secondary time base
- 4.7.3.10 Test No. 24: Effect of variation of ambient temperature—secondary time base
- 4.7.3.11 Test No. 25: Effect of electrical fast transient/burst test
- 4.7.3.11a Test No. 25a: Effect of electrical oscillatory SWC test
- 4.7.3.12 Test No. 26: Effect of radio frequency interference [Go to Page]
- 4.7.3.12.1 Test No. 26a: Radiated interference
- 4.7.3.12.2 Test No. 26b: Conducted interference
- 4.7.3.13 Test No. 27: Radio frequency conducted and radiated emission test
- 4.7.3.14 Test No. 28: Effect of electrostatic discharge (ESD)
- 4.7.3.15 Test No. 29: Effect of storage temperature
- 4.7.3.16 Test No. 30: Effect of operating temperature
- 4.7.3.17 Test No. 31: Effect of relative humidity
- 4.7.3.18 Test No. 32: Mechanical shock
- 4.7.3.19 Test No. 33: Transportation drop
- 4.7.3.20 Test No. 34: Mechanical vibration
- 4.7.3.21 Test No. 35: Transportation vibration
- 4.7.3.22 Test No. 36: Weather simulation test
- 4.7.3.23 Test No. 37: Salt-spray test
- 4.7.3.24 Test No. 38: Rain tightness
- 4.7.4 Harmonics influence—effect of non-sinusoidal waveforms [Go to Page]
- 4.7.4.1 Test No. 39: 90 degree phase fired waveform
- 4.7.4.2 Test No. 40: Quadriform waveform
- 4.7.4.3 Test No. 41: Peaked waveform
- 4.7.4.4 Test No. 42: Pulse waveform
- 4.7.4.5 Test No. 43: Multiple zero crossings on current
- 4.7.4.6 Test No. 44: Multiple zero crossings on voltage
- Section 5 Standards for new and in-service performance [Go to Page]
- 5.0 General principles [Go to Page]
- 5.0.1 Purpose [Go to Page]
- 5.0.1.1 New metering devices
- 5.0.1.2 In-service metering devices
- 5.0.2 Tests [Go to Page]
- 5.0.2.1 As-found tests
- 5.0.2.2 As-left tests
- 5.0.2.3 Metering devices removed from service
- 5.0.2.4 Metering devices returned to service
- 5.0.3 Performance tests [Go to Page]
- 5.0.3.1 Objectives
- 5.0.3.2 New metering device acceptance testing
- 5.0.3.3 In-service metering devices
- 5.0.3.4 Test plans [Go to Page]
- 5.0.3.4.1 Periodic interval plan
- 5.0.3.4.2 Variable-interval plan
- 5.0.3.4.3 Statistical sampling plan
- 5.0.3.4.4 Corrective action for any metering device or group of metering devices failing to meet performance criteria
- 5.0.3.5 Test records
- 5.1 Watthour meters [Go to Page]
- 5.1.1 Accuracy requirements [Go to Page]
- 5.1.1.1 Test loads
- 5.1.1.2 Acceptable performance
- 5.1.1.3 Adjustment limits
- 5.1.1.4 Acceptable performance for electronic registers
- 5.1.2 Tests [Go to Page]
- 5.1.2.1 New meters and as-found tests
- 5.1.2.2 As-left tests
- 5.1.2.3 Meters returned to service
- 5.1.3 Test plans [Go to Page]
- 5.1.3.1 Periodic interval plan
- 5.1.3.2 Performance monitoring of new types of meters
- 5.1.4 Determination of average percentage registration [Go to Page]
- 5.1.4.1 Method 1
- 5.1.4.2 Method 2
- 5.1.4.3 Method 3
- 5.1.4.4 Method 4
- 5.2 Instrument transformers, magnetic (external to meter) [Go to Page]
- 5.2.1 Pre-installation tests
- 5.2.2 Instrument transformers removed from service
- 5.2.3 Performance tests [Go to Page]
- 5.2.3.1 Burden test
- 5.2.3.2 Secondary voltage test
- 5.2.4 Inspection
- 5.3 Coupling capacitor voltage transformers (external to meter) [Go to Page]
- 5.3.1 Performance tests
- 5.4 Integrated communication devices [Go to Page]
- 5.4.1 Performance tests
- 5.5 Service switches (integrated and external to meter) [Go to Page]
- 5.5.1 Performance tests
- 5.6 Demand and interval registers (integrated) [Go to Page]
- 5.6.1 Accuracy requirements [Go to Page]
- 5.6.1.1 Acceptable performance for new demand or interval registers
- 5.6.1.2 In-service acceptable performance
- 5.6.1.3 Test points
- 5.6.1.4 Adjustment limits
- 5.6.1.5 Performance limits
- 5.7 Other energy measurement devices not already listed (integrated and external to meter) [Go to Page]
- 5.7.1 Pulse recorder accuracy requirements [Go to Page]
- 5.7.1.1 Acceptable performance for pulse recorders
- 5.8 Other non-energy measurement devices in a metering device circuit (integrated and external to meter)
- Section 6 Auxiliary pulse devices for electricity metering [Go to Page]
- 6.1 General [Go to Page]
- 6.1.1 Information to be shown on pulse initiator
