Any electrical engineers here?


#1

Wondering if anyone new what system you have in Taiwan, TN-C, TN-S, TN-C-S or TT?

In particular I would like to know what ‘signal’ do the wires from the power company carry in case of a 220V supply.


#2

Earthing … ? Cables with 3 wires?

Is that a pig that just flew past my window?


#3

Taiwan only uses 110V… but what can be done is to phase shift the electricity so what you are getting is -110V and +110V, meaning you get 220V

As regrds grounding why put in a wire… when a human body can be the equivalent… 110V shoudln’t kill you unless you have a pacemaker and remember its not the voltage that kills you anyway… its the current

there are no standards enforced in Taiwan… if a person wires an apartment its not like he can get his license revoked and be held responsbile if the place burns down with everyone inside it so why would he worry if he botches it up… he can easily burn down another aprtment with his next job… and if people won’t hire him anymore he can always go back working at the binglong store again

Power companies in general don’t send 110V from the power station… there is too much loss on transmission… if you go outside your apartment and hear a buzzing sound that is probabily the dodgy step down transformer dropping it down to 110… Luckily transformers are electrically isolated so if they do botch up the supply somewhere and sent a million volts dwon the line… the transformer will explode first… before it gets to your rice cooker…

One thing i can’t figure out here … is how come they put plug outlets in the bathrooms… this is totally against building regualtions in Europe…infact you can’t have a light switch or plug outlet anywhere where you can reach a tap or water outlet thingy


#4

The US allows outlets in bathrooms, but new regulations enforce the special outlets with indiviual circuit breakers.

Outlets in bathrooms are handy for rechargeable shavers, curling irons, night lights, etc.


#5

Thanks for the input but what’s coming out from the transformer then?
Three wires carrying 110V+, 110V- and Neutral or … ?


#6

Going into your apartment via the circuit breakers is 110V AC. There is a thing mounted inside the circuit breaker box that can phase shift the 110V so what you are getting is like a 110V Sine wave and another 110V Sine Wave out of phase.
AC means its alternating current. Alternating also means that over a time (the frequency) the voltage goes between +110V and -110V. The number of times it does this per sec is measured in Hertz… say usually 50-60 Hertz.
Therefore for an instant relative to the other, one is +110V and the other is -110V meaning +220V AC

+110V and - 110V along the same wire means 220V with the other wire being the return. Both wires act in the same way as you have + and - in a battery… the third wire is the Ground so if there is a short circuit in your Air Conditioner the A/C will be grounded through the wire and not through you as people are bad resistors and the muscles in our body that react to electrical impulses from our body react quite badly to electricity…

The reason that Alternating Current is used in homes etc is because for an instant the voltage is zero… if direct current was used and you grabbed something that had electricity running through… the immediate reaction of your hand would be to clasp…since the electricity would make the muscles in you hard and arm contract … Then as the voltage does not go to zero…you couldn’t open and release your grip… and you would be stuck there


#7

The air con runs off a different voltage, yes? And three-pronged plug, yes?


#8
quote:
Originally posted by zhukov: Taiwan only uses 110V.. but what can be done is to phase shift the electricity so what you are getting is -110V and +110V, meaning you get 220V

I don’t think I’ve read quite such a load of old bollocks since I started frequenting this site.


#9

I’m gobsmacked that someone without even the most fundamental grasp of AC theory could sit there hammering at his keyboard giving “expert” advice when its painfully obvious that he hasn’t got a CLUE what he’s talking about.
Priceless …
I especially like the explanation about why power is delivered as alternating current and not direct current. What a gem, and how embarrasing!
Transformers don’t work with direct current dude!


#10

Didn’t actually write this one, so am deleting it. Have to remember to log out in future…some bad people about!


#11

There’s a box on the wall just inside the door of my house that’s where the electricty comes from. If you sneak downstairs at night and open the door of the box real quick, you can sometimes catch a glimpse of the little hamster-type things that live in there.

You have to do it at night, because that’s when the lights are off, so they’re usually resting. When they’re working on the little treadmills, they’re too alert and will run and hide inside the walls when they hear you coming.

I thought everyone knew where electricity comes from.

All this nonsense about currents! Like it was some kind of river or something! Sheesh!

Where WERE you guys during physics class?


#12

Bloody hell Sandman, at leaat your hamster theory stays within the realms of physics. If hamsters were powerful and reliable enough, we could put them on treadmills and generate AC (that’s what generators produce by the way Zhukov) current.
On the other hand, putting Zhukovs on treadmills would just generate a lot of gas. I suppose the gas could be burned and turned into useful energy, but I doubt it somehow…


#13

Monkey

Grab hold of 110 DC and see how long it takes you to get away… then you will undertsand why AC is used

BTW Monkey if you use and Inverter it will invert the 110AC

Monkey can you please point out where I said that transformers work with DC. What I said was the reason that AC is used is because it is safer

“The reason that Alternating Current is used in homes etc is because for an instant the voltage is zero… if direct current was used and you grabbed something that had electricity running through… the immediate reaction of your hand would be to clasp…since the electricity would make the muscles in you hard and arm contract … Then as the voltage does not go to zero…you couldn’t open and release your grip… and you would be stuck there”

Where did I mention tranformers ?

