Gregory's Servercross section of a high power electric car charging cable. the electric current is so high that the copper wires would overheat, but coolant flows through small tubes in the center of each wire.
 36 comments
   @tubetime Why the 4 thick wires though? That size only makes sense for DC charging, and that is two pole? Or is this two positive two negative? Also, lots of tiny wires. What was this, ChaDEmo?  @tubetime I knew DC charging was liquid cooled, at least above 50kW. I always assumed the cooling was in parallel with the conductors. I had no idea it was *inside* them.  @tubetime what happens to the coolant at the ends? I presume it's a tethered cable with a plug only at one end, looping the coolant flow back, rather than any funky connectors with coolant channels and a way of it not all spilling out when unplugged?   @tubetime how are the hollow wires constructed? If they were basically little copper pipes, it would seem like they wouldn't allow the cable to be flexible enough to manipulate @MLE_online i suspect they use a cable braiding machine. probably the same method used to make coaxial cables, only instead of a dielectric and center conductor, they pass the coolant tube into the machine. then lay down more than the usual 2-3 layers to build up the outer conductor.  @tubetime yeah, there is some heavy lifting required to get the charging cable to your car. Even more when some a-hole tangled two or more wires at the same station and you need full reach to not rip out your car socket 😅   @tubetime isn't that excessively overengineered though? Since this is DC, there's no skin effect issue, wouldn't it be much simpler to use bigger cables (thus, with lower resistance)? @tubetime @tubetime FWIW the data cables talk some tcp over HomeAV network protocol to discuss voltage levels, maybe billing… it irritates me that when the car says “failed to initiate charge” I don’t get more useful logs like “connection refused” or “DHCP failed to respond” it's tough to find information about the extra wires in the cable. the center conductor is probably the safety ground (earth). one pair of wires would be the "metering" connection which monitors the voltage at the DC output contact pins (remote sensing). two more wires for PP (proximity pilot) and CP (control pilot) connections. the remaining wires may be for thermistors that sense the temperature at the plug and within the cable. another manufacturer uses these connections and color codes. their cable has fewer wires but the blue/brown color code for the large conductors confirms that this cable is for NACS which can handle either AC or DC. I doubt the center is the safety ground, it's clearly not green/yellow (one of the tiny ones are) and all it has to do is deliver potential but no current. The slightest current in that wire, and everything trips off instantly. My best idea is that it is a "neutral" intended to balance the two load-bearing circuits symmetrically around "ground" potential. That would mean relevant but not full-load currents, which again precludes it from being also protective ground. But I think it also has a machanical role, possibly preventing the cooling channels from collapsing during mechanical abuse. @tubetime is S1 the button that operates the radio transmitter for opening the charge port cover?
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@tubetime are those channels hollow for cooling or something else? maybe optimization for skin effect but this is probably dc stuff.  @tubetime holy crap, is all of this so that it can support an essentially infinite/full duty cycle? I mean I’ve lugged 4160V cables and they don’t need this (I mean, yes, they’re AC and high voltage specifically to reduce current and the resultant heat from I-squared R losses, but still) |
@tubetime I find this solution both ingenious and insane.
What are the smaller diameter wires for?