Webinar 3 Q&A
|Q1||Hello and thank you for sharing with us your presentation. Please if you can explain for us FLA Field Lightning Arresters, they application and Earth values with and without them? KR||Please refer to Question 11 for this answer !|
|Q2||What is your opinion regarding this new lighting protectos in the secondary circuit?||Many airports do NOT (or have not) install the latest protection equipment devices for the secondary circuit protection as defined by the International Electrotechnical Commission (IEC).
See IEC standard 62870
This requirement PELV (Protective Extra-Low Voltage) & SELV (Safety Extra-Low Voltage) are designed to limit the voltage on the secondary circuit hence safeguard the engineering personnel if they are required to work on live secondary circuits. Eg. Fault-Finding function !
I have yet to see this concept to be realistically adopted by airports hence refrain from further comment at this time.
|Q3||Hi Keith, for interleaving RWY circuit, could it be 3 or 4 circuit??||Interleaving is a requirement for all runway & taxiway related AGL systems where applicable. ICAO Aerodrome Design Manual Part 5 gives guidelines on how interleaving should be achieved.
However, Annex 14 Vol 1 refers to interleaving based upon when a circuit fails such that …. in the event of a circuit failure the pattern of the lights in that the system lighting pattern remains uniform.
Hence, a minimum is 2 circuits per system is the normal but if uniformity can be achieved as required … more than two interleaved circuits can be adopted. Take care though because when there is a mix of lighting colours in the same system (Eg Runway centreline) you need to make sure.
|Q4||We need to know more how to calculate the exact location and height of PAPI in case of non-instruments and in case of ILS?||We offer a dedicated specialist PAPI training course which discusses & demonstrates exactly how the PAPI location, local installation, set-up etc is calculated both with or without interfacing with an ILS system to ensure that the correct & safe aircaft wheel clearance is achieved above & upon crossing the threshold during landing. The PAPI calculations are demonstrated with a Glide Slope of 3 degrees AND calculated with your own airport’s glide slope if different from the standard. To achieve this, we would need the land /runway coordinates.|
|Q5||Thanks Robert, |
Could Keith also share his opinion about the new induction technologies in AGL? Its pros and cons.
Thanks in advance.
|Perhaps my view on the inductive technology area is too long to discuss over a Webinar and Q&A. However, it has many features which may prove attractive. eg. Reliable communications for “follow-the-green” A-SMG&CS requirements.
May I suggest you contact me separately.
|Q6||We have had an issue with portable lights for night operations in some airports. Is it advisable to have fully portable lights for night operation without back-ups?||For the portable lights you may be using lights are :
• Battery powered only
• Solar with battery back-up
Whatever system you are using, you need to ensure that the “power supply” is reliable. There are many products on the market which should meet with your night operation requirements.
|Q7||What voltage is recommended to be used to test the insulation?||ICAO Aerodrome Design Manual Part 5 defines the test voltage as 5000 volts AND on a completely new & complete installation you need to test (ONE TIME ONLY) at 9000 volts.|
|Q8||Could you please upload IEC standards?||IEC standards are available from the International Electrotechnical Commission (IEC) and have to be purchased IF the latest Edition + updates/amendments are required. Please contact us directly to discuss.|
|Q9||Hi Keith, Could you please mention the ICAO reference numbers for length of circuit vs. IR values? I know that there is a table in the FAA regulations, but never came across something in ICAO||ICAO refer to HOW you work out the actual Insulation Resistance (IR) value.
Simply, ICAO in their Aerodrome Design Manual Part 5 defines Allowable Earth leakage on an AGL primary circuit is based upon :
1. 2 microamps for each isolating ternsformer
2. 1 microamp for each 100 metres of primary cable
Hence, the calculated IR value is based upon Ohms Law : R=V/I where V is nominated at 5000 volts ( ie. the design value for AGL 6mm square cross section single core cable)
|Q10||Hi Robert, Keith, what is the criteria to the heat dissipation in the manhole against the number transformers to size of manhole, and how it is calculated?||Heat dissipation in any enclosed space is principly based upon the total numerical value of the combined wattage of units and, dependent upon efficiency of the units, will dissipate heat at some 10% of that total value !
This is a big subject and open to interpretation.
|Q11||Another question on using the earth cable as single protection for earthing and lightning?||NO …. An AGL earthing network cannot be used as a Counterpoise for lightning protection.
A counterpoise, is bare copper wire; installed such to protect the primary cabling in the ground; cannot be installed in the same cable run/duct as primary cabling; it is earthed by ground rods suitably spaced in accordance with national standards ( eg. 300 mtere spacing max); it has a greater cross-sectional area to an earthing network cable.
However, IF you have a Counterpoise system …. It can operate as an earthing network for bonding purposes.
|Q12||In case of take off runway, the runway end lights should be serviceable in 1 second, how could we achieved this switch over time in CAT I?||CAT I lighting systems changeover time, in the event of mains failure, shall be in accordance with Annex 14 Vol I Table 8.1 and Aerodrome Design Manual Part 5 Chapter 3 Table 3-2
Precision Approach Category 1
Approach Lighting System 15 seconds
Runway Edge 15 seconds
Visual Approach Slope indicators 15 seconds
Runway Threshold 15 seconds
Runway End 15 seconds
Essential Taxiway 15 seconds
Obstable 15 seconds
8.1.7 For a runway meant for take-off in runway visual range conditions less than a value of 800 m, a secondary power supply capable of meeting the relevant requirements of Table 8-1 shall be provided.
Hence it is defined as 15 seconds.
|Q13||Any equipments to find the exact location of fault in case of open circuit fault finding? (like in case of HV/HT cables we use differential current injecting equipments..)||NO …. The quickest, simplest and SAFEST way is to ensure the circuit is switched off ( ie. NO CCR output capability ) ; use the “common system” of halving the circuit; take a measurement to identify which half has the open circuit ie. identify which direction/leg of the circuit has the open circuit and then carry on in the half-by-halving principle. It does NOT take long to identify where the open circuit is located.
There is a “power-on” process for open circuit identification BUT we do not recommend that this is adopted !
Fault-finding on AGL circuits is covered in our TMS Training Solutions maintenance courses.
|Q14||we need to know more how to calculate the exact location and height of PAPI in case of non-instruments and in case of ILS?||We offer a dedicated specialist PAPI course which discusses & demonstrates exactly how the PAPI location, local installation, set-up etc is calculated both with or without interfacing with an ILS system to ensure that the correct & safe aircaft wheel clearance is achieved above & upon crossing the threshold during landing. The PAPI calculations are demonstrated with a Glide Slope of 3 degrees AND calculated with your own airport’s glide slope if different from the standard. To achieve this, we would need the land /runway coordinates.|
|Q15||Easa say that at last 600m the color is yellow?||By referring to YELLOW, you will be referring to Runway Edge (side row) lights. YES … for the last 600 metres before the end of the runway, the Runway Edge (RE) lights are YELLOW whereas the remaining RE lights are WHITE from the first RE lights from the threshold
up to the 600 metre from the end location.