UL Question Corner — PV Rapid Shutdown Systems

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The 2014 NEC 690.12 requires rapid shutdown of photovoltaic (PV) systems on buildings and that equipment that performs the rapid shutdown be listed (certified) and identified. Does UL List (Certify) these rapid shutdown systems and equipment?

Yes, UL Certifies (Lists) both the rapid PV shutdown equipment and entire rapid PV shutdown systems under two different UL product categories. The rapid PV shutdown equipment is Certified (Listed) under the product category Photovoltaic Rapid Shutdown System Equipment (QIJW) and the systems are Certified (Listed) under the product category Photovoltaic Rapid Shutdown Systems (QIJS). As of this writing (April 2015), there is at least one certification of equipment under the QIJW category. The Guide Information and any certifications can be viewed on UL Product Spec at www.ul.com/productspec and enter QIJW or QIJS at the category code search field.

Photovoltaic (PV) rapid shutdown systems are intended for use in PV electrical energy systems as described in section 690.12 of the 2014 NEC. These rapid shutdown systems are intended to reduce potential hazards and limit exposure to energized PV wiring and equipment to allow first responders to perform work outside the energized area of the PV array.

PV Rapid Shutdown Systems

Photovoltaic Rapid Shutdown System Equipment (QIJW) covers rapid shutdown system equipment suitable for field installation in compliance with ANSI/NFPA 70, National Electrical Code (NEC). It provides specific functionality that allows it to be combined and/or interconnected with other rapid shutdown system equipment to develop a complete rapid shutdown system.

This equipment is intended to be installed as part of a PV system in conjunction with other equipment to perform functions related to rapid shutdown including but not limited to combiners, disconnects, actuators, attenuators, indicators, and/or other system equipment. This equipment is intended to be installed and operated per the installation instructions and also to be used within its electrical and environmental ratings. The operability of complete rapid shutdown systems built from devices covered under this category has not been determined.

This equipment may also be investigated to functional safety standards for a higher level of fault tolerance as defined by the individual certification report; this equipment may be additionally marked “High Reliability Equipment.” The interconnection of multiple pieces of rapid shutdown system equipment designated as “High Reliability” does not result in a high-reliability system. Only systems rated and marked as “High Reliability” have been investigated and found compliant with the increased reliability requirements of a high-reliability system.

The Certification Mark for these products includes the UL symbol, the words “CERTIFIED” and “SAFETY,” the geographic identifier(s), and a UL file number. One of the following product identities appears on the system:   High Reliability Photovoltaic Rapid Shutdown System Equipment or Photovoltaic Rapid Shutdown System Equipment. The word “Photovoltaic” may be abbreviated “PV.”

UL Certifies (Lists) entire rapid PV shutdown systems under the product category Photovoltaic Rapid Shutdown Systems (QIJS) which can be viewed on UL Product Spec at www.ul.com/productspec and enter QJIS at the category code search field.

These rapid shutdown systems are intended to be installed as part of the PV array system and the individual rapid shutdown system equipment that performs functions including but not limited to combiners, disconnects, actuators, attenuators, indicators, inverters, and/or other PV system equipment functionality.

Some systems have been investigated to additional functional safety requirements for a higher level of reliability. These high reliability PV rapid shutdown systems have a higher system fault tolerance and reliability to perform their intended function under foreseeable single-point component/equipment and system failures. Only systems found to comply with these additional functional safety requirements are marked “High Reliability PV Rapid Shutdown System.”

The Certification Mark for these products includes the UL symbol, the words “CERTIFIED” and “SAFETY,” the geographic identifier(s), and a UL file number. One of the following product identities appears on the system:  High Reliability Photovoltaic Rapid Shutdown System or  Photovoltaic Rapid Shutdown System. The word “Photovoltaic” may be abbreviated “PV.”

For multi-piece systems, the Certification Mark appears on the outside of each complete piece of equipment or subassembly constituting a complete rapid shutdown system eligible for certification. The Certification Mark covers only the equipment to which it is affixed; it does not cover other enclosure sections included in the assembly. Each piece of equipment is marked “Photovoltaic Rapid Shutdown System Subassembly” and is provided with a
“____ of ____” marking, where the second blank indicates the total number of assemblies contained in the certified system and the first blank indicates the respective assembly number bearing the Certification Mark.