# Dumb questions!!!! Hooray!!!



## RIVETER

Typically, I do not care about phasing. There are some places that it is extremely important, such as, you must know the proper phasing when wiring a large motor that is mechanically linked up and going in the wrong direction will cause damage. Other than that I don't worry about it.


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## BBQ

kaboler said:


> Do you guys worry about phases at all?


Help identifying phases



> I personally think that the world will eventually have to move back to DC power


And why do you think that?


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## AWKrueger

BBQ said:


> And why do you think that?


 
Because Edison is better than Tesla.........:whistling2:


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## kennydmeek

AWKrueger said:


> Because Edison is better than Tesla.........:whistling2:


But think of the size of the wire you're going to have to use on power lines ...


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## kaboler

I'm talking about linework here.

Anyhow, I think the world will be DC again. It's hard to integrate solar and wind into an AC system, but if everything were DC, it wouldn't be a problem. DC is easier to transmit. The problem is it has to revert to AC. It isn't subject to "skin effect". Your power plant doesn't have to worry about timing when you're far away from the rest of the grid.

Electronics could get smaller. LED lighting could be smaller, cooler, and more efficient (no need for a driver!).


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## erics37

Maybe they could retain the high-voltage AC grid for long distance transmission, and then convert to DC for local distribution and utilization.

All they would need is 20,980,223,490,823 of the world's biggest rectifiers. Or somehow turn the Moon into a battery.


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## Shockdoc

kaboler said:


> I'm talking about linework here.
> 
> Anyhow, I think the world will be DC again. It's hard to integrate solar and wind into an AC system, but if everything were DC, it wouldn't be a problem. DC is easier to transmit. The problem is it has to revert to AC. It isn't subject to "skin effect". Your power plant doesn't have to worry about timing when you're far away from the rest of the grid.
> 
> Electronics could get smaller. LED lighting could be smaller, cooler, and more efficient (no need for a driver!).


Solar is a passing phase, give it ten years or so and it will wind down to a new invention.


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## 480sparky

Shockdoc said:


> Solar is a passing phase, give it ten years or so and it will wind down to a new invention.










​


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## kennydmeek

I like that....this forum needs a like button like Facebook....


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## chrisfnl

BBQ said:


> And why do you think that?


HVDC is the way of the future for transmissions... much more efficient.

No skin effect, no inductive losses, no worries about synchronizing when bringing a plant on line, more capacity then an AC line in same size wires.

Main reason most transmission systems are AC is because much of it was built before the technology for HVDC lines was viable.

(Note: For long range transmissions. Short range, AC is preferable.)


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## chrisfnl

erics37 said:


> Maybe they could retain the high-voltage AC grid for long distance transmission, and then convert to DC for local distribution and utilization.
> 
> All they would need is 20,980,223,490,823 of the world's biggest rectifiers. Or somehow turn the Moon into a battery.


http://en.wikipedia.org/wiki/High-voltage_direct_current

Other way around. DC for transmission, AC for local distribution/consumer use.


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## Wirenuting

480sparky said:


> 480sparky posted the fusion machine picture.


Now that looks like it would make good coffee. 

I built a Home Cold Fusion machine last week in my basement. 
Worked great except that I hate cold coffee. 
So I tossed it in the trash.


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## backstay

Wirenuting said:


> Now that looks like it would make good coffee.
> 
> I built a Home Cold Fusion machine last week in my basement.
> Worked great except that I hate cold coffee.
> So I tossed it in the trash.


That was dumb, go get that thing out of the trash! Cold coffee is all the rage now.


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## CheapCharlie

chrisfnl said:


> HVDC is the way of the future for transmissions... much more efficient.
> 
> No skin effect, no inductive losses, no worries about synchronizing when bringing a plant on line, more capacity then an AC line in same size wires.
> 
> Main reason most transmission systems are AC is because much of it was built before the technology for HVDC lines was viable.
> 
> (Note: For long range transmissions. Short range, AC is preferable.)


We have a huge HVDC system here. I'm operating the station right now. 2000MW here, 1600MW down the river.


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## BBQ

chrisfnl said:


> HVDC is the way of the future for transmissions... much more efficient.


That remains to be seen, the costs of the equipment to raise and lower the voltage of DC makes it only advantageous for large capacity transmission lines at this time.

To me it sounded like kaboler was suggesting we would be moving entirely to DC from source to end user.

Here is what he said.



> Anyhow, I think the world will be DC again. It's hard to integrate solar and wind into an AC system, but if everything were DC, it wouldn't be a problem. DC is easier to transmit. The problem is it has to revert to AC. It isn't subject to "skin effect". Your power plant doesn't have to worry about timing when you're far away from the rest of the grid.
> 
> Electronics could get smaller. LED lighting could be smaller, cooler, and more efficient (no need for a driver!).


