P-E-04 – Generic Procedures for Conducting Installation Verifications of Multiple Customer Metering Systems

P-E-04 – Generic Procedures for Conducting Installation Verifications of Multiple Customer Metering Systems (PDF, 130 KB, 16 pages)

Table of Contents

1.0 Background

The initial installation verification of all multiple customer metering systems (MCMS) are required to be inspected concurrent with the commissioning process where possible, but no later than one year from the date that the system is activated, in accordance with section 7.2 of S-E-04.

2.0 Purpose

This document is intended to provide generic procedures for Measurement Canada Inspectors to perform inspection of MCMS, where device specific procedures are not available.

3.0 Scope

These procedures apply to all MCMS, including those which use separately approved instrument transformers and are being used for the purpose of obtaining the basis of a charge for electricity in Canada.

4.0 Definitions

Commissioning

The process or procedure used during installation of MCMS prior to activation to ensure the system is operating correctly. (For example, the process for assessing that current sensors or instrument transformers are connected to the correct load and associated with the applicable voltage connections).

Contractor

Any person or body that has undertaken to supply electricity or gas to any purchaser.

Metering Point

An individual meter, found in a multiple customer metering system.

Multiple Customer Metering Systems (MCMS) or Device

Metering systems which fulfill one or both of the following criteria:

  1. systems which require on site central processing of meterological information for more than one metering point.
  2. systems which employ external sensors which are integral to the meter. These systems generally are used in multi customer applications, however they can operate as stand alone, single point meters.

5.0 Responsibilities

5.1 The contractor is responsible to provide the original Inspection Certificates and Configuration Charts for the system in question, in addition to a wiring chart of the system showing the physical location of all metering components within the complex, when required.

5.2 The contractor is also responsible to provide a representative with authority to access all metering points.

5.3 The Inspector or Accredited Organization is responsible to verify that the Contractor has fulfilled all general, administrative and technical requirements of S-E-04.

6.0 Guidelines

6.1 Preliminary

Prior to conducting any field inspections, the Inspection Certificates generated from the initial verification of the system and the applicable Configuration Charts are required. These documents should be supplied by the contractor and will show how the system was configured during the initial verification (in a meter shop), indicating number of metering points per unit, type of metering (1, 2 or 3 elements) association between voltage and current sensors and /or instrument transformers, along with the appropriate connection points for each (where applicable).

6.2 Visual Examination

6.2.1 A preliminary visual examination should be conducted on the components of the system required to be inspected to confirm the location of all metering points, terminal interfaces and host meter(s).

6.2.2 Under ideal circumstances, all metering components (host meter, current sensors, voltage sensors, instrument transformers, main disconnects, etc.) will be located in one central location or electrical room, however in situations where this is not the case, it is important to establish the number of metering points and there individual locations in relation to the host meter prior to beginning inspections.

6.2.3 Example worksheets (Appendix A, B and C) are provided, which address the General, Administrative, and Technical Requirements of S-E-04. Appendix A and portions of appendix B worksheets should be completed prior to carrying out inspections. Appendix C worksheet, which relates to technical information may be completed during on-site inspection work. Record any characteristics which are not in compliance with sections 5.0, 6.0 and 7.0 of S-E-04.

6.3 Installation Verification

6.3.1 This section is in reference to section 7.0 of S-E-04 and is to confirm that the installation of the system is consistent with the systems configuration at the time of it's initial verification in the meter shop. This is accomplished by verifying that all voltage and current sensors and /or instrument transformers are properly identified, properly associated with correct phase and connected to the correct point on the host meter.

6.3.2 The systems configuration chart will be required in determining that the system is properly connected. The most effective and efficient means of conducting this work is by visual inspection, whenever possible.

6.3.3 However, if visual inspection is not possible or does not provide conclusive evidence of correctness of the installation, other options may be used, such as taking voltage readings, de-energizing circuits, using circuit tracers or taking cross phase readings.

