Does Radian have Generator Support?

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The Electron
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Does Radian have Generator Support?

Post by The Electron » Thu Oct 24, 2013 4:50 pm

I remember all too well the generator support the FX's were supposed to have....... So does the Radian have Generator Support?

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Re: Does Radian have Generator Support?

Post by dhamilton » Fri Oct 25, 2013 4:30 pm

The Radian does have a support mode where the inverter will support an undersized generator or grid.

The Support 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.
CHARGING:
In this mode, when the charger is enabled, the Radian will use the AC source to charge the battery
bank. (See page 20.) It will proceed through the entire battery charging cycle. After the end of the
Float timer, it will continue to alternate between Silent and Re-Float stages.
BENEFITS:
´âÿ The large loads on the system can be powered while staying connected to the input, even if the input is
limited. Battery power prevents overload of the input source, while at the same time limiting the amount of
battery power used.
´âÿ In this mode, the inverter will offset the loads with excess renewable energy if it is available from the
batteries. (See page 19 for more information on the Offset function.)
´âÿ This mode has a programmable delay time which will allow an AC source to stabilize before connection. In
the MATE3, this menu item is Connect Delay. It is available in either the Grid AC Input Mode and Limits or
the Gen AC Input Mode and Limits menu, depending on which input is being programmed.
NOTES:
IMPORTANT:
If the AC loads exceed the amperage limit setting, the inverter will draw energy from the
batteries. If the loads are sustained, the batteries may discharge to the point of Low
Battery Cut-Out and the inverter may shut down with a Low Battery error. (See pages 15
and 40.) To prevent the loss of backup power, load use should be planned accordingly.
´âÿ The grid-interactive function of the Radian inverter is unavailable in this mode.
´âÿ Because the inverter limits the current draw from the AC source, it will reduce the charge rate as necessary to
support the loads. If the loads equal the amperage setting, the charge rate will be zero.
´âÿ If the AC loads exceed the amperage setting, the charger will begin operating in reverse. It will take power
from the batteries and use it to support the incoming AC current.

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Re: Does Radian have Generator Support?

Post by The Electron » Tue Oct 29, 2013 8:26 am

Thanks dhamilton for the detailed reply. I am sorry for not asking what I really wanted to know. My fault!

I am a little gun-shy when it comes to recommending an Outback inverter that supposed to have FUNCTIONAL generator support. So what I'm looking for is owners/installers who have seen a Radian actually combine power from both to start a load neither could on their own. This has been done successfully for years with Trace/Xantrex/Schneider/What-are-they-called-now. Does anyone have hands-on seeing this work, and work well?

For more information to chew on about the Radian, see http://midniteforum.com/index.php?PHPSE ... opic=501.0, and specifically to my question, look for ChrisOlsen's comments/gripes about the Radian. The first 2 pages of this thread are mostly pictures and banter, but page 3 is where the technical questions start.

I Like Outback's stuff, it's good. Just wanting more info. Thanks in advance!

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Re: Does Radian have Generator Support?

Post by mtdoc » Thu Nov 07, 2013 10:07 pm

FWIW generator support works well on my GVFX 3648. Supposedly the Radian is based on the same tech.

Also keep in mind that Chris Olson by his own admission has not owned or used an Outback inverter. One might even surmise that he has an agenda.... :-s

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Re: Does Radian have Generator Support?

Post by billvon » Tue Nov 19, 2013 1:16 pm

dhamilton wrote:The Support mode is intended for systems that use the utility grid or a generator.
Does the Radian impose different requirements on the power quality (freq stability, voltage range etc) for the generator vs the grid input? In other words, is it "easier" for the Radian to connect to a generator than to the grid?
--bill von

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Re: Does Radian have Generator Support?

Post by The Electron » Wed Nov 20, 2013 8:29 am

Great question BillVon! Really great question. Also, anyone know if the Radians are as picky on input power as compared with the Grid-Tie FX's?

And Mtdoc, I realize Chris is critical. But what I want to see is someone prove/testify he is wrong. Again, need I remind us about the promised gen support that never came on the FX's? ... Sending out a request for someone who has seen this WORK on a Radian. Thanks all. :grin:

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Re: Does Radian have Generator Support?

Post by ChrisOlson » Tue Mar 18, 2014 11:27 am

I am the Chris being mentioned here. Since I had my initial questions, one of our off-grid neighbors bought a Radian and we spent most of one weekend trying to get it to work with a 4.0 kVA Perkins diesel generator, part of one day with the dealer. It did not work. The inverter would qualify the genset, attempt to load it and immediately spit it off. Then repeat. We tried setting the allowable voltage and freq as low as it would go, tried different load settings, etc., all to no avail. The dealer told us the genset is junk. So we loaded it up in the back of my Dodge Cummins with a skid steer loader and hauled it over to my place to test it. It worked perfectly fine on our system.

