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Post by northernfarmer on Jan 10, 2021 13:36:55 GMT -6
Its not too far off topic, after all its electricity although in the case of your co worker a body boost !. Going back to batteries, I've never had it happen but understand it sure can happen with a battery exploding from being boosted and not sure if that was always from creating a spark setting it off or if its possible internal issues in the battery ( like a frozen damaged battery ) would do that as well. So same thing goes for charging a battery that is not healthy at all or over charging a battery that is undersized for the charger setting and causing to boil/gas off.
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Post by kenmb on Jan 10, 2021 15:41:00 GMT -6
I had the privilege of having a battery explode in my face when boosting the combine. Was like a shotgun going off beside my ear. Ears rang for a day. I had turned my face away so didn't get fluid directly in my face. It was a two battery parallel system up on rear deck of Case 1660. I suspect the one battery had gone open circuit while dad was running the combine, plugged it and killed motor. Not enough juice to start, likely because of bad battery, so I think the event was dad hitting the start button while I was there watching, this drew an arc across the open conductor (let's say a internal plate connection rotted open) which ignited explosive gases inside a sealed container and blamo.
So, yes, whenever the booster cables come out I am thinking why I am using them. Because a long slow drain will have me thinking differently then "well, it worked just fine a couple of hours ago".
On a jobsite we don't do any kind of battery maintenance or testing without a faceshield, glases/goggles, some kind of chemical protection clothing.
The farm of course is different. But I do appreciate the ideas such as make your connection to a positive post and then make the ground connection away from the dead battery. I keep that in mind when boosting, not with charging, though would not be a bad idea.
One final thing, that video of the dummy during the fault is basically an explosion going off, thats why the dummy is going backwards. Air and metal is being super heated and expanding rapidly and therefore an explosive force in practice. Explosions are loud. Ear plugs are also a piece of safety equipment when suiting up in arc flash protection gear but is often forgotten by myself and many others. But a battery exploding will make you understand what is true.
Guys with bigger systems like 480v or 600v 3 Ph on the farm need to understand that a shock can be the least of your concerns. Current from a short creating an explosion and burns is often more concerning.
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Post by torriem on Jan 10, 2021 17:38:34 GMT -6
We always stand to the side as we throw the switch on our 480 volt panels. Two springs ago we had two panels that blew up internally in the same week. In one case the panel was on but had blown a fuse which for some reason I was suspicious of. The inside of the panel looked fine so I replaced the fuse and then crouched somewhere safe and used a broom handle to push the breaker on. Sure enough it went bang. Gave me quite a start even though I was prepared for that possibility. A few days later my brother threw the switch in another pump house and had a panel go bang on him too. In these cases the panel contained the explosion, although the electrician had replace the guts (and clean all the carbon out). Both these explosions were probably caused by leaf cutter bees that get into just about everything.
A few years ago my father turned a pump site on that had been off all winter. Unbeknownst to him, a weasel or some other rodent had taken up occupancy inside the panel. Its body shorted across all three legs. The panel erupted in a large electrical fire that burned through the cover and blew molten metal into the pumphouse. My dad was trapped next to the pump while this geyser of electrical fire was going on. He had to hunker down and wait for it to finish blowing. Shook him up pretty badly. The burned out panel door with the big melted hole in it is nailed to the wall of the pump house to this day to remind us about the danger. So now we open the panel and have a good look before throwing the switch while standing off to the side. Also we ensure there are no rodent holes in the sides of the panels.
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Post by northernfarmer on Jan 10, 2021 19:51:53 GMT -6
I can see that being a real problem, insects that naturally want to crawl into small cracks to set up house in a sheltered space. That would be pretty hard to keep bees out unless it was within a sealed containment box or the actual panel was a Nema 4 ( I believe that is the rating ) rated panel box and all electrical lines sealed through the bottom. Those empty boxes with the weather proof door, they are priced beyond insanity.
Ken, that sure would be a wakeup call to have a battery let go like you had, so lucky you were not injured although that may very well have caused some hearing damage. When I boost something I unfortunately am breaking that rule all the time as I do connect to the negative of the discharged battery although maybe I've gotten away with it because of the order in which I am always careful to follow. I first make sure the two ends laying on the ground are not near each other and not laying on something conductive or have someone hold those two ends with instructions to hold them away from each other, then I connect the positive and negative of the discharged battery. Then I take the two loose leads and connect to positive and then finally to the negative of a known good battery in a vehicle. I realize that is where it could bite me in something happening on the boosting vehicle. Then once I am done I remove the cables from the boosting vehicle and lastly on the one that was boosted since it no doubt could have gasses floating around that battery. I find there often isn't a great place to clamp onto that is away from the fan/belts etc that give the jaws something wider to clamp down harder onto.
