Ask me about industrial electricity 2: electric boogaloo

The Something Awful Forums > Discussion > Ask/Tell > Ask me about industrial electricity 2: electric boogaloo

modig: Aug 20, 2002

Some Guy From NY posted:

Compare that breaker to a modern 345KV breaker:

This is the Hitachi HVB. Much more compact and less complicated.

Great thread. I'm a physicist and we use some equipment that runs on 408V, or three phase 210V, also a coworker is currently designing an experiment that will use like 12kV and 200A. But you guys work with way crazier poo poo than that. I have two questions:

1. Why are the arms in this picture ribbed?
2. Tell me about 3 phase power?
3. Bonus question! What kind of connectors do you use, are there some standard quick release/connect that work for your loads?

# ¿ Sep 18, 2011 02:24

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# ¿ May 3, 2024 12:46

modig: Aug 20, 2002

Aliass posted:

They are "ribbed" so if theres dirt/carbon buildup current doesnt "track" aka flow over the outside causing a fault. By "ribbing" it it allows much more time for a buildup of contaminents and also increases the distance/surface area by up to 600%. This combined with the exterior coating of the material and the angled surfaces helps prevent short circuits/earth faults in the hv switchgear.

Cool, thanks.

# ¿ Sep 18, 2011 16:04

modig: Aug 20, 2002

Three-Phase posted:

That's still a hell of a lot of power, and very dangerous. They're taking a lot of safety precautions, right?

Yeah. So far he just has components, and no power supply. At some point he'll have to write up an saftey review and standard operating procedure for the system (a pulsed magnet for low field MRI), and that will get reviewed by some people up the chain. Since nobody in our group knows much about high power electronics, I suspect they will find some other people in the organization to review it, or pay someone from outside to look at it.

# ¿ Sep 19, 2011 16:19

modig: Aug 20, 2002

ANIME AKBAR posted:

Just curious, is he doing prepolarized MRI?

Yeah.

# ¿ Sep 23, 2011 06:20

modig: Aug 20, 2002

ANIME AKBAR posted:

Let me guess, Stanford?

If so you're lucky as hell to work with some of the best engineers in MRI. I'm jealous.

I think they were working on pre-polarizing high field MRI. This is low field MRI using room temperature magnets and cryogenic magnetic field measurements, instead of room temperature measurement and cryogenic magnets.

# ¿ Sep 27, 2011 04:40

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# ¿ May 3, 2024 12:46

modig: Aug 20, 2002

Frozen Horse posted:

I'm not sure how possible that is. Sure, they might have eliminated ohmic drop through cunning superconductor assembly, but there is still a voltage drop due to flux motion resistance. Not enough to worry about unless you're starting to nudge up against the critical current, though.

It is way easier than you would think to make a fully superconducting circuit. Most solder is lead tin solder, both have high Tcs. Lead is about 7 K, tin about 3K. When mixed it can easily be above 4K, which is the typical bath temperature used because Helium boils at ~4K at 1 atmosphere. Also you can now buy a pulse tube, basically a continuous supercharged air conditioner that gets to below 4K, so keeping the magnet cold is relatively hassel free.

But anyway the coolest magnet is the destructive magnet! You wrap a magnet in explosives, put in a huge current pulse, then set off the explosives to compress the copper into a smaller circle to make the field bigger. http://www.magnet.fsu.edu/education/tutorials/magnetacademy/magnets/page7.html

# ¿ Oct 9, 2011 16:17

The Something Awful Forums > Discussion > Ask/Tell > Ask me about industrial electricity 2: electric boogaloo