The problem appeared to be leg imbalance on the system possibly causing either L1 or L2 on the genset to drop out of range and be disqualified by the inverter. We had the Radian opened up and could not see where Outback used any sort of center-tapped transformer to assist in gen leg balancing during generator support, as is common in other split-phase inverters that have generator support function. Gen support on 120V single phase is easy to implement. On split-phase power it isn't.

I had intended to take our PSX-240 to the neighbor's place to try it with that and see if it would work. But the inverter ended up going back to the dealer for other problems and he got a different system.

Based on what I could figure out using my Fluke meter on capture to see what was going on with it - unlike the FX that showed it in the menus but had no hardware for it, gen support is definitely in the Radian. It tries but I think the problem was unbalanced load causing one leg of the genset to "sag". So instead of subjecting the loads to poor quality AC, the Radian takes over and tells the genset to take a walk. I really wish I could've tried it with the PSX-240 because I think it would've worked fine with the transformer on it.

When it comes to generator support, as I said, 120V single phase is really easy for manufacturers to do. And on split-phase, grid support is really easy to do when you have virtually unlimited leg imbalance power available up to the inverter's max input rating. But with generators it can be a bear because gensets do NOT have unlimited power available on imbalance where you have significant current flowing in the neutral. The PSX-240 can "fix" all that by using the neutral current to drive either the transformer primary or secondary to assist the other side. And I'm about 95% certain that's all it would've took to make it work.

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Re: Does Radian have Generator Support?

Post by intellact » Fri Mar 28, 2014 5:01 pm

Reading this thread gave me an idea. :idea: You know what's coming, don't you... :smile:

The latest version of WattPlot 5 now compares the input voltages on L1 and L2 if AC2/Generator is selected. If the voltage difference is more than 5 volts, WattPlot triggers a warning.

This has different meanings to different WattPlot tools. For example, in WattPlot Monitor it might trigger a user-programmed response; while in WattPlot NetMATE, you might receive an email alert that something is amiss. :cool:

Thanks, Chris, for the helpful post and the extra information off-line. :wink:
Andrew Welch, creator of WattPlot

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Re: Does Radian have Generator Support?

Post by tallgirl » Sun Mar 30, 2014 3:24 pm

Andrew,

It isn't unusual, or even "bad", for L1 and L2 to differ by as much as 6 percent, which is 7.2 volts line-to-line on a 240 volt split single phase system (+3% on one leg, -3% on the other -- not 6% of line-to-line). The general guidelines for conductor sizing is 2 or 3 percent, which if you take both legs at the design voltage drop / rise, is that 7.2 volt number.

I don't know the Radian firmware well enough to know how it handles bringing the two FX chassis on-line, but if it works like a pair of GVFX inverters, one FX chassis is going to turn on well before the other, further increasing the likelihood of a phase imbalance. Still within reasonable values, but I do see numbers like 128VAC on L1 with 122VAC or less on L2.

All that said, the correct solution is a balancing transformer. I'd get rather alarmed at seeing alerts whenever I load up L2 (120 volt LEAF charger, dishwasher and coffee pot would do that -- turning on the microwave and vacuuming the hallway would be adding insult to injury!) when the L1 inverter is getting wound up in the morning.

If you're looking for an alert to add, repeated acquisition and loss of grid and/or generator power would be the better bet, but there are a lot of scenarios where L1 and L2 don't balance, which is why a PS-240 on a 40A2P-NC contactor (or energize from the generator when it powers up) with a 120 volt coil is the "best" solution.

One of these days I've got to teach you the finer points of Modbus and/or PLC programming so you can interface with a DAQ that does line frequency measurement. That's the "signal" from most gensets that they are about to be dropped.
Julie in Texas

I ride bicycles. A lot.

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Re: Does Radian have Generator Support?

Post by ChrisOlson » Sun Mar 30, 2014 8:27 pm

tallgirl wrote:It isn't unusual, or even "bad", for L1 and L2 to differ by as much as 6 percent, which is 7.2 volts line-to-line on a 240 volt split single phase system (+3% on one leg, -3% on the other -- not 6% of line-to-line)
You're implying that it's acceptable to have current flowing in the neutral on split phase loads? In over 30 years in the power generation business I have never seen where that is acceptable on a split phase service. Any inverter system that cannot main perfect leg to leg voltage on a split phase system is junk and needs to be thrown in the scrap heap and go buy a good one.

