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3. THERMAL CHARACTERISTICS AND LIFETIME
The thermal operating conditions of the control gear are a critical factor for its lifetime and for the LED street lighting
system into which it is integrated. This is why an understanding of the factors and parameters relating to this aspect
is essential.
Control gear equipped with eSMART technology has been designed to offer maximum performance with the best
thermal efficiency.
Once the drivers have been integrated into the lighting system, the thermal efficiency and lifetime depend on factors
such as the connected load, luminaire design, its capacity to dissipate the heat generated inside the unit and the
relative position of each of its components.
3.1. Temperature inside the casing (tc)
The parameter to control in order to ensure correct operation and life expectancy is the temperature inside the casing
at a point called tc. The tc is a point of reference that represents the conditions under which the driver’s internal
components are working. Particular care must be taken to ensure that the maximum limits specified for each model
are not exceeded.
The simplest way to measure the temperature at this point is by means of a thermocouple attached at the place
indicated on the casing of each driver once thermal stability has been achieved.
NOTE:
The eSMART drivers from the PRO range incorporate a diagnostic mode that indicates the internal temperature value of the driver.
This is for guidance purposes only as it does not necessarily coincide with the tc value.
3.2. Ambient temperature (ta)
The eSMART drivers have been designed to be able to operate within a very wide ambient temperature range. The
maximum ambient temperature limit depends on the operating point, the value of the connected load and, largely, to the
design of the luminaire itself and its ability to dissipate heat outwards.
The maximum permitted ambient temperature for control gear can serve as a guideline or an indicator of the
conditions under which that device is able to work, however must not be used as the control parameter to guarantee
its estimated lifetime.
With the aim of ensuring reliable ignition in ambient temperatures of less than -25ºC, the drivers power up gradually,
applying a start-up process that lasts for a maximum of 10 seconds. Gradual start-up takes place irrespectively of
the driver configuration.
3.3. Lifetime
The eSMART control gear can achieve up to a 100,000 hour lifetime depending on the working temperature at point
tc.
NOTE:
Thermal data and the lifetime of each model can be viewed on their corresponding data sheets, available for download via the ELT
website at
www.elt.es/en
