Working on 220

You are the one who does not know enough . You only have to touch ONE live wire and be standing on damp floor to get a fatal shock. I do not want to start a flame war about "If This" or If that" Suffice to say any live wire, 220 volts or 110 volts, should be considered dangerous every time, because one day you will meet the conditions and be on the way to meeting your Maker.

Don't ever come to Europe with that notion - you'll go home in a pine overcoat. In fact you're dangerously wrong Stateside. The only turkey that'll get cooked in that oven will be you.

Depends upon what "goes wrong" and how many stupid mistakes you make. If you get any kind of shock you likely screwed something up.

The worse case with 240 would be the loss of the protective ground on a metal appliance. You would have no notice of a cross between one of the HOTs and the frame. (The same thing could happen in a J-box.)

In the above, if your feet are dry you just would not know that the frame is HOT. Then, if you make one lapse and touch the other HOT you have 240 going in one hand and coming out the other.

The US style 120/240 is always at least as dangerous as 120 but it can sometimes be many times as dangerous.

That old "neon" tester (sometimes built into screwdrivers) can quickly let you "look before you leap."

| You are the one who does not know enough . | You only have to touch ONE live wire and be standing on damp floor to | get a fatal shock.

If the OP is in North America, that would be only 120 volts instead of

240 volts. Still potentially fatal, but less so than a full 240 volt shock. Down under, you have to worry about a 415 volt shock if you are running on three phase ... line to line as the OP mentioned.

| I do not want to start a flame war about "If This" or If that" | Suffice to say any live wire, 220 volts or 110 volts, should be | considered dangerous every time, because one day you will meet the | conditions and be on the way to meeting your Maker.

And as one ages, and various body parts are operating in a smaller performance tolerance range, even a small shock can easily be fatal. Even 55 volts or less.

I've had the "pleasure" of a 277 volt shock once. Fortunately it was not across the body. It was finger to hand. But I could tell based on that it is not something one ever wants to repeat anywhere.

On Mon, 04 Dec 2006 22:30:25 -0500 Terry wrote: | I was trying to search and find out if ovens have some internal fuse | and came across this web site | |

| | The page warns that you are working on 220 to be careful. | | I know that an oven is 220V but you would have to be almost retarded | to get a 220V shock.

There is also more arc fault hazard with this connection in part due to the higher voltage drawing a longer arc, and the larger conductors not limiting the current as much. The breakers/fuses may also take longer to clear a fault. Even if you don't get burned, eyes on the arc can cause retina damage.

Bullshit. You have ~110 to ground from either leg. You think a ~110 shock is safe? You don't have to be retarded - just careless or uninformed.

Maybe we should just encourage him, and hope that the Darwin Effect will improve the gene pool.

| Maybe we should just encourage him, and hope that the Darwin Effect | will improve the gene pool.

Is that like clearing a DNA fault?

Just so.

I see he didn't like the answers he got on this thread, so he's started another. Subject line "oven fuse". Maybe we should make sure he really understands how dangerous 220v can be...

Compared to 240? It's relatively "safe!"

Higher fault current normally results in faster clearing of faults. Many aspects of the UK wiring regs are geared towards ensuring any fault currents are high enough to clear faults quickly.

I would say that you don't even need to be standing on a floow which was particularly DAMP to get a potentially fatal shock.

His logic was bullshit. So is yours: Your "relatively safe" could be fatal, and the sensible approach is to treat it as such. The cavalier disregard for the shock hazard from 110 volts by calling it relatively safe has no place in this discussion. You should know better, and I think you do.

Ed

Seems this issue keeps coming up.

Someone always brings up the point that, of course, the RDC will break the 240V circuit, so it must be "safer". I have trouble following this logic.

Bottom line, just looking at the AC voltages (and ignoring the difference between 50 and 60 Hz) 120 volts IS, in fact safer than

220.

