Technical Design-in Guide Engine QLE G2 PRE KIT | 01-2019 | 1.0 | en
Intelligent Temperature Guard
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8.7.2. Description
If Dimming on DC is activated the requirements of the DC recognition function are ignored. Even if DC is detected the LED Driver
continues to behave as in AC mode:
8.8. Intelligent Temperature Guard
8.8.1. Description
The Intelligent Temperature Guard function provides protection against temporary thermal overloads. It slowly reduces the output if
the maximum T temperature is exceeded. This way instant failure of the LED Driver can be prevented. Thermal overload protection is
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triggered as soon as the T temperature is exceeded by around 5 to 10 °C. The precise trigger temperature depends on the device.
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The value is selected so that the protection function is not performed until there is a significant impact on rated life.
The output is reduced in small stages that are generally imperceptible to the user. The temperature is checked every two minutes.
8.8.2. Behaviour
The following table shows the exact behaviour and parameters of the Intelligent Temperature Guard function for LCA PRE and LC
EXC
Parameters
Description
Start of power reduction
When maximum operating temperature (Tc) is exceeded by approx. 5-10 °C
(1)
Power reduction rate
Reduction of max level by 1 dim step / 2 min
Power reduction process
and control
Power reduction is dependent on temperature:
Min power level
approx. 50 % dim level
(2)
The present dimming level is retained
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An emergency light level defined for the DC recognition function (DC level) is ignored
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Control signals via DALI und DSI continue to be executed
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WARNING!
The T temperature is the maximum permitted in terms of safety.
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Operating the LED Drivers above the permitted T temperature is not compliant with relevant standards.
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The Intelligent Temperature Guard function does not replace the proper thermal design of the luminaire and does not enable the
lighting to operate for lengthy periods of time in impermissible ambient temperatures.
Power reduction continues if temperature still rises
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Power reduction stops if temperature does not rise anymore or if maximum power reduction is
reached (minimum power level = 50 %)
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If temperature falls below a certain level, power is increased again until 100 % is reached
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If temperature still rises even if maximum power reduction is reached:
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PRE drivers go to 15 % dim level
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