Voltage to ground from ground mount array - what is normal voltage there?

[wonderspark]

I agree with starting over.

I noticed there were no ground bars in either panel, and they landed grounds and neutrals on the neutral bar, hence my thinking that it didn't matter where I landed the ground.

The transfer switch came with all the wires in the FMC pre-installed, and it was stuffed with the sets of wire for the hots, the neutral, and the ground. I knew I couldn't add more than a couple wires to that, so I added in my own second FMC to handle the added neutrals for the AFCI breakers. I then pulled all the wire out of the pre-wired FMC and started over, getting all the hots and neutrals for each panel into each FMC, so they'd be together, since some were going into the lighter left panel, and the rest into the right panel. So wire to left panel is in one FMC, wire to right panel is in other FMC. Both FMC are properly connected to the transfer switch on that end, but in the panel ends, they are just lying in there. That's my bad.

What I'm taking away here is that I started with panels that were possibly not 100% correctly installed, and added my own errors to it.

Given all this, and starting from scratch, I have a dilemma. There are only five open breaker slots on the right panel, but six in the left panel, so I can't move all of them into one panel, unless I did something like use some tandem breakers.

What is the best way forward here? Just undo it all and bring in a better electrician than the one that was hired by the builder, and tell him what my goal is? Or is this salvageable myself? I had wanted to get a second transfer switch to add more circuits, but seeing that I've jacked up the first ten myself, I'd like to get the system correct as it stands now.

 

[outboard1196]

I noticed there were no ground bars in either panel, and they landed grounds and neutrals on the neutral bar, hence my thinking that it didn't matter where I landed the ground.

If you had only one panel N&G can go to same bar ( usually) I'd wait for Tim to chime in before taking next step.

 

[wonderspark]

Thank you all so much. I tried to do my homework, but I failed to get it right.

I have switched all the transfer switches back to main grid power, and turned off the AIO for now. I liked free energy, but I don't want to burn down my new house, haha.

I'm sure I could buy a ground bus bar, mount it in the left panel, and move the ground wires from the circuits to the ground bus bar before removing the bonding screw. At least then I'd have the builder's errors corrected.

 

[zanydroid]

Taking a step back -- it might actually be OK to have two N-G bonds, if the two panels both count as main panels (first means of disconnect after the meter. I'm not 100% familiar with split 320.

(You do want to nuke the N-G bond in the Reliance though)

Assuming the bonds are wrong in these two 200A panels.

So I would start off by ordering ground bars and the ground lug for your EGC/GEC line going down to the ground rod. You can't fit that onto a ground bar without the lug accessory that lets you put a large wire into the bar. This is what it looks like, they're a bit specialized with a notch on the bottom to go neatly onto the groundbar. Now, you can use both halves of your split 320 service. If you consolidate onto one panel, then you only have access to half your service.



If mistakes were made with the original install were pure laziness, they could have done it right with an extra 30 min (if they had the ground bar accessories in place). So I don't think it's worth hiring out, it's easier to fix than what you already did with the Reliance

 

[zanydroid]

Not sure about the risk of burning down your house. The one that scares me the most is the eddy current because it would be happening 100% of the time. Other risks like improperly bonded FMC, only hurts you if you're touching it and there's a fault.

With the split 320, assuming you have two main panels, I believe you cannot have a neutral bar in the Reliance, since that would likely combine neutral from the two panels (and that will cause problems with the pair of N-G bonds). If you bring all neutrals back to the correct main panel, and don't have a shared neutral bar, it is fine.

Things get simpler with two separate Reliance.

Taking a step back, this kind of transfer switch is kind of expensive, in the sense of needing 2x AFCI/GFCI (one in the grid powered panel and one in the AIO powered panel). I don't have a solid alternative in mind but it seems janky. It seems like you're doing this to give you the ability to move loads to/from grid. Does your Delta or whatever have integration with a smart panel of some sort?

 

[outboard1196]

Thank you all so much. I tried to do my homework, but I failed to get it right.

I have switched all the transfer switches back to main grid power, and turned off the AIO for now. I liked free energy, but I don't want to burn down my new house, haha.

I'm sure I could buy a ground bus bar, mount it in the left panel, and move the ground wires from the circuits to the ground bus bar before removing the bonding screw. At least then I'd have the builder's errors corrected.

