110 volt generator - need 240

[Dave Plowman (News)]

What would you use with a 3kW genny that would be worried by 60Hz?

[Dave Fawthrop]

| On Sat, 7 Jan 2006 22:38:34 UTC, "Andrew Mawson"=20 | wrote: |=20 | > > > Use one of those yellow site transformers which are 230 -> 110. | > Beware | > > > that some are only rated for 'tool duty' ie intermittant use. | > These | > > > are graded in 'hernias' and for 3KW you probably want a two man | > hernia | > > > version | > >

| > > What, and put it in reverse? Or step up to 470v or so? | > >

| > Well Bob I would have thought it obvious that I'm proposing putting | > the 110 into the 110 and getting 230 out of the 230. Transformers are | > not unidirectional devices you know so there is no such thing as | > putting it in reverse!!!! |=20 | I'm just concerned that protective devices might actually stop you = doing | that. Not to mention the safety aspect, because of the 'wrong' gender = of | the connectors.

Just put 110V into the 110 V end and take 240V out of the 240 volt end.

Transformers are simple things, there should be no safety devices in the yellow boxes. A few *big* notes in Magic Marker on the yellow box should remind you what to plug in where, and warn others off.

As with doing absolutely anything for the *first* time, I would keep an eye on things and a hand on the main switch.=20

I found this on ebay which is close. =20

vendor will confirm that it can be used in reverse. He should know about it. =20

--=20 Dave Fawthrop

17,000 free e-books at Project Gutenberg! Yorkshire Dialect go to

[Dave Liquorice]

Whilst this will work, as Mr Eager says, the gender of the connectors is wrong. You will have 110v on exposed pins on the end of the "input" lead and 240v on exposed pins on the "output".

[Harry Bloomfield]

So swap the input to a plug on the transformer and the output to a socket.

[Dave Fawthrop]

| On Sun, 08 Jan 2006 08:52:32 +0000, Dave Fawthrop wrote: |=20 | > Just put 110V into the 110 V end and take 240V out of the 240 volt | > end. |=20 | Whilst this will work, as Mr Eager says, the gender of the connectors=20 | is wrong. You will have 110v on exposed pins on the end of the "input"=20 | lead and 240v on exposed pins on the "output".

Maybe a modicum of rewiring could solve that.

--=20 Dave Fawthrop

17,000 free e-books at Project Gutenberg! Yorkshire Dialect go to

[Dave Fawthrop]

| Dave Liquorice formulated on Sunday : | > On Sun, 08 Jan 2006 08:52:32 +0000, Dave Fawthrop wrote: | >

| >> Just put 110V into the 110 V end and take 240V out of the 240 volt | >> end. | >

| > Whilst this will work, as Mr Eager says, the gender of the connectors= =20 | > is wrong. You will have 110v on exposed pins on the end of the = "input"=20 | > lead and 240v on exposed pins on the "output". |=20 | So swap the input to a plug on the transformer and the output to a=20 | socket.

And remember mark up what you have done, "110V input" and "240V output" in *big* letters. =20

--=20 Dave Fawthrop

17,000 free e-books at Project Gutenberg! Yorkshire Dialect go to

[Dave Liquorice]

No. 110v yellow connectors have a diffrent pin/keyway arrangement to

240v blue connectors. You'd would need to replace both connectors on the box.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember [e-mail] saying something like:

Chances are the output windings are in the form of two sets of 110V tails which you then series up. At the moment they'll be paralleled up for 110V.

Simple, easy, cheap and the way it's done normally for 220V on most small gensets.

[Jim Gregory]

At 60Hz... Not suitable, of course, for items using 50Hz synchronous motors &/or mains-based timers /clocks, yet OK for heating, filament lighting; all internal 50Hz transformers would cope with the 20% higher freq. But seek advice on running fluorescent-tube ballasts and brush motors. But just see if the genny config -can- be modified to European... to double the existing voltage... at half the present current handling. Jim

[meow2222]

Use a building site 240:110 backwards is the cheapest option, assuming your tools etc wont run on 110. But it wont give you 240v. I'm not sure what the regulation of those things is, but

- if its 10%, you'll get apx 240v - 20% = 192v full load, 216v no load

- if its 5%, you'll get apx 240v - 10% = 216v full load, 226v no load.

NT

[meow2222]

not for long

NT

[Andy Dingley]

How many things are there that would be happy with a 50Hz generator yet would object to a 60Hz generator ? There are very few that would complain abotu the other way round, and even fewer this way.

If you're running your clock from a generator supply, then you have an obvious problem anyway.

[nickphill]

Sorry 3KVA.

[Dave Plowman (News)]

Not many would be worried about clock or timer stability when running off a 3kW generator. Otherwise they wouldn't bother - the frequency is very approximate.

But in any case the chances are it's 50 Hz anyway. 110 volt generators are common for site use.

[Andy Wade]

No, continuously. That's the advantage of a auto-transformer - think about it.

[Dave Fawthrop]

| [e-mail] wrote: |=20 | > Andy Wade wrote: | >> two windings in series. A 1 kVA rated transformer gives you almost= 2 | >>kVA of output. |=20 | > not for long |=20 | No, continuously. That's the advantage of a auto-transformer - think=20 | about it.

No! autotransformers are more efficient than double wound transformers, and so can be made smaller and cheaper. *But* they are rated on temperature rise so if it is rated at 1KVA that is all you should take out of it. Take 2 KVA out of it and it will eventually produce a nasty smell of burning insulation.

--=20 Dave Fawthrop

17,000 free e-books at Project Gutenberg! Yorkshire Dialect go to

[Andy Wade]

You haven't followed what I was saying. If it's rated at 1 kVA _as_an_auto-transformer_ then, yes, you are clearly right. But I was talking about configuring a 1:1 isolating transformer as as auto-tranny (by connecting the two windings in series-aiding fashion. A 1 kVA 1:1 transformer so configured as a auto-transformer will have a rating close to 2 kVA. Think about the current in the windings...