Xantrex XW6048 Inverter Help

gbaig

Dea All,
II am planning to buy a XW6048 6KV solar inverter and MPPT charge controller. My current setup is Solar>Grid>Battery which means that during the day load comes directly from the PV and not from Grid or battery until it exceeds PV power. Batteries are strictly used for back up when grid goes off (which happens very often)
I have a question: I came to know that XW6048 passes entire load all the time via batteries. Is that True? Any way to avoid such scenario ?
What happens to the battery life if load passes though them all the time? Currently, I have two Infini Inverters 3KV each) which are flexible to program but they are made in china and come with only 6 months warranty, I want to change them with Xantrex 6048 as it also gives remote monitoring as well. I will highly appreciate your feed back on this please.

Blackcherry04

The XW and InfiniSolar Inverters are two totally different concepts. The InfiniSolar is a grid zero concept with direct PV input and the XW is a 10 year old hybrid battery based system. There is really not a way to make the two act the same.

The XW in the hybrid mode is going to use the batteries as the buffer and storage device and going to sell the excess to the grid. Batteries last as long as they last, depends on the batteries cycle life or they die of old age.

Added :

Personally, I'd stay away from the InfiniSolar inverter, I have a Meanwell that is similar ( not Grid Tied.) It has all kinds of weird fixed settings that you can not get around. The battery charging settings are horrible and almost everything else is a fixed algorithm. Service would be almost non existent on them. Hopefully the next generation of Inverters here will have some of the features that people want, like being able to prioritize input and use. I understand the newish Outback Radian has some settings that allow it to do some different things on it's input and output. Here we have had separate charge controllers instead of all in one units. You have to remember our Inverters here developed from the fixed off grid and mobile market and grid tie is relativity new.

BB.

During the middle of the day, the solar panels do supply most of the energy to the AC inverter (charging the battery bank and power to the AC inverter+loads).

However, if you start a large motor (A/C, well pump, etc.) and other than the middle of the day, the batteries are critical to supplying power for your inverter.

In detail, AC inverters do not draw "smooth" AC power but actually draw current in a "sine squared" DC current wave form... It.i.e., at AC sine wave peak voltage, the inverter draws lots of current, and as the AC voltage crosses zero volts, the inverter draws very little current--120 times a second, or 100 times a second for 230 VAC 50 Hz power (assuming you are in Saudi Arabia or similar). So, as the sun goes outside ~9am to 3pm (15:00 hours) period, the batteries can "micro cycle"--Charge/discharge 100/120 times a second.

The XW does take the AC power and pass it directly to the AC load (protected sub panel). And at the same time can also use extra AC power to charge the battery bank (you don't need solar--the XW can act like an UPS--uninterruptable power system). When AC power goes away, the XW supplies the local AC loads.

However--These units are also capable of sharing AC loads--There is a mode call "generator support". You can have a small AC generator or utility power (say 3 kWatt) and if you have more local AC loads than 3 kWatt, the XW can supply additional power from the battery bank to "support" the limited AC input power. Very nice--You can use a smaller/energy efficient genset, and the inverter can supply upwards of 6 to 12 kWatts (peak surge) to start a well pump, etc.

What your loads are may affect your choice of operating mode for an AC inverter/UPS system... One issue with "fail over" type UPS systems is the AC output can be lost for ~1/2 an AC cycle (or sometimes even more)--And if you have computers (as an example), they can "see" the power hit and reboot. For critical applications, a continuous conversion system (AC power to battery bank to AC inverter) can give you cleaner power.If small interruptions are not an issue (no computers, using laptop computer with battery, etc.)--Fail over operation is more energy efficient.

Batteries have a life--They either die from cycling or from age--Standard batteries can last 3-8 years or so... Traction/Fork Lift/Industrial batteries can last 15+ years. Or--If something goes wrong (somebody leaves the loads on, a solar charge controller fails, etc.) -- The battery bank can be killed in a day or a week (lead acid batteries do not like to be cycled below ~50% usage very often and can be killed if taken below ~20% state of charge)..

Gensets can be a solution for random power outages--But the noise, smoke, and cost of fuel/maintenance is a problem too.

