Plastic Fuel Tank Grounding?

[cjmahm]

Can't seem to get a straight answer from previous posts, so I'll just ask for input. I recently removed an aluminum fuel tank and installed a new Moeller plastic tank (permanent) into my boat. I am using an aluminum fuel fill. The previous setup had a ground wire running from the fill to the tank. Does a plastic tank also need this? Moeller says "use an earth to ground connection as needed." Not really the answer I am looking for.

Any input/thoughts are appreciated. Thanks.

 

[90stingray]

Re: Plastic Fuel Tank Grounding?

If the ground is there... just hook it up like it was before. Extra grounding cant hurt. My Glastron doesn't have any grounding on it other than the ground wire to the sending unit attaching hardware.

 

[smokeonthewater]

Re: Plastic Fuel Tank Grounding?

the wire you are talking about is the "bonding" wire... this should be attached to ALL metal items.... fill neck, sending unit, metal fuel pickup fitting, etc.....

 

[cjmahm]

Re: Plastic Fuel Tank Grounding?

so basically a wire needs to run from the fill to the sending unit, then to the pickup, etc.? does it need to finish by going to a negative buss or to the outboard itself as an earth ground? or am i confusing bonding with grounding?

 

[smokeonthewater]

Re: Plastic Fuel Tank Grounding?

The long answer is it should be tied directly or indirectly to the engine, drive (if I/O), negative side of the battery, etc.... the bonding wires prevent corrosion and sparks by tying metal components into ground and also "grounding" in the water.

the short answer is hook it to the negative buss or negative side of the batt

ps, although any color works the same, by code, bonding wires are green.

 

[oops!]

Re: Plastic Fuel Tank Grounding?

smoke has you covered....but lets get you into the electrical forum where other posters can learn

 

[Bondo]

Re: Plastic Fuel Tank Grounding?

The long answer is it should be tied directly or indirectly to the engine, drive (if I/O), negative side of the battery, etc.... the bonding wires prevent corrosion and sparks by tying metal components into ground and also "grounding" in the water.

the short answer is hook it to the negative buss or negative side of the batt

ps, although any color works the same, by code, bonding wires are green.

Ayuh,.... Agreed,... Even plastic tanks need to be bonded, to control static electricity...

 

[TerryMSU]

Re: Plastic Fuel Tank Grounding?

But how do you make an electrical connection to an insulator? Plastic is not an electrical conductor. I am not an expert on the subject of bonding wires, but I suspect that what needs to happen is that any metal part must be bonded to ground (at the motor or battery ground?) One thing I DO know, is that static electricity and gas tanks do no play well together, so get this one right.

TerryMSU

 

[cyclops2]

Re: Plastic Fuel Tank Grounding?

A check into the USCG regulations is cute. The " Boatbuilders hand book " reveals the phrase... grounding or bonding.. as a term for eliminating static. By the National electrical code they are not the same thing. 2 metalllic surfaces can be Bonded with a hole , nut & bolt. Bonded. Setscrews contacting both. ...NO wire is needed.

Grounding DOES require a wire going back to the least positive potential point of the power supply. A battery - post or as close to it as is reasonably mechanically possible. A minus or battery negative buss bar with MANY places to fasten the ground wires to. The ground wires ARE NOT INTENDED to EVER carry RUNNING currents.
They have a very different sizing table of the wires. They are designed to protect people from being shocked if a " hot power wire " accidently touches the metal parts of electrical equipment that is NOT bolted to a ground system.

Example... 3 phase motor mounted on a flatbed trailer. Powered by a 480 volt AC outlet from a building.
If 1 0f the 3 hot wires becomes bare in the motor & contacts the metal frame. No grounding wire in the power cord will set up a very dangerous shock hazared in rainy weather. Standing on wet dirt will allow you to become a current carrying conductor. Not good.

GFCI devices are a help. Some people get angry by constant tripping of them so they remove the sensing wire & or the ground wire. Can be a fatal mistake .

So much safety. So little care. At times.

 

[cyclops2]

Re: Plastic Fuel Tank Grounding?

To draw your own conclusions.

Surf to USCG Boatbuilders Handbook then to Compliance Guideline subpart J ......go to 183.572. You should be great at that point.

