Open ground on tester when connected to inverter

[daonlyillwiz]

Hello all, I have such a weird issue that is driving me NUTS and I need some input on how I can fix this. The setup is as follows:
2 LG panels connected to a Tristar MPPT CC which is then connected to the batteries and the ground terminal is connected to a ground rod at the back of the shed. The batteries are then connected to a 2000 Watt inverter. The ground terminal is grounded to the ground rod in the back of the shed as well. Everything works just fine, I'm able to to use the power in the shed for pretty much everything except charging my Plugin hybrid vehicle. On the charger for the car, it states power fault. When I check the fault it claims HIGH RESISTANCE GROUND. I then took my outlet tester and plugged it into the inverter and according to the tester I have an open ground. I don't see how this is possible because everything is grounded (inverter and charge controller). I read online that the tester is designed for household circuits and aren't meant to be used with inverters and could possibly give a false reading. Is there any way I can get this HIGH RESISTANCE GROUND issue resolved?


The goal is to basically be able to charge my car off my panels/batteries. The car chargers' specs are as follows:
IN: 120V 12.5A
OUT: 120v 12.5A

per my math which i hope is correct P=VI I need an inverter to support 1500 watts. My 2000W inverter should be enough in this case..

[sensij]

What specific model of inverter are you using?

Although the inverter may be able to support it, that discharge rate looks brutal for a battery small enough to be supported by only two solar panels. Have you really thought this through?

[daonlyillwiz]

What specific model of inverter are you using?

Although the inverter may be able to support it, that discharge rate looks brutal for a battery small enough to be supported by only two solar panels. Have you really thought this through?

Using a Krieger KR2000.

I have 4x 12vAGM 125ah batteries.

Since it's a plugin Hybrid it has a 9KwH battery so I figure most of the charging will take place during the day when its nice and sunny

[sensij]

If I'm looking at the right documentation, it is a modified sine wave inverter. You won't be able to use that to charge your car. Also, how many watts of power can you produce from your solar panels? It looks like you would still be running a heavy deficit on the batteries during the day, even when sunny.

[daonlyillwiz]

I've got 2 x 260W 8.8A LG solar panels. so figure in optimal conditions i am getting about 500-520W of power...any inverter you would recommend ?

[sensij]

Without a better understanding of what you are doing, no.. no recommendations. Why not just use the grid? Under ideal circumstances, and depending on where you are located and how the panels are oriented, I wouldn't count on them to produce more than 450 W for more than a couple hours on even the most ideal days. With 6000 Wh of storage, but only 3000 of that available (don't discharge more than 50%), you can only support maybe two hours of 1500 W charging on those very sunny days.

[daonlyillwiz]

Without a better understanding of what you are doing, no.. no recommendations. Why not just use the grid? Under ideal circumstances, and depending on where you are located and how the panels are oriented, I wouldn't count on them to produce more than 450 W for more than a couple hours on even the most ideal days. With 6000 Wh of storage, but only 3000 of that available (don't discharge more than 50%), you can only support maybe two hours of 1500 W charging on those very sunny days.

I can run an extension cord from the car to inside my garage but thats too much hassle. where the car is parked in the driveway it's closer to the shed than it is to the garage. all i really need is to charge approx 40% of the 9kwh battery in the car which is approx 3 hours.

My request for a recommendation was for an inverter not really the setup w/ the panels/orientation as all that stuff is already in place and i do not want to make any changes to that... I just want to know what size inverter to get and if i should be getting a PURE SINE WAVE inverter

[sensij]

I can run an extension cord from the car to inside my garage but thats too much hassle. where the car is parked in the driveway it's closer to the shed than it is to the garage. all i really need is to charge approx 40% of the 9kwh battery in the car which is approx 3 hours.

Wow, that is one of the most expensive solutions to a "hassle" that I've seen posted here. Yes, a pure sine inverter should do what you want, probably 2000 W. I would suggest wiring your batteries in series to 48 V if they aren't that way already, and upgrading your CC to 48 V along with the inverter. 2000 W is difficult to transmit safely at 12 V. At least consider rewiring to 24 V, your CC may be able to handle it already.

[daonlyillwiz]

lol..I can get them to 24v, My CC can handle that since I've got a Morningstar TS-45 and it's rated for 12-48v

Thanks for your input. When I say hassle I mean its a major PAIN

[inetdog]

Hello all, I have such a weird issue that is driving me NUTS and I need some input on how I can fix this. The setup is as follows:
2 LG panels connected to a Tristar MPPT CC which is then connected to the batteries and the ground terminal is connected to a ground rod at the back of the shed. The batteries are then connected to a 2000 Watt inverter. The ground terminal is grounded to the ground rod in the back of the shed as well. Everything works just fine, I'm able to to use the power in the shed for pretty much everything except charging my Plugin hybrid vehicle. On the charger for the car, it states power fault. When I check the fault it claims HIGH RESISTANCE GROUND. I then took my outlet tester and plugged it into the inverter and according to the tester I have an open ground. I don't see how this is possible because everything is grounded (inverter and charge controller). I read online that the tester is designed for household circuits and aren't meant to be used with inverters and could possibly give a false reading. Is there any way I can get this HIGH RESISTANCE GROUND issue resolved?


The goal is to basically be able to charge my car off my panels/batteries. The car chargers' specs are as follows:
IN: 120V 12.5A
OUT: 120v 12.5A

per my math which i hope is correct P=VI I need an inverter to support 1500 watts. My 2000W inverter should be enough in this case..

The charger and the tester expect to see a connection between the neutral wire (grounded conductor in a normal utility system) and the grounding conductor. Your inverter does not provide that. Some MSW inverters simply do not allow you to make such a connection because the "neutral" wire is actually at 60V AC with respect to ground.
If you will be keeping this inverter you need to have an electrician look at your wiring. You may not be able to use that inverter with your charger or you may need a wiring change.

[daonlyillwiz]

I already sent back the inverter and am waiting for my 2000w pure sine wave inverter to come in the mail tomorrow.