S-E-08—Specifications for the installation and use of electricity meters - Standard drawings for electricity metering installations

Category: Electricity
Issue Date: 2023-09-28
Effective Date: 2023-09-28
Revision number: 3
Supersedes: S-E-08 (rev.2)

Table of Contents

1.0 Purpose

The purpose of this specification is to establish Measurement Canada's (MC) requirements pertaining to the appropriate connection of electricity meters to electrical circuits in which legal units of measurement (LUM) are intended to be measured for establishing the basis of a charge for the supply of electricity. These requirements include the standard drawings to which electricity metering installations must conform (refer to Appendix A).

2.0 Scope

This specification applies to all electricity metering installations (as well as installations of self‑contained meters) which are intended to be used in revenue metering with the exception of multiple customer metering systems (MCMS).

3.0 Authority

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

4.0 Definitions

Additive totalizing
(totalisation par addition)
A manner of additive summation whereby the total declared quantity for a given legal unit of measurement (LUM) is established through addition of those LUM values as registered by two or more individual meters connected between an electricity distributor and a purchaser.
Deductive totalizing
(totalisation par deduction)
A manner of deductive summation whereby one meter is connected between an electricity distributor and multiple loads (consumption or generation) and additional meters are connected between that meter and all but one of the loads. This manner of summation is used to determine the unmetered load indirectly by subtracting the value of all metered loads from the value of the total metered load.
Electricity metering installation
(installation de mesure de l'électricité)
An installation that consists of more than one electricity meter installed at the same location and that is used for the purpose of obtaining the basis of a charge for electricity supplied to a purchaser. Electricity and Gas Inspection Regulations, subsection 2(1)
Meter
(compteur)
Any apparatus, such as an electricity meter, used for the purpose of making measurements of, or obtaining the basis of a charge for, electricity or gas supplied to a purchaser. Electricity and Gas Inspection Act, subsection 2(1)
Self-contained meter
(compteur autonome)
A meter designed to be connected directly to a power circuit, without the use of external devices such as instrument transformers or shunts.

5.0 References

6.0 Standard installations

6.1 Meter connections

Each meter (including instrument transformers) forming part of an electricity metering installation must be connected in accordance with the appropriate diagram established in Measurement Canada's standard drawings for electricity metering installations. Refer to Appendix A.

6.2 Wire colour code

The standard wire colour code is established by MC in Appendix B. Colour coding of wires must be continuous from end to end.

6.3 Voltage connection points

All voltage transformers (VTs) and meter voltage terminals must be connected to the line side of the circuit being measured (i.e. between the supply and any current transformers).

6.4 Neutral conductor

Current sensors placed in the circuit neutral conductor must not contribute to the determination of a quantity of any legal unit of measure.

7.0 Non-standard Installations

7.1 Meter connections

Meter connection configurations other than those established in Appendix A may be used subject to the terms established in paragraph 4.2.1 of specification S-E-03.

7.2 Colour code

The use of a colour code other than the standard colour code presented in Appendix B is acceptable subject to the following requirements:

  • the difference between current and voltage leads is clearly distinguishable;
  • the use of green and white is restricted only to purposes which conform to the Canadian Electrical Code; and
  • the code is consistent in other installations owned by the electricity distributor and/or contractor.

7.3 Voltage connection points

Meter voltage terminals may be connected to the load side of the circuit being measured subject to the following conditions:

  • a ring or "window" type current transformer is used; and
  • the installation conforms to standard drawing number 1305 or 1306 in all other aspects.

8.0 Transformer secondaries

8.1 Current transformers

Current transformer secondary returns may be shared via one wire connected from the meter terminals to the test block or switch provided that the wire is of sufficient gauge to conduct the load without imparting a burden which exceeds the burden rating of the transformers.

8.2 Voltage transformers

Voltage transformer secondary returns may be shared via one wire connected from the meter terminals to the test block or switch provided that the wire is of sufficient gauge so as not to impart a burden which exceeds the burden rating of the transformers.

