XW 6048 - A/C Passthru vs. inverter power usage
Dusty
Solar Expert Posts: 271 ✭✭✭
In the evening, when my solar panels are no longer producing any power, the 6048 inverter enters "A/C Passthru" mode. At this point, I've been setting my Midnight Solar E-panel to "bypass" and turning the 6048 off.
I don't want to let the inverter use 30+ watts all night long doing nothing, but at the same time, I know that thermal breakdown of components can shorten the life of a power system. (I'm a Navy radar technician, so my experience is limited to very high voltage, high power systems.)
When the XW-6048 is in A/C passthru, should I be shutting it down every night, or is it wiser in the long run to leave it on?
I don't want to let the inverter use 30+ watts all night long doing nothing, but at the same time, I know that thermal breakdown of components can shorten the life of a power system. (I'm a Navy radar technician, so my experience is limited to very high voltage, high power systems.)
When the XW-6048 is in A/C passthru, should I be shutting it down every night, or is it wiser in the long run to leave it on?
XW6048, 3.4KW PV, Grid-Tied, always tweaking.
Comments
Turn it off, see what happens.
Likely as not the AC stops "passing through" because the XW isn't powered so the relay doesn't click. Not sure that's the way they are wired, but it's what you get with most off-grid inverters: no battery, no power.
You could install a transfer switch to "work around" the inverter if this is the case (switch loads from the inverter's AC OUT to the AC IN so they run 'directly' from the power source).
The Midnight Solar E-panel allows me to bypass AC OUT so I can shut off the inverter without dropping power to the subpanel. In Bypass, the AC1 input goes directly to the sub-panel. However, it was my understanding that even with the inverter in AC Passthru it was still using at least 28 watts. Search mode won't work in my house.
My concern is that I might be reducing the life of the inverter by shutting it completely off every evening, letting all the components cool, and then turning it on the next morning. Saving 300+ watts every night but having to replace a $3k inverter two years sooner because of component breakdown is probably not a good return on investment. Or perhaps I'm just paranoid.
I am not familiar with the Xantrex inverter/chargers. On the Outback inverter/charger I can turn off the charger mode and/or the inverter mode. When I do that the inverter/charger is still connected to the battery and draws a tiny phantom load.
Are you saying that this is not possible with the Xantrex?
--vtMaps
Shut it off, The XW component ratings are way overspec'd. They have to be to meet the MTBF specifications, The inverter pretty much doesnt even get hot during operation. If its one thing that X had it was good electrical engineers who designed this box. Software is another story...
On the System Control Panel (SCP), I can turn off both charger and Inverter modes, but neither the installation or operation manuals indicate what the phantom load would be in this configuration. It only indicates a 28 watt load when idle, and an 8 watt load when in Search Mode.
Maybe I can put the MS E-panel in bypass and then put the inverter/charger in Search Mode. That's worth trying. I can live with a 8 watt load and leave the 6048 powered up.
Thanks Joe, that makes me feel better about turning it completely off at night.
Have you ever used Search Mode in your 4024? If so, does it show up on the SCP status?
I'm hoping that with Sell still enabled at night with the loads disconnected, the unit will still enter Search Mode as long as the PVs are not producing. If I forget to put the loads back online in the morning, the system will still come out of search mode and sell to the grid. (just yesterday I was in a rush to get to work, and I forgot to turn the inverter back on. Missed a whole day's harvest!)
No, mine runs 24/7/365
I think the only way to reduce the phantom load to zero is to disconnect the AC from AC1 / AC2. I think even in search mode, there is some draw from the grid. I am not sure what happens with search and sell, I dont use either mode.
Dont know where you are getting the 30 watts for the phantom load, mine sucks down about 60 - 80 watts off the grid whenever the grid is present. If you do the math, you get 70*24*7*365 which gives you about a 4.3KWH per year suck factor.
In the Operations Manual, Appendix A Table A-1 Specifications states the idle consumption in Invert Mode with no load is 28 watts. In Search Mode it's 8 watts. I know what you mean though--usually when I'm looking at the SCP, the difference between the load and the output of the inverter is more like 50 watts. That's why I was shutting it completely down every night. But forgetting to turn it on on one of the sunniest days I've had so far hurt! My best daily harvest so far was 12.3Kw with 2.6Kw worth of panels (before derating them). On that day, my meter only incremented by one KWh. Of course, that was before the heat wave hit. Now my geothermal heat pump is running, and my daily net usage is around 17Kwh.
I'm not sure if the unit will ever go into Search Mode at night if Sell is enabled, but I'll give it a try. That way, if I forget to take the E-panel out of Bypass before heading off for work, I'll still be selling and not losing the entire harvest.
Disconnect the DC to the inverter. Disconnect the AC loads from the inverter. Disconnect the AC power from the inverter. Pretty sure the consumption drops to 0 then, even with a Xantrex. How convenient it is to do this is another issue.
Dusty, you're looking at the DC consumption for running the inverter full (28 Watts) or in search (8 Watts). Joe is talking about the XW pulling AC from the mains while doing basically nothing.
Meanwhile, vtMaps and I are chanting "so glad I bought an Outback!"
I am not sure that specification tells the whole story when you operate in grid support mode. I do see the 30 watts when I disconnect the grid and look at battery current but in grid support mode, there is a lot more going on. I have seen it get as high as 80 watts but when in GSM, the currents are bouncing all over the place.
