Grounding Confirmation

[DeMac]

I figured dry run. Wise man.

[docmurphy]

Originally Posted by DeMac

I figured dry run. Wise man.

Ha...and trying not to learn the hard way on this one.

This is designed to be 30 amp service shore power

Box is mounted inside, surface mount, assume all wires will be in the same setup when installed.

Circuits are just divided up into legs of power port side, starboard side, etc.

The shore power goes into the inverter then out to the panel, mocked up in picture. Missing from the picture is the ground that would be running from the main lug opposite the neutral lug, as set up.

So if I were to not bond at this point then I would install a separate ground bar and keep things apart...good to go?

I can try to answer any more questions the best I can!

Thanks.

[docmurphy]

From the manual:

"The AC output neutral conductor and the DC negative conductors are not connected (bonded)
to the inverter chassis. Both the input and output conductors are isolated from the enclosure
and each other. System grounding, if required, is the responsibility of the system installer and
must comply with local and national electrical codes and standards. Refer to the Section 2.4
“Grounding Inverters” for more information."

So if I understand this correctly...I would be bonding in the panel I am installing?

[s2mikon]

Does the inverter have a built in transfer switch? This is very important. You do not want it to back feed to mains power and kill someone. If it back fed into the power grid the transformer would do its job and step it up to line voltage. Not good.

[Phatman]

Originally Posted by docmurphy

From the manual:

"The AC output neutral conductor and the DC negative conductors are not connected (bonded)
to the inverter chassis. Both the input and output conductors are isolated from the enclosure
and each other. System grounding, if required, is the responsibility of the system installer and
must comply with local and national electrical codes and standards. Refer to the Section 2.4
“Grounding Inverters” for more information."

So if I understand this correctly...I would be bonding in the panel I am installing?

Why is shore power going to inverter? Is that a transfer switch on the inverter?

[rossvtaylor]

Yes, you need to install a separate ground bar and keep the ground and neutral circuits separate. The bonding of those two will happen in a properly wired shore power panel. You would not want the ground and neutral bonded together on the bus and then again in the shore power panel (receptacle). Now, if the shore power receptacle isn't wired properly then you have a problem...but that's why so many people recommend that you check them before you plug in.

In ideal world, when not connected to shore power, you'd have a ground rod to which you connected your chassis and the ground lug...but that's not practical. The shore power receptacle should do that for you. Maybe I need to devise a hydraulic ground penetrator?

[s2mikon]

Ross, You just mentioned something the ground rod that I should not bring up, but I carry 2 large stainless plates I drive on top of after pouring epsom salt and water under them to create an RF ground for my hf radios. I may have to measure it as a ground some time. but back to the task at hand.

[rossvtaylor]

Originally Posted by s2mikon

Ross, You just mentioned something the ground rod that I should not bring up, but I carry 2 large stainless plates I drive on top of after pouring epsom salt and water under them to create an RF ground for my hf radios. I may have to measure it as a ground some time. but back to the task at hand.

That's actually interesting and not improbable. I have worked in places where it was not possible to drive a ground rod down...so it's permissible to dig a trench and lay the rod...or to use a plate. The plates are buried, not on the ground, but I wondered about a safe earthing option as you described...a plate which you park on, then clip a ground clamp to. We'd have to check the installations with a megohm meter, for wind turbine and tower work, but I would think a ground plate under a tire would be at least somewhat effective. One could pee on the ground, lay down the cheap plate, then park on it...and we could name it the Piss Poor Ground. Okay...I need to lay off the wine and get some sleep. Ni Ni!

[docmurphy]

Originally Posted by Phatman

Why is shore power going to inverter? Is that a transfer switch on the inverter?

Yes, this unit is designed to be a standby power source that can charge a backup battery bank while being fed by the grid. The transfer switch is internal.

