An Urgent Bulletin from CSA Group

Transcription

1 An Urgent Bulletin from CSA Group Photovoltaic Equipment No. 5 Date: September 21, 2015 See Attachment 1 for Effective Dates. See Attachment 1 for Application Due Dates Announcing: Publication of List of Technical Requirements (LTR) No. AE for Photovoltaic Rapid Shut Down Systems Class No: , POWER SUPPLIES - Distributed Generation Power Systems Equipment To purchase the Standard, visit us at Who is affected? Manufacturers of PV rapid shut down devices or systems. What do you do? 1. CSA Group Service Delivery staff will contact you to address compliance with each revision as applicable to the product designs covered in your affected Certification Reports. In addition to updates to your Certificate(s) of Compliance & Report(s), testing may be required to comply with these revisions. 2. Please respond within thirty (30) days of receiving CSA Group s Application for CSA Certification Services and Quotation communication. You must respond no later than the application dates listed in Attachment 1 in order to guarantee the update to your certification is completed by the corresponding effective dates shown in the same attachment. If testing is needed, we will inform you of the samples required. Background and Rationale: The scope of CSA C does not explicitly cover photovoltaic rapid shut down equipment. Those units are designed to maintain controlled conductors at a limit of not more than 30Vdc or 15Vac, 8A and may not exceed 240 volt-amperes to protect emergency personnel. The purpose of this LTR (Attachment 2) is to provide guidance for the uniform application of the related standard requirements. It is not intended to establish requirements or supplant requirements that appear in any Part II Standards. For questions specific to your file or products contact your CSA Group technical staff associate. Go to and enter your Master Contract # and the class numbers associated with this Notice to determine which of your products are affected. For technical questions on this Certification Notice Contact Ze Guo by phone 86 (21) , fax 86 (21) or ze.guo@csagroup.org The standard edition or amendments announced in this Notice may be used for certification as of the date of issue of this Notice. The Effective date in this Notice is the date on which the current requirements, applicable to Certified products listed in the affected class numbers, expire and the standard edition or amendments announced in this Notice become the only requirements that may be used for certification. In the event that currently certified products do not comply with the latest requirements outlined in this Notice after the effective date, the certification of such models may be discontinued. Visit us at Click on "Contact Us" for the online phone listing of our Offices and Partners DQD Rev The Canadian Standards Association. All rights reserved. Ref No: N I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 1 of 9

2 ATTACHMENT 1 Effective Dates Manufacturer of Photovoltaic rapid shut down systems may now make use of LTR AE Photovoltaic rapid shut down systems previously manufactured and certified will continue to be listed until (whichever occurs first): a. October 1 st 2016; or b. Changes to the equipment are made by the manufacturer; or c. Safety related changes are made to LTR AE which would require reassessment of the product. The application deadline is March 1 st ATTACHMENT 2 List of Technical Requirements [LTR] LTR Number AE Subject Keywords Photovoltaic Rapid Shut Down System Background & Rationale In the 2015 CE code rule number Photovoltaic system rapid shutdown, and rule , Markings covered new safety requirements to protect emergency personnel requiring access to buildings having a single or multiple PV arrays installed. This LTR provides guidelines for PV rapid shutdown systems to be used in conjunction with CSA C Photovoltaic rapid shut down equipment is designed to maintain controlled conductors at a limit of not more than 30Vdc or 15Vac, 8A and may not exceed 240 volt-amperes to protect emergency personnel. The purpose of this LTR is to provide guidance for the uniform application of the related standard requirements. It is not intended to establish requirements or supplant requirements that appear in any Part II Standards. Technical Issue This LTR addresses requirements for evaluating the suitability of PV rapid shut down systems. Technical Requirements I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 2 of 9

3 1.1 REFERENCE STANDARDS: CSA-C CSA-C22.2 NO CSA-C M91 CSA-C M90 IEC CSA C22.2 No CSA C22.2 No CSA C22.2 No IEEE C IEC Series General use power supplies Industrial control equipment Moulded Case Circuit Breakers Moulded Case Switches Electromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test - Second Edition Special use switches General-use snap switches Temperature-indicating and regulating equipment IEEE Standard for Withstand Capability of Relay Systems to Radiated Electromagnetic Interference from Transceivers Functional safety of electrical/electronic/programmable electronic safety-related systems 1.2 REFERENCE CLASS DESCRIPTIONS: Class: POWER SUPPLIES Distributed Generation Power Systems Equipment 1.3 LTR SCOPE and DEFINITIONS This LTR applies to Photovoltaic rapid shut down systems and Photovoltaic shutdown equipment used to isolate or attenuate the output controlled conductors of a PV array. Photovoltaic rapid shut down systems (herein referred to as PVRSS) represents an integrated set of discrete components that work together to perform the shutdown of one or more PV arrays. The term rapid shutdown relates to the shutdown of photovoltaic (PV) arrays to a power level safe for emergency personnel. This is reflected in the CE code rule number called Photovoltaic system rapid shutdown. The LTR also refers to safety testing requirements for mechanical equipment used to disconnect or attenuate the AC or DC output of a photovoltaic system. 1.4 Rapid shutdown System Example Figure 1 is a block diagram of a representative shutdown system. The example is used to help identify the component parts used in a system. I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 3 of 9