6.4 Voltage Sensors

6.4.1 Verify that all associated phases and neutral are connected to the appropriate terminals at the voltage disconnect switch and the appropriate meter connection points according to meter wiring diagrams.

6.4.2 For example, if voltage connections are colour coded, verify Red, Yellow, Blue, and White wires are connected to A,B,C, and N phase connection points at the meter.

6.4.3 In systems which utilize external voltage sensors or transducers, you will need to verify correct connection from supply source to primary side of voltage sensor / transducer and then from the secondary side of voltage sensor / transducer to voltage connection points on metering unit.

6.4.4 The configuration chart in this case will show the voltage sensor's serial number, which phase it should be associated with and which connection points on the metering unit it should be connected to. If local codes or labeling is used, the metering equipments manufacturer should be consulted to determine standardized wire coding for both current and voltage sensors.

6.4.5 For example, in referring to the configuration chart in Appendix E, it show's that voltage sensor number A150 should be associated with A phase, and connected to meter connection points 1 and 2. The chart also shows this sensor to be rated for 120 volts.

6.4.6 If visual inspection is not possible or conclusive, then verification may be completed by use of voltage measurements, between initial supply connection point to meter voltage input connections. A reading of "zero volts" will confirm that, for example, A phase meter input is connected to A phase supply.

6.5 Current Sensors / Terminal Interface Connections

6.5.1 If current sensors are directional they need to be verified for correct polarity. Typically, current sensors have a white dot which indicates the line side.

6.5.2 Verify that each current sensor is connected to it's appropriate connection point on the host meter and that each sensor is connected to the proper phase, according to the configuration chart supplied.

6.5.3 This verification requires the inspector to verify that each current sensor has appropriate markings and serial numbers, in addition to verifying that each current sensor is associated with the appropriate meter and appropriate phase for that specific meter.

6.5.4 For example, in referring to the configuration chart in Appendix E, it show's that current sensor,serial number A9950 is a 100 amp sensor associated with meter number 1 and should be connected to A-phase on the customers service. The chart also shows that this sensor is to be connected to points 47(common) and 48 at the host meter, and also that the host meter is programmed to associate meter 1 with the 120 volt pt's. (Refer to pt association column)

6.5.5 If visual tracing of wiring is not possible or conclusive, then the inspection can be completed using a circuit tracer. Typically a signal will be injected into the current sensor wire at the connection point of the host meter. The configuration chart will identify a specific current sensor being connected to this point, as mentioned above. Using the receiving portion of the circuit tracing unit, identify which current sensor is receiving a signal and then confirm it's correctness according to the chart.

6.5.5.1 Depending on the system being inspected, it may be necessary to isolate the circuit to be checked, to prevent the signal from the circuit tracer simultaneously traveling along more than one set of ct sensor wires.

6.6 Approved Instrument Transformers

6.6.1 Systems which utilize separately approved instrument transformers are also required to conform to the applicable Measurement Canada Standard Drawings. Additional inspection requirements would therefore include.

6.6.1.1 Verifying that all instrument transformers are approved.

6.6.1.2 Verifying that standardize wire coding is in effect. This could be the use of Measurement Canada's color code, a local color code or use of standardized labeling for wiring. In either case, each transformers secondary wiring should be identifiable for each phase, supply and return.

6.6.1.3 Verifying that all secondaries of transformers are tied to a single ground point, to ensure secondary current is not bypassing metering sensors.

6.6.1.4 Verifying that polarity of transformers are correct. Typically a white dot will indicate the line side of the transformer.

6.6.1.5 Verifying that Instrument Transformers are appropriately marked as per their respective approval. Ratio check's may be necessary in order to verify that marked ratio's are correct.

6.7 Phasing

6.7.1 Verify correct phasing between the meters voltage connections and the associated current sensors and /or instrument transformers, according to the wiring configuration chart.

6.7.2 Inspections completed under 6.4, 6.5 and/or 6.6 of this document, may have been sufficient to ensure correct phasing between voltage and current connections, however if this is not the case, then it will be necessary to verify that all A , B and C phase current sensor's are actually connected to the same phase in which the voltages for A, B and C are connected.

