Canadian Electrical Code, Part I Full Impact Assessment

Transcription

1 Copyright CSA Group 2015 Canadian Electrical Code, Part I Full Impact Assessment Subject 3644 Polarity identification for photovoltaic (PV) dc system conductors & Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection

2 CONTENTS 1 INTRODUCTION TO THE FULL IMPACT ASSESSMENT PURPOSE OF THE FULL IMPACT ASSESSMENT BACKGROUND OF THE CHANGE Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection THE NATURE OF THE CHANGE Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection How is it different from the status quo? Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection PURPOSE/REASON FOR THE CHANGE What is the issue that the change is intended to address? Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection How does the change accomplish the desired results? Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection What are the implications/consequences if action is not taken? Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection WHY IS ACTION REQUIRED AT THIS TIME? Subject 3644 Polarity identification for photovoltaic dc system conductors Subject 3694 Photovoltaic dc arc-fault circuit protection (14) PREVALENCE OF RULE USE IF ACCEPTED IMPACT ON KEY STAKEHOLDERS (16) Largest type of stakeholder who would benefit (24) Largest type of stakeholder who would be negatively affected (15) Other stakeholders affected on a frequent basis Is the proposed change limited to a specific group/geographic area? What is the affected stakeholders readiness to act on the change(s)? Recommended stakeholder management strategy... 9 Page 1 17/12/2014

3 8.7 Communication and implementation plan ANALYSIS OF ANTICIPATED ECONOMIC IMPACT (20) The jurisdiction or stakeholder s ability to compete, based on incompatibility with other standards (21) Complexity of implementation (is training required to implement the Rule?) (22) Total costs to implement (for example, cost to install, educate, manufacture, inspect, purchase additional product, and of increased use of electricity) IMPACT ON BUSINESS: LARGE AND SMALL (IF APPLICABLE) WHAT IS THE PRACTICE/EXPERIENCE IN OTHER JURISDICTIONS? Are standards consistent with (or lesser/greater than) other jurisdictions? (23) Conflict with other Ministries or Codes Consequences for other Departments/Ministries, e.g., apprentice training Consequences for other Codes from other jurisdictions (US, European standards) CONSULTATION PROCESS PROPOSED EFFECTIVE DATE OF CHANGES APPENDIX 1 CODE RANKING TOOL VALUES Page 2 17/12/2014

4 1 INTRODUCTION TO THE FULL IMPACT ASSESSMENT The Full Impact Assessment follows the rationale of the Canadian Electrical Code Ranking Tool (CRT) and provides supporting information to validate the rankings of the CRT. It includes all the questions of the CRT either verbatim or modified. However, the scope of the Full Impact Assessment extends beyond that of the CRT and, therefore, the assessment includes additional questions that may help to substantiate the rankings. The CRT is referenced throughout the Full Impact Assessment. The questions from the CRT are identified in the Full Impact Assessment by numbers in parentheses. Whenever applicable, chapter titles also include references to the relevant sections of the CRT. The Full Impact Assessment follows the sequence of the CRT as closely as possible but, to enhance the analytical function of the document, risk-related and benefits-related questions have not been separated in the Full Impact Assessment. 2 PURPOSE OF THE FULL IMPACT ASSESSMENT The purpose of the Full Impact Assessment is to provide the provinces and territories with an enhanced rationale and detailed assessment of a particular change to the Canadian Electrical Code, Part I (CE Code, Part I). This assessment is submitted for review to provincial and territorial regulatory authorities to aid with their adoption process for the Code. Jurisdictions may decide to conduct further analyses or to hold additional consultations. 3 BACKGROUND OF THE CHANGE 3.1 Subject 3644 Polarity identification for photovoltaic dc system conductors Unlike traditional ac systems, where connection of incorrectly identified conductors will cause reversal of motors or an overcurrent device to operate, reversal of dc sources can create series circuits that will produce voltages well in excess of the rated system voltage. Some failures during installation are thought to have been caused by increased potential when a photovoltaic array s wiring to combiner boxes was reversed. Minor contaminants, such as moisture or dirt, have been known to start self-sustaining dc arcing faults, even with the fuses in the open position. In some instances, serious fires have been caused by a reversal of the polarity of the wiring between the combiner box and the recombiner. The new Rule mandates colouring and/or coding of photovoltaic output and source circuit wiring in order to reduce the incidence of damage caused by reversal of polarity during installation. 3.2 Subject 3694 Photovoltaic dc arc-fault circuit protection Photovoltaic systems are subjected to extreme environmental conditions, including sun, wind, rain, and temperature extremes. Roof-mounted photovoltaic systems may not be routinely Page 3 17/12/2014

