Hi-tech electronic paranoid panic
RT
your mobile phones" at the servo.
So you do.
And you refuel.
And the fuel fumes drift down around your shins.
Then you engage the starter motor -> 400+ Amps at shin level with arcing
brushes.
But if there ever is a fire at a servo it must be because of the 2 mA at
shoulder level from your mobile phone .
What a crock.
Richard
"RT" <notr....@nowhere.com.au> wrote in message
news:5v11j8F...@mid.individual.net...
> Forget the digital cameras on a/c - the one I really like is the "switch
> off your mobile phones" at the servo.
>
The difference may be that you are not holding the starter in one hand while
holding the nozzle in the other.
Peter Fanelli
Yep that's a classic cause of fires during fueling, climbing in and out of
the car and getting all staticky from the seat materials. Odd that they
don't have warning signs about it. She handled it fairly well, must get
lots of practice :)
--
Made in China.....A label used to warn of dangerous materials.
RT
"Peter Fanelli" <fan...@bellsouth.removeme.net> wrote in message
news:Xns9A25A386641EBf...@216.77.188.18...
> "Richard" <an...@spam.invalid> wrote in news:478b...@news.orcon.net.nz:
>
>>
>> "RT" <notr....@nowhere.com.au> wrote in message
>> news:5v11j8F...@mid.individual.net...
>>> Forget the digital cameras on a/c - the one I really like is the
>>> "switch off your mobile phones" at the servo.
>>>
>> http://www.youtube.com/watch?v=acACmkNfGF0
>>
>> The difference may be that you are not holding the starter in one hand
>> while holding the nozzle in the other.
>>
>>
>>
>>
>
> Yep that's a classic cause of fires during fueling, climbing in and out of
> the car and getting all staticky from the seat materials. Odd that they
> don't have warning signs about it.
Coincidentally I saw a sign about that within the last week or so! Had to
put my glasses on to read it - out of boredom while filling a largish empty
tank - and it actually said to de-zap yourself by touching the metal bowser
before you touched the handpiece. Very sensible - but in much smaller print
than the crock about the mobile phones :-)
Kwyjibo
Wouldn't it be safer to earth yourself using something other than the
bowser? (Maybe the steel bollards that are installed to protect the bowser?)
--
Kwyj.
Dave Kearton
>>
>> Wouldn't it be safer to earth yourself using something other than the
>> bowser? (Maybe the steel bollards that are installed to protect the
>> bowser?)
>>
>> --
>> Kwyj.
Marginally so - if the bollards were continuous (connected to) the bowser.
In this way any spark, that occurs during the connection process, will
happen further away from the bowser. If the bollards aren't
connected to the bowser, there _could_ still be a potential differencce
between you, your car and the bowser.
This is similar to the process of connecting a jumper lead to an engine
fixture, such as a bolt-head while charging a flat battery.
--
Cheers
Dave Kearton
RT
"Paul Saccani" <sac...@omen.net.au> wrote in message
news:0gloo31mssm26rcba...@4ax.com...
> On Mon, 14 Jan 2008 22:07:02 +1000, "RT" <notr....@nowhere.com.au>
> wrote:
>>And you refuel.
>>
>>And the fuel fumes drift down around your shins.
>
>
>>Then you engage the starter motor -> 400+ Amps at shin level with arcing
>>brushes.
>
> sparks inside most petrol tanks too, but - the combustible mixture is
> located where?
>
>>But if there ever is a fire at a servo it must be because of the 2 mA at
>>shoulder level from your mobile phone .
>>
>>What a crock.
> Considering that mobile phones occassionally explode on their own,
a) Quite so - on a quiet night you can hear them exploding all over the
place. Except in Iraq/Afghanistan where some of the noise might be suicide
bombers
b) So you leave them in a bin outside the servo in case they explode while
you're refuelling?
> isn't a great stretch that such an explosion in a combustible mixture
> could cause an even bigger explosion. Nor to do you appreciate that
> many mobile phones are located not at shoulder level but at waist
> level when they ring. Often causing little sparks from the brushes on
> the vibration motor.
>
> But unlike the starter motor, or the brushes on your submersible fuel
> pump, which quite happily spark away in petrol vapour, it would be in
> a combustible mixture.
Rubbish.
Please explain how a combustible mixture replaces cog air inside a mobile
phone during tank refuelling........
Oh, and as a reference point, a saturated petrol vapour - as in a petrol
tank - is not flammable - it's only petrol - no air... Check out the
air-petrol mixtures that will support combustion.
Oh - and explain why a mix of air and petrol vapour at starter motor level
can not be combustible - I quote:
> But unlike the starter motor, or the brushes on your submersible fuel
> pump, which quite happily spark away in petrol vapour, it would be in
> a combustible mixture.
SR20GOER
that static electricity is a risk - possibly more so with AVTUR than mogas -
but the one other issue with mobiles is RF energy should a call be I/C or
made while refuelling and I don't know enuf about that either to argue
either way. I do know in the days of the dash mounted radar detector I got
many a false trigger from a servo nearby so I suspect there is some RF
floating around some of their equipment also.
As a relevance test I note smokers filling cars - both fuel and gas - so I
think the mobile fone thing at servos is another extension of the nanny
mindset.
Brian
Kwyjibo
"Dave Kearton" <dkearton///////@ozemail.com.au> wrote in message
news:478c6765$0$30834$5a62...@per-qv1-newsreader-01.iinet.net.au...
