UL 20:2000 pdf download – General-Use Snap Switches.
5.5 Test Conditions
5.5.1 Dunng the overload, and all endurance tests, a switch shall be connected to a load (as described in the applicable test method) and, except as noted in Clauses 5.73 and 5.7.9, to a supply circuit, the voltage of which is within 5 percent of the rated voltage of the switch. The capacity of the test circuit shall be such 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.
5.5.2 A flush switch that is intended for mounting in an outlet box shall be mounted with a metal flush plate or equivalent metal surface in position over the switch.
5.5.3 With reference to the requirement in Clause 5.5.1, it is impracticable to descnbe the details of connections that must be made in order to obtain all operating conditions because of the different arrangements of terminals of switches of various makes. In any case. however, the connections to a switch in the test circuit shall be such that the load controlled will have the same position, relative to the switch and the supply, that it will have in actual service, except that both 2-circuit and 3-circuit switches may be tested as single-pole devices.
5.5.4 The switch shall be connected in the test circuit between the supply mains and the load.
5.55 A lower power factor, a lower frequency. and a greater rate of operation than those specified in the performance clause of these requirements may be employed if agreeable to those concerned and if it is not a less severe condition of test.
5.6 Overload Test
5.6.1 After being subjected to the applicable overload test. a general-use ac/dc switch shall be electrically and mechanically operable. At the conclusion of the test, the switch shall be capable of performing its intended function and shall show no wear, loosening of parts, or defects of any other description that will diminish the usefulness and reliability of the switch. The fuse described in Clause 5.2.20 and 5.2.21 shall not open at the conclusion of this test.
5.6.2 A general-use acldc switch shall be operated manually by means of its actuating member for 50 cycles at a rate of 6 — 10 cycles per minute, making and breaking the required test current. The rate of speed of operation may be greater than 10 cycles per minute if agreeable to those concerned. If the switch rating is 10 A or less, the test current shall be 150 percent of the rated current. If the switch rating is more than 10 A, the test current shall be 125 percent of the rated current.
5.6.3 A switch rated In horsepower and intended for use In dc circuits only shall be subjected with an overload test for 50 cycles at the rate of 6 — 10 cycles/mm with dc and a noninductive load so that the switch makes and breaks an overload current of the value given in Table 9, equal to 10 times the full load current of a motor of the horsepower rating in question.
5.6.4 A switch rated in horsepower for use on ac circuits only shall be subjected to an overload test for50 cycles at the rate of 6 – 10 cycles/min with ac and an inductive load so that the switch makes andbreaks an overload current of the value given in Table 10 or 11, and having a power factor of 0.40 – 0.50,except that a lower power factor may be used with the agreement of those concerned.
5.6.5 A switch rated in horsepower and intended for use on direct as well as alternating current shallcomply with the applicable requirements when tested with alternating current as well as direct current, withdifferent devices used for the ac and dc tests.