wa8yxm
Davison Michigan (East of Flint)
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TenOC wrote:ALWAYS disconnect the ground lug/wire before touching the positive lug.
That is worth saying again
Always start by disconnecting ground
As to what happened.. Without a video to see how bad the sparks were I can only guess there was a load. perhaps the steps or some other system does not disconnect when you disconnect.. or perhaps you touched something or there was a stray strand of wire you did not see.
Beyond that I can not say more without a video of the event. which I assume you don't have. (I mean why would you?)
Home was where I park it. but alas the.
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mountaintraveler
mountains
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wa8yxm wrote:TenOC wrote:ALWAYS disconnect the ground lug/wire before touching the positive lug.
That is worth saying again
Always start by disconnecting ground
As to what happened.. Without a video to see how bad the sparks were I can only guess there was a load. perhaps the steps or some other system does not disconnect when you disconnect.. or perhaps you touched something or there was a stray strand of wire you did not see.
Beyond that I can not say more without a video of the event. which I assume you don't have. (I mean why would you?)
I do not have any systems that function off this battery when the switch is off, and it was off.
I double checked and there is nowhere metal wrench could come in contact with any metal, all is insulated there.
I cleaned dust off the batteries and wires earlier with slightly moist rug, lots of dust was there, it all looked dry by the time I worked on terminals, I wonder if remaining moisture could conduct current. Sparks were BAD.
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mountaintraveler
mountains
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An if there is a mysterious load with shut off switch off (not possible by design of this RV) how to check this with a multimeter?
These are 2 6v batteries in series.
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StirCrazy
Kamloops, BC, Canada
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Joined: 07/16/2003
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if both were connected and you were just tightening up the positive then you accidently/unknowingly touched something with the wrench or socket. Even with a load on, if you didn't pull the wire off the terminal, you shouldn't get sparks unless it was so loose when you went to tighten it, it twisted and lost contact for a second.
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mountaintraveler
mountains
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StirCrazy wrote:if both were connected and you were just tightening up the positive then you accidently/unknowingly touched something with the wrench or socket. Even with a load on, if you didn't pull the wire off the terminal, you shouldn't get sparks unless it was so loose when you went to tighten it, it twisted and lost contact for a second.
As I mentioned abive I did not pull it off the terminal.
It was not loose and was a rock solid connection.
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MitchF150
Puyallup, WA
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Have you cleaned each post and cable end of those 6v batts?
That's where I would go next just to eliminate a dirty connection even thou they are "tight".
Then confirm that your neg batt disconnect is on the neg cable that goes to the rig.
Other than that, no idea??
Good luck! Mitch
2013 F150 XLT 4x4 SuperCab Max Tow Egoboost 3.73 gears #7700 GVWR #1920 payload. 2019 Rockwood Mini Lite 2511S.
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MrWizard
Traveling
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12v is not going to arc jump through open air and make sparks, (even welders need at least 18v and usually double that plus high current, and you have to start the arc by striking the work piece with the rod or wire from the electrode ) , there was a load something was drawing power and you jiggled the connection or your wrench touched ground,
The only time you can be sure the batteries are disconnected is with a self installed disconnect at the batteries, the factory disconnect, does not insure that everything is disconnected
You did not mention the battery configuration, 6v in series or 12v in parallel, 6v series will have only one negative ground, 12v parallel could have multiple grounds,
I can explain it to you.
But I Can Not understand it for you !
....
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mountaintraveler
mountains
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As I mentioned there is NOTHING in this motorhone that runs in bypass of battery shut off switch. May be in your RV but not in mine
I know how I can test if there is any current bypassing shut off switch. Can turn the switch off, disconnect negative terminal and see if there are amps between that terminal and ground wire.
Seems like the thread is pointless ad people dont even bother to read what I posted. Yes I did pist battery configuration above, if you bothered to read my messages. Moderator can close the thread.
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opnspaces
San Diego Ca
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People are reading what you are posting. But your responses sound like you're not reading their responses.
It's a 12 volt system. Even 2 6 volts in series are considered a 12 volt system.
As the battery sits there is no way for 12 volts to jump an open gap of more than a sub micron. What I'm trying to say is there is no magic to this. In the way you are working a spark will only occur if a connection is made and then broken. Some ideas to what might have occurred and yes some are pretty outlandish but I guess possible.
The sparks on the positive terminal will only occur when there is a break in the path between the post and the wire or between the post and shorting from the post straight to ground through something like your wrench. There's just not any other way to get a spark, the voltage is just too low.
So look at the system again and contemplate where this intermittent gap or break occurred.
Does your RV use wood framing or aluminum framing in the walls? If aluminum framing your wrench might have touched a screw or staple in the bulkhead that is screwed or stapled into the aluminum framing creating a direct short to ground.
Another possibility is a screw in the bulkhead is accidentally driven into a ground wire on the other side of the bulkhead.
I don't know 5th wheels, but on a travel trailer the emergency breakaway is wired around the disconnect switch. Unless you were personally involved in adding the breakaway. Or you can visually see that all wires from the positive post go into the same terminal of the breakaway, are you positive the switch cuts all?
Other possibilities which would need there to be a way around your disconnect switch:
Your positive terminal has corrosion and the positive cable moved while tightening and intermittently broke the connection and then reconnected causing a spark.
Your positive cable has a lot of corrosion under the jacket between the copper wire and the terminal end. When that wire is moved the wire intermittently loses and regains connection with the end terminal.
The battery positive post is actually broken and held onto the lead plates by only the friction of the plastic battery case. When you tried to tighten the bolt the post tilted ever so slightly and broke the connection with the plates in the battery. This seems unlikely to occur without blowing the battery up in your face but I guess anything is possible.
What I'm trying to say is it's not possible to have a spark without current. Somehow, someway by tightening the terminal you intermittently broke and reconnected the electrical path of a live connection. There's just no other way for a spark to occur.
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wa8yxm
Davison Michigan (East of Flint)
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MrWizard wrote:12v is not going to arc jump through open air and make sparks,
For a SUSTAINED arc the formula is V = 24 + 4L where V is Volts and L isMM. but this fails to take into account inductance.
When you "Break" a circuit with current flowing even at lower voltages sparks can indeed fly due to what I call the inductive Kick.
Think of moving something heavy Like a train car.. A few kids pushing over time can get it moving right along. but for sure you don't stop it on a dime. If it hits you think steam roller.
Same with electricity.. Even a fairly small current has those old electrons moving right along.. When you break the circuit they want to keep moving and jump the gap.. SPARKS FLY. You can see some very impressive voltges that way. And I've seen 12 volt systems spark many times.
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