1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared by UL LLC. It is normative for the applicable ULProduct Certification Program(
2、s); however, it is currently not part of the UL Standard(s) referencedbelow.Product Category (CCN): WEVZStandard Number: UL 891Standard Title: Standard for SwitchboardsEdition Date: July 26, 2005Edition Number: 11Section / Paragraph Reference: Sections 6.3.4.4 and 8.6.5A; Clauses 8.1.15.1, 8.6.5,and
3、 8.6.5.2Subject: Add Requirements for “Switchboards Marked for use with InterconnectedElectric Power Production Sources” (NEC Article 705 Applications)DECISION:6.3.4.4 Switchboards marked for use with interconnected electric power production sources6.3.4.4.1 A switchboard provided with connections m
4、arked for use with one or more electric powerproduction sources operating in parallel with a primary source of electricity shall be marked “Suitable foruse with interconnected parallel electric power production sources”, “Suitable for use in accordance withArticle 705 of the National Electrical Code
5、, NFPA 70”, or the equivalent.6.3.4.4.2 Each disconnect or provision for connection for interconnected parallel power productionsources shall be marked “Parallel Energy Source Disconnect”, Prime Parallel Energy Source TapPrime, or the equivalent, or be provided with a space for the sources to be lab
6、eled in the field.6.3.4.4.3 Switchboards with parallel energy source disconnects shall be marked Prime Turning OffParallel Energy Source Disconnect does not deenergize this switchboard. Turn off power from all sourcessupplying this switchboard before working inside.” or equivalent wording.6.3.4.4.4
7、A marking shall be placed near each Parallel Energy Source Disconnect to be visible when theterminals are visible to warn the user that both the line and load terminals may be energized when thebreaker is in the open (Off) position.6.3.4.4.5 For load side connections in accordance with 8.6.5A.1(b),
8、the switchboard shall be marked withthe maximum ampere rating for all disconnects marked for connection to electric power productionsources operating in parallel with primary sources.8.1.15 Equipment on supply side of service disconnect (not for Canada)8.1.15.1 Except for the following, equipment sh
9、all not be connected to the supply side of the servicedisconnecting means:a) meters nominally rated not in excess of 600 V located in the switchboard;b) instrument transformers (current and potential), high-impedance shunts, Type 1 surge-protective devices, and load management devices;c) control cir
10、cuits of power operable service disconnecting means, if suitable overcurrentprotection and disconnecting means are provided, see 8.1.11.1.1;UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULd) Ground-fault protection systems or surge-protective
11、devices, if suitable overcurrent protectionand disconnecting means are provided, see 8.1.11.1.1; ande) taps used to supply load management devices, circuits for stand-by power systems, firepumps, and fire and sprinkler alarms.f) interconnected electric power production sources, such as solar photovo
12、ltaic, wind, or fuel cellsystems.8.6.5 Double-ended switchboards (multiple source) Multiple source switchboards8.6.5.1 Unless intended for parallel operation, the disconnect identified in Figure 2 and Figure 3 as thetie-breaker shall be provided with mechanical, key, or electrical interlocking with
13、the service disconnectsshown in the figures so that sources cannot be paralleled. If the tie-breaker is omitted, all disconnects shallbe provided with mechanical, electrical, or key interlocking so that the sources cannot be paralleled(unless intended for parallel operation).8.6.5.2 If a switchboard
14、 is intended to parallel different sources, synchronizing equipment shall beprovided. Synchronizing equipment shall not be required for an interconnected electric power productionsource as covered by Article 705 of the National Electrical Code, NFPA 70. Switchboards marked for usewith interconnected
15、 electric power production sources, in accordance clause 6.3.4.4.1, shall be evaluatedin accordance with Section 8.6.5A.8.6.5A Switchboards marked for use with interconnected electric power production sources8.6.5A.1 Switchboards marked for interconnection with one or more electric power production
16、sourcesoperating in parallel with primary sources of electricity, in accordance with clause 6.3.4.4.1, shall bepermitted to have provisions for connections as noted in (a) and (b). See 6.3.4.4 for marking requirements.a) Supply Side Connection Switchboards marked for use in accordance with Section70
17、5.12(A) of Article 705 of the National Electrical Code, NFPA 70, shall be permitted to haveprovisions for interconnecting parallel power sources on the supply side of the servicedisconnecting means, see 8.1.15(f). The sum of the ratings of all supply side overcurrentdevices connected to power produc
18、tion sources shall not exceed the rating of the switchboard.b) Load Side Connection Switchboards marked for use in accordance with Section 705.12(B)of Article 705 of the National Electrical Code, NFPA 70, shall be permitted to have one or moreload side disconnects for the interconnection of parallel
19、 power sources. The total rating of allovercurrent devices supplying the switchboard shall not exceed the rating of the switchboard.RATIONALE FOR DECISION:NEC Article 705 includes requirements for the interconnection of non-utility electric power productionsources. These requirements detail how thes
20、e sources are to be integrated with a power distributionsystem. These sources include on-board utility interactive inverters and do not need the type ofsynchronization equipment required in a “double-ended” switchboard configuration. This CRD applies theterminology in clause 3.27 of UL 891 when refe
21、rring to a “multiple source” switchboard by renamingSection 8.6.5 as “Double-ended switchboard (multiple sources)”. Along with this renaming, two newSections (6.3.4.4 and 8.6.5A) are introduced to address “Switchboards marked for use withinterconnected electric power production sources”. These new s
22、ections are similar to ones added to theStandard for Panelboards, UL 67, and include provisions for connection of the alternate source to eitherSTANDARD NUMBER: UL 891 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL(a) the supply, or (b) t
23、he load side of the service disconnect. Sizing of the switchboard and overcurrentdevice(s) would be in accordance with NEC Section 705.12. Markings would reflect that the switchboardis suitable for use in accordance with Article 705.Copyright 2018 UL LLCUL LLC, in performing its functions in accorda
24、nce with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of UL LLC. in practically applying therequirements of the standard. They
25、do not represent formal interpretations of the standard underAmerican National Standards Institute (ANSI) processes. UL LLC shall not be responsible to anyone forthe use of or reliance upon Certification Requirement Decisions by anyone. UL LLC shall not incur anyobligation or liability for damages,
26、including consequential damages, arising out of or in connection withthe use or reliance upon Certification Requirement Decisions. The electronic version of the CertificationRequirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 891 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSTANDARD NUMBER: UL 891 -4-No Text on This Page
