Specifications

32 Philips Fortimo HBMt Gen 3 System Design In Guide

Maximum Thermal power @ thermal interface

The LED Module generates an amount of heat which is represented by the max

thermal Power as:

Pth, max = Pth rear, max + Pth, front max

The major portion (Pth, rear) is transferred via the Thermal Interface Surface by

heat conduction. The Pth, front portion is transferred by means of IR radiation and

convection in the direction of the light beam.

Maximum Allowable Thermal resistance of the Luminaire

Value of the thermal resistance from the Thermal Interface Surface to the

environment for which holds: Tr=Tr,max (unit: K/W). This value is to be dened by

the manufacturer as the temperature at which the Rated LED Module performance

is specied.

Tr=ta +Rth*Pth, rearwhere ta is the average temperature of the air in the vicinity

of the Luminaire and Rth is the thermal resistance from the Thermal Interface

Surface to the environment.

Rated Operating Temperature Tr.max

The Reference Temperature Tr is the temperature at the TIM-Heatsink interface

of a LED module that is thermally connected to the heatsink with this TIM (unit:

K). In practice this temperature is measured in the heatsink near the TIM-Heatsink

interface. The case temperature Tcase is related to this reference temperature Tr

as follows:

Tcase = Tr + Rth TIM*Pth LED Module

The Rated Operating Temperature, Tr,max, is the value of the Reference

Temperature (Tr) at which the rated values are specied.

Table 22. Zhaga luminous ux categories

Recommended Zhaga-compliant Xitanium LED drivers

Flux