Does your inverter have a N-G bond? Can it be disabled?

 

[zanydroid]

I did a quick Google search and Delta owner forums have some decent info on N-G behavior. I didn't sort through it b/c I don't own one and I don't know which specific model OP has.

 

[wonderspark]

Taking a step back -- it might actually be OK to have two N-G bonds, if the two panels both count as main panels (first means of disconnect after the meter. I'm not 100% familiar with split 320.

(You do want to nuke the N-G bond in the Reliance though)

Assuming the bonds are wrong in these two 200A panels.

So I would start off by ordering ground bars and the ground lug for your EGC/GEC line going down to the ground rod. You can't fit that onto a ground bar without the lug accessory that lets you put a large wire into the bar. This is what it looks like, they're a bit specialized with a notch on the bottom to go neatly onto the groundbar. Now, you can use both halves of your split 320 service. If you consolidate onto one panel, then you only have access to half your service.

View attachment 302089

If mistakes were made with the original install were pure laziness, they could have done it right with an extra 30 min (if they had the ground bar accessories in place). So I don't think it's worth hiring out, it's easier to fix than what you already did with the Reliance

I used a similar clamp that allowed me to clamp onto the large bare copper coming off the ground rod and going up in the wall to the two service panels. Down by the floor is an access cover where the ground rod is, and I clamped my #6 wire from the solar array to it. So ground rod --> #6 THHN/THWN-2 to metal box inside garage ground lug --> array frame.

I've read so much on the EcoFlow Delta Pro Ultra that I don't know what's real. I've read that it switches a neutral-ground bond on and off depending on charging and connections, so I don't really know. I read that if you're not charging from the grid, which I'm not, and only charging from solar, which I am, that you don't have to worry about it, but I should find out if that means I SHOULD or SHOULD NOT have the neutral wire from the Reliance transfer switch connected or not.

 

[zanydroid]

You can probably use a multimeter continuity test to figure out whether it’s bonded or unbonded in various situations. By connecting the output to a receptacle and nothing else, and then checking continuity from N-G

Unfortunately these portable/emergency power/whatever units will have to have dynamic bonding to make them useful in the broadest set of conditions. But you need to know what the behavior is, to set things up properly.

Victron is very well documented officially, and also allows you to configure it to use an external bonding relay so you can take complete ownership.

If you have GFCI on all circuits fed from the inverter, floating N-G bond is less bad from a safety angle. Otherwise it gives a high chance of a shock risk.

For Chinese inverters it behooves you to use a popular brand/get good at knowing which vendors and forum people to trust.

 

[wonderspark]

Almost all the circuits are AFCI or GFCI. The water heater isn't, nor is the microwave, but I think that's it. Seven of ten circuits fed by the inverter are either GFCI receptacle or AFCI breaker.

 

[zanydroid]

ElectroBoom has a video on AFCI this week , and I think he found that a lot of AFCI also trigger on ground fault? Though I doubt they guarantee this.

If you have a GFCI receptacle then you are allowed by NEC to use it without a proper ground in retrofit applications. Not for new construction.

Any where you connect an appliance with a ton of metal, you want to be really worried about no N-G bond.

Some appliances like EVSE and gas furnace burner don’t power up in the absence of a N-G bond

You can detect unexpected N-G bonding via failing breakers (like what you saw), or maybe by putting a clamp multimeter around G. There should be ZERO current in normal operation but there may be extra current if there are multiple bonds. However if the breakers trip then you won’t be able to catch the current on the meter as easily

 

[outboard1196]

ElectroBoom has a video on AFCI this week , and I think he found that a lot of AFCI also trigger on ground fault? Though I doubt they guarantee this.

I watched it last night, think he said 30 or 80mA which is way too high.

 

[zanydroid]

I watched it last night, think he said 30 or 80mA which is way too high.

I would consider any ground fault interruption from a AFCI to be a bonus, not something I bet my life on

 

[outboard1196]

I would consider any ground fault interruption from a AFCI to be a bonus, not something I bet my life on

Yeah that's pretty much elecroboom conclusions too.

 

[wonderspark]

I have to talk this out.