9.0 Grounding

The case of each meter (including instruments transformers) forming part of an electricity metering installation must be appropriately grounded.

Instrument transformer secondary wires must be grounded. Secondary wires which are interconnected must be interconnected and grounded at only one point.

10.0 Totalizing

10.1 Additive Totalizing

Additive totalizing of two or more circuits may be performed in one the following manners:

  • via paralleling of current transformer (CT) secondaries;
  • through use of a totalizing current transformer.

10.1.1 Paralleling of current transformer secondaries

Paralleling of CT secondaries is permitted subject to the following conditions:

  • paralleled circuits are of the same voltage and frequency;
  • current transformers have identical ratios;
  • the voltage circuits of the meter are supplied from a common bus to which the primary circuits are connected; and
  • the meter ratings are sufficient for the totalized load.

10.1.2 Totalizing current transformer

A totalizing current transformer may be used subject to the following conditions:

  • the primary circuits are of the same voltage and frequency;
  • the voltage circuits of the meter are supplied from a common bus to which the primary circuits are connected;
  • the primary windings of the totalizing transformers are supplied from corresponding phases of the primary lines;
  • each primary winding of the totalizing transformer in conjunction with its primary current transformer produces the correct proportion of the total secondary current; and
  • the overall multiplier for the totalizing transformer is the sum of the ratios of all the primary current transformers which supply the totalizing transformer.

10.1.3 Totalizing meter

A totalizing meter may consist of two or more complete meter units supplied from separate primary circuits which supply a common meter register subject to the following conditions:

  • the voltage coils of each meter unit are supplied from the primary circuit which supplies the current coils of the corresponding meter unit; and,
  • each meter unit contributes to the totalized value of measurement from its correct proportion of the total load.

10.1.4 Totalized circuits

Summation of volt-amperes and volt-ampere-hour units in totalized circuits must be performed by vectorial addition only.

10.1.5 Peak demands

Peak demands from multiple demand measuring devices may be summed only if the demand intervals are coincident. All the devices must be synchronized together such that the demands to be summed occur in the same interval. Synchronization error must be no greater than 1.0 % of the demand interval length.

10.2 Deductive totalizing

Deductive totalizing is not permitted as a means to determine a quantity of a legal unit of measurement in distinct trade measurement transactions. The resulting calculated quantity declaration can deviate from true value to a degree which is significantly greater than the limits of error prescribed by section 46 of the Electricity and Gas Inspection Regulations. Such a deviation in accuracy of the declared value can occur even if the accuracy of the individual meters are in compliance with the prescribed limits of error.

Deductive totalizing utilized solely for the purposes of apportioning a measured and declared quantity into multiple sub-quantities for rate allocation purposes within a distinct trade measurement transaction is permitted.

11.0 Connection of ancillary devices

Relays, instruments, auxiliary transformers and other devices may be connected between the test block or switch provided that they do not affect measurement accuracy, and do not interfere with testing of the meter and/or installation. In addition, wiring diagrams and all burden details for such devices must be available on-site.

12.0 4-wire circuits metered with 2-element meters

12.1 Delta connection at test block or switch

Acceptable delta connections are established in Appendix A—Standard drawings for electricity metering installations (see the 3400-D series).

12.2 Volt-ampere and volt-ampere-hour measurement

Volt-ampere and volt-ampere-hour measurement is permitted subject to the requirements established in item 6.0 (b) of specification PS-E-08.

12.3 Grandfather clause

New metering installations are subject to the policy established in section 5.1 of bulletin E-24. This means that as of April 1, 2003, new 4-wire installations cannot be metered with 2-element meters.