4 PV shutdown system connected to multiple PV Arrays 3 m PV PV PV SW CB Combiner Box OR Inverter PV-RSE I D A Rapid Shutdown System (PV-RSS) controlling multiple PV Array strings Figure 1 The rapid shutdown system example in Figure 1 is a functional block diagram showing the component parts and interfaces. The system receives a signal from an actuator A and causes each conductor switch SW to activate mechanism that limits each PV source to the specified safe level, and once this is verified as complete, sends a CLEAR signal to the display component, all within 10 seconds. The safe power level is stated below as defined in CE code rule Actuator ( A ) that is manually activated by an operator to start the shutdown process. 2. Display ( D ) that indicates to the same operator that the shutdown has completed successfully. The display unit may also display system status information. 3. One or more switching components ( SW ) that limits the DC voltage output to the specified safe level. A shutdown system may control multiple PV array output conductors. 4. A shutdown control unit PV-RSE controlling the shutdown function. 1.5 DEFINITIONS 1. PV array: Several PV panels combined to result in a single output conductor. 2. Reset Device: A device used to re-enable the power generation of a PV system. 3. DUT: Device under test. 4. Actuator: Switching devices which result in the activation of RSS to disable PV array. 5. Status Indicator: Indication device provides a visual signal and confirmation to the person who activated the shutdown that the status of the intended circuits (if the circuits have been isolated, attenuated or still operate). 6. Reset Device: A device used to re-enable the power generation of a PV system. 2 REQUIREMENTS 2.1 Regulatory requirements CE states: (1) A photovoltaic system rapid shutdown device shall be provided for a photovoltaic system installed on buildings or structures where the photovoltaic source or output circuit conductors installed in or on buildings are more than 1.5 m in length or more than 3 m from a photovoltaic array respectively. I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 4 of 9

5 (2) A photovoltaic system rapid shutdown device shall limit photovoltaic source or output circuits to not more than 30 V and 240 V A within 10 s of rapid shutdown initiation. 2.2 Safety Functions of a PVRSS 1. Display shall indicate CLEAR when the switch operation is complete. 2. The safe level of each conductor shall be 30 Vdc (20 to 0 %) or 15Vac (rms), 8 A not exceeding 240 volt-amperes. 3. All defined output switches must have their operation verified complete within 10 seconds (20 to 0%) after the actuator signal. 4. The 3 safety functions above are noted to illustrate those applicable to Figure 1. The manufacturer is required to state the safety functions that apply to any PVRSS control that is electronics-based, and must provide documentation showing how the safety design incorporates the documented safety functions. 2.3 PVRSS Requirements 1. PV Rapid shutdown system (PVRSS): The System shall disconnect, isolate or attenuate the output controlled conductors of a PV array within 10 seconds of receiving the actuator signal. 2. PV Rapid shutdown equipment (PVRSE): The control equipment in the PVRSS must be able to handle the PV shutdown operation in a safe and timely manner. It shall be able to receive the signal from the defined actuator over either wired or wireless communications, as defined. The PVRSE shall display a confirmation message on a display unit located close to the actuator unit such that it can be seen by one operator. a. A fault detected prior to the start of a PV shutdown shall provide a visible and audible warning. b. A fault in the PVRSS during the PV shutdown process shall result in a shutdown of the PVRSS to a defined safe state, and a display indicating the fault. 3. Actuator: A fault in the actuator function after it has been activated shall cause the PVRSS to shut down to a safe state and issue a warning message that the operation failed. A fault in the actuator function detected at any other time shall result in fault message display providing enough information to take corrective action. 4. Switch unit: The switching unit must respond within a timeframe to allow all defined switches to complete within 10 seconds. A fault that could result in the switch not performing its intended action shall cause the PRSE to shut down to a safe state and indicate the fault on the display with an audible alarm. 5. A power failure during the PV shutdown process shall not stop any alarm function. 6. Status Indicator (display): Shall be located near the actuator unit such that it can be seen by the operator initiating the shutdown. A fault in the display unit during the PV shutdown process shall result in a warning message on the status indicator/display unit such that completion of PV shutdown information is not displayed in error. 7. A PVRSS shall have a means to achieve manual reset function. This includes resetting the PVRSS after a power outage or after the system has had a critical lockout after a failure. 2.4 Related requirements for PVRSS A PVRSS need to be evaluated under to applicative clauses Disconnect means I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 5 of 9