Yup, I hear ya. Things stabilize at night when the unit goes into A/C Passthru.
Regarding Search Mode, here's what the manual says:
Using Search Mode
Why use Search
mode?
Search mode allows the inverter to selectively power only items that draw more
than a certain amount of power, which can result in power savings. The Xantrex
XW Series Inverter/Charger has a no-load power draw of about 28 watts.
Enabling search mode reduces this power draw to less than 8 watts.
Search mode operates differently in single-unit and multi-unit installations.
-Single units: When a single Xantrex XW Series Inverter/Charger has search mode enabled,
the inverter sends electrical search pulses through its AC output. These search
pulses look for connected AC loads. The delay between search pulses is set
using the Search Delay setting. After a load larger than the Search Watts
setting is detected, the inverter starts producing AC output
It doesn't mention how Search Mode interacts with Sell Mode via AC1--only that it monitors the loads on AC OUT. I can't see the system being able to put the inverter in Search mode if it's actively selling to the grid, but I wonder if it would go into Search Mode at night when the system goes into AC passthru. I'll check that tonight.
Oh, I thought the 28 watts was what was pulled from the mains when in grid support and there was no load on AC OUT. I wasn't thinking about the DC wattage. Thanks!
But if I'd bought an Outback, what would I do with all my spare time?!:p
I am not sure that search and sell modes have anything to do with each other. The way search works is to periodically power up the inverter to look for a load. Given that the power goes down by a factor of 3.5 or so that would imply a duty cycle of around 30%. Sell depends on the battery bank voltage. As long as the battery bank voltage is above a certain level, the excess will be pumped back to the grid. Since you have a pretty small battery bank, I would guess that as soon as the PV stops producing, the sell mode terminates. Search mode only looks at the AC loads and therefore I do not believe that the modes will interact but the only way to find out is to try it and possibly uncover new bugs! Good luck....
You'd be reading the bloody programming manual!
I usually shut the inverter down in the evening when the SCP shows <50 watts output from the MPPT-60. My Victron history H1 shows that my deepest discharge has been less than 5Ah so far. I'm sure that you're right--having such a small battery bank, it wouldn't take long for the battery bank voltage to reach GSV -0.5V and turn off Sell Mode. It will be interesting to see what the Victron shows for the SOC when that happens. And I'm still hoping that once the unit goes into AC passthru with the loads removed from AC OUT (E-panel in Bypass), the 6048 will enter Search mode at night. Hopefully it will "wake up" when the PV output is high enough to sell to the grid the next morning.
Wow, a programming manual? You aren't locked into buggy firmware???!
Stop it, just stop it!
Sorry Joe, couldn't resist.
Wind the transformer you need for the 240V well pump.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
With Search mode enabled and all loads on AC Out bypassed, the system would not go into Search as long as Sell was enabled--even if the panels weren't putting out any power. Since My GSV is set to 64V to enable Enhanced Interactive Mode, I wasn't sure how deep the discharge of my battery bank would occur, so I shut the system off when my SOC was about 92%.
This morning, when I turned on the unit, it briefly went into Search mode but then immediately came back out--even though AC Out was still in Bypass. There wasn't any input power from the PV array yet, so I have to assume that having Sell enabled interferes with Search Mode, even if the inverter isn't actively selling.
Congratulations, you found your first new bug... Err I mean "feature" Here is the number for SE tech support
1-866-519-1470
You were just itching to give me that number, weren't you???
This evening, I'll try turning Sell off and see if that "solves" the problem. I didn't want to let my batteries run too far down, but I could have let them go lower than 92%--but that's just a waste of power and harder on the batteries than I'd like.
There are more advanced choices with a combox and XW+ modern firmware.
If you have any grid or gen input you would not want search anyway.
Most offgrid/back-up large power systems, that would use a large inverter like the XW, do not use the search function in my opinion.
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There will be no more firmware because the XW is obsolete and replaced by XW+ about 5 years back.
The XW can have most of its functions controlled by mod bus but that is probably not worth the work of doing.
Search is mainly from the old days of back-up and offgrid when solar was expensive or systems were very small. An extra solar panel would easily make-up for your losses. Maybe someone else will have a glimmer. Good Luck.
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It will last for 10 years and alot more if you have surge protection on DC and AC. I have 3 that have been running since 2007 and in pretty harsh conditions. The only problems I have seen are grid people getting surges or generators that bang the input relays to death.
The reason I mentioned modbus programming is because that will remove the grid and it will function as an offgrid inverter. I have done this with help of a friend who speaks modbus. We did this for a large microgrid.
Using an XW in a grid interactive mode is one of the most complex projects there is. It always surprises me that people who do this including the Outback Radian crowd jump in without using a forum like this to speed up their knowledge. Schneider and Outback have dozens of u-tubes and there are also the individual users who post them.
I have had clients who paid me to read the manual to them and interprete with my experience. Maybe someone else here will give you a better option.
Gotta go we have another wildfire....
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We are fairly safe in that we built the home with the idea that there would be no fire engines to defend us.
A navy radar guy, cool. There generations of navy here including one Italian.
I was thinking of reasons why your problem exists and sometimes it is for other reasons that designers choose to ignore an issue.
If you had multiple inverters (master /slave) the main inverter can not ever be allowed to go to search.
Another reason is if you had a back-up inverter wired, the main can't be in search because the spare will not come on with the search pulses from the main. Probably more reasons....
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