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Post by Albertabuck on Jan 10, 2021 20:42:18 GMT -6
Have a had a few batteries blow up over the years, only one was in my face though lol. First two were in vehicles, turned the key to start the Blazer one time, starter engages then a muffled thud comes from under the hood and everything goes dark. Thought bad connection at first you can get a pop from that, open the hood and fumbling around in the dark and things didn't feel right, then I'm wondering what the hell is dripping on the back of my head...figured things out pretty quick then, luckily had some pop or something cause it was about a half hours walk back home. Second one was in 85 Gm, with the 6.2 is has dual, heading into Devon one nite for supper, just as I'm pulling off 60 into town, weird pop comes from up front, before I even had a chance to start wondering you could smell cooked battery. Pulled over quick, was the bat on drivers side and luckily I had changed the aux battery cables ends over the top post, as when I opened the hood there was fireworks and more going on due the cable connecting it to the main one on the right. Was able to pull the cable apart from the clamped on end and saved the other battery. Truck never died or anything, went to the car wash and hosed everything down good, removed the pieces and went for supper. Drove that truck for while afterwards on just the one, worked ok till fall lol.
Then one day at Rayday, changing out batteries in one them old RD688s, dual six volt on each side behind the front wheels. Thankfully as it turned out it all happened on the righthand side, and it was actually the air cleaner is why I didn't get it right smack in the face when it blew. Due to the air cleaner, I was sitting on my hose spool stool, and being the big SOB that I am, I would have to reach in under the air cleaner to get at the batteries on that side and would lean the top of my head against the cleaner while doing so. Took neg off first, then put wrench on the pos of the outside battery and the instant I pulled the wrench, kaboom! What saved my face and eyes was the flap of my cap, as it stuck down below the bottom of the air cleaner given how I was leaning against it. Got a god shot in the mouth and neck area, front of my covvies as well. I knew what had happened instantly and the eyes snapped shut and I kept them shut as I began to plan my route across the next bay into the washroom. The guys I was working with of course heard the explosion, but didn't think anything of it, as our kid welder was always f*cking around with acetylene balloons, but once they saw me staggering blindly towards the washroom things happened fast then. I very soon had an escort and some help, I remember telling Lloyd just grab a f*cking pail lol, few minutes later while wet, I was ok. GM happened to walk in at this point, was more than willing to get some emergency help if I wanted it, but like I told him, no reason for it. Took my covvies off and we sort of washed them out but they didn't do so well in the end. Had a few holes in my shirt and hat after they both got washed but otherwise everything all good. What had happened was when I had went to loosen the positve cable end, it twisted the post sideways inside the battery and it shorted out internally. Interesting enough, that was the battey that was giveing the grief that triggered the incident in the first place. Other three were all good but they got put into spares as we only ever would install complete sets of new ones. The incident did have some effect on how I handle battery work, but not to where I am anal about it or anything. A good pair of glasses is a good idea, and even then, don't look directly at the battery when doing anything that can trigger them. And that includes cranking down the carbon pile when load testing with an AVR or similar. As Torriem mention, a face mask would def be a good thing too.
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Post by torriem on Jan 10, 2021 22:36:52 GMT -6
Good safety reminders! I hadn't thought about the fact a battery could short internally if the post has broken loose.
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Post by kenmb on Jan 13, 2021 19:43:31 GMT -6
Yeah, good post about the internal short AB. I was trying to figure out how it could happen since the negative was off.
Some good reminders. And as NF noted, I often connect to bad battery first, then the good one, and usually at the good one I will still connect to a frame or something instead of negative post. No hard and fast rules, but past events do influence future methods.
As to what Torrie said about panels blowing up, I wasn't expecting someone on here to have first hand knowledge of what I am mentioning. It really isn't that common. But some safety glasses and standing arm length to the side are good things to keep in mind. Some will argue stand on hinged side, some on other side. There are reasons for either idea, but getting out of direct line of fire is the goal. Safety glasses and live electrical work of any kind is generally a good idea.
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