Calling Electrical Experts

[MarkWard]

I ran into this when I installed my Xantrex invertor which I have since removed. The 110 volt power service comes into the van and is fused below the 110 outlet next to the rear seat. Power then runs to the second 110 outlet in the kitchen. The 110 power comes into the van and is grounded by a green wire that is secured to the chassis at the floor at the rear of the cabinet behind the outlet. Is that really an effective/safe ground for 110 volts? The van is insulated by the tires, but that is not my actual question.

The battery charger I am hardwiring in is from the marine industry. It has positive and negative terminals for charging as many as 3 batteries. It also has a case ground that is supposed to be one gauge smaller than the + for the battery charging. In a wood or fiberglass boat, you don't have the chassis as a ground plane. They use busbars etc for completing circuits. I am inclinded to ground the case of the charger to the chassis of at the same point as the 110 grounds to the chassis. I am mounting the charger in that small cabinet. I recall a thread warning about being careful with the 110 and the ground circuit. Here is a copy of the wiring to help. I appreciate any helpful advice.

Also, since a ground is ground, couldn't I also run the charging ground to the chassis at the same point as the case ground?
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[PDXWesty]

120 volt systems have three wires: Line, Neutral, Ground. The ground is actually carried back through the shore powered connection through the third wire. The chassis is not used for current as in the 12v system, but is grounded to prevent shock. Power is conducted through the line and neutral wires. The system relies on the integrity of the shore system to maintain a system ground (different than a 12v ground).

You do not want to mix grounds.
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89 Westy 2.1 Auto

[MarkWard]

[Westified]

RSXSR. You got me thinking about this. I pulled my kitchen last summer and redid the interior ( kitchen rust). I saw the green AC ground and wondered the same thing. Today I started googling your question. I also have a boat. Based on my research. The ground for your charger would be through the three prong electric plug like PDXWesty said and should not need to connect the separate ground since we aren't dealing with a boat. I would verify this with the charger mfg. From my reading we should each carry a tester to plug in at the camp grounds using rubber gloves. No kidding. Some of these campground outlets are faulty and in some cases can energize the shell of our Vanagons. I also put GFIC outlets in my Westy. See the comments on the camping world site re the tester.
http://www.campingworld.com/shopping/item/digital-line-monitor/24900
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1984 Westy Wolfsburg, owned since 1987. FAS 2.0 NA engine conversion in 2022.

[tencentlife]

You can use the chassis to carry the negative side of 12VDC circuits and act as the equipment ground for 110vac shore power, that's no problem. Both are at zero potential at all times, and there should always be zero current on an ac equipment ground.

The one safety issue here that you must be sure of is that the shore power ac neutral line and the ac equipment ground are only made common, or bonded, at one location, which is standard practice and if the ac service outside the van is wired according to code they will already be bonded at the service panel. From that point on, the ac neutral line like the hot line must remain isolated from all equipment chassis' and the van chassis.

The ac neutral carries the same current at the same voltage as the hot line (it is in fact the same as the hot line, the only difference is that the neutral is grounded), but the equipment ground carries no current. The danger is if the two are bonded at more than one point, they will create a parallel neutral network each side of which will carry half the current but be at full ac voltage, so that any grounded equipment, including the van chassis, will also be hot, or at line voltage above ground potential. You could most easily get a shock by touching the van while standing outside if you weren't insulated from ground.

So you make the equipment ground pole of the ac input connector for the van common with the van chassis. This grounds the van chassis thru the ac service ground when it is connected.

Then the chassis' of ac receptacles should be grounded to the van or have dedicated ground wires to the ac input connector.

