Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Permanent master slave GTIL2
#1
Some possible useful info: I got 2 2000w gtil2s wired to separate 240v breakers then to one 240v breaker in the main panel. I am using a limiting cable I made that has 2 ct clamps (one for each phase-wire) and 2 connectors (one for each inverter).
I am trying to have one inverter stay primary-master every time and the other slave every time. At the moment either inverter could be master or slave depending (I think) on which inverter is more responsive at the time.
The reason I’m trying to accomplish this: I can then install batteries to be the power supply to only the slave inverter. Then the master inverter will supply whatever it can from straight solar and then batteries are only used when first inverter can not fully supply the loads. This would prolong the lifespan of the batteries and also allows the batteries to stay full more often. Also this would allow an offgrid inverter to be installed in line with the slave and not be in line with the master which can be beneficial for several reasons. Any help will be greatly appreciated. The pic is what I’m trying to accomplish.
Reply
#2
Remove post plz...I guess no one knows
Reply
#3
Running both GTI's in parallel at the same load level would extend the life better.

Create a common DC voltage from both solar outputs to the battery and GTI's

Running GTI1 to maximum and then switching on the second would seem to be a lot more problematic due to the way the limiter signal changes the output (i.e. you could not just simply isolate the limiter signal from unit 2) or maybe it just is as simple as removing the limiter signal. Simplest option, disconnect the DC input to GTI2 and switch on/off based on the DC current going into GTI1.

Personally I would have both solar charge the off-grid battery and then have both GTI units powered from the battery this way solar output drops caused by clouds could be leveled out with the batteries, unless you want to retain the battery output just for outages.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
Reply
#4
Was hoping to have one inverter directly connected to pv so it could handle most of my loads thrunoutbthe day and not have to use the second inverter (connected to batteries) very often during the day and then use second inverter at night once first inverter has no more pv. Therefor extremely prolonging the life of the batteries due to not using the batteries most of the time due to master inverter supplying for most of the loads during the day

What u said about switching the slave on and off based on dc current sounds promising...but I just found out that when one 240v inverter is the only inverter turned on-connected to the cts and it is covering all the loads that it slightly backfeeds but the system doesn’t backfeed when having the second inverter connected even if that inverter isn’t supplying power...so I need the second-slave inverter atleast powered up at all times
Reply
#5
slightly backfeeds - the GTIL unit uses a few W on standby so this could be just an additional load cancelling out the export ?

I read (or seem to remember) that someone opened up a GTIL and adjusted the calibration for the CT, unless it was a different inverter. Maybe the first unit just needs calibrating for the CT.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
Reply
#6
But using the dc current of the first-master to turn on the second inverter wouldn’t work during clouds...
Yeah the slight backfeed happens (Error on electric meter) when second inverter is turned completely off and first inverter is covering all loads.. So it might be the power draw of the second inverter that keeps the system from back-feeding,,,but that’s only a few watts which could be enough to stop the backfeed I guess...something tells me that the second inverter somehow (when powered up and splitting the ct cable by paralleling another connector) allows more power to be supplied by the grid...I’m also thinking about putting a 1% resistor in the ct cable instead of the 10% resistor that came with the cable, should maybe stop that backfeed..
U also said about opening up the inverter and calibrating it to the cts..the cts are the cts that come with the inverter...I guess the slight backfeed is just due to the cts supposedly only allow the grid to supply like 7w when the inverter is supplying all of the loads...this is to low of a number and can easily be off by a few watts therefor backfeeding slightly. When both inverters are powered up the inverters show minimum of like 50w combining what both inverters screens say...I think the grid feeding this 50w is safer to not backfeed anyways
Reply
#7
1%, 5%, 10% is just the error of accuracy of the Ohm rating, not what the actual Ohms(resistance) is.
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
Reply
#8
Right so I figure if the ohm rating for the inline resistor is closer to its actual rating then maybe it would be more accurate then it could help send a more accurate signal to the gtil
Reply
#9
It was probably calibrated with the resistor that is there. So changing it, you might need to have it recalibrated. That's my guess anyways, which could be wrong. So, meh
completelycharged likes this post
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
Reply
#10
Resistor would be same ohm just better accuracy to that ohm
Reply


Who read this thread?
26 User(s) read this thread:
hbpowerwall (08-22-2019, 03:06 AM), sl1me (08-28-2019, 03:47 AM), Wolf (08-25-2019, 02:27 AM), Solardad (08-25-2019, 08:10 PM), ajw22 (08-23-2019, 03:26 AM), OffGridInTheCity (08-22-2019, 12:53 AM), 100kwh-hunter (08-24-2019, 12:22 PM), Doin it (08-27-2019, 04:08 AM), solarsteve (08-31-2019, 10:38 AM), Otakar (08-05-2019, 09:38 PM), berthfield (08-24-2019, 01:56 AM), suntan901 (08-14-2019, 01:53 AM), emuland-metroman (08-23-2019, 06:47 AM), neowolf (08-30-2019, 09:23 AM), daromer (08-22-2019, 04:19 AM), Sean (08-25-2019, 08:47 AM), Korishan (08-25-2019, 11:13 AM), jdeadman (08-26-2019, 01:22 AM), wim (08-24-2019, 06:52 AM), watts-on (08-25-2019, 10:00 AM), Geek (08-23-2019, 03:22 AM), Ivo Staelens (08-24-2019, 05:51 PM), CarelHassink (08-25-2019, 06:36 AM), completelycharged (08-24-2019, 08:14 PM), Riplash (08-22-2019, 12:34 AM), nettermann90 (08-20-2019, 10:13 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)