> Kwyjibo wrote:
>
>>>
>>> Wouldn't it be safer to earth yourself using something other than the
>>> bowser? (Maybe the steel bollards that are installed to protect the
>>> bowser?)
>>>
>>> --
>>> Kwyj.
>
>
>
> Marginally so - if the bollards were continuous (connected to) the bowser.
> In this way any spark, that occurs during the connection process, will
> happen further away from the bowser. If the bollards aren't
> connected to the bowser, there _could_ still be a potential differencce
> between you, your car and the bowser.
AFAIK the bollards are attached to the same planet as the bowsers :-)
As they are both earthed and only a few feet apart any potential difference
that may exist would be negligible.
--
Kwyj.
Snapper
> Wouldn't it be safer to earth yourself using something other than the
> bowser? (Maybe the steel bollards that are installed to protect the bowser?)
Why not? Provided that the thing isn't dripping petrol everywhere it should be
intrinsically safe, especially given that it has active electrical circuits and
electronic componentry that is live.
Snapper
> As a relevance test I note smokers filling cars - both fuel and gas - so I
> think the mobile fone thing at servos is another extension of the nanny
> mindset.
Or people opening and closing car doors, with light switches being operated,
none of which are designed to be instrinsically safe around hazardous materials.
Or when you slam the nozzle into the filler spout, the chance of a spark from
the friction or impact between bowser nozzle and surrounding metal is higher.
There are so many potential sources of ignition when filling aircraft or motor
vehicles that can't be accounted for and yet the incidence of fires or
explosions is so rare to to constitute a non-event or that it's so trivial you
gotta wonder why they bother other than the basics of earthing the aircraft, the
filling equipment and the operator during the refueling operations.
Don't forget too, that car tyres aren't insulators. The rubber content in them
is relatively small and they can carry a current, probably enough to keep the
vehicle earthed.
If tyres were made of pure rubber (and hence have about ten kays of life) then
yeah, there'd be cause for concern. But they're not.
Snapper
> But unlike the starter motor, or the brushes on your submersible fuel
> pump, which quite happily spark away in petrol vapour, it would be in
> a combustible mixture.
When you look at the combustability of a gas or vapor what they look at is the
LEL, or Lower Explosion Limit. This is the point where there is sufficient
air/fuel ratio for an explosion to occur.
I don't know the figures for petrol or LPG but it's irrelevant. It's when that
concentration of fuel in air is met that is when the problems occur.
And in a servo that is an open space with ostensibly at least a small breeze, or
local swirls caused by traffic movement, what is the risk of this occuring,
particularly with LPG as it's heavier than air?
Dave Kearton
news:13orclq...@corp.supernews.com...
|
| "Dave Kearton" <dkearton///////@ozemail.com.au> wrote in message
| news:478c6765$0$30834$5a62...@per-qv1-newsreader-01.iinet.net.au...
| >
bowser.
| > In this way any spark, that occurs during the connection process, will
| > happen further away from the bowser. If the bollards aren't
| > connected to the bowser, there _could_ still be a potential differencce
| > between you, your car and the bowser.
|
| AFAIK the bollards are attached to the same planet as the bowsers :-)
| As they are both earthed and only a few feet apart any potential
difference
| that may exist would be negligible.
|
| --
| Kwyj.
Hmmm, if you want. Static bonding is usually defined for me by
engineers with the degrees and indemnity insurance. The last thing you
want is for one component to be at a different potential for even a few
microseconds - that way, madness lies.
As a rule, it's safer to bond everything together, especially where POL or
explosives are concerned.
--
Cheers
Dave Kearton
John Ewing
"Snapper" <snapp...@yahoo.com.au> wrote in message
news:asnqo3ltth3dimpee...@yarwho.com...
Vehicle tyres are in fact very good insulators. Want confirmation? Drive
your car onto the lawn next to the main earthing rod for your house. Use a
Megger (500V/1000V insulation tester) and measure the resistance between the
car frame and the earth rod. You will find the resistance is close to an
open circuit.
It is true that here have been instances of 11,000V overhead lines falling
on to a vehicle, and at this voltage the leakage current in some
circumstances can be enough to cause the tyres to eventually catch fire.
You would be correct in surmising that this conduction is improved by the
carbon compound in the tyre. Further, when this compound breaks down it is
an avalanche effect.
And remember the reason you get a static shock from touching a car door is
because the vehicle is not effectively earthed - because of the tyres.
I can remember back in the fifties and sixties the fuel tankers that made
deliveries to our farm had a trailing steel chain for static discharge.
Cheers,
John
Stealth Pilot
wrote:
>On Wed, 16 Jan 2008 23:57:37 +1000, "John Ewing" <none@needed> wrote:
>
>>It is true that here have been instances of 11,000V overhead lines falling
>>on to a vehicle, and at this voltage the leakage current in some
>>circumstances can be enough to cause the tyres to eventually catch fire.
>>You would be correct in surmising that this conduction is improved by the
>>carbon compound in the tyre.
>
>More commonly by crane booms hitting an active line. It is a hell of
>job to sort out the mess - the wheel bearings are usually welded in
>place. This is no laughing matter on a five axled heavy vehicle.
>
>The fire creates a bit of a problem too. Usually, the tyres don't
>catch fire directly, and of course, the automatic shut off happens
>soon enough.
the welded axles (control hinges) is why you earth bond all the bits
of an aircraft together.
Stealth pilot