120/220, i am still confused

[yamaha_1fan]

maybe my Brother in Law confused me or is just wrong but i am still perplexed about 220 lowering amperage. I think I am overthinking this but really need to confirm this

I understand voltage is potential betwen 2 points? so 220 is twice as much potential as 120?

And Watts=VoltsxAmp or Amp=Watts/Volt

What i was told is when you run 120, one wire goes to the breaker/hot, one goes to common and one is ground. when doing 220, you have 2 hots but on different breakers and your ground. Thats why all your 220 appliances have breakers that are tied to each other.

AM i still on the right path here?

What i am trying to wrap my head around is if you have a 100 amp panel you can run 12,000 watts right? 100x120 = 12000. Now if you take that same same 100 amp panel and connect everything 220, can you now run 22,000 watts through it?

I also believe theres 2 sides to the panel and you can only put half the total load one one side?

If 220 breakers are bigger and take 2 slots, does that mean you need a physically bigger panel if running everything in 220?


Shit, i dont even smoke and my brain is fried after typing that.

 

[MTF-Sandman]

Your main feed is 240v, so 100a/240v will run up to 16k (~5a per 1k @ 240v) of lights...but that doesn't take into account any other devices in the house that may be running.

Having 100a/240v means that you have 2 100a/120v feeds...each one can safely be used at 80% of the breaker's rated capacity.

240v breakers are sometimes available in slim profile models as well...

Do you have any specific questions that you don't understand?

BTW, it sounds like your BIL is giving good advice...it's just a little foreign to you at the moment.

 

[Guest]

240v is like the buddy system.
instead of 1 guy (120v) doing all the work,
you have 2 guys (240v) evenly splitting the work.

in laman terms.

 

[MaxYield]

I understand voltage is potential betwen 2 points? so 220 is twice as much potential as 120?

Well on home wire, the 120V and 220V are RMS(root mean square) value of a alternative (sinusoidal) signal. In fact, a 120V signal goes from -170V to +170V.

220V is made from using 2 phases of 120V each. When they are combined they create a signal of 220V RMS, why not 240?

Because they are out of phase by 120degree, so when one phase hit its max (170V peak) the other phase haven't it it's minimum, so it -140V (instead of -170) creating a potential difference of 310V Peak, not 340V, so when you calculate the RMS value you get 220V.

So no 220 is not twice as much potential as 120.

BTW, for sinusoidal signal the RMS value is Vrms = Vpeak/1.41421

And Watts=VoltsxAmp or Amp=Watts/Volt

Yup, haven't changed since the invention of electricity .

What i was told is when you run 120, one wire goes to the breaker/hot, one goes to common and one is ground. when doing 220, you have 2 hots but on different breakers and your ground. Thats why all your 220 appliances have breakers that are tied to each other.

Well you have common and hot wire just for installation and maintenance, because in reality it doesn't bother to inverse those 2 wires as they see alternative current so their potential change all the time, going from (-) to (+).

What you refer as ground is the case ground, which mean that all object that has a metal casing have a connection between the case and the earth ground. It's done to prevent damage that has occurred to people using product that were not isolated this way and got electrocuted by touching the metal casing.

What i am trying to wrap my head around is if you have a 100 amp panel you can run 12,000 watts right? 100x120 = 12000. Now if you take that same same 100 amp panel and connect everything 220, can you now run 22,000 watts through it?

No, normally those panel have a power rating too, which mean that they can't exceed those power limitation. Sometime it's just a marketing thing, so you need to check it. Since those are breaker panel, so barely just wires, I would think that it should be limited by the power, not current, and the information of 100A given by the manufacturer is rated at 120V and for a 220V you'll need to step down the current. But I'm not definitive on that...

For the rest I can't really help you as I haven't really installed those panels, but I know my basics

 

[Guest]

i think you might have confused him even more maxyield

 

[yamaha_1fan]

i think you might have confused him even more maxyield

actually the whole RMS thing made perfect sense. Basically the voltage is alternating around 60 times per second hence 60hz. So 120/220 is basically the average you get with all those highs and lows?

my understanding is on a 120 line, one wire is doing all the work (alternating) so all the amperage is being carried on that one wire for example 10 amps. But if running 220 there are now two hots running 110/120 each. so each of those wires runs 2.5 amps for a total draw of 5 amps?

Please tell me that is right.

I guess I want to know exactly how this all relates back to installing breakers and designing my panel which i will be doing soon

 

[Guest]

10a @ 120v
5a @ 240v
same power draw, just cutting the work load in half.

 

[MaxYield]

"So 120/220 is basically the average you get with all those highs and lows?"
yup!

"my understanding is on a 120 line, one wire is doing all the work (alternating) so all the amperage is being carried on that one wire for example 10 amps. But if running 220 there are now two hots running 110/120 each. so each of those wires runs 2.5 amps for a total draw of 5 amps?"
nop! Don't forget that a circuit can only work when you can have a closed loop of current. So what you have on 1 wire you have the equivalent on the other one, but in reverse.

signal:
#1 is the 120V phase you are using and is the reference
#2 is the 2nd 120V which is 120 degree in advance from the #1 signal
#3 is the signal if you do like you said, 2x120V sine (not real)
#4 is the actual 220V you are getting when you put those 2 lines together, and is the difference between #1 and #2 at any given time.

You can see why you're not getting 240V, at any given time, the amplitude that a 2-phases signal have is the difference between #1 and #2, you can clearly see that you never see the peak(negative or positive) of #1 and #2 at the same time.

