4. Current ANSI C12.1 Section 5
Issues
• Acceptance testing of new meters is not
mentioned.
• Statistical sampling plans are not adequately
defined.
• Post deployment or performance monitoring of
newly certified meters not covered.
5. Recommended Changes
AMI Devices
• New concept of what is a meter…includes
everything under the cover.
• AMI communications modules and service
disconnect switches.
• Applies sampling and testing requirements to
these devices when part of the AMI meter.
6. Recommended Changes
New Meters & Metering Devices
• New meters are covered by sampling and
testing requirements.
• As-found, as-left, returned to service tests.
• Accuracy classes in C12.20
(0.2% and 0.5%) referenced.
7. Recommended Changes
Statistical Sampling Plans
• In-service statistical sampling plans should
be developed using plans such as:
– ANSI/ASQ Z1.9 Sampling Procedures and Tables for
Inspection by Variables
– ANSI/ASQ Z1.4 Sampling Procedures and Tables for
Inspection by Attributes
• Provides guidance on how to handle
sample failures.
8. Recommended Changes
New Metering Device Acceptance Testing
• Sampling and testing of new meter
shipments
• Uses ANSI Z1.4 (attributes) or ANSI Z1.9
(Variables) for sample size and
acceptance criteria.
• Specifies an Acceptable Quality
Limit (AQL) of 1% or less.
9. Recommended Changes
Performance Monitoring of Newly Certified
Meters
• Evaluate newly certified meters after
installation…. Different than in-service.
• Use statistical sampling plan.
10. Recommended Changes
In-Service Requirements for Other Metering
Devices
• Use of statistical sampling plans.
• Old Standard included:
– Instrument transformers, demand registers, pulse
recorders, coupling-capacitor voltage transformers.
• New Standard includes:
– Instrument transformers, demand registers, pulse
recorders, coupling-capacitor voltage transformers,
meter communication devices/modules, service
switches, non energy measurement features of a
meter.
11. Coordination of ANSI C12.1 &
IEC/OIML Requirements
• ANSI working with IEC to coordinate standards
(new OIML R46). Many issues!
• Working to tie IEC meter specifications to ANSI
requirements. Meters in classes
A - 2%, B – 1%, C – 0.5%, D – 0.2%
• IEC standard does not allow changes to meter
after seal is on without testing (similar to
Measurement Canada).
Firmware changes???
12. Coordination of ANSI C12.1 & IEC
Requirements
• IEC assumes testing done by government
controlled organizations.
• Other differences:
– More tests and are run longer
– Higher RF frequency range. Accuracy tested during
RF application
– Magnetic field strengths higher
– Electrical discharge levels higher
13. Path Forward
New Metering Device Acceptance Testing
• Complete sub-committee work and forward proposed draft to full ANSI C12 Main committee at
April 5, 2012 meeting (next full committee meeting). Hoping for comments and small revisions
then approval and adoption by the October 2012 meeting (Full committee meets twice per year).
• Begin educating EEI members and Utility Commissions that a standard suitable for in-service
testing of “smart meters” now exists and can be used as a basis for post-deployment testing
programs.
• Appoint members of sub-committee 25 to committee to reconcile differences with IEC and OIML.
Members of ANSI committee are already working on both the IEC and the OIML committee but
none of the three has an approved new standard yet.
• Edit and keep the new standards consistent and up to date as new equipment and new features
reach the marketplace.
14. Questions?
Tom Lawton
Tom.Lawton@TescoMeterManager.com 215-688-0298 (cell)
The Eastern Specialty Company