Cables you can connect to your AirPort base station - Apple Support
Cables you can connect to your AirPort base station - Apple Support
Universal Serial Bus (USB)
Connect a USB printer so computers connected to the AirPort network can share the printer. If your base station supports it, you can connect a compatible USB hard disk so computers connected to the network can access the disk. If you have a USB hub, you can connect both a printer and a hard disk.
You will get efficient and thoughtful service from Tongda.
Power adapter
Connect one end of the base station power adapter to this port and the other end to an electrical outlet.
For more information, please visit Airport Cables.
Airport Lighting Series Circuit - Mike Holt's Forum
The runway and taxiway lights at airports are operated on a 6.6amp constant current series circuit with a #8 conductor with 5kv insulation. LED lighting is coming to this industry. We now have the opportunity to use lower current and voltages. Since airport lighting cables often run together in the electical vault or field home circuits I assume any new low voltage circuits for LED lighting will have to maintain 5kv insulation if in proximity with other 5kv cables that are still using the higher voltages? If all the 5kv cables are still being used but now they carry a maximum of 600 volts due to LED lights now being used on all circuits can new cables that are added be just 600 volt rated? Will be glad to clarify if the issues not clear.
Re: Airport Lighting Series Circuit
You seem to be under a mis-understanding. The NEC does not dictate wiring on FAA airfields. The documents you must go by are FAA Advisory Circulars. I work at one of the bigger and busier airports. We have both 6.6 amp CC circuits as well as 20 amp circutis for the majority of our high intensity runway circuits. Some of our runs between the lighting vault and the begining of the runway circuit itself are over 2 miles. We use a #6 LA24 FAA 5kV Type "C" airfield lighting cable.
There has been a huge proliferation in LED fixtures, however, I am of the opinion that they will keep the 5kV level. The load isn't that too different, and you must remember that everywhere there is an airport, there is this installed base of circuitry & regulators. The airfield lighting transformer local to the fixture, marker light, or guidance sign will probably remain. Lets face it; from start to finish there are some circuits that are miles long, and 480 just won't cut it. These fixtures must be able to be operated at the different levels of intensity as desired by weather conditions and the ATC tower. Perhaps a still-to be-built, brand new, smaller to mid size airport may be able to utilize the technology as you indicate, but in the mean time, a great deal must change. I know the LED airfield lighting manufacturers now are seeking to integrate their equipment into existing infrastrure and reap the interim benefits. Re: Airport Lighting Series Circuit
It is true that airport lighting circuits are defined by the FAA Advisory Circulars and NEC requirements as such are not referenced however the NEC requirements provide good sound guidance and will be utilized for reference in future ACs. Due to the existing infrastructure that utilizes either 6.6 or 20 amp circuits series circuits it does make economical sense to keep this infrastructure but the full potential savings that LEDs offer will only be obtained when the series circuit transformers have a good power match with the LED fixture and the CCR efficiency is improved for the lower wattage circuit. The reduction in the power required will result in a less costly power distribution system that supplies the power to the CCRs. In addition safety can be improved and maintenance reduced by reducing both the amperage of the series circuit and the maximum open circuit voltages of the CCRs when powering an all LED circuit. In the future new all LED circuits that don't mingle with 5kv circuits may be able to use 600 volt cable and a smaller conductor . The circuit is a current limited circuit based on the current limiting ability of the constant current regulator (CCR). Nice to get all the comments. Re: Airport Lighting Series Circuit
I am not picking at you, nor saying your ideads are without merit, sewardf, when I say that I don't believe t will happen anytime soon. The FAA is a stodgy bueracracy, that doesn't make radical changes, [ as this would be], quickly. The airlinr industry is not doing all that welll. And for many many municipalities that operate the airport facilities, their operating revenue, and much of that for improvement and expansion, [oooh...a dirty word to some here in Chicgo] are tied to the airlines. The utility bills for the operation of the runway lighting system, as many things I've found aren't always the priority for change. Saving money is important , yes, but it is sometimes curious and sad to see what can be sacrificial.
Airfield lighting is performance and relaibility driven; both attributes of LED technology, so as I stated it will be embraced, but not at the level I think you expect.
