ADB Safegate RELIANCE Intelligent Lighting Platform III, User Manual

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Voltage Limiter Limitations
The Safety Extra-Low Voltage cannot be achieved only by integrating the SRU with voltage limiter (SRU112) into your system,
but need to use a standardized approach for the systemic design of your installation including a specific requirement
framework. The requirement framework for the compliance to the SELV standard (EN 62870) includes the following
prerequisites:
•
Selection of adequate serious circuit transformers to ensure:
1. Safe cut-out
2. Limitation of the type power
3. Limitation of the operating voltage when it comes to insulation
•
Limitation of the serious circuit voltage
•
Sufficient insulation of the primary and secondary circuits against ground
Handling
The supply of the lights with Safety Extra-Low Voltage aims to simplify the maintenance and repairing procedure. The supply
voltage in systems equipped with SELV will not exceed 50 VAC, even in case of light failure.
CAUTION
Risk of
Electrostatic Discharges
(
ESD
) in wet weather conditions or in series circuits with low
insulation values
Wear Personal Protective Equipment (PPE) when working on parts of the circuit
Detailed working best practices for handling and maintenance must be defined by the responsible airport personnel. The best
practices must be complied with for your own safety.
Lights supplied with SELV are marked with the the following symbol: The symbol is located on or next to the light.
Apply the best practices for work related to light fixtures, if this symbol cannot be read or does not exist.
Maintenance Process
Maintain and test the lighting systems according to the requirements laid down in the work instructions to ensure the that
the SELV system keeps functioning. For maintenance and testing focus especially on the followings aspects:
•
Insulation values of the primary cabling
One of the possible protective method is based on an not grounded primary power supply via the series circuit (IT net)
and a secure interruption of the not grounded secondary circuit at the output of the series circuit transformer. Body
currents caused by touching the secondary power supply are being minimized due to the high insulation values. One of
the protective barriers is no longer effective if there is a ground fault in the primary circuit. The insulation values of circuits
with more than 1000 VAC must be kept above 500 k ohm and the insulation values of circuits with up to 1000 VAC above
100 k ohm. Circuits with insulation values less than 500 or 100 k ohm, respectively, must be repaired as soon as possible.
Important
Be especially cautious when working on circuits with low insulation values. Do not work on circuits with low
insulation values unless you wear suitable PPE or have disconnected the system from the mains and protected the
system from reconnecting using a cut-out device.
•
Testing the series circuit transformers when replacing a light fixture:
UM-5005, Rev. 004, 2020/08/06 83
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