240v debate....

[stickboy1375]

I wanted to run a pump at 240v vs 120v, for obvious reasons, voltage drop, wire size, etc. But... I get this a lot from people, 240v is more dangerous. So I'm looking for a better way to explain to people that its just as safe as a 120v circuit but with better benefits.

 

[iwire]

Well both are 120 volts to ground so the chances of them getting a 240 volt shock without them actually opening a j box or enclosure first are pretty remote.

 

[stickboy1375]

Well both are 120 volts to ground so the chances of them getting a 240 volt shock without them actually opening a j box or enclosure first are pretty remote.

With both legs being 180 degrees apart, is it even possible to be hit with a 240v shock?

 

[Dennis Alwon]

With both legs being 180 degrees apart, is it even possible to be hit with a 240v shock?

I don't understand the question ? Of course you can get 240v shock but it would be hard to do as Bob stated.

 

[augie47]

Any rationale you present will probably be accepted only after they accept the fact the the world is not flat.
Explain to them that "220 wire is cheaper" and go on with life

 

[kwired]

With both legs being 180 degrees apart, is it even possible to be hit with a 240v shock?

With that theory how would the intended load ever see 240 volts?

 

[Hv&Lv]

Explain to them that 240 volts will use less energy (kWh), thereby saving them more money in the long run...
(I^2R)
As far as being safer, do they make a habit of playing with live circuits?

 

[Dennis Alwon]

Explain to them that 240 volts will use less energy (kWh), thereby saving them more money in the long run...
(I^2R)
As far as being safer, do they make a habit of playing with live circuits?

Why would it use less energy. The wattage is the same and that is what you pay for.

 

[hillbilly1]

Actually they will use the same amount of energy minus any loss from voltage drop using the lower voltage, if it is a short run, then it would be a wash.

 

[Hv&Lv]

Why would it use less energy. The wattage is the same and that is what you pay for.

Calculate the I^2R using the same size wire.
The resistive losses are less in a 240 v circuit that is using 1/2 the current to do the same work as a 120 V circuit.
It isn't enough to notice in a power bill...

 

[iwire]

Calculate the I^2R using the same size wire.
The resistive losses are less in a 240 v circuit that is using 1/2 the current to do the same work as a 120 V circuit.
It isn't enough to notice in a power bill...

Of course but you would not use the same size wire becuse the current would be half or twice as much depending on which way you are going

 

[Hv&Lv]

Of course but you would not use the same size wire becuse the current would be half or twice as much depending on which way you are going

What if the amps at 120 and 240 was less than the rating of a 14 guage wire?

 

[david luchini]

What if the amps at 120 and 240 was less than the rating of a 14 guage wire?

I wanted to run a pump at 240v vs 120v, for obvious reasons, voltage drop, wire size, etc.

Then the OP wouldn't be having this debate in the first place.

 

[Dennis Alwon]

Calculate the I^2R using the same size wire.
The resistive losses are less in a 240 v circuit that is using 1/2 the current to do the same work as a 120 V circuit.
It isn't enough to notice in a power bill...

But you statement was to tell the customer they will be saving money

Explain to them that 240 volts will use less energy (kWh), thereby saving them more money in the long run...

 

[Smart $]

With both legs being 180 degrees apart, is it even possible to be hit with a 240v shock?

Yes. But body parts would have to contact both lines simultaneously.

 

[Hv&Lv]

But you statement was to tell the customer they will be saving money

You may not notice it in a power bill, but the savings will still be there. :happyyes:

 

[Rick Christopherson]

You may not notice it in a power bill, but the savings will still be there. :happyyes:

If the amperage is low enough that either configuration will use #14 wire, then the difference in the losses will also be incredibly trivial. Blindly stating this as though it was something of some importance is the reason why we have so many DIY'ers suggesting that they should rewire all of their motors to 240 volts, because their "electrician" friend told them they will save money, or the motor will run cooler, or the motor will have more power. :slaphead:

 

[Besoeker]

Yes. But body parts would have to contact both lines simultaneously.

True. And it would also need the person electrocuted so to have been fiddling around with live wires.
But yes, 230/240V is more dangerous if you work on it live. Most people don't.
In UK, domestic supplies are almost always single phase, 230V, 50Hz.
Phase to neutral from the from a star (wye) secondary of a distribution transformer.
Appliances are all 230V, 50Hz. From light bulbs to electric cookers.
Deaths from electrocution are, fortunately, rare.

 

[Hv&Lv]

If the amperage is low enough that either configuration will use #14 wire, then the difference in the losses will also be incredibly trivial. Blindly stating this as though it was something of some importance is the reason why we have so many DIY'ers suggesting that they should rewire all of their motors to 240 volts, because their "electrician" friend told them they will save money, or the motor will run cooler, or the motor will have more power. :slaphead:

My original comments at the beginning of this thread wasn't meant to be taken so seriously as to start an argument about the savings, however trivial, of 120 versus 240.
The comment I made was actually meant to be taken as lightly as Auggies comment: Any rationale you present will probably be accepted only after they accept the fact the the world is not flat.
Explain to them that "220 wire is cheaper" and go on with life.


I am not "blindly" stating anything. I learn much from this forum, and expect to learn much more. I didn't expect to be attacked for for a statement made in jest.
Lighten up.

 

[Rick Christopherson]

My original comments at the beginning of this thread wasn't meant to be taken so seriously as to start an argument about the savings, however trivial, of 120 versus 240..........

I understand. However, after stating it once, you defended it several times. That leaves the perception that it is not quite so off-hand at that point.

Please understand my perspective. From as far back as the early days of the internet, I have been inundated with questions and comments about reconfiguring motors for 240 volt operation. Not all of these come from DIY'ers. Some of the most adamant arguments have come from professional electricians that have cited their lengthy credentials as preface to their arguments. It's not the type of viewpoint that would last long on a forum like this one, but nevertheless, it does exist among some professionals. All it takes is one off-hand mention from a professional to a DIY'er, and it suddenly becomes a near insurmountable piece of misinformation.