Neutral to ground bonding

[Albatross Adventures]

Hello, I have a list of questions. I have little experience with electric so explain in laymen terms and include links where you can please! This is a bluebird I am converting to an rv.

1. I need to know at what point In my circuit I need to bond my neutral and ground. (After my inverter/charger at the 30a breaker I’m using as my main lug? Or somewhere else)
2. Is the 30a breaker between my inverter/charger and shore power plug in pointless?)
3. Should my grounds all be tied together in one spot then put onto the frame or should they all attach to Frame individually

If I need more pictures or anything else please let me know. And I will be taking this to an rv shop to be looked over before plugging it in for the first time. If there is anything that is unnecessary or missing also let me know of that

[turf]

i shouldn't answer questions like this, but i learn as i go so here it goes.

your neutral/ground bond should be at the source. when on shore power, its bonded at the shore source. when on you own solar power, its probably bonded in your inverter. you have to read your inverter instructions.

the 2 sources are connected via a transfer switch. the bonding location should move with the transfer switch.

[Albatross Adventures]

Originally Posted by turf

i shouldn't answer questions like this, but i learn as i go so here it goes.

your neutral/ground bond should be at the source. when on shore power, its bonded at the shore source. when on you own solar power, its probably bonded in your inverter. you have to read your inverter instructions.

the 2 sources are connected via a transfer switch. the bonding location should move with the transfer switch.

I cannot find instructions for the inverter/charger I have. It does have an auto switch in there as well if they would change anything. I can find them for other models, maybe I can take the cover off of and and take a look at the wiring inside? If it is not bonded in the inverter would it be bonded before or after in that case? The fact that it is a combination of an inverter/charger makes it seem more confusing to me.

Also, does the grounding to the frame at the points in my circuit seem appropriate to you?

[ol trunt]

You need to become acquainted with Mike. Mike Sokol that is. His RV electrical articles and utube series can be found at RVtravel.com under the MORE heading.

Here is a utube example:

https://www.youtube.com/watch?v=GuWX9wJwvtU

The questions you posed lead me to believe you need to "study up" before you make any installations.
Jack

[turf]

your picture doesnt make sense to me. both 30a breakers look useless to me in your drawing.

your power sources are: shore or solar.

they each should have their own g/n bond.

they should lead into a transfer switch.

the transfer switch should lead to the electric panel.

you got some learning to do.

[Albatross Adventures]

Originally Posted by turf

your picture doesnt make sense to me. both 30a breakers look useless to me in your drawing.

your power sources are: shore or solar.

they each should have their own g/n bond.

they should lead into a transfer switch.

the transfer switch should lead to the electric panel.

you got some learning to do.

The first 30a breaker was something from a video of wiring the specific inverter charger I have and it was used to protect the inverter charger, with that I will also have a surge protector. If the surge protector will be all the protection I need, I will just remove that initial 30a breaker. The 30a breaker after the inverter/charger that leads into the breaker box is there to act as a main breaker for the 120v system same as a homes circuit breaker panel

[Albatross Adventures]

I’ve been working my way through his book

[Albatross Adventures]

Originally Posted by turf

your picture doesnt make sense to me. both 30a breakers look useless to me in your drawing.

your power sources are: shore or solar.

they each should have their own g/n bond.

they should lead into a transfer switch.

the transfer switch should lead to the electric panel.

you got some learning to do.

I’ve been working my way through his book

[TheHubbardBus]

Originally Posted by turf

your picture doesnt make sense to me. both 30a breakers look useless to me in your drawing.

your power sources are: shore or solar.

they each should have their own g/n bond.

they should lead into a transfer switch.

the transfer switch should lead to the electric panel.

you got some learning to do.

Solar isn't an AC source. It's a DC (charging) source. There is no neutral.

The incoming 30A breaker does serve a purpose. Otherwise you're relying on whatever pedestal you're hooked up to, hoping they did things right. Plus there's the possibility of using an adapter to connect to higher-amp service, which could allow you to draw more power than your wiring / hardware is capable of supporting without tripping anything.

The second main breaker does too, assuming there isn't one incorporated in the inverter itself (ours there isn't - we must supply it). But its sizing may or may not be 30A, & since the OP doesn't give specifics it's impossible to say if it's sized correctly.

That's not saying the diagram is 'right' or complete, assuming it's a final draft. It is not.

