Thread: what happens if 110vtools are plugged into240v

Do you have any idea how expensive (and heavy) a 'trade proof' step down transformer would cost for a medium to large device?

Pricey i know but it's a lot cheaper than your life !

Almost every electrical " accident " on an industrial site can be put down to either unsafe practice or failure to maintain equipment.

running 240 to 110 stepdown at industrial site power levels would be a very large heavy box.....it certainly would not be a safe 1 man lift.....then all the power cords would have to be twice as thick.

one of the absilute worst things about the US is 110v powertools and the limitations that places on what can be done.

Consider that construction site favorite, the 9" angle grinder would need a 20 amp power cable to run on 110v. if you were to run it 20 meters away from the power pack you would need a 30 amp extension cord to allow for the voltage drop

If you think electrical accedents are that common...tell me how many electrical deaths and serious injuries on construction sites in australia due to powertools.

you will almost certainly find the angle grinder alone maims far more.

OH BTW auto transformers are and always have been illegal in australia for supplying appliances of any sort.

Any step down transformer must supply full isolation, which makes it twice as big.

Oh if you want to know exactly what happens.... look at the mythbuster archives to the episode where they were doing CD myths and they spunn up Cds with a 100v dewalt grinder run on 240V.......Adam left the switch on a little too long and the grinder failed in around 15 sec probably less.

In may of the small universal motors they wont blow up at all the rotating wiring or the comutator will come apart in spactacular fashon... many sparks but no real bang.

cheers

We must be at crossed purposes with the Knock down box. The one's i've used on site are about the size and weight of a large car battery. Yes the cabeling is thicker but should things go wrong you get a belt from 110 not 240. I walked around a site the other week and was amazed to see 240v cabel not suspended off the ground and running through mud and water Anything to make the work place safer can't be all that bad. And it comes from someone who's done stupid things onsite

Originally Posted by soundman

Almost every electrical " accident " on an industrial site can be put down to either unsafe practice or failure to maintain equipment.

running 240 to 110 stepdown at industrial site power levels would be a very large heavy box.....it certainly would not be a safe 1 man lift.....then all the power cords would have to be twice as thick.

one of the absilute worst things about the US is 110v powertools and the limitations that places on what can be done.

Consider that construction site favorite, the 9" angle grinder would need a 20 amp power cable to run on 110v. if you were to run it 20 meters away from the power pack you would need a 30 amp extension cord to allow for the voltage drop

If you think electrical accedents are that common...tell me how many electrical deaths and serious injuries on construction sites in australia due to powertools.

you will almost certainly find the angle grinder alone maims far more.

OH BTW auto transformers are and always have been illegal in australia for supplying appliances of any sort.

Any step down transformer must supply full isolation, which makes it twice as big.

Oh if you want to know exactly what happens.... look at the mythbuster archives to the episode where they were doing CD myths and they spunn up Cds with a 100v dewalt grinder run on 240V.......Adam left the switch on a little too long and the grinder failed in around 15 sec probably less.

In may of the small universal motors they wont blow up at all the rotating wiring or the comutator will come apart in spactacular fashon... many sparks but no real bang.

cheers

Soundman.
A bloody good post.

Many people have a strange idea that 240 volts is more dangerous than 120 volts. This is not true.

I've been hooked up to many voltages...up to 415v. I can tell you the only difference is the "jolt" that you feel.
The real difference is all about current (milliamps). 120v has the same ability to kill as 240v & 415v.
A "safe" voltage is considered to be less than 50v RMS or 120v ripple free DC. This is due to the "let go" aspect of the voltage. Above these voltages, the ability to "let go" greatly diminishes.

Back on topic...as many others have said, the appliance would very quickly self destruct if connected to a higher voltage than its design voltage.

Also, for those who think that transformers are the answer for appliance voltage problems, please also consider the frequency. 50Hz motors don't like 60Hz & visa versa.

60hz motors on 50hz will run hotter and will have a higher chance of burning out. Trust the Americans to stick with all the stupid standards (110v @ 60hz, imperial etc)


Most painful voltage for me was a home built high voltage power supply, copped a belt through a plastic screwdriver handle. Would have been at least 25kV, 30mA tops

Originally Posted by elkangorito

Soundman.
A bloody good post.

