Radian 8048 under the covers.

[ChrisOlson]

I've heard really good things about the SMA Sunny Island Inverters.  Nobody I have talked to that has one has any real complaints on it.

But I would still like to see a Radian sometime with a real battery bank on it put thru its paces.  It's a big inverter and I think I would've liked the extra couple kVA capacity for running my welder and stuff.  Although I've loaded the XW well over 8 kVA for up to five minutes and it doesn't seem to have a problem.  It's just the idea that the GS8048 is bigger and got more capacity so maybe I could run my welder when my wife is load testing equipment in the house without having to check to see if the clothes dryer is going first   

Well I think SMA and Schneider are the only 2 doing what I would call TRUE generator support.

They claim the Radian does have Generator Support, but then they qualify it:

Generators fall into two broad categories – high quality, and crappy. Support mode can be used to augment (support) an AC source to help power large loads. It also has the ability to "firm" or clean up the voltage waveform. This can be used with either grid power or a high quality generator. If the customer has a low quality generator with a noisy or irregular waveform, Support may not work

So Gen Support is probably not TRUE Gen Support, as you say.  The shining ray of light with the Trace/Xantrex/Schneider inverters has always been that they will accept virtually anything that puts out alternating current on the AC2 input, and deal with it by supplementing power and "cleaning up" a "dirty" generator during Gen Support Mode.  This is pretty important for off-grid because there's a wide variety of gas and diesel generators out there with everything from slow governors to gen heads with high THD.

I guess we'll have to wait to see what Magnum comes up with in the MSH4024RE.  But it sounds like Gen Support in the Radian is pretty much like Gen Support in the GVFX - it might work and it might not.  And that's why I wanted to see it demonstrated before I bought one.
--
Chris

[onanparts]

From the Radian manual:

Support
This mode is intended for systems that use the utility grid or a generator. In some cases, the amount
of current available from the source is limited due to size, wiring, or other reasons. If large loads need
to be run, the Radian inverter augments (supports) the AC source, adding inverter and battery power
to ensure that the loads receive the power they demand.
In the MATE3 system display, the Grid Input AC Limit dictates the maximum AC draw for the Grid
input. The Gen Input AC Limit sets the maximum draw for the Gen input. This function takes effect if
the AC draw on the appropriate input exceeds its setting.

Radian AC Input Frequency Range 54 – 66 Hz.

GVFX3648 Input Frequency Range 58 - 62 Hz.

As you can see the Radian has a much wider range concerning AC input Frequency.
All other Outback models are very picky about the AC input. The Radian is designed to work with a wide range of Gensets, cheap or high end, along with a wide range of clean or dirty AC grid inputs.

All of my gensets are Onan 1860 RPM 4 pole units with very clean regulated output. I'll borrow the neighbors cheap no name genny, big box store or Harbor Freight etc. and see how the Radian responds to some dirty AC input.

A note on off grid welding:
My primary backup gensets are portable Onan powered welder/generators. A Miller Legend and Trailblazer. The Legend is rated 5KW AC power 120/240 with a 10KW surge rating, 200 amps AC/DC weld side. 1860 RPM power side, 3000 RPM weld side.

The Trailblazer is 4KW AC power with 250 welding amps AC/DC CC/CV and set up for Mig and Tig so it does anything I ever want as far as welding projects. Running a welder off the inverter is not something I ever plan or need to do. Maybe a small 120V Mig for a quick fix repair job etc. but that's it. 

Anybody that relies on a single off grid inverter will at some point be in the dark or stuck running the genset until repair/replacement can be done.

My Radian will be keeping company with a pair of VFX3524 outbacks and in the near future I'm looking forward to a Midnite Inverter joining the club. 

Multiple RE sources, Hydro, PV and maybe Wind + 3-4 quality welder/gensets that should not see much run time and a single inverter failure will not be an issue for me.

I'm on the grid now but when I'm off it Mr. Redundant will be my best friend. 

[ChrisOlson]

In the MATE3 system display, the Grid Input AC Limit dictates the maximum AC draw for the Grid
input. The Gen Input AC Limit sets the maximum draw for the Gen input. This function takes effect if
the AC draw on the appropriate input exceeds its setting.

The whole idea with generator support in an off-grid power system is to use a smaller, more fuel efficient generator to manage peak loads, in conjunction with a smaller and less expensive inverter, and smaller battery bank, and never use the generator for battery charging.

When an off-grid generator starts, the most efficient use of fuel (kWh/gallon) is if the generator runs at it's continuous or prime power capacity.  Correctly sizing the inverter, generator and battery bank requires an intimate knowledge of your average loads, peak loads, and daily consumption.

Since you have never lived off-grid I will inform you right up front that the most expensive thing for off-grid is not inverters or generators, solar panels or wind turbines.  It is batteries.  Do the math.  Just the replacement cost of your battery bank, not taking anything else into account, costs you more money on a monthly basis that it costs to buy grid power.  Our first battery bank lasted us from June 2002 to November 2009.  Our new Surrette bank cost $9,600.  Those batteries cost us $107.86/month just to own them.

