1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFebruary 18, 20051SUBJECT 48AOUTLINE OF INVESTIGATIONFORNEON SIGNS FOR USE IN DWELLINGS (RESIDENTIAL)1February 18, 2005COPYRIGHT 2005 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUT
2、HORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFEBRUARY 18, 2005SUBJECT 48A2No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 General 4CONSTRUCTION3 Enclosure 44 Acce
3、ssibility 4PERFORMANCE5 Abnormal operation .8MARKINGS6 General 9FEBRUARY 18, 2005 SUBJECT 48A 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 This outline of investigation covers cord connected and permanently connected
4、 neon signs intendedfor use in residences. In addition to the applicable requirements in the Standard for Electric Signs, UL 48and the Standard for Neon Transformers and Power Supplies, UL 2161, the following are supplementaryrequirements that also apply to neon signs intended for use in dwellings (
5、residential).2 General2.1 The maximum output voltage shall be limited to 10,000 volts, and 5,000 volts to ground, withmaximum 15 mA output current, or 7,500 volts with maximum 30 mA output current.CONSTRUCTION3 Enclosure3.1 Except as noted in 3.2, all live parts shall be enclosed with no openings pr
6、ovided in the enclosureother than the opening used for the power supply connection when permanently connected to a source ofsupply.3.2 Neon transformers and power supplies may be provided with openings provided they comply with theaccessibility requirements of section 4.4 Accessibility4.1 All expose
7、d live parts shall be inaccessible to contact. Uninsulated live parts internal to a neontransformer or power supply or other component that is in excess of 15 volts rms in a damp or wet locationand 30 volts in a dry location shall be inaccessible to contact by a straight metal strip that is 4 inches
8、(101.6 mm) long by 1/2 inch (12.7 mm) wide, and 1/16 inch (1.6 mm) thick, when applied through theopening with a force not greater than one pound (4.4 N). The ventilation openings of a cord connectedneon transformer or power supply complying with Neon Transformers and Power Supplies, UL 2161, arecon
9、sidered to comply with this requirement. Permanently connected neon transformers and powersupplies that comply with Neon Transformers and Power Supplies, UL 2161, and are intended for use indwellings shall additionally comply with the accessibility requirements in this section.4.2 Where an accessibi
10、lity barrier is provided to prevent contact with live parts in excess of 1000 voltsrms (1414 V peak) to ground, it shall comply with the dielectric voltage-withstand test in Electric Signs, UL48. The test shall be conducted across the combination of the barrier material, spacing between barriersand
11、live parts, and any other material between current-carrying parts and the user or service personnelside of the barrier. The test potential shall be applied between the current-carrying part made inaccessibleby the barrier and the edge of the straight metal strip specified in 4.1. The straight metal
12、strip shall be incontact with the opposite side of the barrier. The test potential shall be 1750 volts plus 1.25 times themaximum operating voltage of the part(s) made inaccessible.FEBRUARY 18, 2005SUBJECT 48A4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PER
13、MISSION FROM UL4.3 Other than those components that have been evaluated to comply with the requirements in thisOutline of Investigation for use in Dwellings, all insulated live parts, including neon tubing electrodes,electrode enclosures, and GTO sleevings, shall be inaccessible to contact by the Ac
14、cessibility Probe, 4.1.This is generated text for figtxt.FEBRUARY 18, 2005 SUBJECT 48A 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFigure 4.1Articulate probe with web stopFEBRUARY 18, 2005SUBJECT 48A6UL COPYRIGHTED MATERIAL NOT AUTHORIZED
15、 FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4.4 Except as noted in 4.5, the sign body and enclosure shall be constructed with no user-serviceableelectrical parts, and shall be assembled by fasteners that are tamper resistant, such as by one-wayfasteners, uniquely keyed screws,
16、 rivets, welding or adhesives.4.5 A neon tubing electrode splice enclosures is considered to be tamper resistant sufficient to bedesignated for use in dwellings where exposed to contact, provided it can withstand without displacementfrom the proper size of neon tubing, a minimum 30 lb straight pull
17、force for one minute without exposinglive parts and reducing electrical spacings.4.6 Neon tubing electrodes shall be recessed such that they are within:a) an enclosure,b) A neon electrode tubing splice enclosure complying with 4.5, orc) A neon tubing electrode splice enclosure that is within a sign
18、body complying with 4.4.Except as noted in 4.7, the amount of recessing in the enclosure or sign body shall be such that theminimum spacing complies with Table 4.1. The minimum spacing is to be measured between the tubingelectrode and the accessibility probe shown in Figure 4.1, when the probe is po
19、sitioned into the openingof the enclosure or sign body that remains when the glass of the neon tubing has been removed.Table 4.1Spacings between neon electrode and accessibility probeTransformer or powersupply output voltageMaximum secondarycurrent,Minimum spacing, Maximum voltage togroundmA inch (m
20、m)1001 5000 30 0.25 6.4 25005001 7500 30 0.50 12.7 37507501 10,000 15 0.50 12.7 50004.7 A neon tubing secondary circuit that is provided with open-circuit protection complying with 5.2 ispermitted to have the end of the neon electrode shell flush with the enclosure or sign body and beaccessible to t
21、he accessibility probe as a result of neon tubing breakage.FEBRUARY 18, 2005 SUBJECT 48A 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULPERFORMANCE5 Abnormal operation5.1 A sign marked for use in dwellings shall either have open circuit prot
22、ection that complies with 5.2 orhave all of the following:a) No more than one neon circuit,b) All neon tubing connected in series andc) No metal in the sign body or enclosure unless it is provided with only one length of neontubing.5.2 A sign provided with more than one neon circuit having a non-met
23、allic or metallic sign body orenclosure shall be used only when the following conditions are met:a) Each neon transformer or power supply that incorporates circuitry that is relied upon tocomply with other requirements in this outline by interrupting power to the output circuit, shall doso within 50
24、0 milliseconds of the existence of an open-circuit condition. Upon opening, theoutput voltage shall not exceed the voltage accessibility limits specified in 5.1.b) The circuitry responsible for providing the overcurrent protection specified in a) shall becapable of normal operation in opening the ne
25、on output circuit upon being subjected to theSecondary Ground-Fault Protection Circuit Abnormal Test conditioning and testing criteriaspecified in Neon Transformers and Power Supplies, UL 2161. The conditions of testinginclude:1) Component fault,2) Thermal aging,3) Overvoltage and undervoltage,4) Po
26、wer supply interruption,5) Transient surge and6) HumidityFEBRUARY 18, 2005SUBJECT 48A8UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMARKINGS6 General6.1 A sign intended for use in dwellings shall be marked on an exterior facing surface, adja
27、cent to thepower supply connection means with lettering minimum 1/8 inch (3.2 mm) high. The marking or itsequivalent, shall be as follows: No User Serviceable Parts, Return To A Qualified Service Center.6.2 A sign that does not have open-circuit protection in accordance with 5.2, shall be marked Dis
28、connectPower When Any Length of Neon Tubing Does Not Light. The location and letter height of the markingshall be as specified in 6.1.6.3 A sign that is intended for use in dwellings, shall be marked For Use In Dwellings or Suitable ForUse In Dwellings.FEBRUARY 18, 2005 SUBJECT 48A 9UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULFEBRUARY 18, 2005SUBJECT 48A10No Text on This Page
