capacitors?

[CenterPointEX]

.......Here in Houston they have oil switches and chicken switches to operate the oil switches. A chicken switch is a toggle switch mounted in a meter base at the bottem of the pole. We attache a twenty five foot piece of string to the toggle and operate it from that far away. Down here in high humidity conditions the conductivity of the air plays a part in the violence of arc explosions.

.... That being said here is my linemanease on the functioning of a Capacitor. The problem Caps try to correct mainly is pressure. The further you get away from the source and the greater the resistance, the lower the voltage and higher the amperage gets. Same as if you were at the far end of water line. The further away, the lower the water pressure. So the Cap bank functions not unlike a water tower. The water is pumped up to the top and the weight of the water prouduces a great pressure. Electrons flowing down the wire then run into the Cap where they spread out on big thin cookie sheets of copper stacked up and seperated by semi conductor.
So electrons are stored on these cookie sheets like water in the tower. If you ground the load side of Cap bank you get a massive expunge of electrons to ground. Same as if you punched a hole in the bottem of the water tower. If a water tower fails the result is catastrophic.

That reminds me of a story... Once several trucks were summoned to a location that fed a huge heavily loaded industerial complex where they were complaining of flucuating voltage... We were out there with four of thier engineers. When I pulled the chicken switch to put the bank online the oil switches started opening and closing rapidly. All the Lineman headed for the hills like a flash of lightning. When I looked over my shoulder I saw one of the engineers with a blank look on his face watching me run. The other three were looking up mesmorized by the noise the bank was making. When they realized their prediciment they all bolted at the same time into each other and fell in a pile... they got up and started to run again when all hell broke loose... again they all lay in a pile... The circuit locked out and no one was hurt... It was mean, but I could not contain myself laughing at the pile of engineers laying on the ground clawing for air and trying to figure out which way was up... the look on thier face at zero hour was priceless...

[dbrown20]

The newer ones here also have the "chicken switches". They have a time delay however that gives you about 30 seconds to move away after you activate the switch. dbrown20

[BigClive]

.... That being said here is my linemanease on the functioning of a Capacitor. The problem Caps try to correct mainly is pressure. The further you get away from the source and the greater the resistance, the lower the voltage and higher the amperage gets. Same as if you were at the far end of water line. The further away, the lower the water pressure. So the Cap bank functions not unlike a water tower. The water is pumped up to the top and the weight of the water prouduces a great pressure. Electrons flowing down the wire then run into the Cap where they spread out on big thin cookie sheets of copper stacked up and seperated by semi conductor.
So electrons are stored on these cookie sheets like water in the tower. If you ground the load side of Cap bank you get a massive expunge of electrons to ground. Same as if you punched a hole in the bottem of the water tower. If a water tower fails the result is catastrophic.

That's more like a description of a reservoir capacitor in a DC system. It doesn't work for an AC system since the cap is alternately charging and discharging as the polarity of the supply changes at 50/60Hz.

I think the primary function of capacitor banks is power factor correction for large transformer arrays where the inductive lag between voltage and current is compensated for by the capacitors leading power factor. This saves on wire and transformer size from the source.

[CenterPointEX]

Yes the purpose of a Cap is to correct the power factor, but who knows what the hell that means? Yes polarity flops... Yes the electrons spread out on the copper sheets in the Cap... Yes when you raise the voltage you lower the amperage which is heat, because there is less heat you can use smaller wire and xfmr. The water tower analogy is just a method to put a mental handle on the magic that is electricity. I mean who the "F" can see an electron. We can see the effect of it the Shat , but they is invisible... Freakin Magic if you will. Tomorrow I will attempt Linemanease definition of Power Factor, Inductive and Capacitive loads. I would be interested in your non-Tech description of Power Factor and or Capacitors B.C.

[BigClive]

Easiest description of power factor is to explain that when driving an inductive load like a trasnsformer the voltage and current go out of phase with each other like two sinewaves side by side. In a transformer this is caused by the back EMF from inducing a magnetic field in the large core and then it's collapse as the sinewave goes down again and the polarity changes. Because capacitors have the opposite effect this cancels out the lag and brings the voltage and current into sync again. The difference between the voltage and current waveforms increases the perceived load and poses a burden on the supply system. This is why large buildings are sometimes monitored for bad power factor and charged accordingly to encourage them to apply local correction.

On appliances and equipment you'll see power factor described as a cos phi value where phi is like an "O" with a slash through it. Perfect power factor is one worst power factor is theoretically zero. Typical values for a tranformer might be about 0.6.

To be honest, your average Joe lineman doesn't really need to know any of this. All they need to know is basic electrics, nuts, bolts and wires. It's the engineers job to monitor power factor and apply protection if required. I'm what you might call an old-school spark who did my apprenticeship at a time when you got taught EVERYTHING! Generation, transmission, distribution, sub distribution, building wiring, control wiring, electronics, older technology, motor control.... The works. It comes in useful from time to time.

