Is it dumb to connect yourself to a car's grounding point
Is it dumb to connect yourself to a car's grounding point
To start off: I was explaining to my friend that I don't have a grounding point in my house (plumbing is PVC, outlets are gcfi protected only, not allowed to drive a grounding rod into the ground, etc...) and that I've just been handling sensitive electronics with just luck and preparation (humidity, moisturizer, no synthetic clothing, etc...) all this time. He told me to just wire myself to a good, multimeter tested, grounding point in a car and that will discharge any built-up static electricity. I'm not smart enough to argue with him on this subject but that doesnt seem the safest. Would that work or should I just keep doing my method? My understanding is that chassis grounding is essentially replacing wires with the frame so the outcome would just be connecting myself to the negative terminal of a car battery.
Tldr: I'm explaining my lack of a grounding point at home for sensitive electronics and is advised by my friend to wire myself to a grounded point in a car to discharge built-up static electricity. However, I'm uncertain about the safety of this suggestion and questions whether my current method of handling electronics with precautions is sufficient.
Edit: lmao people are really getting hung up on the no grounded outlet part. Umm my best explanation I guess is that its an older house that had 2 prong outlets and was "updated" with gfci protected outlets afterwards think the breakers as well. My understanding is that its up to code but I'm not an electrician. As for the plumbing I'm sure there's still copper somewhere but the majority has been updated to pvc over the years. Again it's not my house I don't want to go biting the hand that feeds me. Thank you though, haha
Edit #2: thank you all so much for the helpful advice, I really appreciate all of you!
Edit: I jumped over a detail in my memory. The ground pin goes to neutral in the breaker box and neutral is grounded. The key part is that the ground pin isn't an isolated circuit that just goes to the dirt. I'll leave the below so you can see what people were correctly arguing with me about.
The ground pin in a north American outlet, at least, isn't actually grounded. It's just a dedicated circuit that goes back to the neutral line in the circuit breaker box. It doesn't go to the ground there, either. Not to mention you don't get static sparks when touching dirt anyway because ground is a terrible conductor anyway - it works on a power delivery scale because it's effectively infinitely big. These things only vaguely work for static reduction by being large metal structures that can sink the excess static. That's why doorknobs and coat racks happily shock you.
No, the "ground" in a car is not actually a ground at all. It's a chassis common power point. Ground is the entirely wrong term but people will argue it up and down because it has always been called ground. Mixups in function like this are exactly why I'll argue to use the right terminology. Common supplies power by chassis. Ground sinks stray power away from the device/fingers (hence why I don't argue against calling a house ground a ground).
I think that’s incorrect. The ground pin is a dedicated equipotential reference bonded to the earth via an acyclic wiring path which carries no current. It does go pretty directly to the ground rod via the breaker panel ground bus. Neutral happens to be connected to it at the entrance panel for fault clearing, but not really for any other reason.
Since all metallic chassis, pipes, ducts, etc are connected to it and it is available pretty much throughout a building, it is a logical place to connect ESD-prevention gear, even if the earth has little to do with that. (But, a grounding electrode system installed to code should have less than 25 ohm impedance to ideal earth - not exactly a “poor” conductor)
You are correct. I edited my comment with a note pointing out where I lapsed. Ground is grounded by way of bonding to neutral and neutral being grounded. It's just not a dedicated grounding circuit going straight to a nail in the ground.
The ground pin in a north American outlet, at least, isn't actually grounded
When I had my circuit breaker replaced and went to 200A service a few years ago, we had to have 2 ground rods put in (maybe we reused the old one, I can't remember) plus a wire following our copper water supply lines until just past the meter. Inspector actually made them redo that last one because it stopped just shy of the meter. Maybe there are other ways of going it, but actual honest-to-goodness grounding is also a thing here.
The ground pin in a north American outlet, at least, isn't actually grounded. It's just a dedicated circuit that goes back to the neutral line in the circuit breaker box. It doesn't go to the ground there, either.
Except is special circumstances the ground connection on outlets does go to a separate ground bussbar inside the panel ( as well as acting as the chassis ground for the panel).
That bussbar is typically connected to the neutral, but code requires it to also be connected to an actual earth ground.
Ground is the entirely wrong term but people will argue it up and down because it has always been called ground.
It serves the same purpose so they kept the existing name that hasn't been literal for a very, very long time.
AFAIK, there might an error in the first part, at least in Europe, where you have 3 Phase AC coming to your home, the neutral line connects to ground in the main breaker box, not the other way round. For US, this shouldn't be different.
