Legal Metrology (General) Fifth Amendment Rules,
2026
Regulations for Active Electrical Energy Meters Notified
·
Notification Details: The
Ministry of Consumer Affairs, Food and Public Distribution issued a gazette
notification on September 15, 2026, introducing new regulatory standards.
·
Title & Enforcement: The
regulation is officially named the Legal Metrology (General) Fifth Amendment
Rules, 2026. It will officially come into force 180 days after its
publication in the Official Gazette.
·
New Statutory Scope: The
amendment inserts a new "Part-XIV" specifically targeting
"Active Electrical Energy Meters" under the Eighth Schedule of
the Legal Metrology (General) Rules, 2011.
·
Standardized Definitions: It
establishes clear statutory definitions for various technical meter categories,
including Interval, Prepayment, Multi-tariff, Direct connected,
Transformer-operated, Electromechanical, and Static meters.
·
Metrological Framework: The
rules formally outline technical parameters such as Minimum Current
($I_{min}$), Transitional Current ($I_{tr}$), Maximum Current ($I_{max}$), and
Nominal Voltage ($U_{nom}$) to ensure uniform performance evaluations.
·
Accuracy Classifications: Meter
accuracy is officially categorized into four specific classes: A, B, C, and
D. The rules explicitly mandate strict Maximum Permissible Error (MPE)
bounds under varying current levels and power factors.
·
Mandatory Product Marking: Every
meter must display indelible, easily legible external markings detailing
the manufacturer, serial number, nominal voltage/frequency, accuracy class, and
energy flow direction.
·
Software Security & Fraud Prevention: To
secure metrological data, meters must employ electronic/mechanical sealing,
mandatory cryptographic software verification (tokens/versions), and
tamper-evident audit trails that record parameter updates.
·
Type Approval & Environmental Resilience:
Manufacturers must submit extensive technical documentation for Type
Approval. Meters must pass rigorous testing against external disturbances
like temperature shifts, voltage dips, short-time overcurrents,
and electromagnetic radio-frequency fields.