looking for big inverter

personally, i use jumper cables when needed

you should call an application engineer at one of the reputable manufacturers. i'm sure they would build a unit to your spec. as far as i know, all units of this size are built to order anyway.

Reply to
TimPerry
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| you should call an application engineer at one of the reputable | manufacturers. i'm sure they would build a unit to your spec. as far as i | know, all units of this size are built to order anyway.

They are built to order from an already designed model.

Reply to
phil-news-nospam

An invertor is part of a UPS.

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Reply to
Spokesman

|> I think not. Many UPSes do run tests and exercises on the battery inside |> to check its charge level and charge acceptance quality. External | batteries |> could easily confuse them unless there is attached circuitry. It is NOT a |> trivial, or even safe, procedure to connect a UPS to external batteries it |> was not designed for. |>

|> A plain inverter works different than a UPS, too. A UPS expects a narrow |> battery voltage range whereas many inverters operate on a wider range of |> voltages. |>

|> Why is it that when I and many other people ask straightforward questions, |> a lot of people seem to go out of their way to answer something else? |> I know the difference between an inverter and a UPS and I am looking for |> an inverter. | | An invertor is part of a UPS.

A UPS includes an inverter. But I am looking for a inverter that stands alone by itself. You do know what an inverter is, I presume.

Reply to
phil-news-nospam

A previous post had a whole list of them. Most of the 3-phase units are

120/208, but many 120/240V appliances will work on 208.

If what you have is a bunch of smaller loads, you might be better off splitting them up and running a group of smaller inverters. If you really have large individual loads, they will be more efficient running on 3 phase than single phase.

Many of the grid-tie units also operate independently.

Reply to
Paul Hovnanian P.E.

Reply to
george_corinne

try MGE s4 line or older s2line.these inverters are standard fare in telcom

Reply to
Lee

| A previous post had a whole list of them. Most of the 3-phase units are | 120/208, but many 120/240V appliances will work on 208.

Many, but not all. I've seen things designed for 240 at best just not work on 208, and at worst burn up.

| If what you have is a bunch of smaller loads, you might be better off | splitting them up and running a group of smaller inverters. If you | really have large individual loads, they will be more efficient running | on 3 phase than single phase.

I am considering the split up. But I don't want to be splitting things up too much. So the goal is each section would be a minimum of 60 amps of 120/240. What I could get out of the Xantrex units is 45 amps.

How does 3 phase make larger loads more efficient? It's a lower voltage.

|> Know of any that are not "grid tie" types? | | Many of the grid-tie units also operate independently.

Now for single phase 120/240 (or series stackable 120).

Or a 6-phase unit.

So, is the real answer that no one makes a single phase 120/240 volt 15kw inverter (just inverter) ... or a 7.5kw series stackable 120 volt one?

All these other ideas might be considered. But right now the quest is to find that elusive inverter that in 1 or 2 units can get me 120/240 volts at 15kw (60 amps).

If I do go with three phase, I'd rather have it producing 480Y/277. Then it's a cheap set of three transformers to step it down to 120/240 in three separate single phase systems ... or a 6 phase system if I tie it all together.

And I might just build my own. Then I can try out a pulse density loop design.

Reply to
phil-news-nospam

Reply to
george_corinne

Actually , yes, I do. The burning question is: Do You?

There have been many reasonable answers which you hvae completely ignored. Some of which may have solved your problem. The other part pf the equation is where are you going to get enough renewable energy to power this big mother for more than a few minutes.

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Reply to
Spokesman

|> | An invertor is part of a UPS. |>

|> A UPS includes an inverter. But I am looking for a inverter that stands |> alone by itself. You do know what an inverter is, I presume. | | Actually , yes, I do. The burning question is: Do You? | | There have been many reasonable answers which you hvae completely | ignored. Some of which may have solved your problem. The other part | pf the equation is where are you going to get enough renewable energy | to power this big mother for more than a few minutes.

I fully understand what an inverter is, and what a UPS is. I'm not really questioning whether some others do or do not know that.

But I disagree about the answers being reasonable, with one exception. That's because I did not ask where I could find a bigger UPS. I had in fact already found them. But a UPS would be lest optimal for what I wanted to do, so that's why I was exploring genuine inverters. That exploration on the net yielded relatively few manufacturers and products. But what I did find was just shy (75%) of the level I wanted to be at.

There are lots of ways to get free/renewable energy. How much you can get depends on how much land and other resources you have access to. Solar PV systems are one way. Windmills are another. You can combine them, too. And if you have some flowing water coming across and going down a hill, there's some more. Does it all end at one specific level where no one can possibly get 1/3 more? Surely not.

But alas, it is a common practice on the net for people to answer some other question than the one asked. I just need to be more verbose in how I express the question. I should have added "And I don't want any answers about UPSes because I have already fond big versions of these".

Reply to
phil-news-nospam

On Mon, 06 Nov 2006 18:59:19 -0800 Paul Hovnanian P.E. wrote: | snipped-for-privacy@ipal.net wrote: |> |> On Sun, 05 Nov 2006 17:11:39 -0800 Paul Hovnanian P.E. wrote: |> |> | A previous post had a whole list of them. Most of the 3-phase units are |> | 120/208, but many 120/240V appliances will work on 208. |> |> Many, but not all. I've seen things designed for 240 at best just not |> work on 208, and at worst burn up. |> |> | If what you have is a bunch of smaller loads, you might be better off |> | splitting them up and running a group of smaller inverters. If you |> | really have large individual loads, they will be more efficient running |> | on 3 phase than single phase. |> |> I am considering the split up. But I don't want to be splitting things |> up too much. So the goal is each section would be a minimum of 60 amps |> of 120/240. What I could get out of the Xantrex units is 45 amps. |> |> How does 3 phase make larger loads more efficient? It's a lower voltage. | | Motors, in particular, are more efficient as 3-phase. Easier to start as | well, which should be a consideration when running off an inverter.

