60Hz Supply to a 60Hz Machine through a 50Hz traffo 3

[LoadMonitor]

I have a set up which means I have a 230V 60Hz supply. The machine is 110V 60Hz. Can I use a 50HZ transformer to step down the voltage? In other words if I put 60Hz into a traffo designed for 50Hz will I still get 60Hz out and will there be any side effects?

 

[jraef]

A transformer cannot change the frequency, only the voltage by the ratio of primary to secondary turns. So if you put in 60Hz, you get out 60Hz.

Side effects? Yes. A transformer, or really anything designed with electromagnetic coils to produce induction, is designed based on the expected operating frequency, because (simplified) that effects the magnetism properties. Using it at a frequency it was not designed for might result in significant changes in overall efficiency (in the case of a transformer) which affects the thermal performance. So bottom line, using a transformers designed for 50Hz on a supply that is 60Hz ends up reducing the efficieny and thereby increasing the heat in the transformer. If the transformer is significantly over sized for the load, the heat increase may be survive able, but the efficiency is still lost.

This also by the way begs the question about the rest of the system, because if you have a 50Hz transformer, it might mean the rest of the machine is designed as 50Hz and if so, motors may not work the same either. Being that there are no standard 110V 50Hz motors I know of, it might be that you have changed out the motors to 60Hz designs and are wondering if you need to also change the transformers, but you did not provide adequate details for anything other than conjecture.

"Will work for (the memory of) salami"

 

[ScottyUK]

Yes, you will get 60Hz out if you put 60Hz in.

The increased hysteresis losses caused by the higher frequency will be offset by the lower losses due to a reduced flux density. Whether this results in a slightly better or slightly worse overall performance depends upon detail of the core design which we aren't privy to. If this isn't a big transformer on a utility system somewhere and you aren't loading it to its maximum capability then I think you will be ok in the majority of circumstances.

 

[Skogsgurra]

A 50 Hz transformer will always run cooler at 60 Hz than at 50 Hz. The reason is that the flux is reduced by 17 percent and the hysterisis losses will decrease like B^1.6 (Steinmetz, other exponents exist) while eddy current losses are proportional to frequency and B^2 (where B^2 means that the reduction is 31% when B reduction is 17%).

Overall, the reduction in flux (B) outweighs the effect of increasing frequency. So most/all transformers run cooler at 60 Hz than at 50 Hz if U and I is kept.

The consequence of this is that 400 Hz is used in aerospace because one can use less magnetic material (lighter tranformers, motors etcetera) at 400 Hz than at 60 or 50 Hz.

One of many discussions on this can be found here:

http://users.encs.concordia.ca/~pillay/c28.pdf

This reference is not just a discussion, it contains lots of actual data for different magnetic mateials.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[ScottyUK]

Interesting link Gunnar. Thanks.

 

[prc]

When the 50Hz transformer works on 60Hz, the flux density will come down by 17 % while the % impedance will go up by 20%( result: more voltage drop with load, extra load loss due to more leakage flux and eddy loss increase in copper winding due to higher frequency) .Usually this will be compensated by the reduced core loss from the lower flux density. But a 60 Hz transformer cannot be put on 50 Hz as the core will get saturated and impossible to run.

 

[mikekilroy]

already clearly stated that you can run a 50hz xfmr on 60hz and it will not run hotter.

not implicitly stated is this assumes you run it at its nameplate rated voltages. Just because it may be 1:1 or 2:1 turns ratio does NOT mean you oan run it or any other xfmr on other than rated voltages.

since most 50hz voltages in the world are different than 60hz voltages, make sure YOUR particular xfmr is nameplated for the voltages in and out you plan to use, or the simple fact that 50hz xfmr can always run at 60 is out the window.

http://www.KilroyWasHere<dot>com

 

[waross]

The same V/Hz ratio limit applies to transformers as to motors. A 50 Hz transformer used on 60 Hz may be energized with a voltage that is 60/50 higher.
A 60 Hz transformer used on 50 Hz has a lower maximum allowable voltage of 50/60 of the 60 Hz voltage.


Bill
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"Why not the best?"
Jimmy Carter