5 inspected or maintained and can deteriorate, eventually causing various types of faults to occur, including series arcing faults. There have been reports of fires caused by the failure of various photovoltaic components, including photovoltaic cell/module conductors, solar connectors, combiner box connections and fuseholders, and photovoltaic inverters. Series arcing faults result from a failure in the intended continuity of a conductor or connector. Because of the nature of dc waveforms, which do not change direction every half cycle, sustained dc arcing can persist. To address these risks, the requirements for dc arc-fault circuit protection in Rule (previously ) have been expanded. DC arc-fault circuit protection does not have to be part of a circuit breaker and may be part of the inverter. 4 THE NATURE OF THE CHANGE 4.1 Subject 3644 Polarity identification for photovoltaic dc system conductors (A) Insert a new Rule to read as follows: Conductor marking or colour coding (see Appendix B) (1) Notwithstanding Rule 4-038, dc photovoltaic output circuit conductors, and photovoltaic source circuit conductors installed between a module and the power conditioning unit of the dc system, shall be coloured or coded, or both, as follows (a) for a 2-wire circuit (i) red for positive and black for negative; or (ii) black conductors manufactured with permanent surface printing indicating the polarity on the conductor; and (b) for a 3-wire circuit (bipolar circuit) (i) white, grey, or white with a coloured stripe for mid-wire (identified as the centre tap), red for positive, and black for negative; or (ii) black conductors manufactured with permanent surface printing indicating the polarity on the conductor. (2) The requirements of Subrule (1) shall not be met by field marking or labelling. (3) Notwithstanding Subrule (2), conductor colour coding for multi-conductor cables required in Subrule (1) shall be permitted to be made through suitable field labelling or marking in a permanent manner. (4) Conductor labelling and marking permitted in Subrule (3) shall (a) be made at every point where the separate conductors are rendered accessible and visible by removal of the outer covering of the cable; (b) be made by painting or other suitable means; and (c) not render the manufacturer s numbering of the conductors illegible. Page 4 17/12/2014

6 (B) Add a new Appendix B Note to Rule to read as follows: Rule CSA C22.2 No 271 requires the positive or negative identification on RPV or RPVU multi-conductor cables to be +/, pos/neg, or positive/negative. Single-conductor cables are permitted to be marked in the same manner. 4.2 Subject 3694 Photovoltaic dc arc-fault circuit protection Section 50 has been merged with Section 64, and Rule has been renumbered Revise Rule as follows: Photovoltaic dc arc-fault circuit protection (1) Photovoltaic systems with dc source circuits, or dc output circuits, or both, on or penetrating a building and operating at a maximum system voltage of 80 V or greater, shall be protected by (a) a dc arc-fault circuit interrupter; or (b) other system equipment approved to provide equivalent protection. (2) The arc-fault protection system required in Subrule (1)(b) shall (a) detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, photovoltaic module, or other system component in the dc photovoltaic source and output circuits; (b) not have the capability of being automatically restarted; (c) have annunciation, without an automatic reset, that provides a visual indication that the circuit interrupter has operated; and (d) disable or disconnect (i) inverters or charge controllers connected to the fault circuit when the fault is detected; or (ii) the system components within the arcing circuit. 4.3 How is it different from the status quo? Subject 3644 Polarity identification for photovoltaic dc system conductors At present, there are no requirements that mandate colouring and/or coding of photovoltaic output and source circuit wiring Subject 3694 Photovoltaic dc arc-fault circuit protection Currently, Rule (now ) reads as follows: Page 5 17/12/2014

