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Static electric discharge & cars

This gas station security video:

and this Mythbusters episode:

discuss the dangers and the how-and-why of static electricity and refueling your car.

My question is regarding how to safely discharge such a charge.

The guy from the refueling equipment industry who is interviewed in the Mythbusters' episode says that simply touching the car body when exiting the car is enough to discharge your body's static charge.

But isn't the fact that the car is on rubber tires and you (in this worst-case scenario) are wearing non-conductive shoes, you are not going to provide a ground at all? Yes, you will equalize the charge with the car, but the danger still remains when you reach the nozzle sticking out of your car's filler door that is when the spark will occur (presuming that the nozzle has some grounding lead?).

Help me understand the possible safe paths to ground in this scenario.

Thanks, Dave

Reply to
DaveC
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The biggest issue is the discharge between you and the car. I always touch the metal door frame as I get out in the winter because I hate the powerful zap that I often get otherwise. If you are really paranoid, touch the metal gas pump and the car before you stick the nozzle in, but it really shouldn't be an issue. While fires can and have been caused by static, it really is extremely rare in perspective, maybe one every few years, compared to 50,000 Americans killed every single year in car accidents. You hear of more people killed being struck by lightning than fires from static while pumping gas.

Reply to
James Sweet

A related question: Is the dispensing nozzle grounded?

If the answer is "yes", then the driver simply can touch any bare metal (on the car, the pump, anywhere) to discharge static.

Anybody know the answer?

Reply to
Sparky

Why would you want THAT location to be a point of arcing?

How stupid is that?

NO. You use your BODY to discharge things. The pump, and the dispensing nozzle are already grounded. YOU need to ground the car or any other tank or metallic device you want to contact with the pump, BEFORE you go near it with the pump NOZZLE.

What idiot would use the delivery end of the nozzle for a flammable liquid, as the discharge point for a static electric discharge?

Even if it is before you begin delivery, there are remnants of fuel in the nozzle, and why temp fate to begin with?

DOH!

So, the answer is YES, it is grounded, but NO one does NOT use it to discharge static ANYWHERE EVER!

Reply to
CellShocked

There is a nice fat wire inside the feed tube. If not,your licence to sell fuel is revoked.

Reply to
Sjouke Burry

Ah, the answer I was looking for. Thanks!

Reply to
DaveC

And the car is grounded all the time by the carbon black in the tyres. (Oh tires for the other people). The resistance is quite high but adequate to keep the vehicle at ground potential.

John G.

Reply to
John G

I don't think that's the case. I have a Van De Graff generator that uses a black rubber belt and it generates something in the range of 100KV which would drain through the belt if it was conductive. You can also get those ground straps that dangle from the underside of the car to keep static discharged. If the car were always at ground potential, this problem wouldn't exist in the first place.

Reply to
James Sweet

Not so much anymore. I've often gotten zapped getting out of my truck.

Reply to
krw

Unless you drive the car. Rolling the car across the ground generates static electricity. Also, the potential at one ground location does not equal that at another location, and the car picks up charge from the wind as well.

Never assume the car is grounded until you have discharged it to something you know is grounded.

Reply to
Hope for the Heartless

This is bullshit. While it is true that grounding systems for electrical power fault returns, etc. "see" differing levels of "resistance" in their installations, you can bet that pretty well the entire planet is at the same potential as it relates to sinking a static charge, and only very specific, select areas would have some different "value" with respect to the other

99.9999999999999999999999999999999999999999999% of the planet.
Reply to
Pieyed Piper

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