6.7.3 Typically this can be accomplished by visual inspection or by taking voltage readings from the voltage connection point at the meter to the phase in which the associated current sensors are connected. A zero volts reading will confirm that these two points are associated with the same phase. This process should be repeated for each phase.

7.0 Sealing

Apply installation seals in accordance with section 8.0 of S-E-04.

8.0 Inspection Certificates

Issue an inspection certificate in accordance with section 21 of the regulations, including a summary of findings. Clearly state on the certificate that this inspection has been carried out under the requirements of S-E-04.

9.0 Fees

Charge the hourly rate for inspectors time and expenses as per Part VI, section 47 of the Regulations.

10.0 Written Report

Summarize your findings in a written report to the contractor describing any action required on the part of the contractor to bring the system into compliance with S-E-04, or any other applicable Measurement Canada requirements. Ensure all potential inequities found during this inspection are properly addressed through appropriate channels.

Appendices

Worksheets for Conducting Installation Verifications of Multiple Customer Metering Systems

Appendix A – General

Date:

Insert the date.

District:

Insert the district.

Inspector:

Insert the inspector's name.

General

Contractor's Legal Name:

Insert the contractor's legal name.

Mailing Address:

Insert the mailing address.

Name of Company Responsible for the Installation:

Insert the name of the company responsible for the installation.

Installation Address:

Insert the installation's address.

MCMS Manufacturer:

Insert the name of the MCMS manufacturer.

Date of Activation:

Insert the date of activation.

Model name and number:

Insert the model name and number.

Number of Host Meters:

Insert the number of host meters

Number of Metering Points:

Insert the number of metering points.

General Comments Relating to the Installation:

Insert general comments relating to the installation.

Appendix B – Administrative Requirements

5.0 Administrative Requirements

5.1.1 Is the contractor registered in accordance with the Act?

Insert yes or no and the registration number.

5.1.2 Is the device approved for billing purposes?

Insert yes or no and the approval number.

5.1.3 Has the system been initially verified in-shop?

Insert yes or no, the seal year and expiry year.

5.1.4 Have all installation requirements listed in the approval been adhered to?

Insert yes or no

5.1.5 Has auxiliary equipment been installed as per MC guidelines?

Insert yes or no, with details.

5.2 Has the contractor supplied notification to MC in accordance with requirements?

Insert yes or no.

5.3 Has the contractor supplied a representative in accordance with requirements?

Insert yes or no, and name of representative.

5.4 Has the required documentation been provided by the contractor?

Insert yes or no.

5.5 Have you been provided appropriate access to all installation components?

Insert yes or no.

Comments:

Insert comments.

Appendix C – Technical Requirements

6.0 Technical Requirements

6.2 Are all hardware components safely and securely mounted?

Insert yes or no.

6.3 Are there provisions for connecting test equipment to all current sensors?

Insert yes or no.

6.4.1 Is the voltage being taken from the same source as the currents?

Insert yes or no.

6.4.2 Does the voltage differential ensure that the tolerances prescribed by section 31 of the EGIR are met?

Insert yes or no.

6.4.3 Are the voltage and current circuits separate and distinct?

Insert yes or no.

6.5 Has the installation been wired to facilitate on-site testing?

Insert yes or no.

6.6 Has a voltage test block or disconnect switch been installed?

Insert yes or no.

Is the test block or disconnect switch rated between 120 v and 600 v?

Insert yes or no.

6.7 Does the system utilize instrument transformers?

Insert yes or no.

If so, does the installation have a current test block?

Insert yes or no.

6.8 Is all primary and secondary current and voltage wiring visibly traceable and properly identified?

Insert yes or no.

6.9 Are all sensor serial numbers visible, legible and permanently affixed?

Insert yes or no.

6.10 Can the phase relationship between the voltage and current circuit for any given meter be verified?

Insert yes or no.