Tl; dr - we’re all capacitors, discharging into a bigger capacity capacitor = grounding?
The actual goal of ESD protection in the context of electronics repair is to have your body and the device at the same potential, which doesnt necessarily have to be the same as the actual earth.
If you use a static dissipating mat/surface with wrist strap, it should be pretty darn safe.
Wait so you can use a static dissipating mat without it being connected to a grounding outlet and still be protected? Why do mats even have the option of grounding then, is it just for added insurance?
A static dissipating mat is designed to be somewhat conductive, so that any static charges that build up on a PCB or on yourself are distributed and equalized across the mat and anything in contact with it. The point is that you cannot have a sudden static discharge between two objects which have equalized charges (eg between your finger and a sensitive chip).
With that in mind, it should make sense that, when possible, you want to extend the "reach" of your mat by equalizing it with other things that can hold a charge, such as the floor, the door handle, the light switch, etc. All of those home furnishings are indirectly in contact with terra firma, and do slowly drain any accumulated charge to earth. But your electrical ground system provides a convenient, low-resistance copper path to quickly drain charge. So if it's available, you'd want to electrically "anchor" your mat to the Earth's charge using the electrical ground. Otherwise, just keep everything on or attached to the mat, including yourself by way of the wrist strap.
As an aside, in the electronics lab at my company, the floor was redone to the tune of six figures to install a semi conductive floor, so that engineers could wear ankle straps instead of wrist straps, all to protect from ESD damage. The reason that floor and your matt are only semi conducting is that an all-copper floor or mat could end up shorting out a PCB. So their resistance is a precise value which lets charges equalize but not too low to cause shorting issues.
Opinions may vary, but I say yes. The goal is to equalize your body to the thing you are working on. Equalizing to the earth is a bonus.
What even is a grounding point in a car? I mean if it's a car on rubber wheels, is it even grounded or would that just be like touching the negative side of an AA battery?
You could just directly touch the soil infront of the house, the car seems to be an completely superfluous step anyways.
But it will also not help if the electronics parts aren't grounded and neither is the table they're lying on. Now you're grounded and they might be charged. Same zap like if it were the other way around.
I just do it like you explained. Not wear crazy clothes that are bound to pick up static electricity, don't drag my feet over the carpet moments before touching something, and it should work out fine.
An electrical ground is reservoir into which you can dump charge with altering its potential difference. A car, in and of itself, is ground for the small shocks that occur from static. The earth is a bit overkill here.
Edit: I am about to use the word "safe" on the internet. Normal "don't trust everyone on the internet" warnings apply.
You are correct that connecting yourself to ground of the car is the same as connecting to the negative terminal. You should be safe doing so in a properly wired car.
That is to say, unless you expect to be at different potential differences. When might that happen? In a lightning strike for example. You do NOT want to electrically connected to your car's ground in a lightning strike. (You should be perfectly safe inside the car, not touching the car's ground.) Your car is not a reservoir for that kind of charge.
The earth can handle a lightning strike without a (measurable) change in potential difference. This is why fish are not cooked in lightning storms.
In a car, my understanding is that it is to dissipate energy into the car frame vs catching wires on fire.
Yeah, I think so, too. Unless someone installed a grounding wire that dangles to the ground, a car chassis is mainly used as the return path to the negative side of the battery. You can sometimes skip the additional second wire since the chassis is metal and conductive. Additional benefit: if a hot wire becomes loose and touches the metal or water creeps in, it now blows a fuse instead of for example closing the circuit through the radio or another random component and frying that or starting a fire. And the real reason is, everything is connected and 'grounded' to the chassis meaning there is no static electricity buildup between different components of the car and they're zapping each other. They're all on the same potential level. But it just has to be relative to each other. Not the soil like a grounding rod in an AC system in your house.
And I don't quite get why people install these wires that dangle to the ground. The internet lists some benefits including something with lightning, improved fuel efficiency and sound quality. But I mean a lightning strike is more likely if you're connected to the earth and it's sort of a faraday cage anyways. And the rest sounds like snake-oil to me. There are lots of devices that supposedly increase fuel efficiency, but I've seen too many Mythbusters episodes to fall prey to that. There might be some use-cases for utility vehicles that I don't know anything about, but my car definitely isn't electrically connected to the road.
not allowed to drive a grounding rod into the ground, etc...
What 🤨... how so?
The solution here is to bring a bucket of dirt inside and stick the ground rod in that.
This is what was told to me by an old-timer electrician.
