UL 705 CRD-2016 UL Standard for Safety Power Ventilators - Section Paragraph Reference New Section 11A (Edition 6 January 14 2004).pdf

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): ZACT, ZACZ, ZAJS, ZAXHStandard Number: UL 705Standard Title: Standard for Power VentilatorsEdition Date: January 14, 2004Edition Number: 6Section / Paragraph Reference: New Section 11ADECISION:2.XXX C

3、ircuit, Class2Anlowvoltage circuit with a power of 100 VA or less; or has 30 V dc suppliedby a primary battery; or is supplied by a Class 2 transformer; or is supplied by a combination of atransformer and fixed impedance that, as a unit, complies with all the performance requirements for aClass 2 tr

4、ansformer, or is supplied by a power supply (such as a switching power supply) whose outputmeets the requirements of a Class 2 circuit.A circuit that is derived from a circuit that exceeds 30 V by connecting resistance or impedance, or both,in series with the supply circuit to limit the voltage and

5、current, is not considered to be a class 2 circuit.2.1XXX Circuit, low-voltage A circuit that has an ac potential of not more than 30 V rms (42.4 V peakor 30 V dc).2.2XXX Circuit, hazardous voltage A circuit of any voltage exceeding those of an low-voltage circuit.2.4 MOTORS a) Open Motor A motor ha

6、ving ventilating openings that permit passage of external cooling airover and around the windings of the motor.b) Totally Enclosed Motor A motor that is enclosed so as to prevent the free exchange of airbetween the inside and outside of the case but not sufficiently enclosed to be termed airtight.c)

7、 Totally Enclosed Fan-Cooled Motor A totally enclosed motor with external cooling by a fanor fans integral with the motor but external to the enclosing parts.d) Electronically Commutated Motor (ECM) A motor assembly consisting of the motor and acontrol. The control provides an AC electric signal (ty

8、pically non-sinusoidal) to the motor by aninverter/switching power supply. The sensors and other electronics on the control adjustwaveform and output levels of the signal. The control is often used to provide protectivefunctions to prevent overheating or mitigate other hazardous conditions.11A Separ

9、ation of circuits11A.1 Unless having insulation suitable for the highest voltage involved, insulated conductors of differentcircuits (internal wiring, including wires in a junction box or compartment) shall be separated by barriers,or shall be segregated, and shall, in any case, be separated or segr

10、egated from uninsulated live partsUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULconnected to different circuits. Segregation of insulated conductors may be accomplished by clamping,routing, or equivalent means that ensures permanent separati

11、on from insulated or uninsulated live partsof a different circuit.11A.2 There shall be provision for segregating or separating by barriers field-installed conductors of anycircuit from field-installed and factory-installed conductors connected to any other circuit, unless theconductors of both circu

12、its are or will be insulated for the maximum voltage of either circuit.11A.3 Within a compartment that is not a control enclosure junction box or its equivalent, field-installedlow-voltage (including Class 2) circuit conductors may be segregated from factory-installed conductors ofdifferent circuits

13、 by locating field wiring openings, routing factory wiring, and locating electricalcomponents so that the factory conductors are maintained at least 127 mm (5 in) from a line representingintended routing of the low-voltage (including Class 2) circuit conductors. The line shall allow for droop,and sh

14、all connect the opening provided for entrance of the low-voltage (including Class 2) conductors tothe terminals or leads to which the conductors are attached.11A.4 There shall be provision for segregating or separating by barriers field-installed conductors of ahazardous voltage circuit froma) unins

15、ulated live parts connected to a different circuit, other than wiring terminals; andb) any uninsulated live parts of electrical components such as a pressure-limiting device, motoroverload protective device, or other protective device where short circuiting or grounding mayresult in unsafe operation

16、 of the equipment; except at wiring terminals.11A.5 There shall be provision for segregating or separating by barriers, field-installed conductors of anlow-voltage circuit froma) uninsulated live hazardous voltage circuits; andb) wiring terminals and any other uninsulated live parts of hazardous vol

17、tage electricalcomponents such as a pressure-limiting device, motor overload protective device, or otherprotective device where short circuiting or grounding may result in unsafe operation of the unit.11A.6 If a barrier is used to provide separation between the wiring of different circuits, it shall

18、 be of metalor of suitable insulating material of adequate mechanical strength, and reliably held in place.11A.7 A metal barrier shall be at least 0.66 mm (0.026 in) thick if of uncoated steel, 0.74 mm (0.029 in)thick if of galvanized steel, and 0.91 mm (0.036 in) thick if of nonferrous metal. A bar

19、rier of insulatingmaterials shall be not less than 0.71 mm (0.028 in) thick, and shall be of greater thickness if itsdeformation could be so readily accomplished as to defeat its purpose.11A.8 If the barrier is removable or has openings for the passage of conductors, it is acceptable providedthat in

20、structions for the use of the barrier are a permanent part of the device. In lieu of a barrier, completeinstructions may be provided that, when used in conjunction with the wiring diagram, will provide for theseparation of the circuits of different voltages.11A.9 Field-installed conductors may be se

21、gregated from other field-installed conductors and fromuninsulated live parts connected to other circuits by arranging the location of the openings in the enclosurefor the various conductors, with respect to the terminals or other uninsulated live parts, so that conductorsor parts of different circu

22、its will not intermingle.STANDARD NUMBER: UL 705 -2-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL11A.10 The output of a transformer device supplying circuit shall not be interconnected with the output ofanother such transformer device provi

23、ded as a part of the equipment, unless the voltage and currentmeasurements at the output terminals of the interconnected devices are low-voltage.11A.11 Two or more transformer devices supplying Class 2 circuits and provided as a part of theequipment, shall be treated as separate circuits. If more th

24、an one such circuit is intended to be field-wired,the several circuits shall be segregated or separated by barriers as specified in Clause 11A.2, and thetransformer output of each circuit shall be marked to warn that the separation shall be maintained.RATIONALE FOR DECISION:Power ventilators are now

25、 employing electronically commuted motor that use low voltage controls tocommunicate and control the motor the need for separation of circuits is needed. Currently UL 705 is notclear regarding the separation of circuits; the additional requirements will ensure compliance withseparation of circuits i

26、s evaluated. This Certification Requirement Decision is intended to document theseparation of circuit requirements.These requirements are derived from UL 1995 and reflect present practice in the application of theserequirements in UL 705.Copyright 2016 UL LLCUL LLC, in performing its functions in ac

27、cordance 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.

28、They 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 dama

29、ges, 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 705 -3-UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSTANDARD NUMBER: UL 705 -4-No Text on This Page