[Dan]

I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

[gregz]

DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

You could buy a separate additional isolation transformer, more losses,
heavier. Do you really need isolation?

Here is a 30# thing that will work independently, and I'm not sure where
it's built.

http://www.alliedelec.com/search/pro...x?SKU=70137421

Greg

[Dan]

On Mar 24, 7:03*pm, gregz wrote:
DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

You could buy a separate additional isolation transformer, more losses,
heavier. Do you really need isolation?

Here is a 30# thing that will work independently, and I'm not sure where
it's built.

http://www.alliedelec.com/search/pro...x?SKU=70137421

Greg

Thanks for the reply Greg.
Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).
It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer). That's why I wanted some help on
getting a proper one. Thanks for the link but it seems a bit steep
$500 for 500 Watts. I would appreciate any more comments or advice on
specific brands / makes / models. Thanks!

[John Williamson]

DAN wrote:
On Mar 24, 7:03 pm, gregz wrote:
DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.
You could buy a separate additional isolation transformer, more losses,
heavier. Do you really need isolation?

Here is a 30# thing that will work independently, and I'm not sure where
it's built.

http://www.alliedelec.com/search/pro...x?SKU=70137421

Greg

Thanks for the reply Greg.
Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).
It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer). That's why I wanted some help on
getting a proper one. Thanks for the link but it seems a bit steep
$500 for 500 Watts. I would appreciate any more comments or advice on
specific brands / makes / models. Thanks!

If you're in the UK or Europe, and 110V is acceptable, then you can buy
isolating transformers to use on building sites from your local tool
hire/supply shop for about a quarter of that. They take in 230V, and put
out 110V, centre tapped to earth.

--
Tciao for Now!

John.

[Mike Rivers]

On 3/25/2012 5:06 AM, DAN wrote:

It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer).

An autotransformer is find for running appliances, but it
provides no isolation from ground nor any protection from
surges (nor does a standard two-winding transformer).

You can buy an isolation step-down transformer from an
electrical supply house. Look for "dry transformer."

--
"Today's production equipment is IT based and cannot be
operated without a passing knowledge of computing, although
it seems that it can be operated without a passing knowledge
of audio." - John Watkinson

http://mikeriversaudio.wordpress.com - useful and
interesting audio stuff

[Arny Krueger[_4_]]

"DAN" wrote in message
...

Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).

How do you know that it is an auto-transformer?

I read the spec sheet and the user instructions, and I just don't see it.

Am I missing something?

http://www.powerbright.com/pdf/manua...-VC3000W_B.pdf


It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer).

Even an autotransformer is reasonably safe if you know that neutral is
grounded, and that polarity is going to be preserved through the source
outlet and the power cord.

[gregz]

"Arny Krueger" wrote:
"DAN" wrote in message
...

Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).

How do you know that it is an auto-transformer?

I read the spec sheet and the user instructions, and I just don't see it.

Am I missing something?

http://www.powerbright.com/pdf/manua...-VC3000W_B.pdf




Only that it is like many others using autotransformer. Price might tell
you.

Greg


It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer).

Even an autotransformer is reasonably safe if you know that neutral is
grounded, and that polarity is going to be preserved through the source
outlet and the power cord.

[Arny Krueger[_4_]]

"gregz" wrote in message
...
"Arny Krueger" wrote:
"DAN" wrote in message
...

Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).

How do you know that it is an auto-transformer?

I read the spec sheet and the user instructions, and I just don't see it.

Am I missing something?

http://www.powerbright.com/pdf/manua...-VC3000W_B.pdf




Only that it is like many others using autotransformer. Price might tell
you.

So, you don't know for sure?

10 seconds with an ohm meter...

[JackA]

On Tuesday, March 27, 2012 at 9:51:58 AM UTC-4, Arny Krueger wrote:
"DAN" wrote in message
...

Well, from reading past replies, it seems people generally recommend
against auto-transformers such as this:
http://www.powerbright.com/vc2000.html (that's the one I have - and
don't want to use).

How do you know that it is an auto-transformer?

I read the spec sheet and the user instructions, and I just don't see it.

Am I missing something?

http://www.powerbright.com/pdf/manua...-VC3000W_B.pdf


It scared the hell out of me reading that there's high risk using a
single winding step down (due to no protection whatsoever for my
equipment against 230V surge should the one winding go bust or
something) and also that some have improper wiring, not to mention
that using a power strip (with surge protection) is not advisable (on
a typical cheap auto transformer).

Even an autotransformer is reasonably safe if you know that neutral is
grounded, and that polarity is going to be preserved through the source
outlet and the power cord.

You know what I find "neat"? Let's take a current panel meter. It will now handle 90V to 460V, 50 or 60 Hz without altering switches, plugs, etc..