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Re: Does Radian have Generator Support?

Post by tallgirl » Sun Mar 30, 2014 9:03 pm

ChrisOlson wrote:
tallgirl wrote:It isn't unusual, or even "bad", for L1 and L2 to differ by as much as 6 percent, which is 7.2 volts line-to-line on a 240 volt split single phase system (+3% on one leg, -3% on the other -- not 6% of line-to-line)
You're implying that it's acceptable to have current flowing in the neutral on split phase loads? In over 30 years in the power generation business I have never seen where that is acceptable on a split phase service. Any inverter system that cannot main perfect leg to leg voltage on a split phase system is junk and needs to be thrown in the scrap heap and go buy a good one.
Split phase loads always result in neutral current, unless the two phase legs have identical current, in which case the neutral currents cancel.

Are you sure you're not confusing what I've described with something else?
Julie in Texas

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Re: Does Radian have Generator Support?

Post by intellact » Mon Mar 31, 2014 7:31 pm

tallgirl wrote:Are you sure you're not confusing what I've described with something else?
I might ask the same question. In regards to the original topic, you did catch that we were talking about Generator AC In, not Radian AC Out, right?
tallgirl wrote:I don't know the Radian firmware well enough to know how it handles bringing the two FX chassis on-line, but if it works like a pair of GVFX inverters, one FX chassis is going to turn on well before the other, further increasing the likelihood of a phase imbalance. Still within reasonable values, but I do see numbers like 128VAC on L1 with 122VAC or less on L2.
OK, so you're not familiar with the Radian firmware (and no, a Radian is not the same as just two inverters). It seems obvious from the earlier thread information that Radians do care about phase imbalance on incoming AC, and that the implemented warning is entirely relevant.

In addition, to be sure, the software takes the load amps into account before simply telling the user there's a problem. WattPlot triggers can also be configured with a time delay so that the condition must be maintained for a length of time before being reacted to. :smile:
tallgirl wrote:I'd get rather alarmed at seeing alerts whenever I load up L2 (120 volt LEAF charger, dishwasher and coffee pot would do that -- turning on the microwave and vacuuming the hallway would be adding insult to injury!) when the L1 inverter is getting wound up in the morning.
If you read the entire thread, you will see that this warning is specific to a situation where the Radian is rejecting generator power. This is not a normal situation that the user should ignore. The warning provides additional information about why their generator input is being tossed.

Furthermore, any user who is feeling 'alarmed' can simply turn off that particular notification. :grin:
tallgirl wrote:If you're looking for an alert to add, repeated acquisition and loss of grid and/or generator power would be the better bet.
Too late. That alert is already there. :wink:
tallgirl wrote:One of these days I've got to teach you the finer points of Modbus and/or PLC programming so you can interface with a DAQ that does line frequency measurement. That's the "signal" from most gensets that they are about to be dropped.
Programming lessons? :-k Hmm... Pass. Thanks anyway. :grin:

But seriously, we all do appreciate the wealth of electrical system knowledge and expertise that you share on the forum. =D>
Andrew Welch, creator of WattPlot

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Re: Does Radian have Generator Support?

Post by tallgirl » Tue Apr 01, 2014 1:55 am

intellact wrote:
tallgirl wrote:Are you sure you're not confusing what I've described with something else?
I might ask the same question. In regards to the original topic, you did catch that we were talking about Generator AC In, not Radian AC Out, right?
Yes, I did. But again, irrelevant.
intellact wrote:
tallgirl wrote:I don't know the Radian firmware well enough to know how it handles bringing the two FX chassis on-line, but if it works like a pair of GVFX inverters, one FX chassis is going to turn on well before the other, further increasing the likelihood of a phase imbalance. Still within reasonable values, but I do see numbers like 128VAC on L1 with 122VAC or less on L2.
OK, so you're not familiar with the Radian firmware (and no, a Radian is not the same as just two inverters). It seems obvious from the earlier thread information that Radians do care about phase imbalance on incoming AC, and that the implemented warning is entirely relevant.
LOL! No, I mean familiar with the Radian firmware at the source code level. I sincerely doubt OutBack is going to let me anywhere near Radian firmware source code.
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Re: Does Radian have Generator Support?

Post by tallgirl » Tue Apr 01, 2014 9:09 pm

Here's the sort of project that would likely be handy for those of you with generators --

http://duino4projects.com/power-quality ... g-arduino/

Something like that, which could report real-time line-frequency back to a monitoring program would provide excellent feedback about how a generator is behaving. My software supports revenue grade digital meters, but they cost about $300 to $500 (or more) for a good meter by the time you add CTs, an enclosure and labor.
Julie in Texas

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