Funny here in these topics… if someone tries to give an exaplaination for anything…everybody seems to be on the band wagon to dismiss it eventhough they don’t seem to have a clue about it


#14

Oh and Monkey Boy

Since according to you I don’t know… could you please define the follwing Voltage, Resistance, and Current…

Also how could a 220V A/C work when 110V is the voltage used in Taiwan? I have to hear yet how the hamster can make up the additional 110V


#15

Zhukov, what are you trying to say? That alternating current is somehow inherently more safe for humans than direct current?

Some background on the early days of power generation

Here’s an excerpt …

[b]"The Westinghouse ac system began to get most of the orders rather than Edison’s more expensive, higher-maintenance, and less efficient dc system. Edison’s best remaining argument was that the high voltages that made the ac systems more efficient also made them too dangerous.

The New York State Legislature inadvertently gave Edison one last opportunity for negative advertising by seeking a more humane method to execute criminals than by hanging. Death by electricity was suggested. Edison had previously expressed his disapproval of capital punishment, but he was now desperate to discredit the competition. Thus, he was receptive when an engineer named Harold Brown offered his services to demonstrate the dangers of ac by using it for execution.

Edison made his lab available. Brown, after electrocuting a variety of animals, pronounced ac electricity a perfect medium for execution. Brown acquired three Westinghouse generators and designed the first electric chair, which he sold to the state for $8,000."
[/b]


#16

Come on Zhukov, we all learned the relationship between voltage, resistance, and current in high school. Surely there no need to relearn Ohm’s Law (V=IR) here.


#17

Monkey

What I am saying is that if you are being electrocuted by AC… there is a better chance you can break free…and yes it is more effiecnt than having to keep a constant DC load on the lines

When calculating things for AC it becomes a little more complicated than using Ohm’s Law as Voltage is not constant with time and you have to take things into account such as the frequency and measurements such as reactance and inductance. Also you have Voltage Peak to Peak and RMS voltage. However I am not going to get into this as this is an RF Engineer’s area

And yes 220V (peak to peak) is achcieved by inverting the Sine wave so you have the top of one Sine Wave at +110 and the the bottom at -110, so its like having two sine waves out of phase superimposed on eachother…
The most important thing here is the Difference at fixed time intervals… so it is +110 - (-110) = 220 V AC… it you progress for another instant both voltages will tend to zero and then the voltage that was + will become - and vice versa

Regarding Super Steves’s commments… which motorbike comment was incorrect by me…

Was it when I was describing how 4 stroke engines or 2 stroke work… or was it when I was arguing that disc brakes work better than hub brakes

Maybe I was not such an expert on aerodymanics terminology but judging by what a lot of people argued in the topics they just seemed to be pointing to links and web pages without little understanding of what was being said

Ok which commment was it that was incorrect

  1. Engines run at over 100% on take off
  2. The fuel in the wings helps maintain the center of gravity and dampens the virbrations of the engines…not designed to do this… but a benefit
  3. The most likely time for a crash is on take off and landing… once they are up they tend to stay there
  4. There is a potential flaw in the Airbus design - I am not saying that every plane will crash but…
  5. Doors cannot be opened when flying as they have to be opened in and then out and the pressure stops this…also it is useful if the locking mechanism failed in teh doors
  6. The underbelly of the ariplane does give it additional lift on take off

#18

My bedroom A/C is a 220V unit. Next to it is a 3-pin 220V socket. The unit is not earthed through that socket (because the power cable has only 2 conductors.) How could this arrangement work using your theory Zhukov?


#19

Monkey that is potentially very dangerous… if the Air conditioner shorts and if the chassis is metal and you touch it you will be electrocuted… if it is a plastic chassis… you shouldn’t be electrocuted as plastic acts like an insulator… if the chassis is metal you are a conductor (not a very good one) so current will be drawn through you to GND

The three wires on the plug

Wire No 1 is the live wire coming from the Circuit Breaker (+)
Wire No 2 is the return to the Circuit Breaker (-)

You need to a complete a circuit as such or else it won’t work… this is like the + and - on batteries

I think there is a misunderstanding here… when you invert the AC to get -110 and +110 = 220V, these two 110Vs are not carried on different conductors, they are carried on the same. Electricity is not a physical thing so you don’t have to consider things like space on the conductor to fit another 110 AC. What is important here is the potential difference between the two = 220V AC. Since these two 110V AC are alternating, the result is that the 220V AC is also alternating.

Wire No 3 is the ground wire( it is not necessary to make your A/C work but is there for safety). In a modern apartment( if there are electrical codes used) the apartment is wired so the GND wire is attached to every power outlet. This GND wire then is attached to a bar that is either buried in the basement or outside. Since people are bad conductors and electricity takes the path of least resistance to ground… if you have your appliance grounded and there is a short circuit… the electricity will go to ground via the GND wire and not you.


#20

I’m still looking for a 110V dc source to try an electrocute myself … great leader Zhukov, please tell me where you can find one!