1. A 240V short may produce an arc that is hotter, nastier, and potentially more destructive than a 120V short.

2. While shocks from 120V can kill or injure, doubling the voltage is certain to increase the intensity of the shock, make it harder to let go, and probably hurt a whole lot more.

1. In the North American System, at least, 120V is safe enough to use in a bathroom outlet (with a GFCI) for a hair dryer or electric shaver, for example. No isolation transformer is required. Also, the bathroom light may be controlled by a switch INSIDE the bathroom. The old pull chain, archaic and potentially dangerous, is seldom used. I understand that this is not the case in some Euro countries.

2. Electricians in the USA, as a general rule, will usually use more caution when poking around 240V circuits, vs. 120 V. circuits, for all of these reasons.

Beachcomber

Voltage is higher, but so is system impedance. Is there a difference in protective device trip time? Do you have the results of an arc fault calculation to substantiate this?

I agree.

Why do you think that we use GFCI's on so many circuits now?

Which proves what? Do you have any statistics to substantiate the claim that

120 volts is "safer"?

One Niosh report ("Worker Deaths by Electrocution", May 1998) showed that

33% of low voltage (

Bullshit. We are talking about contacting a bare, live, 120 v conductor with a path through you to ground. That is *UNSAFE*. No comparison to any other voltage makes the situation safer.

It is bizarre to see people call an extremely hazardous and possibly fatal situation "safer" than something else. It is a meaningless comparison, and worse, tends to minimize the danger in the minds of some.

You should NOT treat 120 v wiring with any less respect for safety than you would treat 240 volt wiring. 120 V can kill.

Ed

| Bullshit. We are talking about contacting a bare, | live, 120 v conductor with a path through you to | ground. That is *UNSAFE*. No comparison to any | other voltage makes the situation safer.

But the higher voltage is most certainly less safe.

| It is bizarre to see people call an extremely | hazardous and possibly fatal situation "safer" | than something else. It is a meaningless comparison, | and worse, tends to minimize the danger in the minds | of some.

Would it be bizarre to see people call an extremely hazardous and possibly fatal situation "more dangerous" than something else when its voltage is higher?

Would you agree than 600 volts (single ended 600-0) is MORE dangerous than 120 volts in a like circuit?

Is danger_of_volts(600) > danger_of_volts(120) ? Is danger_of_volts(120) < danger_of_volts(600) ?

| You should NOT treat 120 v wiring with any less | respect for safety than you would treat 240 volt | wiring. 120 V can kill.

You should treat all wiring as sufficiently dangerous that you apply every possible safeguard to ensure the least possibility of tragedy.

I'll stick with my assertions that with all else being equal, higher voltage is _more_ dangerous and lower voltage is _less_ dangerous. I wouldn't even have voltages higher than 600 volts in my house.

Is swimming in ten feet of water less dangerous than swimming in twenty feet of water?

I'm sure you became a "ham" after the vacuum tube era. :-)

No one is being "cavalier."

For example, folks just don't bother to worry about personal safety when checking out 24/28 volt control wiring. The only "danger" is you will accidentally short something.

At 48 volts there is a little concern.

Frankly, most folks who aren't actually afraid of electricity have gotten shocked by 120 volts at least a few times. Sometimes it's because the insulation on a wire was damaged and you didn't notice. Sometimes you are changing a lamp and you get a "tingle" from leakage. Sometimes you are "hot" wiring. In industrial situations, a good amount of "relay logic" is run off of a 120 volt transformer and when checking what's "On" you might get a little careless. It happens.

One of the advantages of working with a lower voltage is the the consequences of a mistake aren't severe.

For more practical purposes there seems to be about a 100 volt threshold below which you don't get much of a shock. My "science" may be bad but it's like the first 100 volts are "free." By that reasoning once you get above 120 volts things get much more dangerous.

But under the US system, in day to day work you don't have to worry about getting a 240 volt shock in residential systems.