Yes, you should always establish a return path to ground! Humanoids don't make good conductors to ground when they find they are one, it's too late *plunk*. I feel more studies have to be done on humanoids carrying current. I offer John W, Scott D. Nil, Phil, Luxey, None, Geoff and the many others here for testing!!

Jack

[Scott Dorsey]

DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.

That's fine, you can still use it on noncritical things like your steam
iron.

Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

You will find it MUCH MUCH easier to find these things in Europe. They
are far more common.

If you want such a thing in the US, your best bet is to go to an electrical
supplier and ask for a NEMA-cased dry transformer. These are intended for
permanent installation but you can add a power cord and outlet box to one,
no problem.

I personally recommend the Acme/Amveco transformers. They are made in India
and seem good quality, at about half the cost of the Square-D and Seimens
equivalents. Tristate Electrical Supply/ Capitol Lighting Supply will
stock them in your state. I don't think Graybar Electric stocks the Acme
ones, but they will have Square-D and some of the other big brands.

Expect them to weigh about twice as much as your autotransformer, since
you have twice as much flux in the core and therefore you need twice the
core volume for the same material. They will cost a lot of ship to Europe.
Better to buy one when you get there.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Dan]

Thank you to all who replied.... While I understand and appreciate your advice, I'm not really a tech minded individual and would like to ideally purchase something which is ready to use "out of the box ready" and can be portable. Is there any quality step down transformer which is available online? Now, correct me if I'm wrong but I should be looking at one which has a separate primary and secondary winding ideally made out of copper? Can someone please educate me when looking for one, what to look for? Is the country that it's made of important? What should I ask when buying or look for specifically? Scott, going through the sites/products you recommend is cool thanks but, again, it's way over my head. Ideally I would like to find an "out of the box ready" product for my needs. Thanks again.

[Dan]

Guys, I think I found something perfect for my needs:
http://www.hammondmfg.com/172.htm
For those who don't have html/graphics, it basically looks like a large power supply with input and output cables. Those things are heavy (good), like 35 LBS for a 1000 VA, much heavier than what I have now but smaller. Also, isn't Hammond Mfg a pretty good company? Looks real good quality. Some specs:
Primary 230VAC, 50/60 Hz. Secondary 115VAC
Circuit breaker in primary.
Provides circuit isolation & steps down primary voltage.
Hi-pot tested to 2 KV RMS.
Electrostatic shield between primary & secondary.
Input (primary) connected to a 5 foot long cord & European (Schuko) grounded plug - NOTE: old inventory only.
Input - due to U.L changes in 2007 - NEW production with the European (Shuko) parts would no longer be U.L. listed. Therefore, we have replaced this input plug with a standard North American 3-wire, 250V plug (NEMA 6-15P).
Output (secondary) connected to a 1 foot long cord & standard North American 3-wire grounded receptacle (NEMA 5-15R).
North American Mark of Safety - C UL & UL listed (File #E211544).

[Dan]

There's also the 289 series:
http://www.hammondmfg.com/289T.htm
Specs:
Primary 240VAC, 50/60 Hz., Secondary 120VAC.
Provides circuit isolation.
Toroidal transformer for high isolation, low noise, light weight, cool operation and low profile.
World wide applications, 50 or 60 Hz. operation, step down (240VAC to 120 VAC).
Standard 3-wire, grounded plug (for use with adaptors for proper grounding).
Input (primary) connected to a 5 foot long cord & standard 250V 2 pole, 3 wire - North American plug (NEMA 6-15P).
Output (secondary) connected to two standard - 3 wire grounded receptacles (NEMA 5-15R).
Features include ventilated black steel case, rocker lighted on-off switch & circuit breaker protected output.
North American Mark of Safety - C UL & UL listed (File #E211544).

[Dan]

Need some advice from you guys again:
Which of the above 2 series would be best, 172 or 289? My country has 230V so I'm wondering if primary 240 or 230 would make a difference? Also some of my gear is 120V and also 117V (and each step down model above has secondary 115 or 120). Those are trivial, right? Non issue? I also see that the two transformers are possibly built different somewhat? I'm a bit confused why the 2 models are a bit different, look great quality but still are a bit different spec'd. What are the main, real world differences here? THanks for your help.

[gregz]

DAN wrote:
There's also the 289 series:
http://www.hammondmfg.com/289T.htm
Specs:
Primary 240VAC, 50/60 Hz., Secondary 120VAC.
Provides circuit isolation.
Toroidal transformer for high isolation, low noise, light weight, cool
operation and low profile.
World wide applications, 50 or 60 Hz. operation, step down (240VAC to 120 VAC).
Standard 3-wire, grounded plug (for use with adaptors for proper grounding).
Input (primary) connected to a 5 foot long cord & standard 250V 2 pole, 3
wire - North American plug (NEMA 6-15P).
Output (secondary) connected to two standard - 3 wire grounded receptacles (NEMA 5-15R).
Features include ventilated black steel case, rocker lighted on-off
switch & circuit breaker protected output.
North American Mark of Safety - C UL & UL listed (File #E211544).

