plug polarity

The wider blade on a 110 volt plug is the neutral side.

Ok

So the marked side of the cable is the neutral.

Thanks

Why does the plug have to be cut off?

That was my question. If it was bought in the US it should already have the correct plug installed.

The marked/neutral wire will be connected to the light colored screw and the other hot conductor will be connected to the black/dark screw.

Ahhh you assumed I was in the US when in fact I am in the UK, easy mistake seeing as I didn't mention it.

I wish to use the charger on a work site and on worksites we use 110 Volt power supplies. The power supplies do not use the US type plugs. That's why I need to know which is the positive and which is the negative wire.

Thanks

Nope I did not assume anything. I asked what I thought was relevant to get to a solution.

Is your 120v stuff 60 cycle? or is it 50? That could be a problem for your battery charger if it is 60 cycle and electronic.

I knew this would be difficult to get a simple answer to a straight forward question from a techy news group. Now you are assuming that I want to gain knowledge about things I haven't asked about. I know this isn't the best way forward in getting my question answered but if anyone out there can assist I would be very thankful.

Regards fred

| Ahhh you assumed I was in the US when in fact I am in the UK, easy mistake | seeing as I didn't mention it. | | I wish to use the charger on a work site and on worksites we use 110 Volt | power supplies. | The power supplies do not use the US type plugs. That's why I need to know | which is the positive and which is the negative wire.

Work site power in the UK is actually a 55/110 volt split system similary to the 120/240 volt split system in the USA. What that does is gives you 1/4 the voltage relative to ground, but still enough to power heavy duty tools.

Such a power system (60/120) is used in the USA for certain audio purposes where ground noise is an issue. But there are rules that restrict its use because not all 120 volt equipment is compatible.

The USA battery charger MAY cause a ground fault when used. If the frame of the battery charger is wired to the NEUTRAL wire (wider blade), plugging it into UK work site power would energize the frame with 55 volts, and trip your leakage breaker when you touch it, or give you a shock if it fails to.

If the charger has a 3-prong plug, then it MAY work. But be sure to wire the ground in as well.

If it only has a 2-prong plug, check how it is wired inside before trying to use it. It may be best to replace the entire cord with a

3-wire cord intended for the UK 55/110 volt work site system that includes ground, and wire the ground wire to the frame and the TWO hot wires to the transformer and switch w/o crossing to the frame.

| I knew this would be difficult to get a simple answer to a straight forward | question from a techy news group. | Now you are assuming that I want to gain knowledge about things I haven't | asked about. | I know this isn't the best way forward in getting my question answered but | if anyone out there can assist I would be very thankful.

In addition to the advice about getting it grounded correctly, the use of 50 Hz (instead of 60 Hz) can sometimes be a problem. A transformer needs MORE iron core to handle either a higher voltage or a lower frequency. Transformers made for the Europe 50 Hz market have more iron core for the same voltage as compared to the 60 Hz market. But in many cases it is cheaper to put just one model in both markets in which case it can be a dual rated 50/60 Hz transformer. Using a 60 Hz transformer on 50 Hz power can do things from humming louder to burning out. Just be careful.

Fred, I do not want to be negative or offend you.

You first asked about positive and negative connections which demonstrated to most that you did not know much about electricity and so more questions flowed to find out what you were trying to do and if the advice given would really fit your circumstances. This happens almost every day on technical groups where the questioner does not give enough info to show he will understand a simple answer.

In the UK you use 230 volt Multiple earthed neutral system for power and

100 volt centre tap earthed transformers for building sites I believe. Both of course at 50 HZ

There is no neutral as such on the 100volt side so connections to the plug are irrelevant (Except of course the ground if applicable.)

Your battery charger may not function correctly on the 20% lower frequency or the 10% lower voltage and may overload the transformer especially as it will be a continuous load

load.http://www.users.zetnet.co.uk/roshepower/site.htm

Thanks for the info Phil. I can at least grasp what you are telling me. The power supply comes from the 240 volt AC mains and a transformer is used on site to reduce the current to 110v AC. The charger I am referring to is a DeWalt battery charger that charges the

18v cordless batteries. It is an American version charger and doesn't have an earthling/ground wire. The unit has only one flex that has a twin core. The case is constructed in plastic. It common here to use these US version chargers and use the 110v site boxes.

Thanks

fred

Fred, what none of these folks have said is that is a double insulated piece of equipment and the polarity is not important at all. Even if it was your system is center grounded so there is no "grounded conductor" AKA "neutral" in the first place. Plug it in, charge your battery and have a Guinesss for me.

If you are using this on an AC source, which it sure sounds like you are doing, there is no Positive or Negative wire. Hot and neutral possibly. If you are running it on a 55/110 split system, it really doesn't matter which wire connects to what pin.

| If you are using this on an AC source, which it sure sounds like | you are doing, there is no Positive or Negative wire. Hot and | neutral possibly. If you are running it on a 55/110 split system, | it really doesn't matter which wire connects to what pin.

But if the device expects USA style power and attaches the neutral wire to the device frame, he now has a device frame energized at 55 volts. That's not good, and will trip GFI/leakage protectors.

| Fred, what none of these folks have said is that is a double insulated piece of | equipment and the polarity is not important at all. Even if it was your system | is center grounded so there is no "grounded conductor" AKA "neutral" in the | first place. Plug it in, charge your battery and have a Guinesss for me.

But if the device expects USA style power and attaches the neutral wire to the device frame, he now has a device frame energized at 55 volts. That's not good, and will trip GFI/leakage protectors. Or has he now determined it does not attach that way?

Thanks to everyone for all the advice. Maybe I prefer Greg's and will have a Guinness or two then think about what to do next. Thanks guys

USA style devices do not connect the neutral to their frame. The safety risks created by assuming that receptacles are always correctly polarized are too great to allow this practice.

Phil that is total bullshit. When was the lastr time you saw something with the neureal connected to the chassis? Your 1946 Dumont TV? He is talking about a drill/driver charger. (construction sites in UK use 120v center tapped). If you connected the neutral to the frame it would trip the GFCI required on US job sites too. These chargers are switch mode power supplies and the input immediately is converted to DC. It doesn't care if the input is 60hz, 50hz or 400hz.

Seems to be some confusion here between "frame" and "chassis". There have been many USA style TV's sold in recent years that have hot (polarized neutral connected) chassis. It eliminates the expense of a heavy transformer that you would sometimes find in older tvs. Voltage doublers and triplers are used to create the high voltage for the CRT. Yet all the external parts are non-conductive plastic, for safety. (I'm old enough to have owned a portable TV with a metal frame, though

- I remember it used to give pretty good shocks!).

This is why isolation transformers have been ( or used to be, anyway) used in TV repair shops. The TV would operate perfectly fine if the polarized plug whas connected in either direction. The position that puts a building hot wire on tv ground/chassis can be dangerous when you are working on it, though. Of course, these days, most TV's don't even have metal chassis anymore, just a big circuit board and module connectors.

Beachcomber