UL 482 Standard For Portable Sun/Heat Lamps

23.9 A sunlamp is to be connected to a circuit of maximum rated voltage for the temperature test.

23.10 A heat lamp having a rated voltage of more than 120 V or less than 110 V is to be connected to a supply circuit of rated voltage for the temperature test; however, if the wattage input to the lamp when so connected is less than the marked wattage rating, the lamp is to be connected to a supply circuit of voltage sufficiently higher to cause a wattage input to the lamp equal to its marked rated wattage. If its voltage rating is within the range of 110 to 120 V, inclusive, the lamp is to be connected to a supply circuit of voltage sufficient to cause a wattage input equal to: 

where W(3) is the marked rated wattage of the lamp and V(3) is the marked rated voltage of the lamp; but, in any case, the voltage of the supply circuit is not to be less than the rated voltage.

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23.11 With reference to paragraph 23.10, the rated wattage of a lamp rated in amperes (rather than watts) is considered to be the product of the rated voltage by the rated current.

23.12 The temperature of a coil or winding is to be measured by means of thermocouples mounted on the outside of the coil wrap and by the change of resistance method. If the coil is inaccessible for mounting thermocouples (for example, a coil immersed in sealing compound) or if the coil wrap includes thermal insulation or more than 1/32 inch (0.8 mm) of cotton, paper, rayon or similar insulation, only the change-of-resistance method need be used. For the thermocouple-measured temperature of a coil of an a-c motor, other than a universal motor (items 1 and 3 in Table 23.1), the thermocouple is to be mounted on the integrally applied insulation of the conductor.