The neutral wire in the transfer switch goes in the input receptacle and on through the L14-30 cord to the EcoFlow inverter. If I disconnect it, the neutral wire in the cord between the inverter and the switch would end there, and the inverter would only be sending L1 and L2 hots to the switch, and on to the house circuits.

Current would go from inverter hots from L14-30 output cord to switch to house circuits to devices and back via house neutral wires to neutral bus bar to N-G bonding screw to ground rod. The only remaining connection is the ground wire in the L14-30 cord.

So since there's a N-G bond in the service panel, the current would complete the circuit via the ground wire in the L14-30 cord?

The inverter has only PV inputs, and AC output connected via that L14-30 cord. It's on a wheeled cart on the garage floor with no other connections. I don't plug it in to the wall, because the garage circuits are ones being powered by the inverter itself via the transfer switch.

Wouldn't I need the neutral connection in the L14-30 cord to go back to the neutral bus bar in the service panel?

I think my only issue is the ground wire connected to the neutral bus bar instead of the ground rod lug, correct?

 

[wonderspark]

Then there are the four AFCI breakers in the transfer switch, each with extra neutrals to the panel AFCI breakers and to house circuit.

It's making me go insane.

 

[wonderspark]

When they built this house, they said they installed two 200A main service panels in parallel, with one meter. We had ordered 320A service and they put in 2 panels to satisfy that.

Both panels have installed bonding screw. There is continuity between all neutral bars in both panels and ground rod, and that was the case before I installed the transfer switch.

So if this is truly a parallel 2 "main panel" service with a single ground rod, how do I avoid a neutral - ground connection in the transfer switch? Connecting the transfer switch neutral wire to the neutral bus bar is simultaneously connecting it to ground.

Everyone seems to have sub panels but I do not. Do I just install a third sub panel and remove the transfer switch?

 

[zanydroid]

It’s possible people are not properly describing their 2x200A set ups

What feeds these panels? Is it direct from meter with no disconnect, or do you have a meter with 2x200A breakers

I’m not sure you’re understanding the bad situation with N-G. The bad situation is creating a new connection from N to G. If you simply connect neutrals to neutrals you are not creating a second bond.

Can you post pictures from transfer switch manual showing the schematic of how circuits flow through it, for the GFCI/AFCI setup.

Also it’s very fuzzy to me what you are doing with the transfer switch. Are you using it to dynamically move loads to power station to save on electric bill? Is it only for emergency?

You also need to provide N-G info for the power station. Maybe ask on a forum for the brand, as to which member the most reliable source of info is. Here, for things like grounding or ESS code you can get opinions on that.

 

[wonderspark]

It's directly from meter on outside of garage, with two panels inside garage, back to back on each side of the wall.

I understand wanting only one connection from neutral to ground, but I'm struggling with how it's wired before I touched anything. They put two panels in parallel with bonding screws in both, and it appears to have parallel service entrance conductors. The meter box outside has a lock tag on it and there's no disconnect switch visible out there. My research makes me think there should have been a main disconnect at the meter to shut off both panels simultaneously, whereas my panels each have a 200A breaker that I can flip separately.

I'm probably going to contact EcoFlow directly to find out how their inverter handles neutral and ground, dynamically it seems.

Thank you for your great input!

 

[zanydroid]

It’s cheaper to go into 2 200A panels set up as mains. Than to buy a 400A breaker or an extra panel that has 2x 200A breakers in it. Probably saved $500-1000 on materials.

Presumably your location does not require externally accessible disconnect. Otherwise they would have been forced to install one of the above configs, or put your main panels outside (which IMO sucks, sun cooks your fancy breakers and requires going outside if a breaker fails)

Think of this set up like 2 houses sharing the same meter and wire from the utility company.

There may be some special things you need to keep in mind for two main panels in one structure

I just found this thread for you that gives some intuition , and corroborates some of what I said.

https://www.reddit.com/r/electrical/s/SY773K2eg3

One Service, One Meter Feeding Two Main Panels???

I have never seen this before until today. A residence with a 200 amp underground service to a meter, then two 100 amp SEU cables tied together on the load side lugs going into the house to two separate 100 main breaker load centers right next to each other. Both panels have their neutrals and...

forums.mikeholt.com