I see that you are a consultant. An airport construction consultant or one that works for the LED fixture people? Just curious. I/we have dealt with many consultants, from national firms to local ones. We have also been innundated by a number of fixture manufacturers pushing their wares.
We have gotten perfect FAA139 ratings, for a number of years now, due, in part, to the diligent work of the airfield electrical crew whaere I work. They have standardized on only -2- manufacturers for their airfield equipment. These manufacturers won our respect and work diligently every day to keep it. As such, we have a smaller, more universal inventory for airfield maintenance.
I also question how a fault somewhere along a 5 mile run length of cable being operated at this suggested 600 volt level would act with the regulators. Right now, we can partially operate a circuit that has gone to ground until it can be repaired.
The LED circuit I envision would still be a series circuit running at a lower amperage than 6.6A and the regulator output voltage may be restricted to 600volts, hence 600 volt rated cable can be used instead of volts when there is no volt cable in the same trench or conduit. The benefits of the series circuit which allows you to have one unintentional ground and still maintain the operation of the circuit would still be with us. The lack of any heat generated does pose a problem for the elevated lights. The FAA is currently requiring a heater which will melt any snow or ice on the globe. This would be thermostat controlled and could use 10 watts of power. To convert an existing circuit to a more efficient circuit would require changing all the fixtures on the circuit to the LED light source and replacing the series circuit transformer with a transformer that is matched to the load of the light and then provide a new CCR that would also match the circuit load and have a lower amperage output and a specified maximum voltage of 600 volts. Re: Airport Lighting Series Circuit
Roger, my point exactly! We have a few runs on which the home run is 2.5 miles. Your two cents are well taken. Sewardf hasn't yet disclosed which interest he respresents as a consulting engineer. I'm just curious; and it would provide a perspective on how sewardf is looking at things. Manufacturers are always trying to get us to use their products due to the prestiege that would come from the notarity of having their stuff installed at ORD.
We have about 100 airfield lighting circuits. Some closer to the regulators in the vaults than others. That would represent a huge number of airfield lightiing fixtures, from in-surface, to rnuway edgelights, taxiway, informational signage, LAHSO, and the numerous other types we have. Perhaps I'm being snobbish because of where I work, but I'm also proud of what we do, and the scale we do it on. Especially after the plow trucks have left the runway after a snowstorm.
The airline business, as we all have seen on the news, is not in the best financial shape. Since they basically end up paying for most everything, I can't imagine any of them willing to replace a system that seems to work, for another similar system.
You seem to be under a mis-understanding. The NEC does not dictate wiring on FAA airfields. The documents you must go by are FAA Advisory Circulars. I work at one of the bigger and busier airports. We have both 6.6 amp CC circuits as well as 20 amp circutis for the majority of our high intensity runway circuits. Some of our runs between the lighting vault and the begining of the runway circuit itself are over 2 miles. We use a #6 LA24 FAA 5kV Type "C" airfield lighting cable.
