Thanks guys for all that great info. Lots of really good advice there. Happy to report both battery packs have now been safely removed and I am still alive!
And looking forward to further discussions on the EVDL. Regards, Matthew 07966 806 727 On 3 January 2017 at 19:56, Cor van de Water via EV <ev@lists.evdl.org> wrote: > Just in the past weeks I have been working on removing and installing > batteries. The key is to have non-lethal voltage as long as you can as > well as avoid short circuits. > When I dig into a Nissan Leaf pack (which I am now re-creating in a > different configuration in my EV truck's battery box) the first thing is > to break the connection between the different sub-packs so each is lower > voltage than the total (380V or 2x 190V as soon as you have pulled the > Service Disconnect mid-pack. > When re-assembling, I deliberately leave the straps/cables that > interconnect the sub-packs off until the very last moment, so I am only > dealing with sets that are about 72V each. > Then there are typically the exposed wire ends. If I can remove the > complete cable on both ends, I do the two ends while I am holding the > cable so there is no point in insulating it. If I need to attach one end > (because it is going into an inaccessible location) but can't attach the > other end yet, then I will wrap it in electrical tape that I can remove > when I am ready to attach the cable. > > When a sub-pack is still a very Lethal voltage, like the Nissan Leaf > having one set that is 190V, I check to see if there is a way I can > protect it (Leaf has 3 covers that go over the connections of this set, > so you can still limit your exposure) or a way to break the circuit, for > example removing the screws from a strap and pulling it up so it breaks > the set in two separate electrical circuits. > > Also: never work with two or more on the pack. If one touches something > on one side and the other person is working on the other side and they > touch each other or both touch the same conducting object (metal battery > box) then they get a nasty shock or worse. Even when working with your > own two hands, keep them together so you don't straddle a high voltage. > There is wisdom in the saying that when interacting with high voltage, > keep one hand behind your back. > Note that this advise is for when working with bare hands - I drop too > many screws when I try gloves and I hate wearing them, so I always work > with my bare hands - which requires me to work very careful. Also use a > Voltmeter to verify that a battery is isolated and not leaking to ground > (frame/enclosure) since that can still build up a nasty voltage. > The only moment I do wear gardeners gloves is to protect my hands from > sharp metal edges when carrying/handling heavy metal assemblies such as > lifting the sub-packs. > > Hope this helps, > > Cor van de Water > Chief Scientist > Proxim Wireless > > office +1 408 383 7626 Skype: cor_van_de_water > XoIP +31 87 784 1130 private: cvandewater.info > > http://www.proxim.com > > This email message (including any attachments) contains confidential and > proprietary information of Proxim Wireless Corporation. If you received > this message in error, please delete it and notify the sender. Any > unauthorized use, disclosure, distribution, or copying of any part of > this message is prohibited. > > > -----Original Message----- > From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Lee Hart via EV > Sent: Tuesday, January 03, 2017 10:02 AM > To: Electric Vehicle Discussion List > Subject: Re: [EVDL] Electrical Safety... > > Thos True wrote: > > Failing to insulated the exposed wires have been known to lead to some > > nasty burns (on crew and vehicle), as well as damaged batteries and > > battery boxes. Hope that this helps! > > That reminds me. Electrical cables have some nasty surprises that can > cause serious mischief. > > Batteries can deliver enormous short-circuit currents. If a cable does > flop around and short to something, the high current makes it into an > electromagnet. It can JUMP and squirm like a snake, and in the process > cause other shorts and mayhem. > > With a high short-circuit current, the insulation can melt off a wire in > > seconds. Now you have a BARE wire lying across your batteries. Or, if > that wire is bundled into a harness, the heat can melt the insulation > off the other wires, causing more short. Now Murphy really has some fun! > > And let's not even think about what happens if someone used cheap non > UL-listed wire with combustible insulation. > > Also, once a high voltage DC arc starts, it is hard to stop. It can > continue to arc across an amazing distance -- many inches when there's > enough molten metal and debris feeding into the arc. Also, an arc can > set melt or set just about anything on fire. > > So it pays to be extra careful! > > -- > "Hold my beer and watch this!" -- (script for a Youtube video for the > Darwin award) > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA > (http://groups.yahoo.com/group/NEDRA) > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... 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