BS EN 50556:2011 pdf download – Road traffic signal systems
The Road Traffic Signal System shall conform to HD 384.4 series. This subclause deals with the additionalrequirements for Road Traffic Signal Systems.
18.104.22.168Criteria -Leakage current
22.214.171.124.1 Road Traffic Signal SystemsClass T1:
For Road Traffic Signal Systems, leakage current protection facilities conforming to HD 384.4.41 shall befitted.Earth leakage circuit breakers conforming to EN 61008 series for nominal currents 20 % greater thanthe expected current and nominal leakage currents ≤0,3 A shall be installed.
No requirement for leakage current protection facilities for the whole system, however the customer mayrequest facilities as class T1.
126.96.36.199.2 Maintenance equipment supply
To conform with HD 60364-4-41,an earth leakage circuit breaker conforming to EN 61008 series withnominal leakage currents ≤ 0,03 A shall be installed.
This subclause applies to the installation or part of the installation which is class I conforming to EN 61188.8.131.52.3.2Protective earth conductor (PE)
The system shall conform to HD 60364-5-54.
Protective earth conductors shall connect together all conductive parts and the PE terminals throughout thesystem. They shall either be created by conductors in a cable or by separately installed wires andlorconstruction parts.
ln controllers the PE conductors shall be connected to the PE terminal / earth bus bar.
NOTE Metallic bodies which, by virtue of their location or smallness,cannot be touched or are ulikely to become live should bedesignated excluded devices, i.e. they need not be connected to the PEconductor.
184.108.40.206.3PE wiring of external equipment
NOTE 1 Examples of external equipment are poles, signal heads and detectors.The system shall be classified according to the following methods.
Accessible conductive parts shall be connected to the PE conductors incorporated in the cables or a separatePE cable.
NOTE2 Armouring of cables may also be used as PE conductors where the cable construction permits.
The enclosure shall provide the mechanical protection to K07(see EN 50102) with the following criteria:No damage shall occur to the equipment contained within the enclosure and the equipment shall continue tooperate to its specification.There shall be no degradation of the lP rating of the equipment.
Enclosures shall provide protection to lP44.When the manual panel is open, the protection provided shall beto lP42. When the enclosure is open the protection shall be to IP20.
Enclosures shall provide protection to lP54.When the manual panel is open, the protection provided shall beto lP23. When the enclosure is open the protection shall be to lP21.
Covers，doors，flaps，or similar allowing access to controls,circuits or live parts when opened, shall becapable of being opened only with the aid of a key or a tool. Keys may be specified either on a country basisor by the customer.
Supply voltages within the enclosure or external to the enclosure shall have excess current protection,generally in accordance with HD 384.4 series.
The system shall be classified according to its access to mains terminations as follows:Class Ho: No separate access to mains terminations.
Class H1:separate access to meters or parts of a mains terminal, etc.
5.1.2Controller Signal outputs
The controller shall provide electrical power to the signals (as described in EN 12368), and the signals shalluse this power.Electrical details of compatible signal heads shall be specified by the controller manufacturerin order to ensure the safety of the system. This should list either those signals know to be compatible or theclass of signals to EN 12368 or CLC/TS 50509 that would by definition make them compatible with thecontrol systems required monitoring performance and prevention of hazardous displays.
The terminal points of the PE conductor on bodies shall be easily accessible and shall bear the identificationmark specified in lIEC 60417.They shall provide bare metallic contact and serrated washers shall be used.220.127.116.11General terminations
The terminal points shall be of corrosion resisting materials.