There are CONDUCTIVE PLASTICS. I do not know if all newer fuel tanks are made of that material. Sure hope so.

 

[CaptainKickback]

Re: Plastic Fuel Tank Grounding?

Cyclops, I don't understand the "Sure hope so."

 

[Bondo]

Re: Plastic Fuel Tank Grounding?

Cyclops, I don't understand the "Sure hope so."

Ayuh,... In this case it's irrelevant...

While We think of plastic as an insulator, it can still hold static electricity...
So long as there's a wire tying the tank to a known ground, it's Safe...
Without a bonding wire,... It Ain't Safe, Period....

 

[cyclops2]

Re: Plastic Fuel Tank Grounding?

A couple ?? of years ago I was told by people that Plastic fuel tanks WOULD have static grounding strap on the tank to stop the problem. Never heard if that has really happened By the USCG or tank manufacturers.

Hope so.

Rich

 

[Silvertip]

Re: Plastic Fuel Tank Grounding?

Remember when fuel tanker trucks used to dangle chains or an anti-static strap on the road? That was to "drain" away static electricity. Nowadays, a ground strap is attached to the truck before anything else happens. If you look at the labels on a gas pump there is a very prominent notice warning about filling a plastic gas can while it is the bed of a pickup or car. That container sliding around can be charged with static electricity. The label tells you to place the container on the ground.

Since the metal shell of the fuel sender in a plastic tank must be grounded for the fuel gauge to work, the very process of connecting a ground wire to that metal shell also "bonds" the plastic tank since the sender mounting screws mesh with metal nuts embedded in the tank. A separate bonding wire is therefor unnecessary but there is no harm in adding a totally separate bonding wire. It will therefore provide an alternate ground as well an alternate bond should either connection fail.

 

[Bondo]

Re: Plastic Fuel Tank Grounding?

Electrically speaking, it makes no difference. I do not know where the idea that a wire connected to one side of a battery drains away a static charge came from but its silly.

Consider a car and its all metal fuel and fill system. It could not be grounded / bonded better and yet a static spark at the fuel neck when filling is the number one cause of fueling fires.

Ayuh,.... Nothin' Silly 'bout it Bubba,....

The Only way to counteract static electricity is to ground the area...
A Better word would be as our British cousins say, Earthed...

With most of our boats, we do this by wire bonding everything in the hull together...
The motor is Earthed to the battery negative, 'n the drive or propshaft is Earthed to the motor...

The only thing remotely Silly 'bout it is the way We generally interchange the words Ground, Earthed, 'n Bonded....
All related, but not really the same....

 

[cyclops2]

Re: Plastic Fuel Tank Grounding?

Nylon , synthetic clothes ARE deadly during DRY winter humidity conditions. Cars DO NOT have a ground chain or strap. The people getting out of the car MAY make the static worse as they SLIDE across plastic seats with plastic clothing on. Only way I know of discharging a person, car or tank is to first touch the metal nozzle to the... CLOSED...plastic tank part / CLOSED car gas cap opening.... for a second or 2. THEN unscrew the tank cap. Hopefully you have drained off the static charges from you & the car to the nozzle.

Plastic tanks in dry air ??? Russian Roulette
Static electricty in the cold winter ? That is why I have a old Johnson Seahorse 6 gallon METAL tank for winter gasoline use at my house. NO PLASTIC cans.
Plastic is for summer use only.

 

[Silvertip]

Re: Plastic Fuel Tank Grounding?

Ayuh,.... Nothin' Silly 'bout it Bubba,....

The Only way to counteract static electricity is to ground the area...
A Better word would be as our British cousins say, Earthed...

With most of our boats, we do this by wire bonding everything in the hull together...
The motor is Earthed to the battery negative, 'n the drive or propshaft is Earthed to the motor...

The only thing remotely Silly 'bout it is the way We generally interchange the words Ground, Earthed, 'n Bonded....
All related, but not really the same....

And of course there is also the term "return" which is the -- well -- return side of a circuit that may or may not be a ground path, an earth path, or a bonding path but may also in fact be all three. The speaker outputs on most auto stereo systems these days have a + and - connection. But that connection is not generally chassis ground. It is the return for that speakers output stage. We really know how to get wrapped up in terminology huh?.