[CenterPointEX]

They also taught us electrical theory. You said a mouthful there... and I understand what you said. Now break it down into english... Explain all that in laymens terms that an eighth grader could understand.

You, I , L.A., and Hemmingray are some sick puppies all of us here this time of day...

[Hemingray Insulators]

well i'm here cuz church don't start till 11 CP.

[Hemingray Insulators]

they do have a bible study b4 church, but most of the youth group is gone on winter retreat, so theres no bible study b4 church today for the teens. well, i'm off to church now.

[BigClive]

To be honest, it's hard to break power factor down into simple language. to understand it completely you need to know the electrical characteristics of inductors and capacitors in an AC application.

It;s easiest to say that if you removed the parallel power factor correction capacitor from the traditional fluorescent light fitting in your kitchen it would make the meter turn faster.

Of course, maybe I'm just too much of a tech head. Your turn to make power factor easy CP.

[CenterPointEX]

To be honest, it's hard to break power factor down into simple language.

Si, Whey... Es Que lo dice antes... That being said... Power factor... matching the truck with the load. Volts times amps equals watts.
Volts times amps equals watts. Watts are a measure of energy or power.

In plumbing terms, the volume of water times the pressure it is under will determine its power. The higher the pressure the lower the volume of water or smaller size water pipe you need to do the work... for instance...

...Lets say you had a pressurized water pipe shooting water at a water wheel turning a motor. If the pressure is low the water dropping on the wheel woul turn it but not at its designed speed. If the pressure was too high it would damage the water wheel. When some one flushes a toilet, the pressure at your shower head drops for a second. If you had a large holding tank inline before the shower head the flushed toilet would not affect the pressure at the shower head. In the same way when a heavy load is suddenly put on a power line the voltage/pressure drops. A Cap bank inline near that load would reduce the pressure drop in the same way the holding tank affects the drop at the shower head. Thats why they put capacitors in AC units... for start up purposes. Ever notice how sometimes when your AC kicks the lights dim for a flash then come back up.



..... If you take a truck and load it half full and send it from point A to point B, you have not maxamized the potential of that truck. Conversley if you over load the truck, the truck is stressed, overheats and generally it's bad for the truck. When the power factor is correct the truck is loaded to its designed capacity the benifit is maximized. If a factory is paying for fuel by the truck load and they are only getting half a load they are getting screwed. If you overload the truck the trucking company is getting screwed.

An amp meter measures the flow of electrons. A high volume of flow against resistance creates heat.


If you raise the voltage/electrical pressure you lower the amperage/volume of electrons. Conversely when you raise the amperage the voltage/pressure goes down. A heavy load slows the truck down. Raises the amperage lowering the voltage.

If you lower the voltage and the amps go up, to many amps will flow thru your light bulb, it will overheat and burn up the fillament. Conversley if the voltage/electrical pressure is too high, the force of the pressure will blow the fillament apart. The electrical pressure/voltage is somewhat akin to water pressure.

In the case of a light bulb electrons flow from the source thru the fillament to ground.

In the case of an electric motor, the energy is used to create an electrical magnet and it does not flow to ground. It takes a lot of magnetic force or load to get a motor spinning, once it is spinning it does not take as much to keep it spinning. This is called an inductive load because unlike the light bulb it does not take electrons to ground but rather uses them to create an induced or magnetic force. Much like when you try to put opposite poles of a magnet togather there is a force between them pushing them apart and conversely the opposite. Industrial motors are three phase meaning they have three electrical lines going to them creating three magnets. these magnets are place around a rotor or metal bar attached to a shaft. It works like the push and pull of magnets. One magnet pulls until the bar gets to it, at that point the polarity on the magnet changes from negative to posative. During that transition at some point it is at zero polarity. When it is at zero, the next magnet in line goes negative and pulls the bar towards it, the magnet it just came from is going posative at that point and pushing the bar away as opposite polls on a magnet do when you try to put them togather. So the bar attached to the shaft keeps turning being alternatively pushed and pulled by the magnets. The phases or lines go from negative to posative sixty times per second here in the united states. The three phases or lines do this ninty degrees apart. When they are in phase the magnets go from negative to posative at just the right time to keep the motor turning. If two of the phases were at the same polarity at the same time the bar would just get stuck between them and not spin. If one of the phases has a lot of light bulbs on it the amount of electrons available to exert the magnetic force would not be the same as the other two unloaded phases. Thus the need for for a water tower/capictor close by to hold a large quanity of electrons to be dumped when the magnet calls for them. The capicitors store pressure if you will so the the pressure is the same on all three phases.

Now it is not all quite as simple as or exactly as I explained it, but these concepts and analogys sort of help wrap the mind around an abstract concept.