-Bill

gbaig

Thanks Bill & Blackberry04 for great information and a guidance, my system components are as follows:
24, 250W sharp panels (6KV), 2 Infini solar Hybrid Inverters and 12 Vision Deep Cycle batteries 200ah design life 10 years (20 hours) (http://www.vision-batt.com/site/prod.../6FM200D-X.pdf)
My main load during the day is LED lights, Refrigerator and few small appliances (winter) in summer one or two Inverter based Air conditioners (3amp each) 18000 BTU,two to three ceiling fans and one LCD TV. The inverter draws load from PV if it exceeds 5%. Any deficit in PV load is compensated by the grid. In the night when some times grids goes off, batteries take it over. The inverter display shows entire activity in a diagram.
When infini inverter replaced with XW6048 (with 2 charge controllers) I will also be connecting Conext Combox to monitor the entire load flow. Can I get same configuration on Xantrex similar to Infini? I am not planning to sell load to the grid, can that be done? You have already answered my question regarding battery life but when continues load flow via batteries, would that impact the battery design life from 10 years to very short life? My entire system is installed in the basement.

BB.

The load really does not flow through the batteries--When the sun is up, the batteries more or less act like capacitors--They "buffer" the input power and output loads. If the AC load drops, the Batteries "accept current" until the charge controller cuts back to the new steady state.

If the batteries need charging, they will take some of the current from the array to charge. And when the array wattage is less than the load wattage, the batteries will send current to AC inverter.

More or less, the battery bank is what "buffers/sets" the DC Battery Bus voltage short term. The Charge controllers are longer term in control of the battery bus voltage (i.e., 14.5 volts charging, 13.6 volts "float", etc.). And, obviously, when the battery bank is is supporting the loads (no sun, no AC mains, no generator running, etc.)--The battery bank and the AC Inverter battery cutoff voltage are the only "regulators" of DC voltage.

Some light reading about batteries.

http://www.windsun.com/Batteries/Battery_FAQ.htm
http://www.batteryfaq.org/
http://batteryuniversity.com/

-Bill

PS: Another interesting Battery FAQ with "gassing voltages" and how to charge Sealed Lead Acid Batteries first posted by mike90045 and Solar Guppy:

www.powerstream.com/SLA.htm

In this next link, is an older bulletin from Rolls (you have to click on this link to see the attachment) on how best to recharge deep cycle batteries. And here is the (text version) of the document. (thank you member "Volvo Farmer")

-Bill

Raj174

gbaig wrote: »

Thanks Bill & Blackberry04 for great information and a guidance, my system components are as follows:
24, 250W sharp panels (6KV), 2 Infini solar Hybrid Inverters and 12 Vision Deep Cycle batteries 200ah design life 10 years (20 hours) (http://www.vision-batt.com/site/prod.../6FM200D-X.pdf)
My main load during the day is LED lights, Refrigerator and few small appliances (winter) in summer one or two Inverter based Air conditioners (3amp each) 18000 BTU,two to three ceiling fans and one LCD TV. The inverter draws load from PV if it exceeds 5%. Any deficit in PV load is compensated by the grid. In the night when some times grids goes off, batteries take it over. The inverter display shows entire activity in a diagram.
When infini inverter replaced with XW6048 (with 2 charge controllers) I will also be connecting Conext Combox to monitor the entire load flow. Can I get same configuration on Xantrex similar to Infini? I am not planning to sell load to the grid, can that be done? You have already answered my question regarding battery life but when continues load flow via batteries, would that impact the battery design life from 10 years to very short life? My entire system is installed in the basement.

Hi gbaig,

I can't speak for the Xantrex, but the Outback Radian has a "grid zero" mode that I believe will do what you want. This is done by a setting in the Mate 3. Set the amount of AC amps you want the inverter to supply to the loads and grid supplies the required amperage above that. Note that in grid zero mode at least 1 amp will be supplied from the grid no matter what the setting.
Check it out here:
http://www.solar-electric.com/inverters-controllers-accessories/inverters/ouin/rasein.html
Read up on Outback grid zero mode here:
http://www.outbackpower.com/downloads/documents/APP_NOTE_RADIAN_GridZero_ABC_2-18-14.pdf
and take the time explore and understand your options before you buy anything.

Rick