110v transformers keep stop working, is it the tool?

[mattysupra]

Hi, we have a electricaly item from abroad. It has damaged 3 transformers now.

Im not sure if its American or Canadian or some where else it came from. I have been told that i think Canada it was uses a different Hz electric to the u.k and this could be why its no good being plugged into our 110volt transformers

It dont have a label saying exactly what the voltage etc is as its a prototype tool.

P.s, not sure if it matters but this tool apparently works very similar to a Microwave where it will heat a special tape through products without transferring heat into the product above.


Any ideas what the issue may be.

thamks

 

[fireman22]

http://www.tlc-direct.co.uk/Main_In.../USA_110volt_Convertor_Transformer/index.html
this may be what your after?

 

[mattysupra]

Thanks, so i take it that there is a difference between our transformers and what they convert the electric to?

To me 110v is 110v, this Hz thing i dont understand.

Sorry if im being dumb.

 

[fireman22]

no you may be right about the Hz thing but if they are sold as transformers for usa kit they may do something different from the normal yellow jobbys, the guys at tlc may know more

 

[flameport]

Hz or frequency might make a difference - depends on what the tool actually is. Does it have a motor in it?

A more likely explanation is that the transformer rating is too low, and using the tool in it causes overheating / melting / fire.

 

[fireman22]

on the technical bit of the tlc page it states 50-60 Hz so it doesnt alter that but it does give a guide to sizing the transformer, this may be your problem

 

[sparkticus]

The standard mains voltage for plug-in items in the US & Canada is 110 Volts AC at 60 Hertz.

The mains is 230 Volts AC at 50 Hertz in the UK (50 cycles/second)

Hertz just means cycles per second. It is the frequency at which the alternating current cycles in each second. There are 50 cycles per second in the UK VS 60 in the US/Canada.


The frequency (measured in Hertz) can have an effect on how much current is drawn by an appliance from a transformer especially if the appliance contains what is know as an inductive load such as a transformer or number of transformers/motors.

As an example and in general something that draws 10 amps at 60 Hertz may draw 11 amps at 50 hertz (only an example) So in general as the mains frequency decreases the current drawn by the same load is increased.

This may well be what is going on. You may have an item designed for 60Hertz which contains a very inductive load that is now running in the UK on 50 Hertz.

You can get something called a frequency changer or an inverter to correct this but that could prove expensive.

Can you send more details on the appliance?

 

[mattysupra]

Thanks for the replies so far.

Im not sure what other information i can give you on the appliance.


All i know is that it works on 'microwaves' . I dont think it has any moving parts inside.

All i know is that we have gone through 3 transformers so far. Maybe under powered ones, but surely they should blow a fuse or simply reset maybe ? The 3 transformers no longer work and fuse has been checked!

Something i don't understand is we have asked the company to make us a 240v version but they say they are cant fit it all inside? I dont understand this, surely 240v parts should take up less room as your supply more power?

Im really surprised at the lack of interest off the company to supply the U.K and fix this issue.

 

[ban-all-sheds]

It's not just the UK, almost all the ROTW uses 230V ±...

Do you not even know what power the device consumes?

Also, I don't know how its innards are designed, but if they are expecting N to be at 0V with respect to earth they are going to be sadly disappointed when you connect them to a site transformer. I wonder if something is shorting out one half of the secondary winding?

 

[bernardgreen]

It dont have a label saying exactly what the voltage etc is as its a prototype tool

"Prototype" and "American" in the description. For me that is alarm bells. They have lower standards in equipment than we do in the UK.

A 1000 watt inductive load designed for use on 60 Hz can take as much as 1400 watts when run on 50Hz so as a safe rule for a 1000 watts of equipment use a 2000 watt transformer.

If it is micro wave and rated at 500 watts heating power you may find it produces 500 watts on average. To produce 500 watts of micro-wave energy could require as much as 600 watts of power. To get 500 watts average output it will for a few seconds output 1000 watts then switches off for the same length of time and repeats this sequence.

So a microwave rated at 500 watts output energy might have a peak load of 1200 watts on the transformer.

The manufacturers may not be interested in selling into the UK due to the need to improve the design to meet the UK and European standards.

 

[ericmark]

1) As already said frequency could be a problem.
2) Yellow bricks are designed for intermittent use.
3) Yellow bricks are overload protected on input not output so any load phase to earth can demand twice the current from a single winding to what the overload is designed to limit.

So the supply should really come from a continuous rated transformer a transformer of this type is far better for long term use. And the output would go through something like this with in the case of transformer shown a 16A double pole MCB. It may also be required to disconnect the central tapped earth and connect one of the lines to earth instead if possible as with many the centre tap is internally connected to earth and I have needed to order a transformer specially designed with no centre tap for USA equipment before now.

Even this does not redress the 50Hz to 60Hz problem and only the supplier of the equipment can tell you if this is a real problem. But since it's the transformer not the equipment burning out I would guess either the centre tap, or the rating/type, together with protective devices on output not input is the problem.

 

[mattysupra]

thanks for all the replies.

 

[Stoday]

It's usual to supply an American appliance through an autotransformer, not through a site transformer.

230/115V auto transformers usually have American style sockets on them, so you can avoid the site type plug problem.

 

[Paul_C]

It's not just the UK, almost all the ROTW uses 230V ±...

A large part maybe, but I think it's something of an exaggeration to say "almost all" of the rest of the world. Canada, Mexico, most of central America, and a substantial chunk of South America also use supplies in the range of 110 - 127V as their main utilization voltage for small appliances, and that accounts for a fairly substantial portion of the world. Admittedly it's rare outside the Americas now, Japan's use of 100V being the major exception.