@JonRB is this within an enclosure/chassis/cabinet, or for building wiring?

@JonRB Random ampacity charts suggest you might be looking for 1000 - 2000 kcmil wire, which is a beast. If it's not DC, then you're also going to be seeing skin effect at 50/60Hz trying to get a cable that big.

I'd probably look for a local industrial electrical supply. Dealing with cable that big is a big pain, you may want to get someone with experience and tools appropriate for the job.

@W5VO oh I know :( I want busbar but being "asked" to consider cabling and not even parallel cabling.

HOWEVER, the fundemental is 1200Hz so the skindepth is 1.88mm...

sorry, didn't realize it was a rhetorical question

so at the moment I am calculating the annulus to say what the real diameter would be. Hopefully forcing

:) I wish it was

working with a current density of 5A/mm2 I need 120mm2 just for the rms current...

1) I want the voltage jacked higher (like 3kV)

2) I want busbar

but for now ... I have to go through the motions :)

sab-cables sell 300mm2 cables

With a fundamental that high, you're just going to be wasting copper with a 300mm2 cable

I don't disagree :) when I was told that by the MD I kind of laughed and so did he.

but it sounds like you're dealing with "chassis" wiring, not building wiring, so that helps a bit with the ampacity

basically in discussion with another company who pre-empted aspects "oh its only 1MW, oh its onlly"

with zero electrical or system appreciation :)

so the mechaical have already gone in with the concept of cables (non-defined) so have asked us to size 6phases. the MD immediatly went that the voltage should be higher and it should be busbars.

The only time I've heard MW being tossed around lightly is when working for a regional power grid operator

but you know "customer knows best"

its not grid, because grid people know this

this is an area where the power needed has quadrupled

so this deadend calc need some effort before I can put some realism into this

I don't even know if 3kV is high enough atm

@JonRB . . Can you consider water cooled cable ? They are used all over the induction heating industry.

@Marla potentially, or some form of water-glycol. just spoke with them they are happy to drop to 5AWG but 6off in parallel. Still looking at about 3kW of losses just in those runs, plus localised heating

@JonRB at those ampacities, is aluminum an option?

that it is

Heya. Pretty sure that the following is not on-topic here, right?

How do you isolate the liquid cooling portion?

Of the cable pictured above?

you would need an iusolated pump/heat exchanger per

well once skin depth was explained to teh customer such that if single cable was used the diameter was silly large (1.8mm skin depth taking 600A...) and the solution was 5AWG but 6off per phase (and thus some nasty failure modes...)

Busbar and potentially increasing the DClink to 3kV was back on the table

@Vogel612 That's an "it depends" question, but the capacitors are supposed to have a discharge circuit. Easier to measure than to guess through the internet

Anyone able to answer a quick question regarding testing for 12v over a RS-232 COM port?

@MichaelFrank Ask away... though, truthfully, I only use RS-232 for I2C and serial reading purposes.

So I have a POS system that has 2 COM ports with adjustable 5V/12V jumpers. I can test out on pins 5 (GND) and 9 (5V/12V) for 5V (when set via jumper) with no problem, but when I try while it's set to 12V I only get somewhere between 5.6-5.8V.

Is it likely that this would have a -V and a +V pin to reach 12V?