OP - I agree with everyone saying you have learning to do. It's not a derogatory statement, nor is it saying this isn't something you can't accomplish yourself in the (near?) future. But you're not there yet. You don't need to know the answer to your questions. You need to understand the answers to your questions. Like why you should only bond neutral & ground at one point, and what can happen if you don't. Shore power should be bonded at the pedestal, which means bonding it anywhere in your build is a mistake.

If you've got some time, keep up on studying. Any specific questions on the basics tons of people here can & will happily answer. But if you have to do it now - get someone to help who knows their stuff.

[Rucker]

Originally Posted by Albatross Adventures

I cannot find instructions for the inverter/charger I have. It does have an auto switch in there as well if they would change anything. I can find them for other models, maybe I can take the cover off of and and take a look at the wiring inside? If it is not bonded in the inverter would it be bonded before or after in that case? The fact that it is a combination of an inverter/charger makes it seem more confusing to me.

Also, does the grounding to the frame at the points in my circuit seem appropriate to you?

I agree with Turf and Hubbard in their comments and add my own.

The ground wire and the common/white/neutral wire in a 120VAC system should only be bonded, that is, electrically connected, at the source of power. This means either at the original distribution panel (if you are on shore power) the generator (if you are on a generator) or at the inverter itself if you are on battery. None of these sources of power should be able to energize your bus together-one at a time, and only one.

If you have autotransfer switches they should operate in mutually exclusive mode-that is, no two sources of power should be active at the same time.

No subpanel or load center in your bus should have the ground wire and the white wire connected, not anywhere.

This bonding is DIFFERENT than device grounding.

There are a few schools of thought on device grounding. My view (and my practice) is to ground every piece of metal I can find in the bus to the bus frame, including the inverter ground, subpanel grounds, and device ground wires if they have them, so that there are a multiplicity of paths back to the source of power in the event of a short. For instance, if you are running shore power, the fault travels back to the main panel; if you are running the generator, the fault travels back to the generator; if you are running the inverter the fault runs back to the inverter, so that the circuit breakers and wire fuses through which that power is feeding can do their job and trip/pop/blow.

You can easily tell whether or not your inverter or generator is bonded. Check resistance between the common wire (neutral or 'white wire') on the inverter 120VAC supply and the ground (turn it off/unplug it first). If there is no resistance, your inverter is bonded internally (as it should be, in my opinion, for use in a bus). If there is no connectivity (open circuit) between the neutral/common/white wire and ground right at the inverter, your inverter is not bonded internally.

Unbonded inverters and generators pose an electrocution hazard because a fault on an unbonded inverter under power doesn't have the benefit of a return path through chassis ground to pop the circuit.

There are YouTube videos that show you how to make a jumper to create a bond between the white and ground wire at the inverter but given that you are a newbie it is best to do research and reach out to someone with electrical skills as you mentioned to set the inverter up for success, success being the least likelihood of electrocution.

Bonus facts: 12VDC systems can share the same ground paths with house voltage because there are no circumstances where the 12VDC positive conductor and a 120VAC positive conductor meet, providing you are using autotransfers.

[Albatross Adventures]

Originally Posted by TheHubbardBus

Solar isn't an AC source. It's a DC (charging) source. There is no neutral.

The incoming 30A breaker does serve a purpose. Otherwise you're relying on whatever pedestal you're hooked up to, hoping they did things right. Plus there's the possibility of using an adapter to connect to higher-amp service, which could allow you to draw more power than your wiring / hardware is capable of supporting without tripping anything.

The second main breaker does too, assuming there isn't one incorporated in the inverter itself (ours there isn't - we must supply it). But its sizing may or may not be 30A, & since the OP doesn't give specifics it's impossible to say if it's sized correctly.

That's not saying the diagram is 'right' or complete, assuming it's a final draft. It is not.

OP - I agree with everyone saying you have learning to do. It's not a derogatory statement, nor is it saying this isn't something you can't accomplish yourself in the (near?) future. But you're not there yet. You don't need to know the answer to your questions. You need to understand the answers to your questions. Like why you should only bond neutral & ground at one point, and what can happen if you don't. Shore power should be bonded at the pedestal, which means bonding it anywhere in your build is a mistake.

