UL 482 Standard For Portable Sun/Heat Lamps

28. Dielectric Voltage-Withstand Test28.1 A sun/heat lamp shall be capable of withstanding without breakdown for 1 minute the application of a 60 Hz essentially sinusoidal potential between live parts and dead metal parts, with the lamp at the temperature attained in use. For a circuit that operates at a voltage of 250 V or less the potential shall be 1,000 V; for a circuit which operates at a voltage of more than 250 V the test potential shall be 1,000 V plus twice the operating voltage of that circuit. If the lamp uses a 2-winding transformer, it shall also be capable of withstanding without breakdown for 1 minute the application of a 60 Hz essentially sinusoidal potential of 1,000 V plus twice the higher operating voltage of the two windings, between primary and secondary circuits.

28.2 To determine compliance with the requirement of paragraph 28.1, a sun/heat lamp is to be tested by a 500 VA or larger capacity transformer, whose output voltage is essentially sinusoidal and can be varied. The applied potential is to be increased from zero until the required test value is reached, and is to be held at that level for 1 minute. The increase in the applied potential is to be at a substantially uniform rate and as rapid as is consistent with its value being correctly indicated by a voltmeter.

29.1 Each appliance shall withstand without electrical breakdown, as a routine production line test, the application of a potential at a frequency within the range of 40—70 Hz, between live parts and dead metal parts. The test potential shall be (1) 1200 V applied for 1 second or (2) 1000 V applied for 1 minute.

29.2 The appliance may be in a heated or unheated condition for the test.

29.3 The test shall be conducted when the appliance is complete (fully assembled). It is not intended that the appliance be unwired, modified or disassembled for the test.

29.4 The test equipment shall include a transformer having an essentially sinusoidal output, a means of indicating the test potential, an audible or visual indicator of electrical breakdown, and either a manual reset device to restore the equipment after electrical breakdown, or an automatic reject feature of any unacceptable unit.