UL 496:2017 pdf download – Lampholders.
0.56 N•m (5 lb-in) for medium or mogul screw-type lampholders. The same lampholders shall then be tested with the “Not Go” gauge. The “Not Go” gauge shall be installed into each Lampholder with an insertion force equal to the wei’it of the gauge.
5.2.5 Screw Base Switched AC/DC Lampholders
5.2.5.1 General
5.2.5.1.1 A lampholcter provided with a switching mechanism shall be capable of performing acceptably when subjected to the overload test and the endurance test in accordance with the requirements in Clauses 5.2.5.1.2 — 5.2.5.3.3. As a result of the tests, there shall not be electrical or mechanical failure of the mechanism, nor shall there be undue pitting or burning of the contacts. The fuse descnbed in Clause 5.2.5.12 shall not open at the conclusion of these tests.
5.2.5.1.2 During the overload and endurance tests, all dead metal parts of the switch that are exposed to user contact, including the intended mounting surface, shall be connected through a 15 A fuse to earth ground or to the neutral (grounded) conductor of the test circuit. This shall be accomplished in accordance with Clause 5.2.5.1.3.
52.5.1.3 The fuse shall be of a type and voltage rating intended for branch circuit protection. The potential rating of the fuse shall be equal to or greater than the maximum potential from the switch to the point at which the dead metal parts and intended mounting surface are connected. The connection shall be such that:
a) on a direct Current circuit, dead metal parts are positive with respect to the nearer arcing point in the switch; and
b) the potential between live parts and conductive dead metal parts is the full test potential.
5.2.5.1.4 For the overload and endurance tests, line connections shall be made to the wiring terminals or leads as En actual service, and the load shall be connected by means of a p’ug or the equivalent to the screwshell and center contact of the larnpholder. Proper connections are shown in Figure 6.
5.2.5.1.5 The load connected to each lanipholder shall consist of a non-inductive load. For endurance testing the switching mechanism of a medium-screw lampholder for double-filament lamps and the switching mechanism of any mogul-screw lampliolder shall be tested with a tungsten-filament-lamp load as described in Clause 5.2.5.3.2.
5.2.5.1.6 The overload test and the endurance test shall be conducted with the lampholders connected to a three-wire, direct-current circuit with grounded neutral. Exposed dead metal parts. such as the cap, shell, metal pull-chain, and the like, shall be grounded. A sine-pole mechanism shall be connected in the ungrounded conductor that is negative with respect to the neutral or grounded conductor of the circuit.
5.2.5.1.7 A switching mechanism shall not be adjusted. lubricated, or otherwise conditioned either before or during the overload or endurance test. This requirement does not apply to a manufacturers regular practice of lubricating lanipholders after they are completely assembled.
5.2.5.2 Overload test
5.2.5.2.1 A lampholder provided with a switching mechanism shall be capable of performing acceptably when operated under the following conditions. The lampholder shall be mounted and wired such that actual service conditions are represented. It shall be operated manually by means of its actuating member and subjected to 50 cycles of operation making and breaking a circuit of current and voltage according to its wattage rating, as indicated in Table 15, at 6 — 10 cycles per minute. The voltage of the test circuit shall not be less than 95 percent or more than 105 percent of the voltage value indicated In Table 15.
5.2.5.3 Endurance test
5.2.5.3.1 A lampholder provided with a switching mechanism shall be capable of performing acceptably when operated under the following conditions. The lampholder shall be mounted and wired such that actual service conditions are repesented. It shall be operated by means of its actuating member either manually or by means of a machine and subjected to 6000 cycles of operation making and breaking a circuit of current and voltage according to its wattage rating. as indicated in Table 16. at 6 — 10 cycles per minute. The voltage of the test circuit shall not be less than 95 percent or more than 105 percent of the voltage value indicated in Table 16.
52.5.3.2 The switching mechanism of a mecum-screw Lampholder for double-filament lamps and the switching mechanism of any mogul-screw lampholder shall be tested with a tungsten-filament lamp load or the equivalent, according to the methods previously described, except that, in the case of a lanipholder for double.filarnent lamps, the load shall necessarily be divided into two sections, one representing each filament of the lamp. Foflowing the usual cycle of high-medium-low-off, this means that the low load actually shall be turned on and off twice during each complete cycle.