400 Hz

Status
Not open for further replies.
stjdat said:
Can I use my 60 HZ electrical equiptment on a 400 HZ generator
Click to expand...

I'm not sure about all components, but I think anything thing with a transformer will be affected. I used to be an airplane technician for an airline and I was always surprised at how tiny the transformers were. I guess the higher freq allowed them to be much smaller than they would normally be.
 
No transformers, capacitors, inductors, and motor windings would be very upset and most likely let the magic smoke out. However you 400 Hz light bulb will work :)
 
Resistive loads such as heaters and incandescent light bulbs will work. Fuses and CBs will typically work, although you may have to do some derating, and the interrupting capacity is reduced.

Most everything else will have issues.
 
If you were to connect an induction motor thats designed for 60HZ and turns a little less that 1800 rpm to a 400HZ source, it would try to turn at 12,000 rpm. I say try, because about half way there, pieces would likely start flying off.

Seriously, most anything purely resistive will work fine. With anything inductive, the design limitations will be exceeded, resulting in catastrophic disintegration of the device.
 
dereckbc said:
No transformers, capacitors, inductors, and motor windings would be very upset and most likely let the magic smoke out. However you 400 Hz light bulb will work :)
Click to expand...

dereck -

Tell me why 60 hz transformers would not work.

When you say "capacitors, inductors" I'm not sure what you have in mind. As far as I know, caps and coils work up into the gigahertz range.

As for motors, assuming you want 3000RPM. You just need an eight pole motor.

The biggest problem I know of is 60 hz xfms, reactors, motors have way more iron in them than they need.

carl
 
micromind said:
... it would try to turn at 12,000 rpm. I say try, because about half way there, pieces would likely start flying off. ...
Click to expand...

One of the first VFD clases I went to in the mid 80s, our test motor was a 2 pole 1/2 hp. The drive would go to 200hz. The first thing we did was program the drive to 200 hz, max ramp rate. The second thing we did was program the drive to reverse from 200hz CW to 200 hz CCW at max ramp rate. Other than having to stand on the motor to keep it from flipping over, it ran fine. At 12,000 rpm, the cooling fan sounds a little like a siren. And I suspect the windage and friction probably sucked up more than the 1/2 hp.

I didn't say it was useful, or would last longer than minutes, I just said it did it.

carl
 
coulter said:
Tell me why 60 hz transformers would not work.

When you say "capacitors, inductors" I'm not sure what you have in mind. As far as I know, caps and coils work up into the gigahertz range.
Click to expand...
The reason is because of a force called reactance. Frequency has a drastic effect on both inductive and capacitive reactance, and reactance has a drastic effect on the impedance of a circuit. Impedance is basically what it sounds like, it impedes the flow of current much like resistance does in a resistive circuit such as a light bulb or a heating element. When you go from 60 hz to 400 hz the inductive reactance increases by over 6 1/2 times and capacitive reactance will decrease by the same factor. Basically what this means is that inductive and capacitive circuits have to be designed for the frequency range they are used at. A tiny coil of just a few turns may represent a very high impedance to a 2 gigahertz frequency while the same coil would look like a short circuit at 60 hertz. An iron core increases the inductive reactance of a coil, if you don't believe this try leaving an AC solenoid coil powered up without its "plunger" in place and you will likely have a meltdown. 400 hertz transformers need less iron and shorter windings than 60 hertz transformers of the same power, this is why they are smaller.;)
Variable frequency drives first convert the power to DC and then "invert" it back into AC, therefore many of them will accept a 400 hertz supply. This may be an option if you need to run a 60 hertz motor from a 400 hertz generator, however not an inexpensive option.:smile:
Hope this was helpful.:roll:
Altis
 
If you apply a 60Hz transformer at 400Hz, then the flux developed in the core would be greatly reduced for a given operating voltage. The transformer would probably work reasonably, with the increased hysteresis losses balanced by the reduced flux density. Such a transformer would be far larger than a proper 400Hz transformer of the same KVA rating.

A 60Hz contactor applied at 400Hz would probably not pull in. If you applied enough voltage to get it to pull in, then it might work accepably, or it might overheat.

A 60Hz motor applied at 400Hz would require higher voltage in order to achieve proper saturation. It would probably overheat from the increased core losses, and would certainly suffer from accelerated mechanical wear if not catastrophic failure.

Some rectifier input supplies (computer power supplies, VFDs, electronic ballasts) can operate at up to 400Hz. This will cause increased rectification losses and could cause problems with power factor correction circuitry. Most rectifier input devices are not rated for this sort of use.

-Jon
 
Altis said:
The reason is because of a force called reactance. Frequency has a drastic effect on both inductive and capacitive reactance, and reactance has a drastic effect on the impedance of a circuit. Impedance is basically what it sounds like, it impedes the flow of current much like resistance does in a resistive circuit such as a light bulb or a heating element. When you go from 60 hz to 400 hz the inductive reactance increases by over 6 1/2 times and capacitive reactance will decrease by the same factor. Basically what this means is that inductive and capacitive circuits have to be designed for the frequency range they are used at. A tiny coil of just a few turns may represent a very high impedance to a 2 gigahertz frequency while the same coil would look like a short circuit at 60 hertz. An iron core increases the inductive reactance of a coil, if you don't believe this try leaving an AC solenoid coil powered up without its "plunger" in place and you will likely have a meltdown. 400 hertz transformers need less iron and shorter windings than 60 hertz transformers of the same power, this is why they are smaller.;)
Variable frequency drives first convert the power to DC and then "invert" it back into AC, therefore many of them will accept a 400 hertz supply. This may be an option if you need to run a 60 hertz motor from a 400 hertz generator, however not an inexpensive option.:smile:
Hope this was helpful.:roll:
Altis
Click to expand...
A very good basic electronics lesson!!
 
benaround said:
stjdat,

Can I use desiel fuel in my gas lawn mower?
Click to expand...

Sure you can. You can also use a 120 Volt lamp on a 240 Volt circuit.

I would not recomend you do either one though.:smile:
 
benaround said:
stjdat,

Can I use desiel fuel in my gas lawn mower?
Click to expand...

sure you can once you get the engine started but try to shut it off good luck with it espcally if your engine is full of carbon some peices in the carbon can act like glow plug and ingite diesel fuel to keep it running.

the same idea with 240 light bulb on 120 circuit it will light up allright but not very bright but go the other way around have nice picture flash :D

Merci, Marc
 
Status
Not open for further replies.
Top