Any hardwired ac equipment such as inverter and charger should also have their chassis' grounded to the van's, but only if you are sure that their own ac neutral connections in or out ARE NOT bonded to their chassis, which can easily be seen in most cases by opening the casing. Many inverters intended for off-grid, RV, or boat use have their neutral bonded to the inverter chassis internally, so be sure to check if you are going to use them in a vehicle that can accept ac shore power.
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Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[MarkWard]

Chris, thank you for taking the time to reply. I figured it was ok to do what I was planning, but wanted to run it by others. We actually don't plug in camping very often even when power is available. The battery I purchased recommended a charge rate at about 23 amps. The charger is rated for 30amps and has the circuitry for a float charging when the van is parked which while I still have job is most the time. Thanks again.
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[J Charlton]

Its wise IMHO to remind ourselves of what a "ground"is in both 12v (negative ground) Direct Current (DC) circuitry and what it is in 120V Alternating Current (DC) circuitry.
In 12V DC, the chassis ground actually supplies the energized electron flow to make the appliance work - the entire chassis is, in fact, one large conductor.
In 120V AC - the 3 wires coming into the van have differing roles - there are usually a black, a white and a bare copper - at a moment in time (and the "moments" occur 60 times a second) - eg the black wire has 120V and the white wire is neutral, 1/60th of a second later this polarity is reversed and hence the name Alternating Current. The bare copper wire is the "ground" and is literally connected to ground back through the outlet, to the corresponding wire coming into the van and at the service panel to the actual ground. It is there to provide a safe (non human) way for the electron passage if either of the black or white lines should become detached and contact a metal outlet box or the frame of a toaster - whatever. Since there will be virtually no resistance in this "grounded" line, all current will flow through it and not through the human about the touch the toaster (eg) frame. Because there is very little resistance, the current flow will be high,causing fuse to blow, or a circuit breaker to open or a GFI outlet to trigger an open circuit.
The term "ground" means two quite different things in 12V DC circuitry and in 120V AC circuitry.
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[MarkWard]

All good information. I talked this over with a friend that is a long time RV'r. To summarize. If the factory "green" wire that connects the chassis to the outlet grounds "copper" were missing. It is unlikely you would notice any difference if everything were proper. The inside outlets are grounded to the power pole not the van's chassis.

If the "green" wire to the chassis were missing and one of the 110 leads were contacting the chassis and it was connected to shore power, it would be possible on a rainy day to approach the van, and by touching the chassis, be electrocuted. The shore power would not be aware of the short, since the van chassis is not really grounded. It is insulated by the tires. The lead to the chassis would provide the short to hopefully blow the shore power breaker and keep you from being electrocuted. So, it is important to have that lead in place. Otherwise it is just along for the ride.

Did I get that right?
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[tencentlife]

Yes, you basically have it right. If you did not ground the van chassis thru the shore power connection, and/or did not ground the chassis' of any ac-handling equipment onboard, it would have no effect on how anything works, as the equipment grounds never handle any current in normal circumstances. Equipment grounding is a safety precaution against shorting of the hot line in any of the various ways that could happen, but if a hot line ever was shorted, a.) having it grounded would probably throw the breaker protecting that line, and b.) it presents a better more conductive path to ground so a person does not end up creating a ground circuit with part of their body and getting a potentially deadly shock.

You do need to heed my other warnings above that the neutral line be bonded at only one location in these types of installations. You can easily determine if any ac-handling equipment like an inverter or charger has its neutral bonded to its chassis, either by using an ohmmeter to see that the neutral line and chassis are isolated, or by opening the case for a look. When facing an edison from the front, the left side, wider tab is the neutral if it has been wired correctly. I prefer to open cases and look, myself, I feel more sure that way.
_________________
Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/

Please don't PM here, I will not reply.

Experience is kryptonite to doctrine.

[redpsycowagen]

I have what's registered as a 72 VW beetle bug but it's a kit car like a manx (haven't proven if it's an early manx or a copy) but I want to under go re wiring the whole thing wire by wire cleaning it up (as it's a rats near of connected crap pieces). I got a new circuit box that takes today's fuses instead of the old stock style and want to know what is most important to have linked to the box as far as wipers, headlights, accessories, turn signals and such. I'm a good mechanic but when it comes to electrical work I'm not the best. I have rolls of wire I want to do myself instead of buying a new harness and gutting it for what I need so I have my own system. Any specialists out there?

[dobryan]