- 6.1.2 Information to be shown on pulse amplifier or relay
- 6.1.3 Information to be shown on pulse totalizers
- 6.2 Tests to be applied
- 6.3 Performance requirements [Go to Page]
- 6.3.1 Test conditions
- 6.3.2 Initial conditions
- 6.3.3 Mechanical load
- 6.3.4 Insulation
- 6.3.5 Performance test
- 6.3.6 Sunlight interference test—pulse devices containing optical sensors
- Appendix A Measurement of power, energy, and related quantities [Go to Page]
- A.1 Measurement of power [Go to Page]
- A.1.1 Introduction
- A.1.2 Blondel’s theorem
- A.1.3 Direct-current services [Go to Page]
- A.1.3.1 Two-wire direct-current services
- A.1.3.2 Three-wire direct-current services
- A.1.3.3 Ammeter and voltmeter method
- A.1.4 Single-phase alternating-current services [Go to Page]
- A.1.4.1 Single-phase two-wire services
- A.1.4.2 Single-phase three-wire services
- A.1.5 Two-phase services [Go to Page]
- A.1.5.1 Two-phase three-wire services
- A.1.5.2 Two-phase four-wire services
- A.1.5.3 Two-phase five-wire services
- A.1.5.4 Balanced two-phase services
- A.1.6 Three-phase services [Go to Page]
- A.1.6.1 Three-wattmeter method
- A.1.6.2 Two-wattmeter method
- A.1.6.3 Balanced three-phase services
- A.2 Measurement of energy [Go to Page]
- A.2.1 Basic considerations [Go to Page]
- A.2.1.1 Voltage-sensor connection
- A.2.1.2 Application of Blondel’s theorem
- A.2.1.3 Watthour meter element
- A.2.2 Direct-current or single-phase services [Go to Page]
- A.2.2.1 Two-wire direct-current and single-phase services
- A.2.2.2 Three-wire direct-current and single-phase services
- A.2.2.3 Single-phase three-wire services with balanced voltages
- A.2.2.4 Large-capacity or high-voltage direct-current meters
- A.2.2.5 Large-capacity or high-voltage alternating-current meters
- A.2.3 Open wye services
- A.2.4 Two-phase services [Go to Page]
- A.2.4.1 Two-phase three-wire services
- A.2.4.2 Two-phase four- or five-wire services
- A.2.4.3 Two-phase five-wire services with balanced voltages
- A.2.5 Three-phase services, all types [Go to Page]
- A.2.5.1 Methods comparable to power measurements
- A.2.6 Three-phase three-wire services [Go to Page]
- A.2.6.1 Two-element method
- A.2.6.2 Three-element method
- A.2.6.3 Balanced voltage and load
- A.2.7 Three-phase four-wire wye services [Go to Page]
- A.2.7.1 Three-element four-wire wye meter
- A.2.7.2 Two-and-a-half-element four-wire wye meter
- A.2.8 Three-phase four-wire delta services [Go to Page]
- A.2.8.1 Possible methods of metering
- A.2.8.2 Three-element four-wire delta meter
- A.2.8.3 Two-element four-wire delta meter
- A.2.9 Three-phase seven-wire double wye-connected services [Go to Page]
- A.2.9.1 Three single-phase three-wire elements
- A.2.10 Basic meter design considerations
- A.2.11 Factors affecting meter accuracy [Go to Page]
- A.2.11.1 Light loads
- A.2.11.2 Variations in voltage
- A.2.11.3 Variations in power factor
- A.2.11.4 Variations in frequency
- A.2.11.5 Variations in temperature
- A.2.11.6 External magnetic fields
- A.2.11.7 Load range
- A.2.11.8 Surges
- A.2.11.9 Adverse environmental conditions
- A.3 Measurement of power factor [Go to Page]
- A.3.1 Single-phase two-wire services
- A.3.2 Single-phase and polyphase services
- A.3.3 Balanced three-phase three-wire services
- A.3.4 System power factor
- A.3.5 Interval power factor
- A.4 Measurement of reactive energy (varhours, quadergy) [Go to Page]
- A.4.1 Q-hour method
- A.4.2 Electronic meters
- A.5 Non-Blondel metering applications [Go to Page]
- A.5.1 Introduction
- A.5.2 The single-phase 2S application
- A.5.3 A vector approach to power computation [Go to Page]
- A.5.3.1 Analysis of 12S and 2S metering of a three-wire single-phase application
- A.5.3.2 Analysis of 4-wire wye metering using two-element meters (Forms 5S, 26S, 45S, 66S)
- A.5.3.3 Analysis of 4-wire wye metering using 2.5 element meters (Forms 6S, 7S, 14S, 29S, 36S, 46S)
- A.5.3.4 Analysis of 4-wire delta metering using two-element meters (Forms 5S, 45S)
- A.5.3.5 Analysis of 4-wire delta metering using 2.5 element meters (Forms 8S, 15S, 24S)
- A.5.4 Conclusions
- Appendix B Standards and standardizing equipment [Go to Page]
