Newbie question - GridBoss/Flexboss21 and EVSE on Smart Ports

[mattman67]

Long time lurker, probably one if the first time posts. Have been doing SMA Grid-tie inverters for 5-10 years. Small solar arrays 8Kw and 3Kw respectively. I bit the bullet and jumped on the EG4 bandwagon after doing a boatload of research.
Here's my issue, I've got the Gridboss and Flexboss21 with 2 EG4 indoor batteries installed into my garage. Been self consumption and off-grid for the better part of the last week. I now want to utilize the Gridboss smart ports to pump all the free solar energy into my EV. For some reason I'm getting a ground fault on the Emporia EVSE and on the tesla portable charger when hooked up to the Gridboss. If I'm on my Garage, which is not passing through the Gridboss, it works just fine.

Have a case open with Signature Solar and went several rounds with a few different techs. No luck. Reached out to Emporia and their tech support says it probably won't work.

I have swapped multiple outlets, thinking one was bad. Didn't matter. Swapped cabling, didn't matter. Is something going on where the EVSE(s) thinks there is no ground or a wiring issue? On the Gridboss circuit, I get 240V across the hots. I get 120V from hots to ground. What am I missing? Something like when generators have to have a neutral to ground plug for it to work properly?

I'm stumped. I'm hoping with all the brain power and experience that someone may have seen this before. I'm still waiting for EG4 support to call me back in the meantime.

Thanks in advanced.

Mattman67

 

[SignatureSolarJess]

Long time lurker, probably one if the first time posts. Have been doing SMA Grid-tie inverters for 5-10 years. Small solar arrays 8Kw and 3Kw respectively. I bit the bullet and jumped on the EG4 bandwagon after doing a boatload of research.
Here's my issue, I've got the Gridboss and Flexboss21 with 2 EG4 indoor batteries installed into my garage. Been self consumption and off-grid for the better part of the last week. I now want to utilize the Gridboss smart ports to pump all the free solar energy into my EV. For some reason I'm getting a ground fault on the Emporia EVSE and on the tesla portable charger when hooked up to the Gridboss. If I'm on my Garage, which is not passing through the Gridboss, it works just fine.

Have a case open with Signature Solar and went several rounds with a few different techs. No luck. Reached out to Emporia and their tech support says it probably won't work.

I have swapped multiple outlets, thinking one was bad. Didn't matter. Swapped cabling, didn't matter. Is something going on where the EVSE(s) thinks there is no ground or a wiring issue? On the Gridboss circuit, I get 240V across the hots. I get 120V from hots to ground. What am I missing? Something like when generators have to have a neutral to ground plug for it to work properly?

I'm stumped. I'm hoping with all the brain power and experience that someone may have seen this before. I'm still waiting for EG4 support to call me back in the meantime.

Thanks in advanced.

Mattman67

Hi! If you'd like to dm me your contact info, I can look at your ticket and see if I can get some fresh eyes on it

 

[CaySol]

Long time lurker, probably one if the first time posts. Have been doing SMA Grid-tie inverters for 5-10 years. Small solar arrays 8Kw and 3Kw respectively. I bit the bullet and jumped on the EG4 bandwagon after doing a boatload of research.
Here's my issue, I've got the Gridboss and Flexboss21 with 2 EG4 indoor batteries installed into my garage. Been self consumption and off-grid for the better part of the last week. I now want to utilize the Gridboss smart ports to pump all the free solar energy into my EV. For some reason I'm getting a ground fault on the Emporia EVSE and on the tesla portable charger when hooked up to the Gridboss. If I'm on my Garage, which is not passing through the Gridboss, it works just fine.

Have a case open with Signature Solar and went several rounds with a few different techs. No luck. Reached out to Emporia and their tech support says it probably won't work.

I have swapped multiple outlets, thinking one was bad. Didn't matter. Swapped cabling, didn't matter. Is something going on where the EVSE(s) thinks there is no ground or a wiring issue? On the Gridboss circuit, I get 240V across the hots. I get 120V from hots to ground. What am I missing? Something like when generators have to have a neutral to ground plug for it to work properly?

I'm stumped. I'm hoping with all the brain power and experience that someone may have seen this before. I'm still waiting for EG4 support to call me back in the meantime.

Thanks in advanced.

Mattman67

Ground neutral bond issue?

 

[mattman67]

Ground neutral bond issue?

The ground neutral is usually done in the first panel that comes off the meter. It hasn't changed.

Matt

 

[chill633]

The ground neutral is usually done in the first panel that comes off the meter. It hasn't changed.

Matt

Is the GridBOSS being used as the first point of disconnect? You mentioned off-grid, so is your EG4 stuff connected to your grid at all? If not, how is it grounded and do you have the ground-neutral bond installed? If it is, same questions.

 

[mattman67]

Is the GridBOSS being used as the first point of disconnect? You mentioned off-grid, so is your EG4 stuff connected to your grid at all? If not, how is it grounded and do you have the ground-neutral bond installed? If it is, same questions.