6 1. The switch or relays used for disconnection or attenuation of the PV array power shall comply with the disconnecting means of C22.2 No Mechanical devices used in PVRSS as part of AC or DC disconnect, means shall comply with the appropriate requirements from CSA-C22.2 NO.14-13, CSA-C M91, and CSA-C M Testing rapid shut down system voltage levels 1. Using ampere meter, voltmeter or multimeter to measure the voltage and current of any conductors or between any conductors and ground. The voltage and power shall be less than 30Vdc or 15 Vac (rms) and 240 volt-amperes after completion of the rapid shut down. 2. The timing for the shutdown shall be 10 seconds or less. 3. The rapid shut down system shall be operated under ± 10% over its rating. The system shall keep its function or provide a signal for indication that its function is disabled. If a rapid shut down system is composed with multiple distributed switching devices, the single fault tests should be conducted. The individual equipment failure should be simulated to check if the whole system will be affected. If the whole system loses its function, the simulated fault equipment shall be evaluated as a High Reliability Equipment and System according to The safety control circuitry and the devices relied on for the control or switching of current or voltage shall be conducted on Humidity Cycling test for 6 cycles. See picture 1 for the detailed cycling requirements. 5. A control circuit or system shall be subjected to radiated immunity tests as described in IEEE and IEC61000 series (not applicable to mechanical equipment) Battery Power supply This clause applies where a critical safety functions relies on a battery power source. 1. The shutdown system shall initiate an audible or visual alarm when the battery reaches a condition where the battery has 72 hours remaining before the related function becomes inoperable or where it may cause an unsafe condition. 2. The alarm shall remain for at least a period of 4h hours. 3. After 48 hours, the system shall go to a non-operational state. 4. A reset command shall be required to initialize the system after the battery has been replaced or recharged High Reliability Equipment and Systems Equipment and systems containing electronics or programmable electronic components shall be evaluated for functional safety in order to provide the required reliability. Since functional safety deals with the operation of the PVRSS system as defined above, successful evaluation of an individual component such as the PVRSE or an actuator is not equivalent to and does not result in a High Reliability PV Rapid Shutdown System. Only a PVRSS system evaluated with all components, as defined in 1.4, found to comply with these requirements can be marked as a High Reliability PV Rapid Shutdown System. PVRSS equipment evaluated in this section are only evaluated for operation within their electrical, and environmental ratings and against the applicable functional safety requirements. Adverse effects due to exposure to fire or fire fighting suppression material or fire equipment are not addressed. High reliability PVRSS and PVRSE components evaluated to meet their functional safety requirements shall include a risk assessment that identify potential electronic hardware and the software related faults that could impact the safe operation of the PVRSS. Two options for meeting the functional safety requirements are outlined below. Approved equipment shall be marked as per I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 6 of 9

