UL 16998-2018 pdf free download

UL 16998-2018 pdf free download.Photovoltaic ( PV ) DC Arc-Fault Circuit Protection.
27.2.1 A representative device shall not trip when subjected to the surges described in 27.2.2 — 27.2.5.
Note For devces deriving their power from a photovoltaic DC source, this is a pre-condiliornng test only.
27.2.2 AN devices shall still be functional following the application of the ring wave surges. Functionality of a device shall be verified by connecting It to an appropriate power source and actuating the test circuit.
27.2.3 DevIces deriving their power from a commercial light or power source shall be subjected to ten random applications or three controlled applications of a 3 kV surge applied at 60 second intervals. When three controlled applications are employed, one application is to be essentially at zero of the supply voltage wave, one at the positive peak, and one at the negative peak.
27.2.4 Devices deriving their power from a photovoltaic DC source shall be subjected to three random applications of the 3 KV surge applied at 60 second intervals.
27.2.5 The surge generator is to have a surge impedance of 50 ohms. When there is no load on the generator, the waveform of the surge is to be essentially as follows:
a) Initial rise time, 0.5 microseconds between 10 percent and 90 percent of peak amplitude;
b) The period of the following oscillatory wave. 10 microseconds; and
C) Each successive peak, 60 percent of the preceding peak.
27.3 Surge immunity test (Combination wave)
27.3.1 The same device subjected to the Unwanted Tripping Test shall be subjected to the Surge Immunity Test without demonstrating, either duflng or after testing:
a) Emission of flame, molten metal, glowing or flaming particles through any openings (preexisting or created as a result of the test) in the product;
b) Ignition of the enclosure; or
C) Creation of any opening in the enclosure that results in accessibility of energized parts, when judged in accordance with Accessibility of Energized Parts, Section 17.
27.3.2 The device is permitted to trip during surge immunity testing. If the device trips, it shall be reset prior to the next surge application.
27.3.3 Following the application of the Surge Immunity (Combination Wave) surges. the device shall be In a condition to continue the test sequence In Table 24.1. Functionality of the device shall be verified by connecting it to an appropriate power source and actuating the supervisory circuit.UL 16998-2018 pdf free download.