UL 60950-1-2019 pdf free download

UL 60950-1-2019 pdf free download.Information Technology Equipment – Safety Part 1 : General Requirements.
PJROTEC11VE BONDING CONDUCTONS and their terminals of non-standard constructions. such as orinted wirina Drotective traces. shall also be evaluated in accordance with the Limited Short-Circuit Test in CSA C22.2 No. 0.4. Bonding of Electrical Equipment, PRCTEC11VE BONDING CONDUCTORS that can be determined to meet the eouivalent of the minimum conductor sizes in Table 2D and are provided with terminals not more than one size smaller than the sizes in Table 3E (see 3.3.5) shall be considered to comolv without test.
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Compliance is checked by inspection, measurement and, for PROTECTIVE aowo coucros that do not meet the minimum conductor sizes in Table 3B (see 3.2.5) throughout their length or whose terminals do not all meet the minimum sizes in Table 3E (see 3.3.5), by the following test.
The voltage drop in a PROTECTIVE BONDWG CONDUCTOR is measured after conducting the test current for the time period specified below. The test current can be either a.c. or d.c. and the test voltage shall not exceed 12 V. The measurement is made between the main protective earthing terminal and the point in the equipment that is required by 2.6.1 to be earthed. The resistance of the PROTECTiVE EARTHING CONDUCTOR is not included in the measurement. However, if the PROTECTIVE EAR THING CONDUCTOR is supplied with the equipment, It is permitted to include the conductor in the test circuit but the measurement of the voltage drop is made only from the main protective earthing terminal to the part required to be earthed.
On equipment where the protective earth connection to a subassembly or to a separate unit is by means of one core of a multicore cable that also supplies mains power to that subassembly or unit, the resistance of the PROTECTIVE BONDING CONDUCTOR in that cable is not included in the measurement. However, this option is only permitted if the cable is protected by a suitably rated protective device which takes into account the size of the conductor.
If the protection of an SELV CIRCUIT or a rivv ccwr is achieved by earthing the protected circuit itself in accordance with 29.4 e), the resistance and the voltage drop limits apply between the earthed side of the protected circuit and the main protective earthing terminal.
If the circuit is protected by earthing the winding of a transformer supplying the protected circuit, the resistance and the voltage drop limits apply between the unearthed side of the winding and the main protective earthing terminaL The aa.sc surso’i between the primary and secondary windings is not subjected to the single fault testing required by 5.3.7 and 1.4. 14.
Care is taken that the contact resistance between the tip of the measuring probe and the conductive part under test does not influence the test results.
The test current, duration of the test and test results are as follows.UL 60950-1-2019 pdf free download.