© 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
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
CONTENTS
1 INTRODUCTION TO THE FULL IMPACT ASSESSMENT................................................... 3 2 PURPOSE OF THE FULL IMPACT ASSESSMENT............................................................. 3 3 3.1 3.2 BACKGROUND OF THE CHANGE ...................................................................................... 3 Subject 3644 — Polarity identification for photovoltaic dc system conductors ................... 3 Subject 3694 — Photovoltaic dc arc-fault circuit protection................................................ 3 4 4.1 4.2 4.3 THE NATURE OF THE CHANGE ......................................................................................... 4 Subject 3644 — Polarity identification for photovoltaic dc system conductors ................... 4 Subject 3694 — Photovoltaic dc arc-fault circuit protection................................................ 5 How is it different from the status quo? .............................................................................. 5 4.3.1 Subject 3644 — Polarity identification for photovoltaic dc system conductors........5 4.3.2 Subject 3694 — Photovoltaic dc arc-fault circuit protection ....................................5 5 5.1 PURPOSE/REASON FOR THE CHANGE ............................................................................ 6 What is the issue that the change is intended to address? ................................................ 6 5.1.1 Subject 3644 — Polarity identification for photovoltaic dc system conductors........6 5.1.2 Subject 3694 — Photovoltaic dc arc-fault circuit protection ....................................6 5.2 How does the change accomplish the desired results? ..................................................... 6 5.2.1 Subject 3644 — Polarity identification for photovoltaic dc system conductors........6 5.2.2 Subject 3694 — Photovoltaic dc arc-fault circuit protection ....................................7 5.3 What are the implications/consequences if action is not taken? ........................................ 7 5.3.1 Subject 3644 — Polarity identification for photovoltaic dc system conductors........7 5.3.2 Subject 3694 — Photovoltaic dc arc-fault circuit protection ....................................7 6 6.1 6.2 WHY IS ACTION REQUIRED AT THIS TIME? ..................................................................... 7 Subject 3644 — Polarity identification for photovoltaic dc system conductors ................... 7 Subject 3694 — Photovoltaic dc arc-fault circuit protection................................................ 7 7 (14) PREVALENCE OF RULE USE IF ACCEPTED ............................................................. 8 8 8.1 8.2 8.3 8.4 8.5 8.6 IMPACT ON KEY STAKEHOLDERS .................................................................................... 8 (16) Largest type of stakeholder who would benefit ........................................................... 8 (24) Largest type of stakeholder who would be negatively affected ................................... 8 (15) Other stakeholders affected on a frequent basis ........................................................ 8 Is the proposed change limited to a specific group/geographic area?................................ 9 What is the affected stakeholders’ readiness to act on the change(s)? ............................. 9 Recommended stakeholder management strategy ............................................................ 9 Page 1
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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
8.7 Communication and implementation plan .......................................................................... 9 9 ANALYSIS OF ANTICIPATED ECONOMIC IMPACT ........................................................ 10 9.1 (20) The jurisdiction or stakeholder’s ability to compete, based on incompatibility with
other standards ............................................................................................................................... 10 9.2 (21) Complexity of implementation (is training required to implement the Rule?) ............ 10 9.3 (22) Total costs to implement (for example, cost to install, educate, manufacture,
inspect, purchase additional product, and of increased use of electricity) ...................................... 10 10 IMPACT ON BUSINESS: LARGE AND SMALL (IF APPLICABLE) .................................. 10 11 WHAT IS THE PRACTICE/EXPERIENCE IN OTHER JURISDICTIONS? ......................... 11 11.1 Are standards consistent with (or lesser/greater than) other jurisdictions? ...................... 11 11.2 (23) Conflict with other Ministries or Codes ...................................................................... 11 11.3 Consequences for other Departments/Ministries, e.g., apprentice training ...................... 11 11.4 Consequences for other Codes from other jurisdictions (US, European standards) ........ 11 12 CONSULTATION PROCESS .............................................................................................. 11 13 PROPOSED EFFECTIVE DATE OF CHANGES ................................................................ 12 APPENDIX 1 — CODE RANKING TOOL VALUES ...................................................................... 13 Page 2
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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
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
Subject 3644 — Polarity identification for photovoltaic dc system
conductors
3.1
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 64-212 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
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Subject 3644 Polarity identification for photovoltaic (PV) dc system conductors
Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection
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 64216 (previously 50-014) 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
Subject 3644 — Polarity identification for photovoltaic dc system
conductors
4.1
(A) Insert a new Rule 64-212 to read as follows:
64-212 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.
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Subject 3644 Polarity identification for photovoltaic (PV) dc system conductors
Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection
(B) Add a new Appendix B Note to Rule 64-212 to read as follows:
Rule 64-212
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 50-014 has been renumbered 64-216.
Revise Rule 64-216 as follows:
64-216 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?
4.3.1
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.
4.3.2
Subject 3694 — Photovoltaic dc arc-fault circuit protection
Currently, Rule 50-014 (now 64-216) reads as follows:
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Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection
50-014 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?
5.1.1
Subject 3644 — Polarity identification for photovoltaic dc system conductors
The introduction of Rule 64-212 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.
5.1.2
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 64-216 to all
photovoltaic arrays.
5.2
How does the change accomplish the desired results?
5.2.1
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.
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Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection
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 50-014 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?
5.3.1
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.
5.3.2
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?
Subject 3644 — Polarity identification for photovoltaic dc system
conductors
6.1
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.
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Subject 3694 Photovoltaic (PV) dc arc-fault circuit protection
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
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maintenance personnel where applicable. Training programs and
literature, including
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.
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9
ANALYSIS OF ANTICIPATED ECONOMIC IMPACT
(20) The jurisdiction or stakeholder’s ability to compete, based on
incompatibility with other standards
9.1
The revision should not affect a jurisdiction’s competitive position.
(21) Complexity of implementation (is training required to implement the
Rule?)
9.2
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.
(22) Total costs to implement (for example, cost to install, educate,
manufacture, inspect, purchase additional product, and of increased use of
electricity)
9.3
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.
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
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.
11.2
(23) Conflict with other Ministries or Codes
No conflict has been observed.
11.3
Consequences for other Departments/Ministries, e.g., apprentice training
Not applicable.
Consequences for other Codes from other jurisdictions (US, European
standards)
11.4
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;
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(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 2015.
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APPENDIX 1 — CODE RANKING TOOL VALUES
3694 & 3644
Subject #
Reason for Change
Safety consideration (Severity)
10
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
53
Extent of Use & Value Add
Prevalence of rule use if accepted
9
Number of stakeholders affected on frequent basis
10
Largest type of stakeholder who would benefit
10
Benefit to society
10
Total Score for Extent of Use
39
Risk for Changing Rule/Staying Status
The jurisdiction or stakeholder's ability to compete based on
incompatibility with other standards
0
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
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