Comparable Inverter?

RobertMfromLI · September 2011

Hello all, I am trying to find an inverter that is comparable to the Xantrex SW4048/SW Plus 4048 series. I've seen many store sites that recommend various inverter/charger units (such as Outback or Magnum), but not one that actually is recommending something comparable.

Some details on the application:

12 hours, power will be provided by batteries through the inverter
12 hours, power will be provided by a generator, through the inverter (which will also charge the batteries through/with the inverter)
Needs to output decently clean power (true sine preferred)

Eventually, we are (or may be) considering supplementing with solar, but still working out site surveys, rebates and all that - may take into next summer at this rate.

Theoretical details of use before solar:

At start of day/cycle, generator turns on (custom timer and starter unit)
The inverter registers "line"/generator power and feeds that to load
The inverter charges the battery bank
After preset time frame, AC generator power gets disconnected and generator gets shut down
At this point, inverter draws power via the batteries
After preset period of time (or charge level), cycle restarts

Hookup details:

Generator gets hooked up to gen-in on inverter
Batteries get hooked up to batt-in on inverter
Grid current *MAY* get hooked up to grid-in as additional backup

At a later date (as noted above), we hope to supplement the charging cycle with solar (and slightly expanded battery capacity), thus reducing generator use.

So... with that in mind, we're trying to find something comparable to the SW4048 series which can be paired for 8KW split on two 120V legs.

Thanks,
Rob

RobertMfromLI · September 2011

Re: Comparable Inverter?

Answers to some questions that may crop up:

Generator creates 11KW, split 240V (120/120 opposed freq)
Genset will be set to 7KW generation (same split power output)
Engine is rated to run continuously, 24/7, except for standard maintenance intervals
Engine is rated to handle a gennie a bit larger than this
Was planning on interconnecting two SW4048 together, feed 120V leg to each from genny, and outgoing power to mains
Yes, the engine really is rated for 24/7 operation, with many seeing well well over 100,000 hours (minus "maintenance") - they are often used in "no grid anywhere nearby" 24/7 power generating setups - some of which have been in service for over 30 years.

Cariboocoot · September 2011

Re: Comparable Inverter?

You're probably aware that the SW4048 has been replaced by the XW 4548: http://www.solar-electric.com/xaxw12hyin.html

It's got 240 VAC IN/OUT with split phase output. It costs $3,000, and for $400 more you can get the 6 kW version (XW 6048 http://www.solar-electric.com/xaxwhyin1.html ).

For about $1,000 less money you can get the Magnum MS4448 http://www.solar-electric.com/maenms4444wa.html which is comparable but without the grid-tie capability of the Xantrex unit. Both are pure sine and I think either would work in this application. Outback does not make an inverter over 3.5 kW nor do they have any with 240 VAC output.

RobertMfromLI · September 2011

Re: Comparable Inverter?

Cariboocoot wrote: »

You're probably aware that the SW4048 has been replaced by the XW 4548: http://www.solar-electric.com/xaxw12hyin.html

Yes, alas, I am. I'm having a hard time finding a site with a comparable specs list. Inotherwords, there are features missing on it (or on the specs lists online) that show up on the SW4048's specs I can find online. Is there a better site that I can compare the specs on both? And yes, based off rating (and cost), it appears that we'd need two 4548s (6KW isn't quite enough).

Have you ever worked with them? What do you think of the XW series? I've seen tons of the SW series installed with little to no complaint, but not one XW yet.

Thanks,
Robert

BB. · September 2011

Re: Comparable Inverter?

What motor/genset brands/models are you using? They sound very nice.

-Bill

Cariboocoot · September 2011

Re: Comparable Inverter?

I'm not a big fan of Xantrex or the XW series. No point buying the GT capability if you can't make use of it, for one thing. Schneider/Xantrex's customer support for another. The merger seems to have confused things even more. There are two Xantrex guys on the forum, and several others who really know the XW equipment but are not connected with the company.

I don't know what info you can't find about the XW, but perhaps they can help. NAWS has a data sheet here: http://lib.store.yahoo.net/lib/wind-sun/XW-Inv.pdf

SW's being discontinued finding info on them is difficult. Even hunting down an IB can be a problem (someone on here has one - 13meg PDF file). They're also pretty difficult to repair these days as parts are drying up.

I think I'd prefer the Magnum in this case (data sheet here: http://lib.store.yahoo.net/lib/wind-sun/Magnum-MS-PAE-datasheet.pdf). You can parallel four of them, if need be. So you'd have two @ 8kW for about 50% more money than one XW @ 6kW.

But then I'm a cheapskate.

RobertMfromLI · September 2011

Re: Comparable Inverter?

BB. wrote: »

What motor/genset brands/models are you using? They sound very nice.

-Bill

Hi Bill,

On the generator, not sure (don't remember off the top of my head and don't have access to the specs right now).

On the motor (which I *do* remember, because the claims seemed absurd, so I spent a week researching it), a new (yet old design) Lister type diesel generator, the 16/1 to be specific. Uses 1.5 pints per hour under load at the loads we are using... roughly 2.25 to 3 gallons a day at 12 hours run time.

So... I did a lot of digging and found some in use on farms, in 3rd world countries and so on, which had been in use for decades. Also found innumerable charts, owner reports and so on about the fuel usage. They burn almost anything: diesel, bio, kerosene, Jet a-1, JP-4, waste hydraulic oil, rendered animal fat, waste veggie oil and more... emissions using veggie oil becomes well within acceptable ranges for home/farm/business full use generators.

Best,
Rob

RobertMfromLI · September 2011

Re: Comparable Inverter?

Cariboocoot wrote: »

I'm not a big fan of Xantrex or the XW series...