Appendix D – Work Sheet – Installation Inspection

7.0 Installation Inspection
Host Meter Meter Number Are all voltage sensor and/or voltage connections correct (section 7.3.1)? Are all current sensor and/or transformer connections correct (section 7.3.2)? Is phasing between voltage and current correct (section 7.3.3)? Is the correct unit or customer connected (section 7.4.4)?
Insert Host Meter Number Insert Meter Number Insert Yes or No Insert Yes or No Insert Yes or No Insert Yes or No

Note: This chart should be copied for additional meters.

Note: Additional inspection requirements for systems utilizing separately approved Instrument transformers can be found on following page.

Appendix D – Continued – 6.0 Installation Inspections

7.4 Systems Utilizing Separately Approved Instrument Transformers

Note: This chart should be copied for additional meters.

7.4.1 Is the system using a standard wire code?

Insert yes or no, and identify code.

7.4.2 Is grounding of secondary wires for instrument transformers correct?

Insert yes or no.

7.4.3 Are the instrument transformers installed according to polarity markings?

Insert yes or no.

7.4.4 Do all instrument transformers have nameplates and appropriate markings?

Insert yes or no.

What is the type of transformers used?

Insert the type of transformers used.

What transformer ratio is marked on the nameplate?

Insert the transformer ratio.

Is the transformer ratio confirmed via dynamic check?

Insert yes or no.

Comments:

Insert comments.

Appendix E – Configuration Chart – Example

Configuration Chart – Example
Meter # Phase CT # CT Connection point CT Rating PT # PT Connection Point PT Rating
1 A/Red A9950 48 and 47 100 A A150 2 and 1 120 V
1 B/Yellow A9951 50 and 49 100 A A151 4 and 3 120 V
1 C/Blue A9952 52 and 51 100 A A152 6 and 5 120 V
2 A/Red A7770 54 and 53 200 A B250 8 and 7 347 V
2 B/Yellow A7771 56 and 55 200 A B251 10 and 9 347 V
2 C/Blue A7772 58 and 57 200 A B252 12 and 11 347 V

Appendix F – Wiring Diagram – Examples

Figure 1: Wiring diagram illustrating sensing transducers integral to the metering system
MCMS Wiring Diagram

Description of Figure 1

This is the first example of a wiring diagram for installations utilizing sensing transducers considered as integral to a multiple customer metering system (MCMS). The diagram illustrates a connection of a transformer-type, 3-element MCMS in a 3-phase, 4-wire, Wye-connected circuit with three voltage sensors and three current sensors.

The four circuit conductors are referred to as Phase A, Phase B, Phase C and neutral. The meter has only one set of secondary current sensor inputs. A customer switch cabinet is connected between the primary circuits and the current sensors. A voltage disconnect switch is connected between the primary circuits and the voltage sensors. A test block is connected on the secondary circuits between the current sensors and the MCMS.

The Phase A to neutral voltage transformer is connected as follows:

  • The polarity marked primary terminal is connected from the Phase A service conductor to the bottom of the voltage disconnect switch in position one with a red wire (the positions are referenced from left to right as numbers one through four).
  • The top of the voltage disconnect switch is connected to the voltage sensor primary in position one with a red wire. Its secondary is connected to the MCMS in position one with a red wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase B to neutral voltage transformer is connected as follows:

  • The terminal of the primary on which the polarity is marked is connected from the Phase B service conductor to the bottom of the voltage disconnect switch in position two with a yellow wire.
  • The top of the switch is connected to the voltage sensor primary in position two with a yellow wire. Its secondary is connected to the MCMS in position two with a yellow wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase C to neutral voltage transformer is connected as follows:

  • The terminal of the primary on which the polarity is marked is connected from the Phase C service conductor to the bottom of voltage disconnect switch in position three with a blue wire.
  • The top of the switch is connected to the voltage sensor primary in position three with a blue wire. Its secondary is connected to the MCMS in position three with a blue wire.
  • The unmarked primary terminal is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase A, B and C current sensors are connected through a wiring conduit.

