Specifications

Design-in guide Philips Fortimo LED Line High Voltage System 23
Thermal management
The critical thermal management points of the LED Line and driver
are set out in this section to facilitate the design-in of Fortimo LED
Line Systems. If these thermal points are taken into account this will
ensure the optimum performance and lifetime of the system.
Temperature and lifetime of the Fortimo LED Line
The Tc rises as the ambient temperature increases. The temperature offset
between Tambient and Tc depends on the thermal design of the luminaire.
The Fortimo LED Line System has been designed for indoor use and ambient
temperatures from 0 °C and higher. The Tc of the LED Line must be complied
with at all times. For LEDs it is the junction temperature that is the critical factor
for operation and lifetime. Since there is a direct relation between the case
temperature and the LED junction temperature, it is sufficient to measure the
case temperature at the Tc point on the upper side of the LED Line. This Tc
point must not exceed the maximum values shown in the table below. This table
also shows the Tc at which the performance specifications of the LED Line are
valid.
Fortimo LED Line
Tc nominal *
°C
Tc life**
°C
Tc max***
°C
LED Line 1ft 650 lm 3R HV1
35
56
70
LED Line 1ft 1100 lm 3R HV1
35
62
70
LED Line 2ft 2200 lm 1R HV1
35
58
70
LED Line 2ft 1250 lm 2R HV1
35
55
65
* Nominal Tc at which performance is specified
** Maximum Tc at which lifetime is specified
*** Maximum Tc for safety
Definitions
The definitions used in this chapter are as follows:
 Driver temperature: temperature measured at the Tc point of the driver.
 Driver ambient temperature: temperature inside the luminaire around the
driver.
 Luminaire ambient temperature: temperature outside the luminaire.
Lumen maintenance of the Fortimo LED Line
In case both the current and Tc are kept below the recommended values for
50,000 hours lifetime, the following lumen maintenance curves apply. The graphs
below show the estimated lumen depreciation curves at Tc life and I life. Both
B50 and B10 curves are shown, representing 50% and 90% of the population.
These estimations are based on 9000 hours of LM80 testing and calculated
according to the TM-21 guideline. After 50,000 hours the lines are dotted,
because officially we cannot predict lumen maintenance beyond 50,000 hours.
Lowering the drive current will increase the lumen maintenance time.
The test results of the LEDs of the Fortimo LED Line 1ft 650lm 3R HV1 and