Originally Posted by rossvtaylor

Yes, you need to install a separate ground bar and keep the ground and neutral circuits separate. The bonding of those two will happen in a properly wired shore power panel. You would not want the ground and neutral bonded together on the bus and then again in the shore power panel (receptacle). Now, if the shore power receptacle isn't wired properly then you have a problem...but that's why so many people recommend that you check them before you plug in.

In ideal world, when not connected to shore power, you'd have a ground rod to which you connected your chassis and the ground lug...but that's not practical. The shore power receptacle should do that for you. Maybe I need to devise a hydraulic ground penetrator?

Add a ground bar, make sure all is separated.
Should I bother going down through the floor to tie into the frame or will one of the hoop frame members/hat channel do the job?
Also, what gauge wire should I run for the ground wire? I have quite a few options but I would assume bigger is better in this application?

Definitely a great point about checking the power pole/shore receptacle...that would make for a really bad day.

I am sitting a reading through the manual now. With that and this thread I am gaining lots of knowledge.
I really appreciate the help! Now onto figuring the setup and getting it done...

[s2mikon]

8 ga copper ground wire.

[s2mikon]

Your frame and body should already be bonded together.

[s2mikon]

Is there a mains disconnect on the inverter?

[docmurphy]

Originally Posted by s2mikon

Is there a mains disconnect on the inverter?

I have a main disconnect. Cuts power to the inverter. Its not built into the inverter.

[DeMac]

Originally Posted by docmurphy

Ha...and trying not to learn the hard way on this one.

This is designed to be 30 amp service shore power

Box is mounted inside, surface mount, assume all wires will be in the same setup when installed.

Circuits are just divided up into legs of power port side, starboard side, etc.

The shore power goes into the inverter then out to the panel, mocked up in picture. Missing from the picture is the ground that would be running from the main lug opposite the neutral lug, as set up.

So if I were to not bond at this point then I would install a separate ground bar and keep things apart...good to go?

I can try to answer any more questions the best I can!

Thanks.

Assuming:
The line side is 240v/split phase,
with proper grouding and bonding(Green bonding screw) at the main breaker of the home or business,
is protected by a 2p/30a breaker on the line,
Not sure why its passing through the inverter.
Does it have automatic transfer switch (ATS)? Is it passive? What is the amp load of the inverter?

The 10/3 ought not be exposed. Use conduit or the inside of a wall.

The line neutral is terminated correct, each load neutral terminate to same block, one per termination screw.

Add a ground bar (8 screw) using machine screws. Drill & tap the holes or use nuts. NO self tappers.
All six grounds (line, load, chassis) terminate on added bar, one wire/screw. Ground #8 solid to heaviest steel (nearby), frame if you can drill thru the floor. Clean the metal, use washers, lots of good contact.

The romex:
#12 on the 20A
#14 on the 15A
Also not exposed, protected from physical contact.
Two romex per connector, ok. One better. NOT four. Drill 7/8" holes & use two or more connectors. (1" KO seal for old hole)

**Big Deal**
That disconnect is rated 30A, you have a twin 20A breaker on one leg. 16A x 2 = over rating of that leg of the device. Use twin 15a on both legs, better.

You ought to use $35 sub panel that has the proper wire space inside and rated as such.

Every service electrician has changed melted 30A disconnects due to shorts and overloads. Heat takes time to build, wont happen as soon as you turn it on.
Disconnects are not sub panels. Too small inside to be approved for this use.
But thats your bus(iness).

I'm hip to using as much grounding as possible. Can't have too many ground rods or rebar incased in concrete. CAN have not enough. Steel is a lousy conductor, worse on DC. Steel will never be the path of least resistance if aluminum, copper, or flesh are available.
Just wanna help you be safe, I love humans.

[docmurphy]

First and foremost I wanted to say THANK YOU so much to everyone for walking through this with me and spending time to read and ask questions. It is what makes this type of interaction so valuable and accessible.