You dig a hole, 2m x 2m x 1.5m (or as deep as you can dig with a shovel). You take the load cylinder from an old washing machine. Weld a rod to that thing (on the side of the cylinder, not the middle). Make the welds good cuz that thing will go under ground and the elements will eat through it in a matter of years if it's not welded correctly. Put the cylinder with the rod in the ground. Make a mixture of about 3 to 5kg of salt with soil (depending on the size of the cylinder and the type of soil) and fill the cylinder up with that. Put the rest of the dirt in the hole. Voila, a grounding solution that will last at least 50 years (or at least that's what he told me).
Ohh its not my house and homeowner said it will be potentially expensive and will need professional help finding a suitable place to drive the rod in to not cause damage. I agreed and that was that
So the rod itself is a trivial cost, if all you are really interested in is a grounded workbench.
For ESD, hammer a 2' bit of copper pipe into the ground outside near your workbench, and if you have 2 prong only at your workbench, connect the pipe with whatever gauge wire to an adapter like this
https://www.rona.ca/en/product/globe-electric-2-pack-15-amp-3-wire-grounding-white-adapter-58746-0079591?viewStore=55250This is not good enough for safety faults, but it will give you the same 0v reference on everything you plug downstream from the adapter. Put the wire on any metal furniture and shelving you will interact with while you work at the bench.
GFCI covers the safety requirements of an actual ground.
I should have mentioned, grounding out the panels and outlets properly is the expensive part. You don't need the whole house done.
Tell him what I proposed in the comment above. It's not expensive at all and works great (have done it in a few houses).
Maybe OP's a renter?
Rental properties usually have to comply with electrical standards, including grounding. If they don’t, then dropping a grounding spike isn’t going against any municipal bylaws, just the building manager.
If the building is grounded, you could patch into the grounding line (in NA, that’s the domed slot on an outlet) — but I’d advise against it if it’s a multi-tenant building, as you have no clue what others have connected to ground.
As long as the battery is disconnected, a car sounds like a great option, as it can easily take the amperage you’re likely dealing with. Even with the battery connected, a car should work as long as you’re confident there aren’t any grounding faults in it (test first).
No, yes, sort of.
You are correct that you would just be connecting yourself to a conductor connected to the negative terminal of battery. However, it’s a really really big conductor, about a ton of steel. Not as big as the actual earth, but still pretty big by electronics standards.
So, no, I would not recommend using a car as ground. But it’s not completely ineffectual.
That said, I’m shocked your house s does not have a ground and you’re not allowed to install one. That’s definitely not up to regulations in all jurisdictions I have ever lived in.
This is in the US, yes? Don't they have this two phase system of 220V that offers 2x110V, with ground being the center?
Yes, the center (neutral) is connected to ground somewhere, but is not a suitable ground reference - because current on the neutral creates a voltage drop along the neutral conductor. A North American outlet box has Hot (L1), maybe another Hot (L2), Neutral, and also an earth/ground conductor.
Neutral is not ever treated as ground; it’s impermissible to connect it to any bare metallic surface. Other than not being switched, and being the side that ends up on the threads of a light socket, it’s handled the same way as a hot/line conductor. Just like a 240V system.
It would dissipate static fine, if you were allowed to touch it.
Only on some homes, mostly modern ones or houses that had 220v made available for some appliances. Our standard outlets are 110v single phase with a ground pin that earths the home side with a rod driven into the water table.
No, the parent is correct. We have 240v (not 220), and that gets split into pairs of 120v outlets.
Technology Connections did a video that explains it better than I ever could, so I'll just link that instead.
How old is this house?
In 1971, the US National Electrical Code (NEC) required grounded receptacles in all locations of the home (effective January 1, 1974).
https://en.m.wikipedia.org/wiki/Cheater_plug#Use_in_residences
You can check with a $6 electrical receptical tester.
It could be that the electrical system was grounded to the waterlines that enter the house (those should definitely be copper).
While the NEC does generally require grounded receptacles, there remain a lot of old homes which don't have the ground wire (formally the "equipment grounding conductor") in the junction box to actually connect to said grounded receptacles. Fortunately, the NEC provides a rule in 406.4(D)(2), allowing an upstream GFCI to be used in lieu of the safety of a ground wire, and permitting a 3 prong receptacle to be installed. This is a practical consideration by the NEC, since obviously rewiring homes to add the ground wire would be safer, but economically, a GFCI provides a pretty good degree of safety; the NEC makes these compromises all the time, in pursuit of "good" rather than an implausible "perfect".