7 Photovoltaic dc arc-fault circuit protection (1) Photovoltaic systems with dc source circuits, dc output circuits, or both, on or penetrating a building and operating at a maximum system voltage of 80 V or greater, shall be protected by (a) a dc arc-fault circuit interrupter; or (b) other system equipment approved to provide equivalent protection. (2) The arc-fault protection system required in Subrule (1)(b) shall (a) detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, module, or other system component in the dc photovoltaic source and output circuits; (b) not have the capability of being automatically restarted; (c) have annunciation, without an automatic reset, that provides a visual indication that the circuit interrupter has operated; and (d) disable or disconnect (i) inverters or charge controllers connected to the fault circuit when the fault is detected; or (ii) the system components within the arcing circuit. 5 PURPOSE/REASON FOR THE CHANGE 5.1 What is the issue that the change is intended to address? Subject 3644 Polarity identification for photovoltaic dc system conductors The introduction of Rule is intended to reduce the risk of damage caused by reversal of polarity during installation by mandating colouring and/or coding of photovoltaic output and source circuit wiring Subject 3694 Photovoltaic dc arc-fault circuit protection Arc-faults can occur in all photovoltaic systems, regardless of where they are located. Arc-faults in ground-mounted photovoltaic arrays can cause grass, brush, and even forest fires, which can result in deaths and significant property damage. This risk can be addressed by photovoltaic arc-fault protection. This change expands the coverage required by Rule to all photovoltaic arrays. 5.2 How does the change accomplish the desired results? Subject 3644 Polarity identification for photovoltaic dc system conductors At present, without a requirement for colouring and/or coding of photovoltaic output and source circuit wiring, numerous branch conductors entering a combiner box could all have black insulation. The odds of making an error could be as high as 50%. Colour and/or coding of such conductors would help to reduce those odds significantly, thus reducing the risk of fire and damage. Page 6 17/12/2014

8 5.2.2 Subject 3694 Photovoltaic dc arc-fault circuit protection The change extends the requirement for arc-fault protection methods to ground-mounted photovoltaic arrays. The incidence of rooftop fires caused by photovoltaic arc-faults has been significantly reduced since Rule was introduced. It is anticipated that expanding the Rule to include ground-mounted photovoltaic arrays will help to prevent grass, brush, and forest fires. Using a technology that is designed to detect arcing faults and de-energize the faulted circuit will not only help to prevent fires, it will also help to avoid other damage caused by dc arcing faults. 5.3 What are the implications/consequences if action is not taken? Subject 3644 Polarity identification for photovoltaic dc system conductors Introducing colouring and/or coding requirements for photovoltaic output and source conductors will help to eliminate confusion when conductors are being terminated, thus reducing the frequency of reversed dc polarity Subject 3694 Photovoltaic dc arc-fault circuit protection Without the incorporation of dc arc-fault circuit protection in ground-mounted photovoltaic array systems, the risk of grass, brush, and forest fires will remain unaddressed. Such fires can result in deaths and significant property damage. The new technology referenced in the change was tested and confirmed to prevent fires effectively. 6 WHY IS ACTION REQUIRED AT THIS TIME? 6.1 Subject 3644 Polarity identification for photovoltaic dc system conductors The ever-growing popularity of photovoltaic arrays has led to an increase in photovoltaic installations. If colouring and/or coding of conductor wires is not mandated, the frequency of damage caused by errors in wiring termination will increase. 6.2 Subject 3694 Photovoltaic dc arc-fault circuit protection The advances in technology, development of applicable product standards, and the availability of photovoltaic dc arc-fault circuit protection have made this change possible. The change is also prompted by the need to harmonize with the National Electrical Code (NEC), which mandates the expanded use of dc arc-fault circuit protection. Page 7 17/12/2014