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## Big John

I do wonder: With everything going to 5VDC USB connections, and tons of things already running off low-voltage DC power supplies, will we ever get to a point where receptacles also have DC jacks built in where they're powered from one central supply in the house?

I don't believe we will ever go to DC distribution. I wonder if we will eventually start using switching power supplies in place of the AC pole transformers we use now, though. 

-John


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## Jlarson

Damn the grid is gonna go the way of Apple. Every year there's some new "improvement" implemented or planned out.


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## BBQ

Big John said:


> I do wonder: With everything going to 5VDC USB connections, and tons of things already running off low-voltage DC power supplies, will we ever get to a point where receptacles also have DC jacks built in where they're powered from one central supply in the house?
> 
> I don't believe we will ever go to DC distribution. I wonder if we will eventually start using switching power supplies in place of the AC pole transformers we use now, though.
> 
> -John


I rented an Infinity a few weeks ago and it had DC receptacles and a knob to adjust the voltage being supplied.


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## chew

Jlarson said:


> Damn the grid is gonna go the way of Apple. Every year there's some new "improvement" implemented or planned out.


Really you didn't call iGrid, coming to a home near you :thumbsup:


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## londer

Jlarson said:


> Damn the grid is gonna go the way of Apple. Every year there's some new "improvement" implemented or planned out.


Wireless distribution?


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## jhall.sparky

londer said:


> Wireless distribution?


Without interference? Huh............ Possi.........nah it would neve.......
Shoot ! Your on to something ...... Ill call it..........WIFI. 

Its an acronym for Will Ignite F**king Instantly.........


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## gold

What grid?

http://fuelcellresidential.com/

Its here.


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## gold

and this one


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## brian john

BBQ said:


> I rented an Infinity a few weeks ago and it had DC receptacles and a knob to adjust the voltage being supplied.


 
INFINITY....Aren't you Mister Money:laughing::laughing:

I did the same thing while in Florida, those nice cars really spoil you. AC blowing through the seat, cooling my tushie down.


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## Chris1971

kaboler said:


> Do you guys worry about phases at all? Can you look up at a tower and say, "that one is phase 1, that one is phase 2, and that one is phase 3"?
> 
> I personally think that the world will eventually have to move back to DC power (as well as someday get rid of pennies, both equally challenging!!!!). What's your take on, not really why, but would it make your jobs easier and such. HVDC.
> 
> TY!!!


Coming from you, we expect stupid questions.:thumbsup:


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## airfieldsparky

I recently went to an airfield lighting seminar and the system of the future for airfield lighting is going to be 5kv dc series loop carrying nominal amperage. way safer for the electrician no need for transformers inside every light to power the led's like current 5kv 6.6 amp ac series loop airfield circuits:thumbsup:


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## jmellc

Shockdoc said:


> Solar is a passing phase, give it ten years or so and it will wind down to a new invention.


I have long thought solar is best used for water heating, greenhouses & such. That is solar in its simplest form. I have seen old hippies set up a solar WH from an old propane tank & run hoses to a shower stall. Worked well, with one afternoon's work from people that were not particularly gifted in mechanical skills. Most anyone could set up something like this. I should have done it myself years ago, but haven't found the time.

If we could come up with tanks that don't rupture & leak, the attic would be a perfect place for solar WH's. Or a loft in the attic, closed with removable panels. Could produce hot water every day from about May to September where I live.


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## don_resqcapt19

airfieldsparky said:


> I recently went to an airfield lighting seminar and the system of the future for airfield lighting is going to be 5kv dc series loop carrying nominal amperage. way safer for the electrician no need for transformers inside every light to power the led's like current 5kv 6.6 amp ac series loop airfield circuits:thumbsup:


 Why would the 5kV DC series loop be "way safer" than the 5kV AC series loop?


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## jmellc

don_resqcapt19 said:


> Why would the 5kV DC series loop be "way safer" than the 5kV AC series loop?


And why put lights in series? 1 goes out, they all go out. Or dothey have some kind of shunting device?


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## airfieldsparky

jmellc said:


> And why put lights in series? 1 goes out, they all go out. Or dothey have some kind of shunting device?


Its not so much the fact that dc is safer its the fractional amperage that can be used in the dc airfield lighting system instead of the current 5 kv 6.6amp ac loop. When one light dies the whole loop doesn't die because each individual light has an isolation transformer which means there is no mechanical connection between the primary and secondary windings so if a light dies there is no effect on the rest of the system


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## ColoradoMaster3768

jmellc said:


> And why put lights in series? 1 goes out, they all go out. Or do they have some kind of shunting device?