There has been a huge proliferation in LED fixtures, however, I am of the opinion that they will keep the 5kV level. The load isn't that too different, and you must remember that everywhere there is an airport, there is this installed base of circuitry & regulators. The airfield lighting transformer local to the fixture, marker light, or guidance sign will probably remain. Lets face it; from start to finish there are some circuits that are miles long, and 480 just won't cut it. These fixtures must be able to be operated at the different levels of intensity as desired by weather conditions and the ATC tower. Perhaps a still-to be-built, brand new, smaller to mid size airport may be able to utilize the technology as you indicate, but in the mean time, a great deal must change. I know the LED airfield lighting manufacturers now are seeking to integrate their equipment into existing infrastrure and reap the interim benefits. Re: Airport Lighting Series Circuit
It is true that airport lighting circuits are defined by the FAA Advisory Circulars and NEC requirements as such are not referenced however the NEC requirements provide good sound guidance and will be utilized for reference in future ACs. Due to the existing infrastructure that utilizes either 6.6 or 20 amp circuits series circuits it does make economical sense to keep this infrastructure but the full potential savings that LEDs offer will only be obtained when the series circuit transformers have a good power match with the LED fixture and the CCR efficiency is improved for the lower wattage circuit. The reduction in the power required will result in a less costly power distribution system that supplies the power to the CCRs. In addition safety can be improved and maintenance reduced by reducing both the amperage of the series circuit and the maximum open circuit voltages of the CCRs when powering an all LED circuit. In the future new all LED circuits that don't mingle with 5kv circuits may be able to use 600 volt cable and a smaller conductor . The circuit is a current limited circuit based on the current limiting ability of the constant current regulator (CCR). Nice to get all the comments. Re: Airport Lighting Series Circuit
I am not picking at you, nor saying your ideads are without merit, sewardf, when I say that I don't believe t will happen anytime soon. The FAA is a stodgy bueracracy, that doesn't make radical changes, [ as this would be], quickly. The airlinr industry is not doing all that welll. And for many many municipalities that operate the airport facilities, their operating revenue, and much of that for improvement and expansion, [oooh...a dirty word to some here in Chicgo] are tied to the airlines. The utility bills for the operation of the runway lighting system, as many things I've found aren't always the priority for change. Saving money is important , yes, but it is sometimes curious and sad to see what can be sacrificial.
Airfield lighting is performance and relaibility driven; both attributes of LED technology, so as I stated it will be embraced, but not at the level I think you expect.
I see that you are a consultant. An airport construction consultant or one that works for the LED fixture people? Just curious. I/we have dealt with many consultants, from national firms to local ones. We have also been innundated by a number of fixture manufacturers pushing their wares.
We have gotten perfect FAA139 ratings, for a number of years now, due, in part, to the diligent work of the airfield electrical crew whaere I work. They have standardized on only -2- manufacturers for their airfield equipment. These manufacturers won our respect and work diligently every day to keep it. As such, we have a smaller, more universal inventory for airfield maintenance.
I also question how a fault somewhere along a 5 mile run length of cable being operated at this suggested 600 volt level would act with the regulators. Right now, we can partially operate a circuit that has gone to ground until it can be repaired.
it does make economical sense to keep this infrastructure but the full potential savings that LEDs offer will only be obtained when the series circuit transformers have a good power match with the LED fixture and the CCR efficiency is improved for the lower wattage circuitWho's gonna pay for all this? That's really all I'm saying. Re: Airport Lighting Series Circuit
The LED circuit I envision would still be a series circuit running at a lower amperage than 6.6A and the regulator output voltage may be restricted to 600volts, hence 600 volt rated cable can be used instead of volts when there is no volt cable in the same trench or conduit. The benefits of the series circuit which allows you to have one unintentional ground and still maintain the operation of the circuit would still be with us. The lack of any heat generated does pose a problem for the elevated lights. The FAA is currently requiring a heater which will melt any snow or ice on the globe. This would be thermostat controlled and could use 10 watts of power. To convert an existing circuit to a more efficient circuit would require changing all the fixtures on the circuit to the LED light source and replacing the series circuit transformer with a transformer that is matched to the load of the light and then provide a new CCR that would also match the circuit load and have a lower amperage output and a specified maximum voltage of 600 volts. Re: Airport Lighting Series Circuit
Roger, my point exactly! We have a few runs on which the home run is 2.5 miles. Your two cents are well taken. Sewardf hasn't yet disclosed which interest he respresents as a consulting engineer. I'm just curious; and it would provide a perspective on how sewardf is looking at things. Manufacturers are always trying to get us to use their products due to the prestiege that would come from the notarity of having their stuff installed at ORD.
We have about 100 airfield lighting circuits. Some closer to the regulators in the vaults than others. That would represent a huge number of airfield lightiing fixtures, from in-surface, to rnuway edgelights, taxiway, informational signage, LAHSO, and the numerous other types we have. Perhaps I'm being snobbish because of where I work, but I'm also proud of what we do, and the scale we do it on. Especially after the plow trucks have left the runway after a snowstorm.
The airline business, as we all have seen on the news, is not in the best financial shape. Since they basically end up paying for most everything, I can't imagine any of them willing to replace a system that seems to work, for another similar system.
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