9 7 (14) PREVALENCE OF RULE USE IF ACCEPTED These changes will affect photovoltaic array installations for residential, commercial, and industrial use. As such, the Rule will be implemented very frequently. 8 IMPACT ON KEY STAKEHOLDERS 8.1 (16) Largest type of stakeholder who would benefit The Rules are being introduced for safety reasons. The largest group who will benefit from their use is industrial and commercial facility owners, installers (including contractors), and the general public. Manufacturers of dc arc-fault circuit interrupters will benefit from increased demand for the devices. 8.2 (24) Largest type of stakeholder who would be negatively affected Although positively affected by an increased safety factor, industrial and commercial facility owners will be negatively affected by the increased cost of purchasing and incorporating both the dc arc-fault circuit interrupters and colouring and/or coding of photovoltaic conductors in their installations. Large scale solar farm installations will face additional cost as previous Codes only required arc-fault protection for photovoltaic installations located on, or penetrating, a building. 8.3 (15) Other stakeholders affected on a frequent basis These changes will affect a broad range of stakeholder groups, as follows: Engineers/ Designers: This stakeholder group will be directly affected by the changes because it is their responsibility to specify dc arc-fault protection methods at the design stage. New colouring and/or coding of photovoltaic array source and output conductors will also have to be specified at the design stage. This group is interested in providing costeffective and safe designs and installation requirements to minimize the risk of injury to personnel, damage to facilities, and insurance and legal costs. As such, they will need to receive a communication about the changes (e.g., a formal letter from the authority having jurisdiction). Electrical contractors: This group of stakeholders is responsible for the application of the Code. As such, they need to be informed about changes to it to help ensure full compliance with its requirements. The updates can be delivered through formal training or through industry literature, depending on current practices in a particular jurisdiction. It is the responsibility of individual contractors to keep themselves informed about changes to the Code. Trainers: This is a broad group that may include those providing training to other stakeholder groups, such as electrical contractors and installers of equipment as well as repair and Page 8 17/12/2014

10 literature, including Canadian Electrical Code, Part I Full Impact Assessment maintenance personnel where applicable. Training programs and electronic content, will need to be updated to include the change. Other standards development organizations (SDOs): All references to the provisions of the Code that are being changed will need to be updated in documents published by other SDOs. Provincial/territorial electrical regulatory authorities: This group of stakeholders is responsible for enforcement of the Code and will therefore need to be informed of changes to it. Insurance: Insurance policies contingent on following the Code will need to be updated. Builders: This group will need to be informed of the changes because the new requirements will have to be implemented in new construction. Inspectors: This group of stakeholders is accountable for enforcing compliance with the Code and needs, therefore, to stay informed about changes to it. It is the responsibility of a particular province or territory to make the information on Code changes available to electrical inspectors. Depending on the practice in a particular jurisdiction, changes can be communicated through training (provided by the jurisdiction or a third party) or through jurisdiction-specific or national industry literature. 8.4 Is the proposed change limited to a specific group/geographic area? These changes will have nationwide application. 8.5 What is the affected stakeholders readiness to act on the change(s)? Research has not revealed any evidence of the market not being ready to implement these changes. 8.6 Recommended stakeholder management strategy Not applicable. 8.7 Communication and implementation plan Not applicable. Page 9 17/12/2014

