Document UT-MT-0872-EN
Page 8 of 31
Edition 27/09/2018
LIMS INSTRUCTION MANUAL
3.1.4
LEDs Luminous Source
The signs are illuminated by strips LEDs
(Figure 5) inserted in suitable supports.
High efficiency white LEDs are used, with
an average life of 60.000 hours.
The positioning of the LEDs has been
determined through photometric tests in
order to meet the luminance values as
required by ICAO Specs - Annex 14.
Three different strips lengths are used
(720, 960 and 1200 mm) for the different
signs lengths (see Table 4).
3.1.5
Electrical circuit
Constant Current supply (AGL Series Circuit)
Signs for constant current series circuits are equipped with an
electronic current converter housed inside a water proof
aluminium box, mounted on a side of the external frame.
About the luminance levels, two versions are available:
-
1 luminance level over the whole input current range 2.8
A ÷ 6.6 A;
-
2 luminance levels depending on the input current
value: in the standard version the current threshold at
which the luminance level changes is 5.9 A (but
optionally this threshold is customizable).
An option in available to monitor the light sources status,
compliant with the fail open operation (see 3.1.8).
Further, to facilitate the feeding of the sign with different
topologies of CCR, an optional stabilization circuit is available,
composed by an inductor and a capacitor (see Figure 12Figure
12: Wiring diagram (sign with circuit stabilizer).
For the electrical connection to the isolating transformer the sign is equipped with a two-pole
cable lead with L-823 plug, style 1, protected by a corrugated pipe.
Figure 5: LEDs luminous source
Figure 6: Electronic board
