EG4 6500ex-48 with generator

[EscapedAritst]

Hi All,

So I've bought - and will soon assemble - the following equipment for two off-grid setups (two different homes):

4 EG4 6500ex-48 inverters
36 455W panels (9s each going to one inverter...no combiner)
6 (soon to be 12) EG4 48v batteries
15kw Generac generator (to be purchased this week) just for one of the homes

I have a couple of questions about hooking up the generator (at one home) or the grid-as-a-backup (at the second home). I know the inverter has AC inputs for either the grid or the generator. What I can't find information on is automation and transfer switching. I have read on other inverters, that I can set them to start the generator. I think there is some kind of switch on the EG4 but I can't find it in the manual description.

Then on the other home, the AC from the grid will be connected as a backup (not grid tied). On this one, I assume this is the same problem but without an on/off for the generator. However, it still needs to know when the AC from the grid should be used and when it should be ignored. Also, I assume you can set it so that it can never back feed the grid?

 

[Samsonite801]

Hi All,

So I've bought - and will soon assemble - the following equipment for two off-grid setups (two different homes):

4 EG4 6500ex-48 inverters
36 455W panels (9s each going to one inverter...no combiner)
6 (soon to be 12) EG4 48v batteries
15kw Generac generator (to be purchased this week) just for one of the homes

I have a couple of questions about hooking up the generator (at one home) or the grid-as-a-backup (at the second home). I know the inverter has AC inputs for either the grid or the generator. What I can't find information on is automation and transfer switching. I have read on other inverters, that I can set them to start the generator. I think there is some kind of switch on the EG4 but I can't find it in the manual description.

Then on the other home, the AC from the grid will be connected as a backup (not grid tied). On this one, I assume this is the same problem but without an on/off for the generator. However, it still needs to know when the AC from the grid should be used and when it should be ignored. Also, I assume you can set it so that it can never back feed the grid?

First off, are you positive you can get away with 9s on the panel layout (in relation to max PV input voltage at coldest temp Voc coefficient)? We've had several shareholders in my co-op buying these 6500EX, and I've helped them decide panel series string count, and we've found with for example, the CS 445w bi-facials it is safer to run 8s (with these modern, high wattage, higher volt solar panels).

Ref:

Solar panel maximum voltage calculator - How to work out the max voltage

To get the maximum solar panel voltage you should expect from your solar panel, use our solar panel maximum voltage calculator.

gold-coast-solar-power-solutions.com.au

Next up, the EG4 do not have a separate generator AC input on them. They have only one AC input (can be grid or generator, not both at same time), for use with the grid charging during bypass power mode.

If you will run with generator and grid power, you need to add in an upstream ATS... EG4 does have a dry contact relay to control the generator starting.

The EG4 is not like a Solark for example, where you can feed AC back to the grid, it is just for bypass mode to supply house loads, and can only charge the batteries from grid while in bypass mode (from what I understood reading the manual, it operates with same attributes as the MPP Solar LV6548 models)...

 

[EscapedAritst]

Hi Samsonite,

Thanks so much for your feedback. I am in Costa Rica so will not have cold induced high VOC issues. 9 panels * 50 VOC per panel is 450 VOC and the inverters are rated for 500 max. So, I'm assuming I have a small safety window. Do let me know if you think this is too dangerous...I'm a newbie but the math seemed simple.

I do understand that the inverter does not have separate grid and generator backup; only one or the other. One project will be on generator and one on grid backup. Neither is feeding back to the grid. However, you may know the answer to this question. Bypass mode I am assuming is a software setting where I pick a low SOC for the batteries and the bypass kicks in when that threshold is met. Then, the inverter starts the generator (if connected), and the alternate power source (either gen or grid) starts supplying power to the house and charging the batteries. Is this a correct understanding of how it would work?

Thanks again!

 

[akitawpo]

Hi Samsonite,

Thanks so much for your feedback. I am in Costa Rica so will not have cold induced high VOC issues. 9 panels * 50 VOC per panel is 450 VOC and the inverters are rated for 500 max. So, I'm assuming I have a small safety window. Do let me know if you think this is too dangerous...I'm a newbie but the math seemed simple.

I do understand that the inverter does not have separate grid and generator backup; only one or the other. One project will be on generator and one on grid backup. Neither is feeding back to the grid. However, you may know the answer to this question. Bypass mode I am assuming is a software setting where I pick a low SOC for the batteries and the bypass kicks in when that threshold is met. Then, the inverter starts the generator (if connected), and the alternate power source (either gen or grid) starts supplying power to the house and charging the batteries. Is this a correct understanding of how it would work?

Thanks again!

Hello, I'm installing a similar system currently in Puerto Rico, From what I have read on the manual you are correct. Also there is a setting that does do "back-feeding" to the grid. But it states that it needs a firmware update.

 

[Ozzy308]

Hi Samsonite,

Thanks so much for your feedback. I am in Costa Rica so will not have cold induced high VOC issues. 9 panels * 50 VOC per panel is 450 VOC and the inverters are rated for 500 max. So, I'm assuming I have a small safety window. Do let me know if you think this is too dangerous...I'm a newbie but the math seemed simple.

I do understand that the inverter does not have separate grid and generator backup; only one or the other. One project will be on generator and one on grid backup. Neither is feeding back to the grid. However, you may know the answer to this question. Bypass mode I am assuming is a software setting where I pick a low SOC for the batteries and the bypass kicks in when that threshold is met. Then, the inverter starts the generator (if connected), and the alternate power source (either gen or grid) starts supplying power to the house and charging the batteries. Is this a correct understanding of how it would work?

Thanks again!

I've also purchased the EG4 6500EX-48 and have a Generac 15KW on the way. I live in a climate with little sun during the winter and need the penny to supplement on cloudy days. After reading through the manual once, I'm confused at how the EG4 would remote start the generator. Following to see if anyone has additional information on this.

 

[mtbguy]

I know this post is a bit old so the hardware may be different version. I just purchased and installed my EG4-6500 EX-48's and they have dry contact on the removable display (#14 in picture). This dry contact behaves differently depending on modes USB vs SBU. I will be using SBU. The contacts are NC, C, NO.
When batt voltage is less than setting #12 (voltage point back to utility) NC/C is open and NO/C is closed. When batt voltage exceeds #13 (setting voltage point back to battery mode) NC/C is closed and NO/C is open.