11 9 ANALYSIS OF ANTICIPATED ECONOMIC IMPACT 9.1 (20) The jurisdiction or stakeholder s ability to compete, based on incompatibility with other standards The revision should not affect a jurisdiction s competitive position. 9.2 (21) Complexity of implementation (is training required to implement the Rule?) The implementation of these changes will be complex. Training will be required on the proper use and installation of dc arc-fault circuit interrupters as well as new colouring and/or coding requirements for photovoltaic conductors. 9.3 (22) Total costs to implement (for example, cost to install, educate, manufacture, inspect, purchase additional product, and of increased use of electricity) The change is expected to increase installation costs, driven by the additional equipment mandated by the changes. Manufacturers are now integrating arc-fault circuit protection into system combiner boxes. The cost of a combiner box equipped with a dc arc-fault circuit interrupter is approximately 50% greater than a standard unit (retail prices are used for this analysis; business/bulk prices may be lower). Increased market demand, coupled with advances in product technology, is expected to bring the unit cost down. New arc-fault circuit interrupter and conductor colouring and/or coding requirements can be incorporated into existing photovoltaic installation training material. This is not expected to significantly increase training costs. 10 IMPACT ON BUSINESS: LARGE AND SMALL (IF APPLICABLE) Compliance costs. Compliance will increase project costs for ground-mounted photovoltaic arrays. Costs are expected to decrease as market availability increases and advances in product technology bring unit costs down. Ultimately, the costs are transferred to industrial and commercial facility owners. Change of investment. Not applicable. Job creation/job loss. Not applicable. Labour mobility. Not applicable. Impact on import/export of goods. Not applicable. Page 10 17/12/2014

12 Certification and licensing. Not applicable. Insurance. Not applicable. 11 WHAT IS THE PRACTICE/EXPERIENCE IN OTHER JURISDICTIONS? 11.1 Are standards consistent with (or lesser/greater than) other jurisdictions? Currently, there are no deviations from these requirements of the national Code in provincial electrical codes. Input from other jurisdictions is pending (23) Conflict with other Ministries or Codes No conflict has been observed Consequences for other Departments/Ministries, e.g., apprentice training Not applicable Consequences for other Codes from other jurisdictions (US, European standards) Not applicable. 12 CONSULTATION PROCESS Representatives from the following groups of stakeholders were involved in the consensus approval of this change as part of CSA Group s standards development process: Note: For details about the standards development process as it applies to the CE Code, Part I, please refer to Appendix C of the Code. Regulatory authorities from various provincial, territorial, and municipal electrical inspection authorities Owners/Operators/Producers from groups with national stature, representing the viewpoints of electrical equipment manufacturers, electrical installation designers and installers, and electrical installation users General interest groups with national stature, representing the viewpoints of (a) fire chiefs; (b) electric utilities; (c) committees responsible for related electrical codes and standards; (d) fire insurers; (e) labour; Page 11 17/12/2014

13 (f) issuers of building codes; and (g) educators. A regulatory/legislative body may want to hold additional consultations with all or some of these groups within its jurisdiction to clarify issues specific to the jurisdiction. 13 PROPOSED EFFECTIVE DATE OF CHANGES These changes will be included in the 2015 edition of the CE Code, Part I, to be published January Page 12 17/12/2014

14 APPENDIX 1 CODE RANKING TOOL VALUES Reason for Change Safety consideration (Severity) Subject # 3694 & Safety consideration (Frequency) 10 For clarity 7 Crucial to harmonize 8 Purely administrative 0 Community's desire to change - Environment, Health, Safety 10 Technological change/new Rule 8 Total Score for Reason for Change Extent of Use & Value Add Prevalence of rule use if accepted 53 9 Number of stakeholders affected on frequent basis 10 Largest type of stakeholder who would benefit 10 Benefit to society Total Score for Extent of Use Risk for Changing Rule/Staying Status The jurisdiction or stakeholder's ability to compete based on incompatibility with other standards Complexity of implementation 8 Total costs to implement, e.g. cost to install, to educate, to manufacture,or inspect, increased product cost, increased cost of electricity. 9 Conflict with other Ministries or Code 0 Largest type of stakeholder who would be negatively affected 9 Total Score for Risk of Changing Rule/ Staying Status Quo 26 Total 118 Page 13 17/12/2014