converting 240v to 110v

[cozzie]

hello

Recently i puchased a cordless drill from America. the charger runs on the standard American 110v, so to use my charger here i was going to plug the charger into my stepdown 240v to 110v 3.3KVA transformer (one of the yellow ones you see on every building site). but on the transformer it says "the EN61558 standard for intermittent operation allows for 5 minutes "on" and a resting of 15 minutes "off". now the battery takes 45 minutes for a full charge. considering that this charger needs little power and there will be no stopping and starting will the transformer work away for the 45minutes

regards
cozzie

 

[breezer]

try it and see.

the description you have given sounds like running at full load. (which it wont be)

the other thing to baer in mind the yellow trasnsformer you have is not the samwe 110 as in america

In america they have 110v and neutral

the transformer you have has 55v-0v-55v

also in america theey have 60hz we only have 50hz

you may be better off looking of an English charger or similar

just a thought does this charger have a 110 / 230 switch?

 

[cozzie]

the charger has a reset button alright. its a lithium ion battery charger. i presumed that 110v was 110v the world over. could this damage the batteries or will they be okay. the UK spec charger for the drill is very expensive,should i just chance it considerring many of the nowaday chargers are multivoltage

 

[plugwash]

It will almost certainly be fine to use your american charger on your site transformer. I wouldn't try it directly on british mains unless it explicitly states in the ratings that its suitable for our voltage.

The warning on the site transformer is to stop people running it at full rated continously (which those transformers aren't built for). There may be a seperate continous rating printed on the transformer but even if there isn't i doubt your charger draws anywhere near enough to cause problems.

the CTE thing will have no effect if the charger doesn't have an earth and probablly won't be an issue even if it does.

the frequency is the biggest potential issue. Most equipment can cope but some may overheat due to the lower inductive reactance and/or core saturation in transformers.

 

[cozzie]

so the most damage i can do is to the battery charger itself. presume that this will cause not cause damage to the lithium ion battteries (the expensive oart of the cordless)

cozzie

 

[scottandrew14]

I have just done the same thing ( bought an american drill with the thought that i'd simply change the plug to the yellow 110 ones we use) can you tell me how it worked out for you please?[/b]

 

[electronicsuk]

I very much doubt cozzie is coming back. If the charger was happy to run at 50Hz then I'm sure it all worked out fine.

If your charger is built around a switching power supply then chances are it'll not care all that much about the supply frequency, as the AC is rectified in the first stage of a switch mode power supply anyway.

 

[Risteard]

the transformer you have has 55V-0-55V

Reduced low voltage system.

 

[electronicsuk]

the transformer you have has 55V-0-55V

Reduced low voltage system.

Makes no difference as far as the charger is concerned - more than likely it's a class II appliance and wont even use the centre-tapped earth from the transformer anyway.

 

[RF Lighting]

I've got a US charger for my drill so I can charge it with site power.

Works a treat.

 

[1john]

I have a US milwakee jigsaw that runs on a site tranny, friends of mine have makita LiIon chargers from US charging on site trannies too.

 

[plugwash]

The main thing I would advise against importing and using on a transformer is bench tools. Small hand held tools tend to use "universal" motors which don't really care too much about frequency. bench tools OTOH tend to use induction motors which will likely run considerably slower and hotter on 50Hz than on 60Hz

Washing machines would have the same issue and you may also run into the issue that some large US stuff expects a 120-0-120 supply and sometimes uses a combined neutral and earth.