...But then I'm a cheapskate.

LoL, and so am I. I will look into those others. Thanks for the quick replies!!!

-Rob

BB. · September 2011

Re: Comparable Inverter?

Where are they made? India? They can be made to be reliable--but some of what I have read seems to indicate problems with springs, castings, piping (breakage, sand, leaks, etc.).

Here in California--I would think that the new air pollution regulations would probably make these illegal now.

Are you having good luck with the AC alternator? A slow turning one lung engine can cause the lights to flicker (from what I have heard).

-Bill

RobertMfromLI · September 2011

Re: Comparable Inverter?

BB. wrote: »

Where are they made? India? They can be made to be reliable--but some of what I have read seems to indicate problems with springs, castings, piping (breakage, sand, leaks, etc.).

Here in California--I would think that the new air pollution regulations would probably make these illegal now.

Are you having good luck with the AC alternator? A slow turning one lung engine can cause the lights to flicker (from what I have heard).

-Bill

Hi Bill,

They are made various places, including India - just no longer made in the UK. Plenty of aftermarket parts, and this is an assembled, cleaned and tested unit (being sold by a reseller in the states who builds the whole genset assembly) - and we will be inspecting before purchase anyway.

The air pollution issues are rather simple; veggie oil and some of the exhaust mods out there - not suited for running in a residential area without some sort of exhaust mod anyway (kinda loud without one).

As for the generator - it's a regular genny head, 11KW. No AC alternator deal like some people do on the lower HP (such as the 5/1) engines. It spins at it's real and rated speed. As for variances due to load, they are minimal due to the two massive flywheels and speed governor. Thus, when load jumps, the governor "speeds up" (maintains speed of) the engine long before flywheel energy can be exhausted. And of course, since the generator is an actual genset running at proper speeds, no light flicker, and "perfect" 60Hz output (big flywheel pulley to small generator pulley).

mike95490 · September 2011

Re: Comparable Inverter?

XW6048 user here & listeroid 6/1 owner. Have not hooked up the cooling yet, but all indications from the http://www.microcogen.info/index.php forum, I should be in good shape. Just tear the engine down and clean all the casting sand out of the crankcase before you run it.

Mike

RobertMfromLI · September 2011

Re: Comparable Inverter?

mike90045 wrote: »

XW6048 user here & listeroid 6/1 owner. Have not hooked up the cooling yet, but all indications from the http://www.microcogen.info/index.php forum, I should be in good shape. Just tear the engine down and clean all the casting sand out of the crankcase before you run it.

Mike

Will do... we're planning cooling via a standard auto thermostat and radiator, closed loop system. We're also thinking of getting a bit inventive and venting the heat into the battery room (one building, wall down the "middle" with genny/engine on one side, and batteries/inverter on the other). Figure, a temperature controlled louver so, during the winter months, it opens into the battery room when the room's temp falls below 70F, closes when it reaches 80F.

Cariboocoot · September 2011

Re: Comparable Inverter?

Great: an engine you have to disassemble and clean before you've used it even once.:roll:
Mr. Lister wouldn't be happy about that. The brand has been around for a very long time with quite a reputation for dependability. What a shame to see them fall to such lows.

RobertMfromLI · September 2011

Re: Comparable Inverter?

Cariboocoot wrote: »

Great: an engine you have to disassemble and clean before you've used it even once.:roll:
Mr. Lister wouldn't be happy about that. The brand has been around for a very long time with quite a reputation for dependability. What a shame to see them fall to such lows.

Agreed, but fortunately, it does not seem to be the norm, nor all manufacturers. There seems to be one that it's reported to happen to, and that's not the manufacturer who made ours (fortunately) - though it's still a good idea to check anyway I guess. And it's only a small handful of bolts to pull the engine apart. If one is familiar with the old Honda motorcycle engines, the block comes apart much like them. Four long bolts and the cylinder and cylinder sleeve come right off the crank case. An hour or two for full tear down and re-assembly (or so I've heard).

mike95490 · September 2011

Re: Comparable Inverter?

RobertMfromLI wrote: »

Will do... we're planning cooling via a standard auto thermostat and radiator, closed loop system. ....

Oh no ! The O ring seal at the bottom of the cylinder liner is rated for about 2 psi. when you build pressure, even from the water heating and expanding, at 180F, you will blow your water into the crankcase. They were designed for thermosiphon, and if you set it up right, with a large bore radiator, you will get flow. And you need to drill a small hole in the thermostat to allow a bit of flow, or the 'stat does not open well, and the system "oscillates"

RobertMfromLI · September 2011

Re: Comparable Inverter?

mike90045 wrote: »

Oh no ! The O ring seal at the bottom of the cylinder liner is rated for about 2 psi. when you build pressure, even from the water heating and expanding, at 180F, you will blow your water into the crankcase. They were designed for thermosiphon, and if you set it up right, with a large bore radiator, you will get flow. And you need to drill a small hole in the thermostat to allow a bit of flow, or the 'stat does not open well, and the system "oscillates"

Sorry, I should have been clearer...

Not "closed" as in, single, continuous loop with no place for the pressure buildup to vent to.

The "closed" part is the overflow... the thermostat has to be carefully selected. Also, the radiator cap must be carefully selected as well (very low pressure cap), so pressure vents into the overflow. Then, the overflow needs to be appropriately maintained and able to flow back on cooling. Bad choice of terms on my part... sorry about that.

Dave Angelini · September 2011

Re: Comparable Inverter?

Buy an XW 6048. There is nothing better and I wish there were! It will surge and gen support like no other. If your loads need these kinds of attributes then your search is over.

Comparable Inverter?

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