Judoal
New Member
its an 0ff grid inverter, need GT inverter
Sol-ark question re additional AC coupled array
- Thread starter Judoal
- Start date
Ampster
Renewable Energy Hobbyist
As much as I posted earlier in this thread about the value of AC coupling, I do not see a need for AC coupling in this situation. As I read more of this thread I think the lack of production on that one string may simply be incorrect Charge Controller settings or production being curtailed because the batteries may be full. I have asked for kWh data to support the need for more production and none has been forthcoming. I suggest you spend more time documenting the performance of your system and determine what your needs actually are in terms of kWh capacity before you decide whether AC coupling is what you actually need.
How many kWhs does your system produce in a year and what is your consumption on an annual basis?
Last edited:
Judoal
New Member
Judoal
New Member
Without the 4th array, I’m losing 25% production (2900 kwh)
400bird
Solar Wizard
I'm not sure you'll find a GT inverter that will work with your ~ 100 VDC negative grounded array.
The 100 VDC could be rewired pretty easily in the combiner box to increase the voltage, however the PV negative to ground connection isn't helping. I'm pretty sure that every modern inverter I've seen is meant for floating (not grounded) PV array.
If you're willing pull new wire to the array, picking a GT inverter will be easy.
Judoal
New Member
150’ through a tight conduit? cost would be high.
Ampster
Renewable Energy Hobbyist
Do you have any data (kWhs) about how much of that array is charging your batteries? How much energy are your batteries providing to the loads overnight?
400bird
Solar Wizard
If not running a new ground through the conduit, maybe you can find a 10-20 year old grid tie inverter that will work with a grounded PV array.
Or maybe someone here knows of a grid tied inverter that will be happy with a grounded PV wiring.
Or maybe someone here knows of a grid tied inverter that will be happy with a grounded PV wiring.
Judoal
New Member
havent used the batteries except for backup. we live in a rural area and can have outages. I thought about time of use but we are not charged for peak hours. Have a dumb net meter
Ampster
Renewable Energy Hobbyist
That explains why your charge controller is always in float stage because the batteries are full. There is nothing wrong with your charge controller. If you want to get that array to put out more power you could always run your system on batteries overnight and charge them during the day from the charge controller. That is the least expensive way to get some of the 25% production you are trying to get.
Judoal
New Member
my new Sol-Ark 12k inverter is running just fine with the negative side grounded!
Judoal
New Member
I got the CC to sell 1500 watts. Set float voltage to the same as the inverter and put the inverter in time of use mode. When Vbatt < Vfloat, CC kicked in and a lot more power was sold than than from the arrays connected to the inverter. Still a few problems to solve yet.
Ampster
Renewable Energy Hobbyist
Glad to hear that. That was a cost effective solution. How many kWhs do you think you can produce each day?
Judoal
New Member
Dunno. This was just a test today. There wasn’t much sun for one thing so 2500 watts output from the CC was pretty good for an aging array. When I stopped the test, the batts recharged from the grid rather than from than from the arrays. But making progress.
As for estimates,due to poor sun and shorter days, the 3 arrays were producing less than 20 kwh. I have to figure out how to get batteries recharged from the arrays rather than from the grid.
As for estimates,due to poor sun and shorter days, the 3 arrays were producing less than 20 kwh. I have to figure out how to get batteries recharged from the arrays rather than from the grid.
Last edited:
Ampster
Renewable Energy Hobbyist
As mentioned several times throughout this thread it is all about the settings and the SOC of the batteries when the sun comes out. You will want the batteries at a low SOC at daybreak so the charge controller will charge them. That means you want the SolArk to use the batteries overnight so the charge controller can charge them in the morning and you want to set the SolArk settings to charge as last resort. If that is too difficult you may need to spend some money to better utilize that one array. Because it has a different voltage from the other three, it would have to be on a separate MPPT controller and configured to put out enough voltage to meet the minimum to work with the SolArk. That means the existing three arrays would have to all go to one of the MPPT inputs. There is not enough information to know if that is possible or even an option. There is not much more I can offer beyond what has already been said.
Last edited:
Judoal
New Member
The sol-ark works just fine thankyou
400bird
Solar Wizard
You responded to my one post twice, so I decided to do the research for you.
From the Sol Ark manual:
From the warnings on page 5
Page 21, step C
From the fault list:
Attachments
Judoal
New Member
I mispoke. Neither of the PV leads at the array are not grounded else the gfci eill not not work. Sorry for the confusion.
Judoal
New Member
I have the batteries selling at 1-2KW. Setting the voltage at float voltage, the system sells power while the battery stays at the float voltage (100% SOC) maintained by the DC coupled CC as long as there is solar gain. It was ammatter of figuring out the TOU settings. Only negative is keeping an eye on the sky and turning TOU on manually. But thats a lot cheaper than buying a new inverter. Ampster (I think) given me a clue when had indicated previously that the CC was thinking the battery was full. Thank you.