Originally Posted by DeMac

Assuming:
The line side is 240v/split phase,
with proper grouding and bonding(Green bonding screw) at the main breaker of the home or business,
is protected by a 2p/30a breaker on the line,
Not sure why its passing through the inverter.
Does it have automatic transfer switch (ATS)? Is it passive? What is the amp load of the inverter? 120/240 VAC split-phase output, 4000 watt, 30-amp per leg AC pass-thru capability

The 10/3 ought not be exposed. Use conduit or the inside of a wall.Roger that.

The line neutral is terminated correct, each load neutral terminate to same block, one per termination screw.

Add a ground bar (8 screw) using machine screws. Drill & tap the holes or use nuts. NO self tappers.
All six grounds (line, load, chassis) terminate on added bar, one wire/screw. Ground #8 solid to heaviest steel (nearby), frame if you can drill thru the floor. Clean the metal, use washers, lots of good contact. Roger that

The romex:
#12 on the 20A
#14 on the 15A
Also not exposed, protected from physical contact.
Two romex per connector, ok. One better. NOT four. Drill 7/8" holes & use two or more connectors. (1" KO seal for old hole) I will make sure that I separate the romex lines so that they don't enter the same KO.

**Big Deal**
That disconnect is rated 30A, you have a twin 20A breaker on one leg. 16A x 2 = over rating of that leg of the device. Use twin 15a on both legs, better. I understand this concern. The AC load is not going to be vast so it is entirely possible to reduce the size of the breakers; all four 15 amp.

You ought to use $35 sub panel that has the proper wire space inside and rated as such.
Roger that .I will look into this.
Every service electrician has changed melted 30A disconnects due to shorts and overloads. Heat takes time to build, wont happen as soon as you turn it on.
Disconnects are not sub panels. Too small inside to be approved for this use.
But thats your bus(iness). The panel that I am using is a 2 slot breaker panel, the smallest one I could find, as space is an issue, but what isn't on these things! I will check into a larger panel box and see what is available.

I'm hip to using as much grounding as possible. Can't have too many ground rods or rebar incased in concrete. CAN have not enough. Steel is a lousy conductor, worse on DC. Steel will never be the path of least resistance if aluminum, copper, or flesh are available.
Just wanna help you be safe, I love humans.
I am reading the manual now it alls for some pretty stout grounding cables #6 AWG for DC, #8 AWG for AC. I am planning on using some heavy duty grounding lugs to the hat channel framing just above the bus floor (interior) and through the floor directly to the frame.

Another question I have thought of from reading everyones posts is when boondocking or dry camping and not attached to a power pole, would it be necessary and/or beneficial to have a grounding rod that would be pounded into the ground when stopped? I am imagining having some grounding rod that I would sledge into the ground a foot or so to improve the grounds....but not sure how that goes over with property owners/managers and if its really necessary in the long run. Just trying to suss out the the level of "you can never have too many grounds".

Again, thank you so much for helping out. I am planning on uploading the build and all that once I am finished up enough to get the house on the market and sit down for more than 5 minutes!

[DeMac]

Ground rods are $13. its a good invesment, at least at your home RV connection.
RV lots ought to have good grounding. If its an older establishment, it may not.
I live in the lightning capital of Earth, so I put ground rods everywhere that I have power leave the dirt, on my property.

I must drive a rod each time I move my electric fence. Sometimes tough to get 'em back out. I use a leverage tool that's made for pulling up metal fence posts.

Update this thread and we'll stand with you until it's safe.

what isn't on these things?
Space:
Clearance between the live parts (shorts)
Ambient temp. (heat disappation)

[Phatman]

Don’t forget, if you have more than one ground rod, they should be bonded together with a #6 copper.

[docmurphy]

Originally Posted by DeMac

Ground rods are $13. its a good invesment, at least at your home RV connection.

Update this thread and we'll stand with you until it's safe.

Totally agree. I will look into getting one set up for sure.

Originally Posted by Phatman

Don’t forget, if you have more than one ground rod, they should be bonded together with a #6 copper.

Roger that! I think I will most likely try to start with one and see what I need from there.