S-E-03—Specification for the installation and use of electricity meters—input connections and ratings

Category: Electricity
Issue date: 2021-07-28
Effective date: 2021-07-28
Revision number: 1
Supersedes: S-E-03


Table of contents


1.0 Scope

This specification applies to electricity energy and demand meters which are verified pursuant to the Electricity and Gas Inspection Act and installed after the effective date of this specification. This specification does not apply to the connections between external sensors and the main body of the meter of multiple customer metering systems.

2.0 Authority

This specification is issued under the authority of subsection 12(2) of the Electricity and Gas Inspection Regulations.

3.0 Background

Meters have traditionally been designed with input ratings that typically correspond to the standard voltage and current ratings of the electricity distribution system in Canada. While it's generally understood that any given voltage or current rated meter is to be installed and used on a similarly rated service, specific technical criteria have not been established.

Metrological performance tests for meter approvals and verifications are based on the voltage and current ratings specified on the meter under test, and presuppose that the meter will be installed and used in the service that's most compatible with the meter's ratings. For example, while a 240 V rated meter can be installed and used in a 120 V service, it isn't the intended condition under which the meter is assessed for approval or verification. The same applies to a 100 A rated meter installed and used in a 5 A service. The installation and use of a meter in a service with significantly different voltage and current ratings from those specified on the meter can have an important metrological impact since the meter's performance was not assessed for approval or verification under those conditions.

As technology evolves, there are increasing numbers of meters designed with input ratings that don't directly correspond to the standard ratings of the electricity distribution system that exists in Canada, particularly with respect to current ratings. Therefore, there is a need to clearly establish the installation criteria for selection of meter ratings which are suitable for a given service rating, as well as the requirements for related input connections.

4.0 Installation and use

4.1 General

4.1.1 Each verified meter to be used in obtaining the basis of a charge for electricity supplied must be installed and used in the manner established in:

  1. the notice of approval or conditional notice of approval, as applicable, in addition to this document;
  2. other Measurement Canada installation and use requirements, as applicable, in addition to the manner specified in this document; and
  3. the manufacturer's technical specifications and criteria.

4.1.2 In any situation where a requirement of (a), (b) or (c) above exclusively contradicts another requirement of (a), (b) or (c), the details must be reported to Utility Metering Division of Measurement Canada through the appropriate regional electricity specialist.

4.2 Transformer-type meters

4.2.1 Meters must be connected to instrument transformers in accordance with the appropriate diagram established in the Measurement Canada standard drawings for electricity metering installations. Other connection configurations may be used only if a formal drawing showing the actual connections is provided by the owner of the installation, and the drawing is determined to be acceptable to Measurement Canada's Engineering and Laboratory Services.

4.2.2 The minimum current rating of the meter installed must not be greater than 4% of the output rating of any current transformer connected to the meter input circuits. Also, the minimum current rating of the meter installed and used in service must be of a rating included in the applicable notice of approval.

4.2.3 The maximum current rating of the meter installed must not be less than the rating factor of the connected current transformer multiplied by the secondary rating of the connected current transformer. Also, the maximum current rating of the meter installed and used in service must be of a rating included in the applicable notice of approval.

4.2.4 The operating voltage of the meter installed must have a marked voltage rating that is between 90% and 105% of the nominal output voltage of the transformer connected to the meter inputs.

Note: A nominal single voltage or range of voltages within the approved range of voltages may be marked on the meter's nameplate. Meters so marked will only be verified for the marked voltage or range, and, as such, may only be connected to transformer secondaries rated to within the marked voltage or range.

4.2.5 Each wire or cable that connects from the output of any instrument transformer to a meter input must be individually identifiable or traceable. It is preferable that wires be identified in accordance with the colour code established in the Measurement Canada standard drawings for electricity metering installations.

4.2.6 Meter inputs must be connected to instrument transformer outputs via an appropriate test switch or other similar mechanism which will facilitate safe meter removal, shorting of current transformer secondaries, and connection of circuit analysis and test equipment. This requirement applies to all new and reconstructed metering installations connected after the effective date of this specification.

4.2.7 The combined burden of the meter, associated wiring and connections, and any other secondary connected devices must not exceed the burden designation of any instrument transformer connected to the meter input circuits.

Note: The combined burden could be determined by adding the manufacturer specified burden ratings of all the applicable devices.

4.3 Self-contained meters

4.3.1 The operating voltage rating of the meter installed must have a marked voltage rating that is between 90% and 105% of the service voltage at the meter installation site.

Note: A nominal single voltage or range of voltages within the approved range of voltages may be marked on the meter's nameplate. Meters so marked will only be verified for the marked voltage or range, and, as such, may only be connected to transformer secondaries rated to within the marked voltage or range.

5.0 Revisions

The purpose of revision 1 is to clarify the installation limitations for meters approved to a certain voltage range, but marked with only a single voltage or subset of the voltage range.