A green wire is connected from the brown wire that is connected to the voltage disconnect switch to a ground point.

Figure 2: Wiring diagram illustrating separetely approved instrument transformers
MCMS Standard Wiring Diagram

Description of Figure 2

This is the second example of a wiring diagram for installations utilizing separately approved instrument transformers not considered as integral to a multiple customer metering system (MCMS). The diagram illustrates a connection of a transformer-type, 3-element MCMS in a 3-phase, 4-wire, Wye-connected circuit with three voltage transformers and three current transformers.

The four circuit conductors are referred to as Phase A, Phase B, Phase C and neutral. The meter has only one set of secondary current inputs. A customer switch cabinet is connected between the primary circuits and the current transformers. A voltage disconnect switch is connected between the primary circuits and the voltage transformers.

The Phase A to neutral voltage transformer is connected as follows:

  • The polarity marked primary terminal is connected from the Phase A service conductor to the bottom of the voltage disconnect switch in position one with a red wire (the positions are referenced from left to right as numbers one through four).
  • The top of the voltage disconnect switch is connected to the voltage sensor primary in position one with a red wire. Its secondary is connected to the MCMS in position one with a red wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase B to neutral voltage transformer is connected as follows:

  • The polarity marked primary terminal is connected from the Phase B service conductor to the bottom of the voltage disconnect switch in position two with a yellow wire (the positions are referenced from left to right as numbers one through four).
  • The top of the voltage disconnect switch is connected to the voltage sensor primary in position two with a red wire. Its secondary is connected to the MCMS in position one with a yellow wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase C to neutral voltage transformer is connected as follows:

  • The polarity marked primary terminal is connected from the Phase C service conductor to the bottom of the voltage disconnect switch in position three with a blue wire (the positions are referenced from left to right as numbers one through four).
  • The top of the voltage disconnect switch is connected to the voltage sensor primary in position one with a blue wire. Its secondary is connected to the MCMS in position three with a blue wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A brown wire is connected from the unmarked terminals of the three voltage sensors, on both the primary and the secondary.

The Phase A current transformer is connected as follows:

  • The polarity marked secondary terminal is connected from the Phase A service conductor to the bottom of the terminal shorting block in position one with a red wire (the positions are referenced from left to right as numbers one through six).
  • The top of the terminal shorting block is connected to the MCMS in position one with a red wire.
  • The unmarked terminal of the secondary is connected from the Phase A service conductor to the bottom of the terminal shorting block in position two with a white and red wire
  • The top of the terminal shorting block is connected to the MCMS in position two with a white and red wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A green wire is connected from the unmarked terminals of the three current transformers to the ground.

The Phase B current transformer is connected as follows:

  • The polarity marked secondary terminal is connected from the Phase B service conductor to the bottom of the terminal shorting block in position three with a yellow wire (the positions are referenced from left to right as numbers one through six).
  • The top of the terminal shorting block is connected to the MCMS in position three with a yellow wire.
  • The unmarked terminal of the secondary is connected from the Phase A service conductor to the bottom of the terminal shorting block in position four with a white and yellow wire
  • The top of the terminal shorting block is connected to the MCMS in position four with a white and yellow wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A green wire is connected from the unmarked terminals of the three current transformers to the ground.

The Phase C current transformer is connected as follows:

  • The polarity marked secondary terminal is connected from the Phase C service conductor to the bottom of the terminal shorting block in position five with a blue wire (the positions are referenced from left to right as numbers one through six).
  • The top of the terminal shorting block is connected to the MCMS in position five with a blue wire.
  • The unmarked terminal of the secondary is connected from the Phase A service conductor to the bottom of the terminal shorting block in position six with a white and blue wire
  • The top of the terminal shorting block is connected to the MCMS in position six with a white and blue wire.
  • The unmarked terminal of the primary is connected to the neutral service conductor. A green wire is connected from the unmarked terminals of the three current transformers to the ground.