That said, the lack of a grounded receptacle has some notable limitations, since technically some appliances must have a properly grounded receptacle to be used, although it's rarely checked. And in OP's case, the lack of ground wires means OP cannot leverage the convenient earth ground point.
Disclaimer: I am not an electrical engineer, I am just an idiot on the internet.
I think this would be fine if it's just a matter of discharging static electricity. If static is building up on your body, touching the car frame will redistribute that energy across both yourself and the car frame. By that point, there's not enough potential energy in your body to damage whatever electronics you're working on.
Also, if you happen to be working on computers, they're pretty damn resistant to static shocks. Better safe than sorry of course, but it's hard to kill a computer with static. ElectroBoom and LTT made a pretty good video about that a while back.
Why do people feel like grounding while handling electronics products is relevant? What is sensitive electronics? I have handled/soldered bare ICs, expensive GPU/CPUs, ... and never had and issues with static (the things were not broken after installation) without any sort of grounding or any other thought spent on this topic. Note that I never get static shocks unless during very specific weather conditions when getting out of my car (maybe 4x per year).
Also, how can you be connected to the grid without any sort of ground? How is that not on breach of code(s)?
PS: obviously in a professional setting it makes sense
I have handled/sundered bare ICs, expensive GPU/CPUs, ... and never had and issues with static (the things were not broken after installation) without any sort of grounding or any other thought spent on this topic.
It varies a lot with for example humidity, the kind of floor you have installed, the clothes you are wearing.
When I handle electronics in a personal capacity, I usually wing it. Professionally I always ground myself.
Yeah no question professionally I never even heard of any issues. ICs contain ESD protection anyway. They would not survive much without it. I assume that takes care of most things.
You probably live in a humid place. Try doing that in a desert.
Not really humid, no. But also not super dry. RH somewhere around 30...60 %.
Many modern chips can tolerate a certain static discharge. Also if you're like me, you have ~30% humidity indoors and engineered laminate flooring. I can't remember the last time I experienced a zap touching a doorknob. I've also handled many dozens of ICs building boards and I can't think more than a few times I've had a problem that might be attributable to ESD. I still take precautions when handling PC components just in case.
Three prong grounded plugs weren't required by the NEC in new homes until the 70s so two prong, ungrounded outlets are common in old houses.
The thing is, it may not “break” them but may introduce difficult to localize unreliable operation - which you may even explain away as buggy software.
IC’s, especially small feature size CMOS, absolutely are subject to ESD damage.
Often there’s some circuitry to minimize the risk to sensitive components on a professionally designed board too.
My understanding of the issue with static discharge is not necessarily that everything must be at the same grounded voltage as your home's circuitry per se, but that your body's voltage (static electricity potential) must be the same as the component's voltage. You can accomplish this by "grounding" yourself to the component by touching bare metal away from any IC components before handling it. You can also use anti-static wrist straps that essentially do the same thing continuously by maintaining a connection between your body and the component you're handling.
I am open to someone who knows more about this chiming in to correct me here.
I think that's basically it as far as I know.
Static electricity is an imbalance in electrical charge or, in other words, electrons.[1]
When two objects touch, like a hand and a doorknob, electrons can flow from one to the other. They do this because they repell each other. So they maximize their distance from each other.
It's like electrons are introverts and stuck in a crowded room. When someone opens a door to another emptier room, some of the introverts will go into the new room and everyone will have more space between them.
So where does static charge come from?
When certain materials slide across each other, electrons move from one to the other. For example, fur and rubber rod. Rub the rod vigorously with the fur ( ͡° ͜ʖ ͡°) and a static charge builds up on the rod.
For what it's worth, I've noticed many of the modern ICs I work with list a certain tolerance for static discharge in their data sheets. I no longer go crazy overboard on cheap stuff. I only bring out the mat and strap when adding or removing expensive PC components.
Good info, thank you!
If the electronics your handling have a metal frame just use that. Your unlikely to causing damaging static shocks if you take precautions you've already been carrying out.
Any large metal structure would cause the static to dissipate. Your cars only good if your working in your car, it is likely to be a different voltage from anything else it doesn't share a ground with. The metal frame of your electronics will likely be connected to their reference ground.
If you have a PC and plug it in, the outside of the power supply and therefore the computer case is connected to ground. You can get one of those grounding wrist straps and bolt the ground wire to a spare screw on there
I also think even with GFCI protection, static electricity will go to ground without tripping the GFCI since the amount of current is basically 0
Appreciate it and yeah I did the test already. There's no equipment ground and its labeled as such
How sensitve of an electronics are we talking here? For common household electronics, including computers, static is not dangerous.