Wouldn't that also justify having 3-phase power in all homes. Of course if 3-phase, or 2 lines of it, had been the standard the US used since the early days of electrical service, then all the higher power appliances would be 208 volt instead of 240 volt (unless someone decided to go with

240 delta). But 3-phase is a big hassle because of the different between L-L voltage in that and single phase.

| Other than lots of motor loads, or resistance heat, residences don't | really need that much capacity, particularly at 240V.

Usually, that is true. But sometimes there are peak loads. We have had the stove running full tilt about once or twice a year. If I end up with a lot of free natural energy pickup, and the energy storage is all full, I might as well feel free to use it.

I want to avoid using fossil fuels, so changing the stove/oven over to gas just to avoid electricity isn't the goal. I may still have some gas just because it makes some cooking better. While direct solar water heating can be practical, many other things don't work so well directly fed by the natural energy. Some may work directly fed by DC, such as incandecent lights.

Reply to
phil-news-nospam

That may be so, but is the price right?

Bill

-- Fermez le Bush

Reply to
Salmon Egg

| On 11/6/06 4:01 PM, in article snipped-for-privacy@news2.newsguy.com, | " snipped-for-privacy@ipal.net" wrote: | |> But alas, it is a common practice on the net for people to answer some |> other question than the one asked. I just need to be more verbose in |> how I express the question. I should have added "And I don't want any |> answers about UPSes because I have already fond big versions of these". | | That may be so, but is the price right?

Many of the UPSes are quite expensive. They need to have features that are often rather different from a need for just an inverter alone. Based on somewhat smaller inverters I have found, an expected price for a 15 kW inverter would be about $8000.

Reply to
phil-news-nospam

Sorry about that. I was talking about the price of the advice--zero. It is true, however, that the value of the advice might be negative.

Bill

-- Fermez le Bush

Reply to
Salmon Egg

On Tue, 07 Nov 2006 20:14:01 GMT Salmon Egg wrote: | On 11/7/06 11:10 AM, in article snipped-for-privacy@news1.newsguy.com, | " snipped-for-privacy@ipal.net" wrote: | |> | That may be so, but is the price right? |> |> Many of the UPSes are quite expensive. They need to have features that |> are often rather different from a need for just an inverter alone. |> Based on somewhat smaller inverters I have found, an expected price for |> a 15 kW inverter would be about $8000. | | Sorry about that. I was talking about the price of the advice--zero. It is | true, however, that the value of the advice might be negative.

It won't have an impact. I know what a UPS is (but it seems I cannot convince some people that I do) so I know what responses to ignore. This is a classic Usenet problem. I've seen it happening for years. I try to make my question as specific as I can. But it seems no matter how specific, there will always be from one to a few people that want to broaden it, usually under the assumption I know nothing about the many alternatives that have in mind. On the other hand, if I make a long detailed question and include a list of the things I don't want any answers about, it tends to turn people off from even reading the question at all.

Anyway, it seems that even with all the "green energy" oriented people around, there is perhaps nothing on the market for anything more than just running a few small appliances on an inverter. Maybe the rest is run directly from DC (that might not be so bad an idea).

Reply to
phil-news-nospam

Reply to
Paul Hovnanian P.E.

(Damned cat jumped on the 'Send' key in mid edit)

Single phase is much cheaper to build for rural electrical distribution systems. Back when energy was cheap and rural customers were happy to get any power, let alone three phase, that's what the utilities built. As load density increases, there is a point where three phase becomes more economic.

I don't know why the difference between line to line and line voltages are a 'hassle' if you design for them. They may be if you are trying to adapt single phase loads to such a system.

Reply to
Paul Hovnanian P.E.

| Single phase is much cheaper to build for rural electrical distribution | systems. Back when energy was cheap and rural customers were happy to | get any power, let alone three phase, that's what the utilities built. | As load density increases, there is a point where three phase becomes | more economic. | | I don't know why the difference between line to line and line voltages | are a 'hassle' if you design for them. They may be if you are trying to | adapt single phase loads to such a system.

The problem is, appliances are what have to be designed for the difference in voltage. And that just not done. Many things do work adequately over that differents. But things work less than adequately. Many things just don't work right at all. And even when things do work, new issues occur, such as the 208 volt circuit needs more amps.

If absolutely _everything_ worked on L-N, then that's how standardization should be done. If absolutely _everything_ worked on L-L, then that's how standardization should be done. The problem is we use _both_ L-N and L-L. We need to stick to just ONE of those. And I think L-L is a better choice.

Most of the loads that benefit from L-N are switched lights in screw base sockets. Grounding the outer part of the shell and using only a single pole for the switch is preferred. Additionally, the lower L-N voltage is good for incandescent lights. Given this, that is why I proposed using an even lower voltage (24 or 12) for these lights, and use a higher voltage for the L-L loads (like 240 to 288). L-L at 240 is safer than L-N at 240. We could, of course, go even higher with the L-L voltage.

Would could choose to standardize on single phase (2.000:1 ratio between L-N and L-L) everywhere.

Would could choose to standardize on three phase (1.732:1 ratio between L-N and L-L) everywhere.

Would could choose to standardize on L-N everywhere regardless of phases.

Would could choose to standardize on L-L everywhere regardless of phases.

We instead chose to have a mixed up scheme. At least the Europeans have chosen one of the above.

Reply to
phil-news-nospam

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