UL 1054:2000 pdf download – Special-Use Switches
UL 1054:2000 pdf download – Special-Use Switches.
12.6 In addition to the tests mentioned in 11.3. a switch with mercury contacts shall be subjected to the Limited Short-Circuit Test, Section 20.
12.7 A switch having two o more on and off positions of the switch mechanism, such as a 2-circuit, 3-circuit, 3-pole, or series-parallel switch, Is to be tested undet conditions representing those of actual service, including each position that involves the making and breaking of the maximum current.
12.8 During the testing of a switch, all metal parts of the frame and the enclosure that may be grounded when installed under conditions ol actual service or that are exposed to contact by the user are to be connected to ground or to a conductor of the test circuit. See 12.9.
12.9 For the overload and endurance tests. dead metal parts are to be connected through a 15-ampere or less fuse. The potential rating of the fuse is to be equai to. or greater than, the potential to ground or to the conductor of the test circuit to which dead metal parts of the equipment are to be connected. The circuit is to be connected so that:
a) On direct current, the dead metal parts will be positive with respect to the nearest arcing point in the switch, and
b) The potential between live parts and conductive dead metal parts is the full test potential.
Exception: A switch, other than a television switch, rated 2400(250 volts that is not marked as described in 24A may be tested with one-half the test potential between live parts and conductive dead metal parts.
12.10 Duflng the overload and endurance tests. a switch is to be mounted and wired so that conditions of actual service will be represented. The switch is to be connected to a load and, other than as noted in 16.5, to a supply circuit having a voltage that is within 5 percent of the rated voltage of the switch, The test circuit is to have such capacity that the potential across the load, measured at or adjacent to the switch, will have the required value when the switch under test is closed in the circuit with the required test current flowing.
12.11 With reference to the requirement in 12.10, it is impracticable to describe the details 01 connections that are to be made to obtain operating conditions identical with those In actual service because of the different arrangements of terminals. The switch is to be connected in the test circuit so that it will have the same position, relative to the load controlled and the supply mains, that it will have in actual service.
12.12 As a rule, the switch is to be connected in the test circuit between the mains and the load.
12.13 A lower power factor, a lower frequency. and a greater rate of operation than those specified in the performance sections of these requirements may be employed if agreeable to those concerned and if it is not a less severe condition of the test.
12,14 Whenever tests are conducted with alternating current. the circuit frequency is to be the same as the rated frequency of the switch. Other than as noted in 12.15 or, if no frequency is specified. 60-hertz alternating current is to be used.
12.15 A switch rated 50 hertz may. it agreeable to those concerned, be tested on a 60-hertz circuit, except that the currents used for the overload and endurance tests are to be 120 percent of the current that would be used if the switch were tested on a 50-hertz circuit.
12.16 In testing a switch,a cycle of operation includes operation of the switch from the off positionthrough every electrical position of the switch,back to the off position.
12.17 A switching mechanism is not to be adjusted, lubricated, or othenwise conditioned either before orduring any of the tests.Switches may be lubricated as a regular practice when they are assembled by themanufacturer.