Many people have a strange idea that 240 volts is more dangerous than 120 volts. This is not true.

I've been hooked up to many voltages...up to 415v. I can tell you the only difference is the "jolt" that you feel.
The real difference is all about current (milliamps). 120v has the same ability to kill as 240v & 415v.
A "safe" voltage is considered to be less than 50v RMS or 120v ripple free DC. This is due to the "let go" aspect of the voltage. Above these voltages, the ability to "let go" greatly diminishes.

Back on topic...as many others have said, the appliance would very quickly self destruct if connected to a higher voltage than its design voltage.

Also, for those who think that transformers are the answer for appliance voltage problems, please also consider the frequency. 50Hz motors don't like 60Hz & visa versa.

Is that a complicated way of saying that its the wattage that kills?
Watts = Volts x Amps

Cheers

Graeme

actualy the truth is that if you get properly hooked up 110V will kill you just as dead as 240V.
The only real difference is a small margin of difference in pain for minor shocks.
In fact it can be validly argued ( slim argument I'll admit) that 110V ac can actulay be more dangerous in some situations.

with 110, because there is twice the current, there is a bigger likleyhood of switchgear failures and fires

The is a very small difference in electrical safety between 110V and 240V.

The issue is electrical safety not the voltage in question.

There are two issues that make a far greater difference than almost any other safety measure.

1. earth leakage or residual current circuit breakers. Earth leakage protection is compulsory on building sites and all industrial work places and is compulsory on all new electrical installations and as of last year ( i think) compulsory on all rental dwellings ( in QLD anyway)

2. double insulated tools......not compulsory but most hand held power tools are double insulated these days.

AGAIN I say the vast majority of electrical accidents are due to wrecklessness.. pure and simple.

..........Again in QLD the penalties for electrical wrecklessness are massive......unfortunately lots of people don't get it....... let me tell you you do not want to be on the wrong end of the electrical safety act.....& if you are looking for a loop hole... unless you are a foreign diplomat there aren't any.......if you are aware of an electricaly dangerous situation anywhere, any how, anytime...... no matter who you are.....YOU have some sort of responsibility regarding it.

cheers

It's the amperage (at 60/50 Hz) which kills - not wattage, not voltage - a tsunami of speeding electrons kill.

The world's greatest scientific genius (Nikola Tesla - followed by Howard Florey of course) demonstrated this when he calmly passed 500,000 volts through his body in a public demonstration - very low amperage was the trick . He knew it but at the time no-one else did and didn't the audience nearly die!!!

60 or 50 Hz is perfectly suited to kill as well - thank Thomas Edison for that piece of nasty work and his machine 'Old Sparky' which was the first electric chair. This was why Tesla put on his spectacular demonstration. Oh, and by the way a fuming Edison still lost the Niagra Falls Power Station contract to Tesla and his new fangled AC generator but the vindictive Edison got his own back when through his contacts in the Californian Legislature managed to specify in the contract that the frequency output was 60 Hz. 60/50 Hz is idea for the creation on tetanic muscle contraction.

Had the frequency of AC production been fixed above 100hz then the chances of a human dying from electric shock would be dramatically reduced to a fraction of one percent (muscles cease to contract above this frequency - check this for yourself in Electrophysiology).
In our everyday lives, we continue to suffer the consequences of this vicious power struggle in Edison's lust for money.

Love those residual current earth leaking devices!

Originally Posted by terraaustralis

It's the amperage (at 60/50 Hz) which kills - not wattage, not voltage - a tsunami of speeding electrons kill.

Not quite correct terraaustralis.

As you may well know, current flow can't exist without voltage & voltage can't be present without a resistance. This applies to DC as well.
Therefore, Ohm's Law is the key factor.

One of my favourite sayings is "It's the combination of current & voltage that kills".

Correct, you need both current and voltage to kill.

And having mains AC @ 100hz is not a good idea, at those frequency's you will suffer horrible burns not to mention transformers and motors don't like anything that quick.

For what is worth, I have a 1 kw 240/110 transformer(bloody heavy), that somebody may have a use for. It was pulled out of some electronic equipment, seems to have all the smoke still in it!

regardless of it being current or voltage that kills you....... there is still more than plenty in a 110V circuit to do it....

cheers