120 volt 400Hz

[brockbone]

Isn't 400 Hz usually aircraft??

Yes that's exactly what it is for

 

[petersonra]

there is a move afoot to over-all wild frequency power.

yep. feeds an inverter that puts out nice clean perfect 200/115V 400 Hz or 60 Hz power. the 400 Hz power is for aircraft systems and the 60 Hz power is for convenience outlets so passengers can plug in their computers and such.

 

[Jraef]

I once worked on a test stand for the Power Take Offs on the engines for 777 aircraft. They were used to run 400kW 400Hz generators that were the size of a desktop PC. We had to simulate the engine's response to connecting the 400kW generator at full load, which was all but negligible to an 11,000HP machine. So we used a 6,000HP 4 pole AC motor running at 50Hz, going into a 6:1 gearbox to get to the required shaft speed of the turbine. The large gear on the gearbox box was so big that they redesigned the building to have thicker concrete wall just in case that thing broke out and took of rolling toward Seattle...

 

[drcampbell]

Flywheels and turbine-engine rotors are tested in lead-lined pits. The soft lead captures the shrapnel when the SHTF.

https://www.testdevices.com/wp-content/uploads/2015/11/spinSafe_art_TD2w1.pdf

 

[Ainsley Whyte]

Isn't 400 Hz usually aircraft??

400 hz is Definitely in the Aircraft industry. And the reason for using that high frequency is all about reducing cable wire size, reducing weight as in aviation the challenge is to make the craft as light as possible so as to maximize, more useful weight that needs to be transported.
F= PL/A where F is the frequency
P is resistivity
L is Length
A is area

Therefore A=pl/F SO BY MAKING THE FREQUENCY HIGH then the wire size A can be much smaller therefore much lighter

 

[winnie]

Flywheels and turbine-engine rotors are tested in lead-lined pits. The soft lead captures the shrapnel when the SHTF.

In the case of turbines, a failure usually means that the fan hits the....

 

[winnie]

Therefore A=pl/F SO BY MAKING THE FREQUENCY HIGH then the wire size A can be much smaller therefore much lighter

Are you sure about that? AFAIK increased frequency does nothing to increase the amount of power that can be delivered by a given wire.

It clearly reduces the size of motors and transformers, and thus saves lots of weight there; but if anything it increases the losses in the wire because of skin effect.

-Jon

 

[hbiss]

I questioned that too. It would reduce the size of the transformers and motors but 20A at 60Hz is still 20A at 400Hz.

-Hal

 

[GeorgeB]

F= PL/A where F is the frequency
P is resistivity
L is Length
A is area

Therefore A=pl/F SO BY MAKING THE FREQUENCY HIGH then the wire size A can be much smaller therefore much lighter

I see 2 have already questioned you, but in 55+ years of electronics and electricity, I've never seen that relationship. Indeed, if the wire is large enough for skin effect to be of any significance, the opposite would, IME, be true.

Where did you get that relationship?