Website Math Error?

[jehan2256]

I noticed something peculiar on Tesla's website today...

It says that if you charge at 24A on a 3-phase circuit, you'll get 16.5kW of power.

If we do some math...

16500W/24A = 687.5V

I don't know of any household circuit with such a high voltage.

What's I noticed, however, is that 687.5 is approximately 3 times 230, which is the standard household voltage (in most countries).

So it seems like whoever wrote this information was under the impression that 3-phase power gives you 3 times the voltage of single phase, whereas it actually gives you the square root of 3 (1.73) times the voltage.

So, am I missing something, or did Tesla get their figures wrong?

 

[ABC2D]

I'm not really an expert but I think you might be confusing calculations with line to line voltage (which uses square root of 3) with line to neutral voltage (which uses 3 times the voltage)

 

[ItsNotAboutTheMoney]

It would be _400V_ 3 phase. Each phase is 400/3^0.5 = 230.94.

400 x 24 * 3^0.5 = 16.627.
(= 400/3^0.5/phase * 24A * 3 phases)

 

[McRat]

Yes, it's why 3ph kicks arse. There are 3 hots. Each one pulls amps.

If EVs in the USA would accept the common 3-ph at a mear 24a (30a breaker):
208vac 3ph = 3 lines x 24 amps x 120v = 8.6 kW
480vac 3ph = 3 lines x 24 amps x 277v = 20 kW

This can be done on a dedicated short run of 10 awg THWN-2 with 30a breaker. Cheap setup

 

[jehan2256]

Thanks guys, that cleared up some confusion.