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208 three phase, 200amp

On Mon, 20 Nov 2006 04:22:20 GMT Dale Farmer wrote: | snipped-for-privacy@hotmail.com wrote: |> snipped-for-privacy@hotmail.com wrote: |>> Hi, |>>

|>> can someone help in this one plzzz |>>

|>> Our compnay is purchasing some equipment from USA which runs on 208 |>> three phase, 200amp service. Our standard in this country is 240V 50Hz, |>> 1p/3p.... what can be done or any solution in which conversion cn be |>> provided to run the equipment here..... |>>

|>> Regards |>> John |> |> |> |> Thanks for help Everyone |> |> Its medical equipment and we are getting (in middle east - Qatar) every |> thing is ready... fit and forget, all electricals distribution is |> preplanned... we hv been told about motor generators but I still like |> to know the best solution possible. |> |> John. |> | the manufacturer probably has a version of the exact same machine | that runs on your particular flavor of power. For life support levels | of reliability, I would not use any sort of converter arrangement. | I am sort of curious as to what kind of medical device needs a 200 | amp power feed. Only one I can think of would be an NMI imager, which | needs to supercool the magnet.

If a USA manufacturer of (obviously) high-end medical equipment cannot make models specifically for the domestic voltage and frequency in the world market, then such a company just isn't doing what they need to do to compete in the world. Come on ... just how hard is it to make some device like this be operable on 240 volts 50 Hz ... in terms of percentage of the total overall cost. A medical device that needs a 208 volt 200 amp

60 Hz electrical service (maybe only uses all of that for short times) is certainly going to have a lot of other design costs. A power supply for such a thing is going to be big and almost certainly a module if not a whole separate cabinet. Just design two to four different power supply units based on a reasonable variety of power systems. Something that big probably ought to be running on 480Y/277 in the USA itself, which puts it in the range to be easily run from 400Y/230. If most of it uses DC, such as the magnets if it's something that needs that, then likely a power supply can be versatile 50-60 Hz relatively easily (cost not exceeding the cost of having twice as many models). And then voltage ranging is not too hard, either ... anywhere from 346Y/200 to 480Y/277 at 50/60 Hz should not be that hard to do.

The OP needs to tell us more. If we knew what and from whom, I think the answers that come rolling in would be more along the lines of suggesting that someone made a major mistake in placing the order. And it might not be all that hard to correct (field swap the power supply module).

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phil-news-nospam
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I think the electrical equipment manufacturers in Canada wanted something that was not very common in North America so they would have the majority of the Canadian market.

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Spokesman

thank you everyone for the answers... we have disscussed the issue with our supplier and they will provide us the equipment matching our electrical standard.

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xiibweb

|> >And how did Canada come to be using the 600 and 600/346 volt system, | which |> >I presume to be originally 550 (and 550/318 if wye came before the | voltage |> >change). It's not an unknown voltage in the US, but very rare. Canada |> >does have a lot more 480/277 than the US has 600/346 though. | | | | I think the electrical equipment manufacturers in Canada wanted something | that was not very common in North America so they would have the majority | of the Canadian market.

Thing is, there's plenty of 480Y/277 in Canada, about as much as 600Y/346. Canadian business that are buying equipment probably have an easy choice. I've heard of a few cases where businesses in teh US buy something from Canada and it's 600Y/346 and they need to figure out how to get that kind of voltage. One place I used to work (running a small ISP) actually had

600Y/346 and it was in Texas. I have also seen 600Y/346 listed in the service guides of a couple power companies in the USA.

Anyway, I would dispute the theory on the grounds that having such a voltage, if exclusive, doesn't really give them an advantage in terms of an exclusive market. It may give them an advantage in terms of more efficient use of power.

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phil-news-nospam

| snipped-for-privacy@hotmail.com wrote: |> Hi, |>

|> can someone help in this one plzzz |>

|> Our compnay is purchasing some equipment from USA which runs on 208 |> three phase, 200amp service. Our standard in this country is 240V 50Hz, |> 1p/3p.... what can be done or any solution in which conversion cn be |> provided to run the equipment here..... |>

|> Regards |> John | | thank you everyone for the answers... we have disscussed the issue with | our supplier and they will provide us the equipment matching our | electrical standard.

Yay! That's the right path.

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phil-news-nospam

I suspect the 127V is Mexico or some other place that uses 127Y/220 service, at least in some places.

Back in those days there weren't many switching power supplies. Motors draw more current and I suspect induction motors slip more and use less power, but not proportional to V^2 less like a resistor.

I'd be curious to how much of the load is incandescent lights, other resistive heating, motors, switching power supplies and other. How do fluorescent lights (non electronic ballasts) appear as a load?

Reply to
Michael Moroney

On Sat, 25 Nov 2006 01:37:28 +0000 (UTC) Michael Moroney wrote: | snipped-for-privacy@ipal.net writes: | |>I've seen that, too. I've also seen things listed with 125V and 127V |>and even 130V and 140V. In some cases I think it's "max volts". Some |>light bulbs do come in 130V rating, probably to extend life. | | I suspect the 127V is Mexico or some other place that uses 127Y/220 | service, at least in some places. | |>| I'd guess 440->460->468->480 happened as the same time as the |>| corresponding 110->120V transitions, as I'd assume they made the |>| conversion one substation at a time (possibly by simply changing taps), |>| rather than replacing zillions of perfectly fine pole pigs. Also, I |>| remember they had 'brownouts' (voltage decreases) during the energy crises |>| of the '70s (rather than rolling blackouts like they'd do now if they had |>| to), and I'd assume that was also done by simply changing taps. | |>But are brownouts really effective? Motors in particular, and most |>things with switching power supplies, just compensate with more current. |>With more current downstream, line losses increase. So unless there |>are enough things like light bulbs that go down in current to account |>for the current losses in what goes up, a brownout could these days |>have the opposite effect of what is desired. Maybe that is why they |>are doing blackouts. Soon more people will be installing energy |>reserve systems to deal with that, which means more current when the |>power is on. | | Back in those days there weren't many switching power supplies. Motors | draw more current and I suspect induction motors slip more and use less | power, but not proportional to V^2 less like a resistor. | | I'd be curious to how much of the load is incandescent lights, other | resistive heating, motors, switching power supplies and other. How | do fluorescent lights (non electronic ballasts) appear as a load?

For inductive ballast, I suspect the current will be a function of the voltage across the inductor and its inductance. That will depend on the voltage drop across the bulb once it gets started by whatever means. So the voltage reduction could possibly have more of an effect since the drop in the bulb is relatively constant. That would then result in even less current. That's just my guess. There are things about such lights I still don't understand.

Electronic ballasts will be different and depend on the behaviour of the ballast design, which could vary. They could have a constant pulse width or a constant current or even be adjusting for a change in voltage.

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