Notifications
Clear all
Topic starter
January 17, 2025 6:25 pm
I've had my 18KPV on line since late August and have been really enjoying it and being off grid as much as possible. I've had a second 18KPV setting in the shipping container since then.
Yesterday, my wife and I hung the second one in the garage, approximately 8 feet away from the first one.
The communications cables don't appear to be long enough to reach, can I make my own, longer cables? Are they the "standard" ethernet, or do they do a "crossover"?
My plan is:
A. hang second inverter in garage with welded supports, and the bracket welded to the supports. (it is a metal garage.)
B. supply power from the existing battery bank.
C. attach the WIFI and begin communications. Update one or both of the inverters. CALL SIGNATURE SOLAR IF/WHEN NEEDED for assistance?!
D. make the first inverter main and the second as slave.
E. make sure all settings are in sync.
F. supply grid power to second inverter using a 60A circuit breaker.
G. attach output to subpanel in garage using 60A circuit breaker and energize.
So, my question is: I always thought that I would have enough needs for this second inverter. Last week with four of EG4's 12000 BTU heat pumps, our hot tub, plus two 1500 watt space heaters for our shop (required because it is an unheated shop (40x14) but our water softner is in there and requires the pipes to be above freezing. I have ONE infrared heater directed to the water softner. The second is a 750 BTU heater located in a bathroom in the garage. The garage itself is heated via a infrared tube gas heater that keeps the 50x40 garage area about 60 in single digit temperatures.)
During last weeks cold snap I hit 13K out of the 18KPV for a couple of minutes. The lights did flicker a couple of times while we cooked dinner and made coffee.
1. The second 18KPV should give me plenty, should it not?
2. Am I missing anything in the above steps? Current solar will be unaffected, but needs to be updated because of deep shadows during December. Plan on doing this during the spring/summer. Too late in the winter, too cold for me, to do it now. New solar WILL go into the second 18KPV.
January 29, 2025 12:36 pm
They product may be slightly different. I added second to mine and it was a little weird. I only use one sync cable. This worked for months, until I upgraded one, then my parallel system locked down. It Really takes two CABLES, found this out after months of working. You need two cables for the Parallel communication. I am completely offgrid so my UPS were keeping my internet alive while finishing up work. Yes it should handle your loads they seem to balance the power pretty easily.
Things to note, You displays may not look the same. They have an LCD firmware update finally, however they took away the ability to see all your PV strings individually. SS needs to bring this back, I like the summary of the system, but also need the Volts and Watts of each string or Realtime data.
Make sure your L1 and L1 for the parallel output match phases, I did not do this and it tripped out the AC breaker.
Call Signature solar when you have everything set, there are weird things that happen differently with various Firmware to get this working.
Ideally I bought two to get double the solar capacity, the Ideal way they should work is Primary, Secondary. I can completely take out them my secondary and everything transfers to primary. That would allow me to upgrade secondary while keeping load power to my HOME which is completely offgrid. You can take the secondary or primary load breaker and everything will work, for about 10 mins, so if moving an AC breaker, or managing wires you are good. However maintenance will not work so good. During a firmware update if para comms goes down then it will put you in the dark.
I just found out you can do to online upgrades very close in secession to prevent this so that both will be complete around the same time, but it will still put you in the dark, get flashlights ready.
I just got on 1E1E. I was two firmware versions behind so I was about 40 mins in the dark trying to get the second up.
You also will lose EG4 Battery comms, or at least I did. Then it went dark, you have to change to lead acid for a bit to get power back.
So this leads me to a request from EG4. There are very few differences between a Primary single inverter and a Parallel. I want the ability that is one or the other inverter goes down to run my whole house. One is none two is one. To this point I cannot do this without a lot of head ache.
Example, my comms cable is removed, keep working let the primary take the load, give me a WARNING ONLY but do NOT shut down my inverter.
If my load temporarily goes off one, Keep running, it currently does this but unreliable, not sure if it is a timeout, but I can seem to get like 20 minutes.
If my battery comm goes out KEEP running if there is voltage. You have about 10-30 second delay before it shuts down.
I have not tested any of these feature since 1E1E firmware and LCD 18. But every time I touch the system it is an entire day of freak out trying to get it back as I do not have a grid to rely on.
Good luck.