 
Series street lighting used to be "the thing," especially several decades ago. Series lighting uses less wire—one conductor versus two for parallel lighting (multiple lighting) systems—and, no, they all do not go out when one goes out (that will be explained shortly; nevertheless, it is admitted that that phenomenon will occur with a cheap set of Christmas tree lights.) 


Series street lighting, as well as runway distance markers, taxiway lighting, and approach lighting for airfields, are usually supplied by a constant-current regulator (sometimes referred to as "floating-core transformers"). Constant-current regulators, usually designed for delivering 6.6-, 15-, or 20-Amps constant-current are rated in kW, not KVA as are other transformers. 


The primary service voltage for these regulators covers the field of voltage supplies across the country. I have worked with 7,200 volt primaries, as well as 208/360 volt primaries, and it is my understanding that 2,400/4,160 volt primaries were common too. Constant-current regulators usually have a fixed primary coil and a secondary coil that "floats" or travels on a set of rails. The weight of the secondary coil is offset, or "balanced," with a counterbalance system, much like that of a cable-driven elevator. 
The principle behind this system is based on magnetic repulsion. As the current field weakens, which weakens the magnetic field surrounding the coils, the coils move closer together, which increases the voltage. (There is a mechanical-stop to prevent the coils actually touching.) As the coils move closer together the voltage increases in order to overcome any resistance that may be impeding the current. 


As you can imagine, lowering the intensity of the magnetic field lowers the repulsion between the coils, which allows them to move closer together. This, in turn, increases the voltage. Hence, the counterbalance system is one way of regulating the output voltage of these units. Removing some of the counterbalance weight makes it easier for the secondary coil to move closer to the primary coil, thereby, increasing the voltage output; _i.e., __with less counterbalance weight, _more magnetic repulsion is required to keep the coils separated. Therefore more voltage is introduced into the secondary. A typical "open-circuit" voltage would be 2,000 volts. 


_Constant-current regulators are very dangerous to work with__._ Neither grounding nor short-circuiting the secondary windings will cause the constant-current regulator to fault, or shut down. Nevertheless, it is _these characteristics_ that make constant-current series-circuits invaluable for airfield lighting systems—because it is so difficult to shut them down. Imagine, if you would, what could happen if the runway lights, taxiway lights, or approach lights suddenly failed at night while an airplane was on approach, landing, or taxiing to the terminal—to say the least, the "pucker-factor" increases by a ten-fold magnitude (goodbye seat covers). Moreover, opening the secondary will only cause constant-current regulators to increase the secondary voltage output to its maximum—the open-circuit voltage. _Therefore, the ONLY SAFE way work with the secondary on these systems is to physically disconnect the conductors from the regulator to establish a visible Point of Clearance, and then properly lock, block, and tag them out in order to prevent reconnection while you are working on the system._ 


For incandescent, series street lighting circuits, the lamp, usually mogul-based, has its screw-shell connected to two tongs called film-disc terminals. These terminals are separated from one another by an insulated film-disc cutout. This mogul-based assembly, along with the film-disc terminals, clips into a set of closed, spring-tensioned terminals. This separates the spring-tensioned terminals, thereby configuring the circuit through the bulb's filament. Hence, the spring-tensioned terminals are now separated (opened) by the mogul-based assembly, which places the bulb in series with the circuit. 


The film-disc cutouts operate in this manner: When the incandescent light bulb burns out, the circuit becomes open. This causes the current to drop, which in turn lowers the magnetic repulsion between the primary and secondary coils in the regulator. The secondary coil then moves closer to the primary coil. This increases the voltage in the secondary coil which is designed to overcome nominal resistance—the open filament in the bulb in this example. As the voltage increases, the insulation threshold of the insulated film-disc cutout is breached, and the insulation surrounding the film-disc cutout fails, thereby allowing the current path to be re-established via the film-disc cutout to the rest of the circuit. 


For incandescent lamp fixtures used for runway distance markers, taxiway lighting, and approach lighting for airfields, each lamp fixture is supplied via an isolation transformer having a one-to-one ratio. In this case, the light bulb is connected in parallel to the series-connected isolation transformer. So when a light bulb burns out the affects are limited to only that fixture.