- B.1 General
- B.2 Final authority [Go to Page]
- B.2.1 Electrical units [Go to Page]
- B.2.1.1 Current
- B.2.1.2 Time
- B.2.1.3 Force
- B.2.1.4 Energy
- B.2.1.5 Power
- B.2.1.6 Electric potential
- B.2.1.7 Resistance
- B.2.1.8 Charge
- B.2.1.9 Capacitance
- B.2.1.10 Magnetic flux
- B.2.1.11 Inductance
- B.3 [This section has been removed]
- B.4 Establishing a local reference standard of energy [Go to Page]
- B.4.1 Meter laboratory2F
- B.4.2 Meter shop
- B.4.3 Independent standards laboratory
- B.5 Laboratory conditions [Go to Page]
- B.5.1 Reference temperature and humidity
- B.5.2 Laboratory power sources
- B.6 Laboratory reference standards [Go to Page]
- B.6.1 Stability of reference standards
- B.6.2 Basic reference standards [Go to Page]
- B.6.2.1 Intercomparison
- B.6.3 Transport standards
- B.6.4 Voltage references [Go to Page]
- B.6.4.1 Standard cells
- B.6.4.2 Unsaturated standard cells
- B.6.4.3 Solid state voltage standards
- B.6.5 Standard resistors
- B.6.6 DC ratio devices [Go to Page]
- B.6.6.1 Reference standard volt box
- B.6.6.2 Reference voltage dividers
- B.6.6.3 Universal ratio set and Kelvin-Varley divider
- B.6.6.4 Resistance bridges
- B.6.6.5 Direct-current comparator
- B.6.7 AC ratio devices [Go to Page]
- B.6.7.1 Transformer test set
- B.6.8 AC-DC transfer standards [Go to Page]
- B.6.8.1 Stability
- B.6.9 Reference standard of energy
- B.6.10 Time interval
- B.6.11 Periodic verification of reference standards
- B.7 Laboratory secondary standards [Go to Page]
- B.7.1 Voltage measuring equipment
- B.7.2 Indicating instruments [Go to Page]
- B.7.2.1 Measurement uncertainty
- B.7.2.2 Instrument bearings or suspensions
- B.7.2.3 Range extension
- B.7.3 Watthour meters
- B.7.4 Calibration checks [Go to Page]
- B.7.4.1 Voltage measuring accessories
- B.7.4.2 Digital voltmeter (multimeters) calibrations
- B.7.4.3 Calibration of indicating instruments
- B.7.4.4 Watthour meters
- B.8 Shop instruments [Go to Page]
- B.8.1 Indicating instruments
- B.8.2 Portable standard watthour meters
- B.9 Performance records [Go to Page]
- B.9.1 Importance of records
- B.10 Abnormal conditions
- B.11 [This section has been removed]
- B.12 Acceptable performance of standard watthour meters [Go to Page]
- B.12.1 General [Go to Page]
- B.12.1.1 Optional provision for pulse output
- B.12.1.2 Overcurrent protection
- B.12.1.3 Nameplate
- B.12.2 [This section has been removed]
- B.12.3 Mechanical requirements for reference standard meters [Go to Page]
- B.12.3.1 General
- B.12.3.2 Adjusting devices
- B.12.3.3 Device orientation
- B.12.3.4 Case
- B.12.3.5 Sealing
- B.12.3.6 Window
- B.12.3.7 Terminals
- B.12.3.8 Digital readouts [Go to Page]
- B.12.3.8.1 Readout reset
- B.12.3.9 Provision for pulse output
- Appendix C Registration and meter constants [Go to Page]
- C.1 General
- C.2 Symbols
- C.3 Object of the test
- C.4 Test procedure
- C.5 Allowed effect
- C.6 Mandatory testpoints
- Appendix D Periodic testing schedule
- Appendix E Variable interval plan
- Appendix F 90 degree phase fired waveform definitions [Go to Page]
- F.1 Fourier construction of 90 degree phase fired current waveform with same peak as Iref
- F.2 Sine construction of 90 degree phase fired current waveform with same peak as Iref
- Appendix G Type B optical test output port (OTOP) [Go to Page]
- G.0 Type B—separate port for OTOP
- G.1 Physical specifications
- G.2 Output optical characteristics
- Appendix H Historical background [Go to Page]
- H.1 Preface to the First Edition (1910)
- H.2 Preface to the Second Edition (1922)
- H.3 Preface to the Third Edition (1928)
- H.4 Preface to the Fourth Edition (1941)
- H.5 Preface to the Fifth Edition (1965)
- H.6 Preface to the Sixth Edition (1975)
- H.7 Foreword to the Seventh Edition (1982)
- H.8 Foreword to the Eighth Edition (1988)
- H.9 Foreword to the Ninth Edition (1995)
- H.10 Foreword to the Tenth Edition (2001)
- H.11 Foreword to the Eleventh Edition (2008)
- H.12 Foreword to the Twelfth Edition (2014) [Go to Page]
Copyright 2025 Compu-tecture, Inc.
All Rights Reserved.
About Us /
Careers /
support@madcad.com /
1.800.798.9296