7 Using CSA C22.2 No. 0.8, Safety functions incorporating electronic technology 1. Equipment containing solid state and microprocessor based controls shall be evaluated for functional safety using CSA C22.2 No Safety requirements of CSA C22.2 No apply. 2. Where the actuator is a remote device and is connected by a signal wire to the PVRSS, clause in CSA C22.2 No applies. 3. Where the actuator is a remote device and uses a wireless means to communicate with the PCRSS, clauses and in CSA C22.2 No apply. 4. The PVRSS shall have a self test function operating at least once / 24 hr. Failure of the self-test shall initiate an audible and visible alarm, which will continue until the unit is reset manually. 5. The self-test function shall be checked with simulated fault conditions on critical sensors or devices which could prevent the PVRSS from operating as expected. 6. The functional safety of the PVRSS system, including related equipment, shall be evaluated to the following clauses in CSA C22.2 No : i. Control class is class B, and fault tolerating time is 10 seconds ii. Protection techniques as per Clause 5.5 iii. Software evaluation as per Clause 5.6 iv. Integration and testing of software a per Clause 5.7 v. Software changes to be managed as per Clause 5.8 vi. Software tools shall meet Clause 5.9 vii. Where a subcontractor is used for software development Clause 5.10 applies 7. On loss of control power, the PVRSS shall shutdown with the controlled conductors in a safe state. 8. Operating instructions shall meet Clauses and in CSA C22.2 No In addition the manual shall include: i. Label information and its meaning ii. Installation instruction explaining the self-test feature as per 2.7 (6). iii. The method of connecting the PVRSE see 2.6 (5). iv. The operation items see 2.6 (6) Using Standard IEC 61508, Functional safety of electrical/electronic/programmable electronic safety related systems 1. High reliability PVRSS equipment that include electronic or programmable electronic components shall comply with a minimum of SIL Where the SIL rating applies to one or more components that are part of the PVRSS, this may not that the PVRSS can be marked as High Reliability PV Rapid Shutdown System. The evaluation must cover all components that make up the PVRSS. 2.5 Markings A PVRSS or component shall be provided with the following ratings: a. Maximum system voltage on Controlled Conductors - (DC) b. Maximum current on Controlled Conductors - (DC) c. Rated input operating voltage (DC or AC Frequency) d. Rated input operating current e. Maximum Over current Protection rating. f. Maximum Number of controlled circuits I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 7 of 9

8 g. Operating Ambient Temperature range ( C) h. Enclosure Ratings A PVRSS shall be marked Photovoltaic (PV) Rapid Shutdown System ; PVRSE shall be labeled Photovoltaic (PV) Rapid Shutdown Equipment PVRSS and PVRSE comply with may be marked as High Reliability Photovoltaic Rapid Shutdown System and High Reliability Photovoltaic Rapid Shutdown Equipment, the label need to be located on the main shutdown device unit A photovoltaic system with a rapid shutdown device shall comply with CSA C Marking (2). 2.6 Requirements for Supplied Documents Installation and operation manual shall meet the following requirements: (1) A PVRSS shall include the following information: Buildings or structures with both utility service and a PV system, complying with CE Code Part I , shall have a permanent plaque or directory including the following wording: PHOTOVOLTAIC (PV) SYSTEM EQUIPPED WITH RAPID SHUTDOWN. (2) The installation instructions for PVRSE or a PVRSS found compliant with the requirements in 2.3 may refer to High Reliability Photovoltaic Rapid Shutdown System and High Reliability Photovoltaic Rapid Shutdown Equipment. (3) The installation shall include or the equivalent: The indicators shall be located near actuator to ensure the operator can view the system status in a timely manner. (4) All PVRSS and PVRSE shall be provided with detailed installation instructions necessary for proper operation of the system including but not limited to details such as minimum control wire size, maximum control wire length. (5) PVRSE shall include details in the installation explaining the self-test functions which are incorporated into the product. The method of connection to the end use system, the operating voltage, current, and frequency, as well as necessary communications protocol information shall be provided. (6) The operation of a self-test system shall be explained in detail in the operating instructions including: a. The recommended frequency for manual tests. b. The procedures to follow to conduct the test. c. The system elements being checked. d. The means to identify failures which occur. e. The appropriate actions to be taken shall be explained. (7) A description of the error conditions on the display unit shall be described. Picture 1: Cycling Requirements Pictures I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 8 of 9

9 Note: The upper temperature should be the maximum one between the maximum rated ambient temperature and 55ºC; the bottom temperature should be the minimal one between the minimum rated ambient temperature and -20 ºC. Each transition shall be accomplished within 3hrs+0.5hrs, each dwell time should between 3 to 12 hours. All the tolerance limited on temperature is ±2 ºC. The humidity when the chamber air is at the upper temperature should be 85 ± 5%. CSA ( ) NRTL () This LTR is applicable to the following programs ( ) CB Others: () () Impact on Existing Certification There is an impact on previously certified products under Class No: POWER SUPPLIES Distributed Generation Power Systems Equipment. Duration of this document: until publication or adoption of a standard. Experts Consulted Distribution of this LTR Peter Voldner Alternative Energy certification staff and management This LTR was issued by Ze Guo on This LTR replaces previous LTR dated yyyy mm dd yyyy mm dd If you require additional technical information, please contact: Ze Guo 86 (21) [Phone] 86 (21) [Fax] ze.guo@csagroup.org [ ] Copyright CSA International All rights reserved I:\Wgm4\DOC_CTRL\Notices\P-S\PhotovoltaicEquipment05.doc Page 9 of 9