UL 8750-2021 pdf download – Light Emitting Diode (LED) Equipment for Use in Lighting Products.
SC1 Scope SC1.1 These requirements apply to Temperature Limited (Type TL) LED drivers. SC2 Definitions SC2.1 CALCULATED T ref max – The calculated temperature limit for the LED driver at T C under normal operating conditions. SC2.2 MEASURED T ref – The measured temperature at T C under normal operating conditions. SC2.3 TEMPERATURE MEASUREMENT POINT, T C – A specific temperature measurement location assigned by the manufacturer on the LED driver case (exterior surface). SC2.4 T ref max – The temperature limit for the LED driver at T C , under normal operating conditions, as assigned by the manufacturer. SC3 Construction SC3.1 A Type TL LED driver shall comply with all applicable construction requirements of this standard and the following criteria to facilitate parity amongst LED drivers that meet thermal profile requirements of this Supplement: a) The driver shall not rely upon external overcurrent or over temperature protection for compliance with requirements of this standard; b) The driver shall not rely upon external heat management methods such as forced air cooling or non-integral heat-sinking or external temperature sensors for compliance with requirements of this standard; c) The driver shall be provided with both an integral fire and electrical enclosure in accordance with the applicable requirements described in Section 6; Exception No. 1: A driverwith wiring leads, terminals, orpush-in terminals. Exception No. 2: A driver that is intended for installation on or over an outlet box, in areas where the outlet box will serve to complete the enclosure ofthe equipment undertest. d) The driver shall be provided with supply connections that comply with 7.4.1 and one of the methods described in 7.4.2 (i.e., conduit connection, wiring leads, terminals, or push-in terminals). The driver shall be provided with load connections that comply with 7.4.1 and 7.4.4; and
SC4.1 A Type TL LED driver shall comply with all applicable performance requirements of this standard and the requirements in this section (SC4.2 – SC4.5, temperature testing, SC4.6 – SC4.8, abnormal testing, and SC4.9, leakage current measurement testing). SC4.2 During the Temperature Test per Section 8.3, temperatures at T C and other exterior surface test points are monitored. Testing is performed at ambient temperatures noted in Table 8.2. The Measured T ref and the Calculated T ref max value is determined as follows: a) The temperature measured at T C is normalized per 8.3.4 as necessary. The result is designated as the Measured T ref . When the driver is subject to multiple temperature tests based on the requirements of this standard, the highest Measured T ref value is designated. b) The difference between the maximum permitted temperature (per Table 8.1 and SC4.4) and the measured temperature is calculated for each component (T C and other exterior surface test points ΔT 1 . . . ΔT n ). The values are normalized per 8.3.4 as necessary. The smallest difference is designated ΔT. When the driver is subject to multiple temperature tests based on the requirements of this standard, the Calculated ΔT values shall be determined for each test ΔT t1 . . . ΔT tn . The lowest value for all tests is ΔT.