UL 469:2006 pdf download.Musical Instruments and Accessories.
7.1.7 A material for which the requirement in note (b)(2) of Table 7.1 applies shall have a volumeresistivity of at least 50 megohm-centimeters as measured after conditioning for 40 hours at 23.0±1.0RC(73.4±1.8°F) and 50 ±5 percent relative humidity as indicated in Procedure A of the Standard Method ofTests for Conditioning Plastics and Electrical Insulating Materials for Testing，ASTM D618-1971, and 10megohm-centimeters after being conditioned for 96 hours at 35.0±1.0·C (96.8土1.8°F) and 90 15 percentrelative humidity as indicated in Procedure C, conducted in accordance with the Standard Methods ofTests for D-C Resistance or Conductance of lnsulating Materials,ASTM D257-1976.These are minimumvalues usually characteristic of the majority of materials classed as insulators.
7.1.8 A molded part shall have the necessary mechanical strength and rigidity to withstand the stressesof actual service.
7.2 Guard and barrier insulating material for rendering live parts inaccessible
7.2.1 A guard or barrier of insulating material employed to render live parts inaccessible shall:
a) Not be less than 0.028 inch (0.71 mm) thick.
Exception No.1: Fiber, or the equivalent, that is not less than 0.013 inch (0.33 mm) thick may beused to cover a splice within the overal enclosure.
Exception No.2: A covering of paper that is not less than 0.028 inch (0.71 mm) thick may be usedon an electrolytic capacitor or similar part.
Exception No.3: A fiber shell of a metal-jacketed pilot lampholder covering all live parts may benot less than 0.020 inch(0.51 mm) thick.
b) Comply with the requirement in 7.1.2.