 

[LED_experiments]

hey, are you all americans and have 120? 220 also has one line and one neutral - not two lines (as somebody mentioned). the sinus amplitude is about 2 times greater than at 120V. there also is a frequency difference - you americans have 60Hz, europeans have 50Hz. the main difference is as you found out - the current is app. 2×higher at the same power consumption (that is why you need thicker wires, more Cu, more amp. fuses and therefore more money for the wiring). there also is a difference in efficiency. the looses at the transport are calculated by the formula R×I×I. if you want to get lower resistance, you have to use thicker wires (more money), but if the resistance is the same if using 'european' wiring, then you have 4 times more looses because your current is two times higher than european.

 

[MaxYield]

Here we have 120V (Canada).

220 also has one line and one neutral - not two lines (as somebody mentioned).

Well you're right and wrong. It depends on where you're living. As I found while I searched, because your statement gave me some questions about power transportation.

In the USA, you're right, they receive 220V from the distributor, but here, we receive 120V, so when we want 220V we have to put 2 phases together so you no longer have a neutral but have to use 2 lines.

Sorry, I was basing my explanation on the condition we have here.

You forget that the electricity transport is relatively high, in the kV range, the lower voltage is only divided at the transfo on your street, so the real difference is from the transfo to our houses.

Another thing, we have longer distance to transport the electricity than Europe, so their again, we have more wire which mean more resistance so more looses.

I agree with you, we should get higher voltage product so we can use the electricity more efficiently, but higher voltage product mean higher cost of production and I think that the choice as been made toward $$ saving not efficiency, which I think is pityfull.

 

[LED_experiments]

i understand that. i also know that there are kV lines used for the transportation (to get minimal losts - the current should be minimalised, so therefore the high voltage is used). there are transformers (also different types, different voltage) and at the end you get 220 (or 120). i live in europe, so here we have 220, 50Hz (or they say 220-240). but i wanted to say that our houses are more efficient than american. you have to use thicker wires (more money), the fire risk is higer, looses are a bit higher,...
i think american goverment is using that voltage because they claim that 220 can be very dangerous if touched. i touched it several times and i'm still alive.

so if i got you right, you have to connect 2 lines to power your lamp? seems similar to our wiring for high wattaged electromotors - 3 phases, 120° difference between them, but there also are some different ways. you can still have neutral (4 contacts) or you wire without neutral.

 

[MaxYield]

no, generally our products work on 120V, so 1 line, in fact I think that only the dryer uses 220 in my house. But this is for Quebec, I don't know about the rest of Canada nor USA. But the good thing is that here we have Hydro electricity and wind powered no nuclear nor carbonate, also the electricity is the provincial government property, so the cost of each kWh is really low (like 6.9cents cnd/kWh) and never fluctuate.

for 220, we don't have a neutral only ground for the chassis.

On 120, the return line(your neutral or common) and ground are connected together, on 220 we use the return line to make a connection between the 2 phases, so we lose the neutral, but we still have the ground for chassis.

As you said, 220 is not more dangerous than 120, the problem comes when you have Joe Knowitall playing with electricity when they know nothing about it.

 

[Guest]

voltage is not what kills you , its the amperage on the line that does you in.
straight 3 phase does not require a neutral.
120v = 1 hot wire 1 neutral
220v= 2 hot wires
220/120v= 2 hot wires 1 neutral

 

[Guest]

Then theres 277/480V 3 phase,that shit hurts amperage being the culprit or not lol!277V 1 hot 1 neutral,single phase 480V two hots,three phase 480 three hots.Getting in between the three hots on a 480V circuit will make you holler like a schoolgirl,if you're lucky

 

[MaxYield]

voltage is not what kills you , its the amperage on the line that does you in.

And certainly depends on where the current passes through. If it goes to the hearth, a few mA is enough to kill someone, and with much higher current you can get hole in your body which leads to internal bleeding and death.

 

[Guest]

Yup if you make contact with your thumb and your index finger is grounded,no amount of voltage/current will kill you.You could lose your hand.If the contact point is your hand and the nearest ground is your foot,a small amount of amps can kill you.

 

[LED_experiments]

if you want to kill yourself, it is better to grab each wire with each hand - line into one hand, ground into other and the current goes through your chest (heart). that is why we were told to put your not-working-hand into your pocket when handling powered circuit.

 

[Guest]

Someone frickin told you to work a hot circuit with one hand lol?You are fuckin kidding right?If someone actually told you this he needs to be reported to his superiors immediately.Thats not stupid,its criminally idiotic.What happens when you have to splice on to a hot wire?Thats what working a hot circuit is basically you gonna do that playing pocketpool lol?If you're serious bro that guy needs a checkup from the neckup.NEVER go near a hot wire unless you are mentally and physically capable.Having one hand stuffed into a pocket puts a slight crimp on your physical capabilities lol.O god I cant believe we're having this conversation.

 

[Guest]

well soilman, i have to side w/LED here.
i was also taught to leave one hand in my back pocket if not needed for the job.
i still teach the new guys this same trhing.
in the beginning of first working w/ live shit, working w/ one hand will teach you to be even more careful.
obviously if you need the 2nd hand to get the job done, pull it out of your back pocket.

 

[Guest]

Man I was union trained local #26 Wash DC and I've never ever heard of such a thing.I wouldnt put a hand in my pocket on any construction job period,you may have to move quick!Maybe its a new thing,but I worked up until 6 years ago and never heard one thing about that.Personally I wouldnt train anyone that way,mental preparation is everything when working hot circuits.If you must have a pocketed hand you're not very mentally prepared IMO lol.Forgive my earlier incredulation on the subject,I sure didnt expect to hear that from Thorodee.Must be common nowadays