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## CheapCharlie

ColoradoMaster3768 said:


> Series street lighting used to be "the thing," especially several decades ago. Series lighting uses less wire—one conductor versus two for parallel lighting (multiple lighting) systems—and, no, they all do not go out when one goes out (that will be explained shortly; nevertheless, it is admitted that that phenomenon will occur with a cheap set of Christmas tree lights.)
> 
> 
> Series street lighting, as well as runway distance markers, taxiway lighting, and approach lighting for airfields, are usually supplied by a constant-current regulator (sometimes referred to as "floating-core transformers"). Constant-current regulators, usually designed for delivering 6.6-, 15-, or 20-Amps constant-current are rated in kW, not KVA as are other transformers.
> 
> 
> The primary service voltage for these regulators covers the field of voltage supplies across the country. I have worked with 7,200 volt primaries, as well as 208/360 volt primaries, and it is my understanding that 2,400/4,160 volt primaries were common too. Constant-current regulators usually have a fixed primary coil and a secondary coil that "floats" or travels on a set of rails. The weight of the secondary coil is offset, or "balanced," with a counterbalance system, much like that of a cable-driven elevator.
> The principle behind this system is based on magnetic repulsion. As the current field weakens, which weakens the magnetic field surrounding the coils, the coils move closer together, which increases the voltage. (There is a mechanical-stop to prevent the coils actually touching.) As the coils move closer together the voltage increases in order to overcome any resistance that may be impeding the current.
> 
> 
> As you can imagine, lowering the intensity of the magnetic field lowers the repulsion between the coils, which allows them to move closer together. This, in turn, increases the voltage. Hence, the counterbalance system is one way of regulating the output voltage of these units. Removing some of the counterbalance weight makes it easier for the secondary coil to move closer to the primary coil, thereby, increasing the voltage output; _i.e., __with less counterbalance weight, _more magnetic repulsion is required to keep the coils separated. Therefore more voltage is introduced into the secondary. A typical "open-circuit" voltage would be 2,000 volts.
> 
> 
> _Constant-current regulators are very dangerous to work with__._ Neither grounding nor short-circuiting the secondary windings will cause the constant-current regulator to fault, or shut down. Nevertheless, it is _these characteristics_ that make constant-current series-circuits invaluable for airfield lighting systems—because it is so difficult to shut them down. Imagine, if you would, what could happen if the runway lights, taxiway lights, or approach lights suddenly failed at night while an airplane was on approach, landing, or taxiing to the terminal—to say the least, the "pucker-factor" increases by a ten-fold magnitude (goodbye seat covers). Moreover, opening the secondary will only cause constant-current regulators to increase the secondary voltage output to its maximum—the open-circuit voltage. _Therefore, the ONLY SAFE way work with the secondary on these systems is to physically disconnect the conductors from the regulator to establish a visible Point of Clearance, and then properly lock, block, and tag them out in order to prevent reconnection while you are working on the system._
> 
> 
> For incandescent, series street lighting circuits, the lamp, usually mogul-based, has its screw-shell connected to two tongs called film-disc terminals. These terminals are separated from one another by an insulated film-disc cutout. This mogul-based assembly, along with the film-disc terminals, clips into a set of closed, spring-tensioned terminals. This separates the spring-tensioned terminals, thereby configuring the circuit through the bulb's filament. Hence, the spring-tensioned terminals are now separated (opened) by the mogul-based assembly, which places the bulb in series with the circuit.
> 
> 
> The film-disc cutouts operate in this manner: When the incandescent light bulb burns out, the circuit becomes open. This causes the current to drop, which in turn lowers the magnetic repulsion between the primary and secondary coils in the regulator. The secondary coil then moves closer to the primary coil. This increases the voltage in the secondary coil which is designed to overcome nominal resistance—the open filament in the bulb in this example. As the voltage increases, the insulation threshold of the insulated film-disc cutout is breached, and the insulation surrounding the film-disc cutout fails, thereby allowing the current path to be re-established via the film-disc cutout to the rest of the circuit.
> 
> 
> For incandescent lamp fixtures used for runway distance markers, taxiway lighting, and approach lighting for airfields, each lamp fixture is supplied via an isolation transformer having a one-to-one ratio. In this case, the light bulb is connected in parallel to the series-connected isolation transformer. So when a light bulb burns out the affects are limited to only that fixture.


Isn't google a wonderful thing....I love it. lol


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## ColoradoMaster3768

CheapCharlie said:


> Isn't google a wonderful thing....I love it. lol


 
What does Google have to do with my post?


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## kaboler

Remind me not to work on this kind of lighting. What the....


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## airfieldsparky

CheapCharlie said:


> Isn't google a wonderful thing....I love it. lol


Great post! I only do new installations and renovations on airfields no service work and I wondered how the film disc cut out system worked. It is used only on certain lighting systems that can not afford to have even one light in the string out. Not sure exactly how to explain it but on threshold lighting, and overt covert landing systems, inside each light is 2 bulbs only one is on, when the first bulb dies the film disc shorts together creating a connection to the backup bulb


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## jmellc

londer said:


> Wireless distribution?


I saw a partial video somewhere of someone working on a Tesla coil. Supposedly, Tesla thought wireless power was possible & practical, but never got far along with it. Someone has had some success powering light bulbs several yards away from the coil.


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## joethemechanic

I wonder what the I^2R losses are for wireless transmission?


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