PS. Brent from SS thought I could just use the primary as a standalone while I update secondary, but said to remove the parallel comms cables, did that, and primary shut down and lost my load. So taking out the comm cables shut the unit down. Played with trying to get primary to be standalone, by changing phases etc. without the parallel cables, did not work. Just stayed in dark till second one fully upgrades.
You should be able to take the 2ndary and put it into standby for upgrade, but when you do, it takes the entire system into standby. So SS needs a way to work and update individual inverters without power loss. Image if you have 4 18KPV units, the update downtime would be crazy, when theoretically you should be able to do a rolling update them with a single one taking the entire load.
January 29, 2025 4:27 pm
What you describe is putting the 18kpv's in Series. The communications between 18kpv's doesn't work that way. They are designed to be Put in parallel:
Both 18kpv's have the same grid connection point.
Both 18kpv's have the same load connection point (grid supply to the main panel).
Ideally, both also have the same battery connection point.
At that point, the Master can control what it needs the Slave to do (put power to the load, or export to the grid, etc.).
I would suggest getting the Gridboss, and connecting each 18kpv to the Inverter Port. The Gridboss has an upgraded computer, so can control any mix of: 18kpv, 12kpv, and Flexboss21. If one 18kpv goes down, you can easily take it out for service (one power connection between the gridboss and 18kpv.
Topic starter
January 31, 2025 4:49 pm
What you describe is putting the 18kpv's in Series. The communications between 18kpv's doesn't work that way. They are designed to be Put in parallel:
PARDON me, I misspoke... Parallel it is.
Both 18kpv's have the same grid connection point.
they do
Both 18kpv's have the same load connection point (grid supply to the main panel).
they are
Ideally, both also have the same battery connection point.
they do
At that point, the Master can control what it needs the Slave to do (put power to the load, or export to the grid, etc.).
I see that now. I do not export anything to the grid. I just wasn't sure how it would distribute the load.
I would suggest getting the Gridboss, and connecting each 18kpv to the Inverter Port. The Gridboss has an upgraded computer, so can control any mix of: 18kpv, 12kpv, and Flexboss21. If one 18kpv goes down, you can easily take it out for service (one power connection between the gridboss and 18kpv.
I essecntially made my own grid boss using a grid disconnect to a using a 150A breaker and a seperate box to house the breakers for both inverters. Since the 18KPV has it's own 200 A transfer switch I feel that adding yet another transfer switch in the Flexboss21, at this time, would be redundant.
Each of my 18KPV goes into a seperate sub panel which then connects to the remainder of the property, ie: shop, garage, home.
If one of my 18KPV goes down, I can simply (manually) turn off that inverter's load, load circuit breaker, and the grid input circuit breaker.
(I do have a third 18KPV in the original shipping carton in my garage just incase of emergency replacement requirements. That way I will not have to wait for up to 90 days (As I had to do with my first 18KPV.) or so for the warranty claim to be processed and a replacement to be shipped. I would just have to remove one, and hang the second (maybe I can reuse the dongle, maybe I can't, we'll see then.) )
This third 18KPV may, or may not, be actually installed at a later date depending on overall load. The single 18KPV did it's job well enough from the end of August to late December when the four (4) mini-split 12K EG4 Heat Pumps were working full blast to provide heat at 11 degrees F here in the Texas Panhandle. I did find out that 11 degrees is the minimum temperture that they would continue to adequatelly heat my house without auxilary heat required (which I have in the form of gas wall heaters.) At that time the heat, the hot tub and cooking with the electric appliances demanded just a bit over 13K at times which pushed the 18KPV to the limit. Turning off the hot tub fixed that problem but caused the hot tub to grow an unwanted amount of alge. (which because of the cold outside temps hasn't been addressed completely).
When this post was made I had not put the second in operation, I was more courious if the load would be split more or less equally between them and would the AC charging would be split the same. That was the intent of my first post as I found no where what that tidbit of information was addressed.
I have four(4) strings of solar panels of ten (10) panels each consisting of 370 watt Aptos bi-facial panels. Two (2) of these strings went into #1 and #2 inputs the other two were split into #3 and #4. Now the two (2) original strings remained with the original 18KPV and the second two (2) strings are now going into #1 and #2 of the second 18KPV.
I can't wait for another week to pass and get full output of my panels once again for the shadows from late November to late January severely curtail my solar production!
During the spring/summer I will be adding another twenty (20) panels (one (1) new string of ten (10) to each inverter) in a location that will be more favorable to winter production at my location.
