Good brand of 3KW 2:1 transformer?

Chinese-made

A good brand, Acme, Square D, CH now Eaton, GE and

I missed the intended use so to speculate more useless.

The dimensions scare me. This looks pretty small for a 3Kw 120/240V unit. I suspect that it is an autotransformer (core and windings equivalent to a

(PS Hammond units do what was required but the ones I've seen weren't noted for good efficiency or regulation -skimp on material to keep capital cost down) -- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer

Thanks SQLit and Don for the info.

Seems like I need to do more homework.

My application is mostly power tools, with occasional heating applications. Which kind of trafo would be best for this?

Thanks again.

rf

| I want to buy a 3KW 2:1 transformer and have seen one at a very reasonable | price - $120.

What purpose will this be used for?

What duty cycle of usage? How many minutes on and how many hours off?

| PowerBright brand - made in China | | 220-240 volt to 110-120 volt AND from 110-120 volt to 220-240 volt. | Features | FREE Grounded Adapter Included ($3 Value) | On and Off Breaker Switch | Fuse protected | 2 Spare Fuses Included | 1 Year Parts and Labor Warranty | | Specifications | Capacity 3000 watts | Input 110/200/220/240 Volt | Output 110/220-240 Volt | Dimensions (W x H x D) 7.2 x 6.0 x 9.8 in. | | The specs are pretty sparse.

There is no heat rise spec. I consider that important.

| Are these transformers typically the usual primary and secondary windings | on a steel core, with no electronics? If so, they should be simple and | reliable. With | electronics, their reliability could be questionable, like the Chinese-made | Altec Lansing | speaker system I bought a couple of years ago that went belly up. They have | no | replacement components and gave me the number of .the replacement model. I | told them | what to do with it ;-)

A transformer can be made for very light duty usage and be made to fit in those dimensions. If you want to run it for no more than 5 minutes per hour it might last a year or two.

Transformers with no electronics can fail. They waste power and build up a lot of heat, damaging cheap insulation and eventually shorting a winding.

| I have also seen some great looking Chinese made furniture recently. Looked | exactly like mahogany | but most of it was CARDBOARD!!!

The sad part is that so many people prefer cheap cheap cheap regardless of quality issues like this. And the Chinese know it.

| I would rather pay more for a trafo with a good reliable brand. .

I actually priced this size about a year ago before I decided to just run my computers on 240 volts directly (after a 240 volt UPS). I only looked for reliable brands, and found prices from $500 to $1500. You could buy an expensive Square-D or Cutler-Hammer model and know it would keep on working for years of continuous usage at 25% above rated power.

Otherwise, look on EBay every couple days for a month or two and see what shows up.

My application is mostly power tools, with occasional heating applications.

No more than about an hour continually. Usually something like 5 mins on and

Good to know

Yup, and our garbage dumps will know all about it in the future.

You have convinced me that I should sell my 110v stuff and buy 220v in Europe.

Thanks again for that great input.

rf

You are the second to mention Cutler Hammer transformers, so I have to ask, do they even make transformers? I understood they did not.

I have seen them advertized several places on the www. Maybe they just market them - stick their label on a product made by someone else - just like Sears does.

| You have convinced me that I should sell my 110v stuff and buy 220v in | Europe.

You can find decent transformers. They just aren't as cheap as junk models coming from China. Not all manufacturers in China make junk. But the ones making decent quality are going to be mid range in price, below European/US prices, but higher than the cheapest. Identifying which ones are good will be the hard part as the junk makers will be promoting theirs as good, too.

British work-site voltage is 55v. But some of the transformers output two sides, giving 110v line to line, with the ground in the middle. One option is to get one of these and retro-fit it to ground one side instead of the middle. Another option if you are going to trade in your tools is to get the 55v ones instead of 220v.

| You are the second to mention Cutler Hammer transformers, so I have to ask, | do they even make transformers? I understood they did not.

They certainly list a wide range in their catalogs, from small 100 VA versions for various appliactions all the way up to 2.5 MW pad mount and some even larger substation models I've never spent any time looking at. About the only thing the don't appear to sell is pole pigs (but you can get those from GE and Kuhlman).

| | |>

|> I actually priced this size about a year ago before I decided to just |> run my computers on 240 volts directly (after a 240 volt UPS). I only |> looked for reliable brands, and found prices from $500 to $1500. You |> could buy an expensive Square-D or Cutler-Hammer model and know it would |> keep on working for years of continuous usage at 25% above rated power. |>

| | You are the second to mention Cutler Hammer transformers, so I have to ask, | do they even make transformers? I understood they did not.

They certainly sell them. Like their circuit breakers, these are product lines formerly part of Westinghouse, which I understand made most of their own product, so supposedly Eaton/Cutler-Hammer does now as well.

Here are some catalog sections:

--------------------------snipped

CH now Eaton Electric has a xfmer plant across the boarder from El Paso in Mexico. As for if they make control transformers, I do not know.

They also build really high tech constant voltage xfmers in Canada. I believe that the constant voltage ones start out at 112.5 kva. It has been a few years since I worked for them so things might have changed some. These are REALLY expensive. So before you think you want to check them out measure your pocket book. They work in the sub cycle range so they are perfect for computer server rooms. Not to be mistaken for a PDU.