It is grid connected. Have 200amp main panel after the meter with a breaker(outside). Power is brought into a TAP box in the garage for distribution. Subpanel for the garage(100amp) is directly connected to the TAP buss bars. Power from the outside mains feeds directly into the GB(Installed Eaton disconnect, even though not needed). This is ground, neutral and Hot legs. From the GB, the backed up output goes to feed the house.
Hope that helps...

 

[chill633]

Both the Emporia and Tesla chargers have built-in GFCI. Is the Tesla charger reporting Ground Fault (1 flash) or Ground Loss (2 flashes).

 

[mattman67]

Both the Emporia and Tesla chargers have built-in GFCI. Is the Tesla charger reporting Ground Fault (1 flash) or Ground Loss (2 flashes).

Tesla charger has just a steady red light on it. No audible beeps like the Emporia EVSE. Car screen just shows no charging available.

 

[CaySol]

It is grid connected. Have 200amp main panel after the meter with a breaker(outside). Power is brought into a TAP box in the garage for distribution. Subpanel for the garage(100amp) is directly connected to the TAP buss bars. Power from the outside mains feeds directly into the GB(Installed Eaton disconnect, even though not needed). This is ground, neutral and Hot legs. From the GB, the backed up output goes to feed the house.
Hope that helps...

I moved my ground neutral bond into the gridboss and my ev charger (Rivian) is on the smart port and works fine. Could you disconnect the grid connection and try having a bond there to see it that works?

 

[mattman67]

I moved my ground neutral bond into the gridboss and my ev charger (Rivian) is on the smart port and works fine. Could you disconnect the grid connection and try having a bond there to see it that works?

definitely like the thought there. It would show locally if it worked. Not sure how that would affect the garage since its coming off of the TAP box. Would probably need to move the garage as a Smart port off of the GB?

 

[chill633]

Is the garage the only thing coming off the TAP?

 

[mattman67]

Is the garage the only thing coming off the TAP?

Yes. House is coming off of the GB.

 

[mattman67]

Here's a simple line diagram.

 

[CaySol]

Here's a simple line diagram.

Tap box just a split?

 

[Quattrohead]

I have a totally off-grid system comprising a pair of 18 kpv and the grid boss. My neutral ground bond is in my breaker panel.... I could probably move it to the grid boss now.
I am running the portable Tesla charger off of one of the smart ports and it has not complained.
I know they are rather particular about their neutrals and grounds so I would pursue that avenue some more.

 

[Usernameinuse]

I have the same setup as OP, and have 2 EV chargers hanging off smartports. Even hung a garage heater off one of the same circuits. No issues whatsoever. Can you show your wiring inside the GB?

I know they are rather particular about their neutrals and grounds so I would pursue that avenue some more.

No Neutral required for EV charger.

 

[mattman67]

With the help of my Signature Solar support tech. Shout out to Phil. I found the issue....Its me. I pulled two ground wires from the TAP to the GB. However, I only hooked up one end on each wire. I was using my multimeter to check continuity since there was nothing between the ground and neutral buss bars in the GB. However, the TAP was showing the neutral/ground correctly. The Smartport circuit works as it should. Charging the car as we speak.

Now the second part to the puzzle is how to have the Emporia charger know how much solar is available while using the GB smart port. (it just turns it on or off). It used to use the grid tie solar circuits to know how much power is coming into the system. Could the CTs be used on the DC solar circuits? Or is it only AC?

Mattman67

 

[chill633]

With the help of my Signature Solar support tech. Shout out to Phil. I found the issue....Its me. I pulled two ground wires from the TAP to the GB. However, I only hooked up one end on each wire. I was using my multimeter to check continuity since there was nothing between the ground and neutral buss bars in the GB. However, the TAP was showing the neutral/ground correctly. The Smartport circuit works as it should. Charging the car as we speak.

Now the second part to the puzzle is how to have the Emporia charger know how much solar is available while using the GB smart port. (it just turns it on or following upoff). It used to use the grid tie solar circuits to know how much power is coming into the system. Could the CTs be used on the DC solar circuits? Or is it only AC?

Mattman67

Awesome! Thanks for following up. Good to know

 

[SignatureSolarJess]

With the help of my Signature Solar support tech. Shout out to Phil. I found the issue....Its me. I pulled two ground wires from the TAP to the GB. However, I only hooked up one end on each wire. I was using my multimeter to check continuity since there was nothing between the ground and neutral buss bars in the GB. However, the TAP was showing the neutral/ground correctly. The Smartport circuit works as it should. Charging the car as we speak.

Now the second part to the puzzle is how to have the Emporia charger know how much solar is available while using the GB smart port. (it just turns it on or off). It used to use the grid tie solar circuits to know how much power is coming into the system. Could the CTs be used on the DC solar circuits? Or is it only AC?

Mattman67

Wonderful!