Arc blast - is is something for “normal” people to worry about?

[tom66]

I think they at least have fuses per cell or per module.
At least cars are Lion or LiFe and not LiPo.  The amount of energy you can pull from a shorted LiPo is insane.

There are EVs which use LiPos.  For instance the Nissan Leaf and Chevy Bolt.  My ID.3 uses Prismatic cells which are kind of in-between the two technologies.

It really makes no difference. The cylindrical cells that Tesla use have a short circuit current of around 80A each.  In the 84P arrangement that's a prospective short circuit current per module bank of about 6700A, though the resistance of contactors, bond wires, etc. reduces it to around 2000A in the real world.

[Siwastaja]

There are EVs which use LiPos.  For instance the Nissan Leaf and Chevy Bolt.

Yeah. The correct term is "pouch cell" or sometimes "polymer pouch cell" signifiying the fact there is plastic in the vacuum packaged wrapping (it's plastic-aluminum sandwich).

"LiPo" refers to lithium polymer which refers to a technology using solid state polymerized electrolyte. None is commercially available as I know of, and never was. It was supposed to a be a big thing in 1990's but never realized. The name stuck.

[SeanB]

Yes, got some pouch cells that are puffy, going to discharge them and then recycle them.

[Shock]

240v mains supplies enough current to vaporize/instant molten copper in a dead short. That's pretty spectacular and undesirable in your face. Arc/stick wielding is an example of current, I'm sure if you find the right circumstances you can be badly burnt. Hand and internal burns can be quite nasty as well.

No rings or metal watch, wear safety glasses and use safe probing and handling techniques for mains on the bench. Even if you are super careful you should still use safety glasses due to shorts and exploding caps etc.

[Gyro]

Quite timely. Our street is just being rewired with new 3 phase main cabling to replace the old failing paper insulated one. This had been bent too much during original installation, 40 years ago, and has failed in many places over the years. I remember on one occasion, just outside our house, the ground was still steaming when they dug it up and there was a roughly 8 inch stalactite of melted Aluminum down the outside, where the insulation between one phase and the Neutral outer had burned away. This would undoubtedly have been an arc flash event if the whole thing hadn't been embedded in clay soil under the tarmac pavement.

I know these guys are are used to working live in trenches, but when the next upstream fuses are the big ones at the local substation (UK system, no pole pigs), the danger from an accidental arc flash is still significant. It's interesting to watch them work.

[bill_c]

Troubleshooting a 480V transfer switch, I found the problem, but it sure was bright for .03 seconds. Melted all the corners off the copper lugs and many of the  smaller control wires were just gone.  So that is what plasma tastes like...