If you've got some time, keep up on studying. Any specific questions on the basics tons of people here can & will happily answer. But if you have to do it now - get someone to help who knows their stuff.

I will not have solar on my bus for a while so it is just shore power from the pedestal and a generator. I have an AIMS 2500w pure sine inverter/charger with an automatic switch. As far as only one point having a neutral/ground connection at the source of power and only at that one point to avoid objectionable current, I understand that, but it’s when I am not on shore power but I am using my battery to power my 12v and 120v system, at that point, would it be the neutral/ ground bond in the inverter/charger that I would rely on?

[Albatross Adventures]

Originally Posted by Rucker

I agree with Turf and Hubbard in their comments and add my own.

The ground wire and the common/white/neutral wire in a 120VAC system should only be bonded, that is, electrically connected, at the source of power. This means either at the original distribution panel (if you are on shore power) the generator (if you are on a generator) or at the inverter itself if you are on battery. None of these sources of power should be able to energize your bus together-one at a time, and only one.

If you have autotransfer switches they should operate in mutually exclusive mode-that is, no two sources of power should be active at the same time.

No subpanel or load center in your bus should have the ground wire and the white wire connected, not anywhere.

This bonding is DIFFERENT than device grounding.

There are a few schools of thought on device grounding. My view (and my practice) is to ground every piece of metal I can find in the bus to the bus frame, including the inverter ground, subpanel grounds, and device ground wires if they have them, so that there are a multiplicity of paths back to the source of power in the event of a short. For instance, if you are running shore power, the fault travels back to the main panel; if you are running the generator, the fault travels back to the generator; if you are running the inverter the fault runs back to the inverter, so that the circuit breakers and wire fuses through which that power is feeding can do their job and trip/pop/blow.

You can easily tell whether or not your inverter or generator is bonded. Check resistance between the common wire (neutral or 'white wire') on the inverter 120VAC supply and the ground (turn it off/unplug it first). If there is no resistance, your inverter is bonded internally (as it should be, in my opinion, for use in a bus). If there is no connectivity (open circuit) between the neutral/common/white wire and ground right at the inverter, your inverter is not bonded internally.

Unbonded inverters and generators pose an electrocution hazard because a fault on an unbonded inverter under power doesn't have the benefit of a return path through chassis ground to pop the circuit.

There are YouTube videos that show you how to make a jumper to create a bond between the white and ground wire at the inverter but given that you are a newbie it is best to do research and reach out to someone with electrical skills as you mentioned to set the inverter up for success, success being the least likelihood of electrocution.

Bonus facts: 12VDC systems can share the same ground paths with house voltage because there are no circumstances where the 12VDC positive conductor and a 120VAC positive conductor meet, providing you are using autotransfers.

So no bonding in the panels to avoid objectionable current. And no deriving power from battery and shore simultaneously? This should be handled by the automatic switch in the inverter/charger correct? If my generator and inverter/charger (2500w pure sine AIMS inverter/charger) aren’t neutral/ground bonded I need to bond it there on my own? But if I have 120v shore power coming in and it is going through my inverter charger which is now bonded wouldn’t that be a second point of bonding creating an issue? When you say the auto transfer switch should be mutually exclusive, is that a fact they all are or that it should be that way? I’m assuming that the battery will be getting charged but no power will be drawn from it while plugged into shore right?

[TheHubbardBus]

Originally Posted by Albatross Adventures

I will not have solar on my bus for a while so it is just shore power from the pedestal and a generator. I have an AIMS 2500w pure sine inverter/charger with an automatic switch. As far as only one point having a neutral/ground connection at the source of power and only at that one point to avoid objectionable current, I understand that, but it’s when I am not on shore power but I am using my battery to power my 12v and 120v system, at that point, would it be the neutral/ ground bond in the inverter/charger that I would rely on?

I can't speak to your particular model of inverter / charger, but here's a great description of how things work with similar Samlex products. I'd be surprised if yours didn't operate in a similar, if not identical, manner. The following article is also a great education on the subject of neutral/ground bonding in rv/marine applications, so it's worth the read regardless. I actually went with Samlex, at least in part, because of their extensive and unequaled documentation.

https://samlexamerica.com/wp-content...plications.pdf

[turf]

Hey AA,

this is why i shouldnt answer. i said my piece and am at my limit of knowledge. however, i got questions now too, dammit.

your original drawing has AC as a 120v load. is your intention to run the AC on battery power?

every electric setup is unique. there are 100 ways to skin a cat, so there is more than 1 correct way to get where you want to be.

big electric loads like AC can be setup to be shore only. it may be more cost effective than trying to build a battery system to run your AC. i think i read you have a 2500 watt inverter, and i have my doubts you can run an AC with that.

idk, but its my impression, that solar to run it all is very pricey. the price jump to running your AC off of solar is going to cost you bigtime.