It looks like both transformers are isolated circuit. Normally, isolation
transformers have one leg tied to ground. If your using ground for the
circuit, it's not going to have circuit isolation, regardless.

Greg

[Scott Dorsey]

DAN wrote:
Guys, I think I found something perfect for my needs:
http://www.hammondmfg.com/172.htm
For those who don't have html/graphics, it basically looks like a large pow=
er supply with input and output cables. Those things are heavy (good), like=
35 LBS for a 1000 VA, much heavier than what I have now but smaller. Also,=
isn't Hammond Mfg a pretty good company? Looks real good quality. Some spe=
cs:

The Hammonds are fine... but they only make them up to 1KVA or so. And
they are made in Canada so you're already paying duties when you order them
in the US....
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

In article 25661586.6.1332814952009.JavaMail.geo-discussion-forums@pbjk9,
DAN wrote:
Thank you to all who replied.... While I understand and appreciate your adv=
ice, I'm not really a tech minded individual and would like to ideally purc=
hase something which is ready to use "out of the box ready" and can be port=
able.

I don't know if something is available in the US like that, although it is
certainly available in Europe.

Is there any quality step down transformer which is available online?=

Sure, but since it's big and heavy you are MUCH better buying from a local
electrical supply house than buying online.

Acme part T-1-81219 is a 2KVA isolation transformer, 240 or 480V primary,
120V secondary. Total shipping weight is 80 lbs. Someone will need to
add plugs and cords. You can have an electrician do that.

Now, correct me if I'm wrong but I should be looking at one which has a se=
parate primary and secondary winding ideally made out of copper? Can someon=
e please educate me when looking for one, what to look for? Is the country =
that it's made of important? What should I ask when buying or look for spec=
ifically?

You want a 240-120V transformer that is an isolation transformer, not an
autotransformer. That is, it has two windings, not just one.

Scott, going through the sites/products you recommend is cool tha=
nks but, again, it's way over my head. Ideally I would like to find an "out=
of the box ready" product for my needs. Thanks again.

You can find them all over the place in Europe but if you want one in the
US, it will be somewhat more difficult. You can get a pre-assembled box from
any of the shops on the Edgeware Road in London, but finding it in the US
will be much more difficult.

And, if you're moving into a space you own, you might be better off with a
permanently installed unit anyway.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

Checkout the au-2000 by Acupwr.com I've been using it for years. Made in the USA so you knows it's good quality

[Scott Dorsey]

wrote:
Checkout the au-2000 by Acupwr.com I've been using it for years. Made in the USA so you knows it's good quality

Well, you're replying to a message that is three years old to begin with.

But secondly the AU-2000 appears to be an autotransformer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Murray[_8_]]

On Saturday, 24 March 2012 21:46:36 UTC+11, DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.


I suggest that you buy one manufactured for 50 Hertz power as the North American ones will all be 60 Hertz.

The difference is that 50 Hz transformers have more iron in them and hence are more efficient. When used in Europe they will have less core losses to run at a cooler temperature. You may find the cost prohibitive to achieve the additional 100% power handling capability.

Auto transformers are potentially lethal if the mains connections are transformed and the European power plugs are often lacking a fixed polarity - meaning Active and Neutral can be transposed by the way the socket is wired or the plug is inserted. So be very, very careful if you resort to the Auto transformer option.

I wish you luck. Ultimately, you may need to have a custom transformer built or try to source one from Europe. - Good luck.

[JackA]

On Saturday, March 24, 2012 at 6:46:36 AM UTC-4, DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

Make sure of 60Hz vs 50Hz transformers. Running a 60Hz one on 50Hz will most likely saturate the core, it may be noisy and get warm to hot w/o loading..

Auto transformers don't offer line isolation, but, depending upon voltage ratio, can be a lot smaller (physically) than an isolation transformer. In other words, let's say you need 240V In - 120V Out @ 1000VA. The actual physical size would be equivalent to: 240-120/240 x 1000, or 500VA in an auto transformer.

Jack

[JackA]

On Saturday, March 24, 2012 at 6:46:36 AM UTC-4, DAN wrote:
I thought I bought a fairly heavy and quality 2000 Watt step down/up
transformer but then read some of the posts here about the poor safety
margin of this, what appears to be an auto type transformer.
Thankfully I haven't used it much and wish to purchase instead a
proper isolating step down transformer (to use North American
Electronics in Europe). I see tons of these available but can't find a
proper one.... I wish to purchase a proper step down tran in the USA
or Canada (not made in China). I don't need more than about 1000 Watts
(will probably use half that at any one time). Can someone please post
some specific names or links of what to look for, which product and
company to buy from? Thanks for your time.

Plus, I'm still not sure why you feel uncomfortable with an auto transformer. I'd be recommending it, not an isolation transformer.

Jack