400hz vs 60 hz

[markinnh]

I notice that the 400hx gensets sellon GL at a much lower price, and some have very low hours. What does it take to rework these gensets to be 60Hz?

Some say its just the speed of the rotor...some say the windings...is there a transmission or gearset between prime mover and rotor?...most are direct coupled.

Thanks

 

[Isaac-1]

There is no practical way to change these over, at best they are potential deals for the engines alone, particularly if you have one of their 60 hz cousins with a bad engine. The vast majority of the 400 hz units use different rotors, different instrumentation different voltage regulation, etc. The only practical use for these units is to power large resistive only loads (like heating elements, light bulbs, etc.) that don't care about frequency.

Ike

 

[papakb]

Mark,

As long as you're just running lighting with them they're fine but anything with a transformer in it will choke on the 400Hz. I've never tried powering some of the new "universal" power supplies with one but it might be worth a try. Most of todays switching power supplies convert the input power directly to DC and then regulate it and might not care about input frequency. Like Ike says, there are some parts that would be useful on 60Hz sets and the engines are good.

You can always use one to power up your AN/TRC-75!! LOL

Kurt

 

[TexAndy]

Just get yourself the accessory to go with it... you know, like a Huey.

 

[armytruck63]

The reason the 400 Hz generators are so much cheaper is that there are so few uses for them in the civilian world.

Like Ike said, incandescent light bulbs and heater elements are about all you can run with them.

 

[KsM715]

Do search on here. Its been discussed several times.

 

[Isaac-1]

Here is an example of the 60 hz rotor (2 pole 3600 rpm from a MEP-016B) vs its 400 hz cousin

Ike

 

[Speddmon]

I notice that the 400hx gensets sellon GL at a much lower price, and some have very low hours. What does it take to rework these gensets to be 60Hz?

Some say its just the speed of the rotor...some say the windings...is there a transmission or gearset between prime mover and rotor?...most are direct coupled.

Thanks

Some of the people you quoted in your post are only partially correct. The speed of the rotor determines the frequency of the output power, but there is also a huge difference in the windings of the rotor to make it a 400 Hz generator. You could never cut the fuel back far enough on a 400 Hz machine to get it slow enough to only put out 60 Hz. It would stall out in a heartbeat, you would need to slow the generator rotor down to about 300 RPM's to make 60 Hz. But in doing that you would not create enough voltage for the self excitation and thus you would burn up all of your electronic voltage regulation equipment

And there is almost never a transmission or gearbox between the prime mover and the head. Almost all of them are direct coupled with the exception of maybe some of the DC gas turbine generators. The main reason for the 400 Hz in avionics is due to the weight involved, or lack there of. There is a whole lot less iron in the cores of 400 Hz generators and transformers, thereby making them considerably lighter.

To rework a 400 Hz machine into a 60 Hz machine would mean you need to have the generator head completely changed...not just rewound, due to the increased number of poles in a 400 Hz head. And the voltage regulators would need swapped, as well as the metering devices and CT/CVT assemblies, and various other components. It would be much more cost effective to just buy a 60 Hz generator from the start.