RV electric is the biggest misunderstood topic online. that why i jump in, i learn something every single thread.

listen to the others. we are trying to help

[Rucker]

So no bonding in the panels to avoid objectionable current.
-Correct.

And no deriving power from battery and shore simultaneously?
-Correct. No running the inverter off battery power when you are on shore power. I'm assuming most buses use the same receptacles that are powered either by the inverter or by shore power. If you have a dedicated shore power receptacle that is never powered except by shore power (not connected to the inverter) that would be the exception.

This should be handled by the automatic switch in the inverter/charger correct?
-Correct.

If my generator and inverter/charger (2500w pure sine AIMS inverter/charger) aren’t neutral/ground bonded I need to bond it there on my own?
-To ensure you do not have bonding in more than one place, specifically the source of power, yes, that is correct. See next question though.

But if I have 120v shore power coming in and it is going through my inverter charger which is now bonded wouldn’t that be a second point of bonding creating an issue?
-Yes, it would. Fortunately for you AIMs 120V devices all transfer the ground from shore to 'bond' when they switch (according to the user documentation). I'm guessing that is how these inverter/chargers are set up in general, but I would verify via a resistance check while in inverter mode, just to be sure.

When you say the auto transfer switch should be mutually exclusive, is that a fact they all are or that it should be that way?
-The transfer will result in only one source of power active on the circuits at any time. If you only have one autotransfer, they will be mutually exclusive. You can install autotransfer switches in series (where you set up a hierarchy that determines which source gets precedence) and each of those will be mutually exclusive. Rotary switches are similar in operation..

I’m assuming that the battery will be getting charged but no power will be drawn from it while plugged into shore right?
-It depends. I think with your device (again, from the literature) the battery is charged while you are on shore power, and it is not possible to invert (that is, get 120VAC)from the battery. There's no reason you can't get 12V power from the battery-that depends on how your 12V distribution lines are set up.

-

[Bluthebus00]

DON'T BOND YOUR NEUTRAL AND GROUND!
This is dangerous and is against code.

The shore connection is already bonding neutral and ground an it's main panel. All sub panels must have neutral and ground separated. This includes RVs. The elective system in an RV is considered a sub panel while the main panel for the shoreline hookup is considered the main panel. The main panel will always have neutral and ground bonded.

Binding them on your RV can result in "hot skin" if there's any wiring issues with the shore power setup.

Also, one ground line is fine running from your breaker panel to the frame of your vehicle.

Also, an elder full time RVer have me his advice: "Always keep an electrical tester with you and test the podiums before connecting your RV to it."

[kazetsukai]

Originally Posted by Bluthebus00

Also, an elder full time RVer have me his advice: "Always keep an electrical tester with you and test the podiums before connecting your RV to it."

Yeah, don't trust shore.



On this topic, there are RV "surge protectors" out there that test for open neutral, bad voltages, surges (duh) etc and will disconnect on known failure scenarios. These come in the form of "dog bones" (put between your rig and the connection to shore) and hardwired (internal- by virtue of plugging in you're protected).


Ours is the latter (there's also a 30A version):
https://www.amazon.com/gp/product/B003AN1UA8


You plug in, the device watches the connection for about one minute and if everything looks good it connects you. If not, it has a display with an error code. During brownouts or surges, the device will disconnect (which we wouldn't notice due to the inverter taking over near instantaneously if not for the audible "thunk" of the relays in it) and then once things are looking good again for a minute, reconnect.

[Bluthebus00]

Agreed, surge protectors are also a must.
I installed a hardwired 30A 120V SurgeGuard on our rig when building out our electrical system.

It is fantastic. Protects for over/under voltage, over current, bad wiring, grounding issues, reversed polarity. It's wonderful.

Here's what I bought: https://www.amazon.com/gp/product/B01BDWQL8S/