[This is Part#2 of the Energy Meter Series. You may access Part#1 here.]

 

In exercise of the powers conferred by sub-section (1) of Section 55 and clause (e) of section 73 read with sub-section (2) of section 177 of Electricity Act, 2003, the Central Electricity Authority made a regulation called Central Electricity Authority (Installation and Operation of Meters) Regulations, 2006.

 

 

Broadly there are three kinds of meters, viz. (i) Interface Meters, (ii) Consumer Meters; and (iii) Energy Accounting and Audit Meters.

 

 

  1. Type of Meters
  • Interface Meters – means meters used for accounting and billing of electricity, connected at the point of interconnection between electrical systems of generating company, licensee and consumers, directly connected to the Inter-State Transmission System or Intra-State Transmission System (ISTS) who have to be covered under ABT and have been permitted open access by the Appropriate Commission.
  • Consumer Meters – means meters used for accounting and billing of electricity supplied to the consumers but excluding those consumers covered under Interface Meters.
  • Energy Accounting and Audit Meters – means meters used for accounting of the electricity to various segments of electrical system so as to carry out further analysis to determine the consumption and loss of energy therein over a specified time period.

 

  1. Standards

The meters are to comply below standards:

  • Bureau of Indian Standards (BIS)
  • British Standards (BS)
  • International Electro-technical Commission (IEC) Standards

Preliminary meters are to follow BIS. But in the case of non-availability of suitable BIS standard for the particular quality requirement, meters are to be made adhering BS and/or IEC standards.

 

  1. Ownership

Interface Meters,

    • All interface meters installed at the points of ISTS for the purpose of electricity accounting and billing are owned by CTU
    • All interface meters installed at the points of interconnection with Intra-State Transmission System excluding the system covered for the purpose of electricity accounting and billing shall be owned by STU.
    • All interface meters installed at the points of interconnection between the two licensees excluding those covered under above two sub-clauses, for the purpose of electricity accounting and billing shall be owned by the respective licensee of each end.
    • All interface meters installed at the points of interconnection for the purpose of electricity accounting and billing not covered under above three sub-clauses shall be owned by the supplier of electricity.
  • Consumer Meters:
    • Consumer meters shall generally be owned by the licensee.
    • If any consumer elects to purchase a meter, the same may be purchased by him. Meter purchased by the consumer shall be tested, installed and sealed by the licensee. The consumer shall claim the meter purchased by him as his asset only after it is permanently removed from the system of the licensee.
  • Energy Accounting and Audit Meters
    • Energy accounting and audit meters shall be owned by the generating company or licensee, as the case may be.

 

  1. Location

 

Sr. No.

Stage Location

A.

Interface Meter

1

Generating Station Main Meter

· On all outgoing feeders

Check Meter

· On all outgoing feeders

Standby Meter

· HT side of Generator Transformer

· HT side of all Station Auxiliary Transformers

2

Transmission Line Main Meter

· On one end of the line between the Sub-Station of the same Licensee

· On both ends of the line between the Sub-Station two Licensees. Meters at both the ends are to be considered as main meters for the respective Licensees

Standby Meter

· No separate Standby Meter

· Meter installed at the other end of the line in case of two difference Licensees is to be treated as a Standby meter.

3

Interconnecting Transformer Main Meter

· HT Side

Standby Meter

· LT Side

4

Consumers connected directly to ISTS As decided by the State Regulatory Commission

5

Consumers connected to DISCOM but granted for Open Access As decided by the State Regulatory Commission

B

Consumer Meters

1

Consumers connected directly to ISTS At or outside the Consumer premise

C.

Energy Accounting and Audit Meter

1

Generating Station · at a point after the generator stator terminals and before the tap-off to the unit auxiliary transformer(s),

· on each incoming feeder of 3.3 kV and above

· low voltage side of each incoming transformer feeder of low voltage (415 V) buses, and

· on all high tension motor feeders.

In case, numerical relays having a built-in feature of energy measurement of requisite accuracy are provided in high voltage or low voltage switchgear, separate energy meter is not necessary.

2 Transmission System · all incoming and outgoing feeders (if the interface meters do not exist)
3 Distribution System · all incoming feeders(11 kV and above)

· all outgoing feeders (11 kV and above)

· sub-station transformer including distribution transformer- Licensee may provide the meter on the primary or secondary side or both sides depending upon the requirement for energy accounting and audit.

 

Accuracy Class

  • Interface Meters : 0.2S
  • Consumer Meters:
    • Upto 650 V: 1.0 or better
    • Above 650 Volt and up to 33 KV: 0.5S or better
    • Above 33 KV: 0.2S
  • Energy Accounting and Audit Meter:
    • At Generating and Transmission Stations: 0.2S
    • At Distribution System: 0.5S or better

 

 

We shall talk further technical aspects of Utility grade energy meters in subsequent posts.

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