Ground is the most confusing part of van conversion electrics. Why? Because of how much conflicting information there is on the internet about it! Today we will cut through the noise and learn all about ground for your campervan! We will look at the types of ground, what appliances we should ground, and how we wire up ground in our campervans. I'm Shane, I've been teaching people to convert campervans for many years, I'm the author of The Van Conversion Newsletter, the van conversion instructor at Udemy, and the proud owner of a beautiful self-build campervan called Beans. So let's jump in and have a look at ground for van conversions!
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Index
Note: Did you know that you can get a free electrical wiring diagram by signing up to The Van Conversion Newsletter 🙂
What is ground?
Quite often ground means different things to different people, hence why there is often so much confusion over it (especially in the world of van conversions!). For example ground to an electrician can mean something different than ground to an electronics engineer.
Proper grounding is a critical safety precaution across the world of electrics. We ground electrical equipment so that internal wiring failures don't raise the voltage to dangerous levels. Essentially ground is an alternate pathway for electricity to go; if there's a fault in your system, electricity can flow to ground to save your wires, appliances, and hopefully stop a fire.
As we know, a circuit must be complete for current to flow (think of a simple DC system)
Well, we can also use ground as the circuit return path
The most obvious example of this is in a vehicle. The vehicle chassis is the common return path for all return current to the battery
In the world of van conversions, ground is a simply a connection (from negative) to the chassis of your vehicle.
Types of Ground
While there are many types of ground (GND), we are going to focus on just two: Earth ground and chassis ground.
Earth ground
Earth ground is a direct and physical connection to our beautiful planet earth. It is true 0V.
In our house, the third prong in a plug socket is physically connected to earth ground.
And earth ground looks like this (an earthing electrode - a conductive rod driven into the ground):
Chassis ground
Chassis ground is the ground we have in our vehicles. It is a point in the chassis of the vehicle to which we connect the negative terminal of our batteries and any other relative appliances.
Unlike earth ground, chassis ground is not a physical connection to our planet earth, but to the chassis of the vehicle. This makes the van chassis is the common return path for all return current to the battery.
AC ground vs DC ground
The main difference between AC and DC ground is that no current should flow into AC ground during normal operation, while all current should flow into DC ground.
Why?
DC appliances don't have a "ground" per say, because the negative (which people are calling "ground") is itself at the same potential as the chassis. The Negative terminal of your leisure battery is ground for the appliances.
Which appliances should I ground in my van conversion?
Here are the items I grounded in my conversion (you can get a free wiring diagram of my system by signing up to The Van Conversion Newsletter):
At a bare minimum you should ground your leisure batteries (usually done by wiring the negative bus bar to the ground point). This will be enough in most circumstances.
But, you can also ground (individually or by running them to the negative bus bar):
The Inverter
The Split Charge Relay
The Solar Charge Controller
Garage Consumer unit (if you have shore power)
It is important that all your grounds are connected together (ie. to a single ground point), this can help avoid step voltages.
How to install ground in a van conversion
All vehicles have a ground point pre-built into the chassis. A quick google for your van's ground point should show you where you can find it. However, sometimes it might be very far away or inaccessible (eg. under the hood / bonnet of the van). If this is the case, you will need to make your own ground point. Here's how:
Sand down some of the paint on the chassis of the vehicle (on an interior / inward-facing part of the chassis). This gives a clean connection point against the bare metal.
Drill a hole into that point
Pop a large bolt through that hole - this is our ground bolt. Everything gets grounded to this
Note: The typical color of for ground wire is green an yellow (not that nasty red I used in the photo above 😆)
Conclusion
I hope you found this explanation of van conversion ground electrics useful! You're now better equipped to build out a safer electrical system in your self-build campervan! Don't forget to subscribe to The Van Conversion Newsletter for everything you need to get started with your own van conversion (I'll send you a free wiring diagram when you sign up).
Be sure to check out the rest of the Electrics Guides. Related articles include: leisure batteries, campervan electrics explained, Campervan wiring diagram explained.
If you're converting a van but unsure of how to do it, you could also check out the Van Conversion Course on Udemy. In the course, you'll learn directly from me how to convert a van into your dream home - no prior experience needed!
Until next time,
Shane ✌️