13.0 Polyphase circuits metered with single-phase meters

The use of two single-element meters to meter a 3-phase 3-wire circuit and the use of three single-element meters to meter a 3-phase 4-wire circuit is permitted only where the units of watthour and/or var-hour energy are measured. The single element meter must be approved as bi-directional or net meters. This form of metering is not permitted for volt-ampere-hour measurement nor for demand measurement.

14.0 Revisions

The purpose of revision 3 was to:

  • clarify the position of Measurement Canada with regards to ABC versus CBA rotation and the vector diagrams in the standard drawings,
  • update the document according to the latest formatting requirements, which included modifying the document numbering.

The purpose of revision 2 was to:

  • include additional drawings for single-phase installations with test blocks,
  • amend Appendix A to remove standard drawings depicting meters that do not meet the requirements of bulletin E-24 or representing outdated measurement techniques and meters that are now obsolete (legacy drawings),
  • correct minor errors and add missing information,
  • make additional changes to make this document more accessible.

The purpose of revision 1 was to:

  • include clarification of the requirements pertaining to totalizing in section 9.0 and consequently to add definitions for "additive totalizing" and "deductive totalizing",
  • modify section 5.4 to allow current transformers connected into the neutral conductor, provided they do not contribute to the determination of a LUM,
  • add paragraph 9.1.6 to clarify totalizing requirements when pertaining to demand measurement,
  • delete item 9.1(c) and section 9.4 as they are no longer applicable,
  • amend section 12.0 to require bidirectional or net meters where single-element meters are used to measure the load in polyphase circuits.

15.0 Additional information

For additional information regarding this specification, please contact the Centre of Expertise specialist responsible for electricity measurement.

Appendix A—Standard Drawings for Electricity Metering Installations

This appendix is available upon request due to its large size. To obtain a copy, please send an email to mcinfo-infomc@ised-isde.gc.ca.

Appendix B—Standard colour code for electricity metering installations

Table 1: Standard colour code for electricity metering installations
Application Phase Current Transformer Leads Voltage Leads
Line Load Line Load
  • 3-phase, 3-wire, delta
  • 2-element meter
  • 2 CTs
  • 2 VTs
 A Red – White Red – Black Red Yellow
B        
C Blue – White Blue – Black Blue White
N        
  • 3-phase, 4-wire, Y
  • 2-element meter
  • 3 CTs, (delta at test links)
  • 2 VTs
 A Red – White Red – Black Red Yellow
B Yellow – White Yellow – Black    
C Blue – White Blue – Black Blue White
N        
  • 3-phase, 4-wire, Y
  • 2½-element meter
  • 3 CTs
  • 2 VTs
 A Red – White Red – Black Red Yellow
B Yellow – White Yellow – Black    
C Blue – White Blue – Black Blue White
N        
  • 3-phase, 4-wire, Y
  • 2½-element meter
  • 3 CTs
  • No VTs
 A Red – White   Red  
B Yellow – White      
C Blue – White   Blue  
N   White   White
  • 3-phase, 4-wire, Y
  • 3-element meter
  • 3 CTs
  • 3 VTs
 A Red – White   Red  
B Yellow – White   Yellow  
C Blue – White   Blue  
N   White   White
  • 3-phase, 4-wire, delta
  • 3-element meter
  • 3 CTs
  • No VTs
 A Red – White   Red  
B Yellow – White   Yellow  
C Blue – White   Blue  
N   White   White
  • 3-phase, 4-wire, delta
  • 2-element meter
  • 3 CTs, (all secondaries to test links)
  • No VTs
 A Red – White   Red White
B Yellow – White      
C Blue – White   Yellow Blue
N   White    
  • 3-phase, 4-wire, delta
  • 2-element meter
  • One 3-wire CT, one 2-wire CT,
    (all secondaries to test links)
  • No VTs
 A Red – White Red – Black Red White
B        
C Yellow – White Yellow – Black Yellow Blue
N        

Note: Green is used only for non-current carrying ground conductors. Also, white is used for current-carrying neutral or common conductors.

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