There's some factors when you live off-grid:
-big inverters require big battery bank to use the inverter at its full capacity
-Big battery bank costs more money in the long term
-Batteries store and deliver the same amount of energy over their useful life whether you shallow cycle them or deep cycle them
-the inverter and generator together should be sized to meet peak loads with their combined output, plus 25% reserve
-the generator should be sized no bigger than what is required to meet the bank's C/10 charge rate with the inverter/charger, or get max capacity from the inverter's charger, whichever is smaller
-the battery bank should be sized based on daily consumption minus peak load support from the generator times 1.5
-using a generator to charge batteries with an inverter/charger is one of the most horribly inefficient setups ever invented by man
-using a generator for peak load support where gen power goes directly to loads to take the load off the RE system, and thereby reduce your battery expense long term, is very efficient use of an off-grid generator.

Outback missed the mark in several areas with the Radian, IMHO, for off-grid power.  They had nothing that could compete with the XW, so the Radian was the answer.  Except the XW is available in three different sizes and two different price ranges and voltage configurations, and has integrated AGS (necessary to properly implement Gen Support).  The Radian is more suited to grid-tie with battery backup because few people who live off-grid are going to spend the money on the battery bank it requires to operate the thing at full rated capacity for even two hours (see above on the cost of batteries).
--
Chris

[vtmaps]

Although we do have a Outback product - a PSX-240 on the distribution panel for split-phase leg balancing   

I didn't realize that a PSX-240 made enough breeze to measure with an anemometer    --vtMaps

[onanparts]

Since you have never lived off-grid I will inform you right up front that the most expensive thing for off-grid is not inverters or generators, solar panels or wind turbines.  It is batteries.  Do the math.  Just the replacement cost of your battery bank, not taking anything else into account, costs you more money on a monthly basis that it costs to buy grid power.  Our first battery bank lasted us from June 2002 to November 2009.  Our new Surrette bank cost $9,600.  Those batteries cost us $107.86/month just to own them.



Chris

20+ years of comfortable and efficient Micro-Hydro off-grid living behind us with more to come. Amazing how many people don't know what the first three letters in ASSume mean. 

Feel free to take your dissatisfaction concerning the Radian inverter to the OUTBACK FORUMS.

[ChrisOlson]

I didn't realize that a PSX-240 made enough breeze to measure with an anemometer    --vtMaps

That's the spare one.  I don't know how it ended up on top of the transformer - must've looked like a good place to put it at the time   

Feel free to take your dissatisfaction concerning the Radian inverter to the OUTBACK FORUMS.

Not dissatisfaction - reservations as to whether they did it right and a dealer that couldn't show me that they did it right.  When they start talking about Gen Support and setting it with a single setting based on input amps, the alarms go off because that's now its done with a generator.  That's a grid-tie adaptation from the Grid Support side of it with the word "Gen" tacked on it.  The inverters that do real gen support not only have an AC2 input limit for surge capacity from the generator for support, but also a Gen Support Amps setting that is set to the prime power rating of the generator.  This prevents a gen from getting disqualified during surge so it can immediately resume load instead of sitting there burning fuel waiting for inverter to requalify it because the surge load went past the AC2 input limit.  This is how the GVFX and GFX do it, and it's not true Gen Support.

We burn thru an average of 25 kWh/day and roughly 6 kWh of it comes from the generator every day on peak load support.  It's a very important feature for us that HAS to work properly because our system is designed around it.  The XW was "known quantity" because it "just works".  I haven't met anybody, including talking with tech support at Outback, that can show me how it works on a Radian, or demonstrate it in a real everyday off-grid installation.  And being they don't have an integrated AGS with the proper settings in it to tune it, well, that would be a good start.

The GS8048, just like the FX-series, only has an AUX output.  It does not communicate with the gen controller directly.  And I'm not about to drag a laptop out to the utility room just to program a frickin' Atkinson controller when it should be able to done right at the inverter's control panel.

I have no interest in the Outback forum.  They're the ones that tried to sell us a Radian inverter and failed to demonstrate what I wanted to see, or know about how it works.  They could also not tell me if it even has a PF corrected charger in it, which is also important for Gen Support efficiency because the generator uses it between the Start Load and Stop Load amp settings to recover the bank from an overload on the time delay before the inverter starts it on Load Amps.

So these are all the factors.  You got a "known" that has a proven track record and has been around for years.  And you got an unknown that was supposedly bred and born from a previous architecture where these features were always talked about but never implemented.  When you have to make that decision the "known" is generally a better bet.  And that's why I was interested to find out out if there's really a FX inverter in each one of those modules in a Radian.  Because if there is then Gen Support is not properly implemented in it, and all they did was take Grid Support and tack "Gen" on it.
--
Chris

[ChrisOlson]

On this Gen Support issue in off-grid inverters, Magnum Energy is supposed to be releasing their new MSH4024RE this quarter.  It's been over a year in testing.  It will be 120V only, only available the 4 kVA 24V model and non-stackable.  But it has dual AC inputs, so you should be able to hook two generators up to it.

Being Magnum has been testing this thing for a year, and I talked to them about a year ago about it, it will be very interesting to see how they implemented the Gen Support feature.  The price on it is a few bucks higher than than the standard MS4024 (they got it on their price list).

I have a feeling that if Magnum gets this one right, they will become the new standard in off-grid inverters with Gen Support.  Just because they're available in 24V (which is way more common than 48V for off-grid cabins and whatnot), and are a smaller, lighter form factor that's easier to install.  I've been waiting for that MSH4024RE for the last year because I want to buy one for our boat.  We got an old PowerTech 24V inverter in the boat that's older than dirt, and noisier than our onboard Yanmar diesel generator.
--
Chris

[onanparts]

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Official reports from the Magic Kingdom indicate the cause is due to budget cuts.
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Radian Dual Differential Comparators