Microwave 50Hz/60Hz issue

[Pelagic]

I need to replace my Microwave oven here in the Philippines but their peculiar electrical standard is 220v 60hz. while my onboard power via Generator or Invertor is the more universal 220v 50hz

Unfortunately they only sell 60hz in the stores.

Is there any practical frequency convertor for a small appliance or just order from overseas?

[Albro359]

Sorry, there is no inexpensive way to convert frequency.
Microwave ovens are so cheap these days, just order a 220V 50Hz appliance from wherever...it will be the shipping that costs you !

[Pelagic]

Yes, that's what I thought.

Even at the marina, I am mostly on solar/invertor these days but use shore power if running all the aircons.
Just need to remember not to use microwave if on shore power.

[Wotname]

Hmm... yes microwaves are very cheap, so cheap that I would be tempted to try using one ignoring the frequency issue. You won't damage your generator or shore power connection and you probably won't damage the microwave if the frequency doesn't match. Just keep an eye on it the first few times you use it for abnormal operation.

My guess is the biggest issue will be the speed of rotation of the turntable. If the frequency is wrong, it won't do stop in the same spot after say 1 minute of operation.

Again, this only an opinion, a slightly educated one but certainly not an expert one .

[Pelagic]

Originally Posted by Wotname

Hmm... yes microwaves are very cheap, so cheap that I would be tempted to try using one ignoring the frequency issue. You won't damage your generator or shore power connection and you probably won't damage the microwave if the frequency doesn't match. Just keep an eye on it the first few times you use it for abnormal operation.

My guess is the biggest issue will be the speed of rotation of the turntable. If the frequency is wrong, it won't do stop in the same spot after say 1 minute of operation.

Again, this only an opinion, a slightly educated one but certainly not an expert one .

Hi Wottie,
I already did that (not on purpose) after I got my solar going and recently switched over from shore power to invertor.
Everything worked except the magnetron so nothing warmed up
Switched back to shore and it heats up with apparently no damage.
Have been researching since I started this and Panasonic has an "invertor" type compact microwave that may be dual frequency.

Will contact Singapore to see, but if you could find out in Oz, that would be more reassuring before I ship to the Phils.

[Wotname]

Hmm... further investigation (by google) suggests one can't use the "wrong" frequency.

I can't find a simple (i.e. cheap) dual frequency unit, probably because there would be only a very small market for a dual frequency model.

[a64pilot]

We took ours to Germany when I was in the army and ran it off of a transformer. Ours was a 60Hz machine and Germany is of course 50Hz.
It did sound different, but ran fine for those three years on Germany and was used every day, plus for years after when we got back to the US.
We ran all our US “stuff” TV, VCR, etc, etc on 50 Hz power, it all ran fine

[Pelagic]

I also thought Microwave would work on either frequency, but this local bought Whirlpool (60hz) will not.

Turntable turns, Timer works but no him from Magnetron.

Yet works fine on shore power.

This technical review seems inconclusive
https://www.instructables.com/topics...th-my-230V-60/

Sample post
Steve it was my job.
Someone would buy a machine from Europe and I would rewire, rewind the motors, rewind the magnets, and rewind the transformers.
European service electronics to North American standard service.
Some things you can just plug in and go, others just fry the instant you plug them in, and some only work partially.
10 cycles do not sound like a lot but it will make an induction motor go from 1750 rpm to 2100 rpm by the way the 60 cycles increases the speed of the rotating magnetic fields in the stator, and when loaded most of the motors burn because of the loss of power.
With transformers and magnets they loose power just like most motors.

[Wotname]

I think it would be very easy to design a microwave oven that would tolerate 50 and 60 Hz however it definitely cost more to build. When the price was much higher (say 2+ decades back), the difference in cost would have been proportionally smaller than now (with the lower unit cost). There would be only a very small market for such ovens.

This is all supposition of course but suggests to me that Pelagic would have to search hard to find a new oven that is designed/ manufactured for both 50 and 60 Hz operation. As for trial and error, IMO the smaller / cheaper the oven, the less likely it would be suitable for both line frequencies.

FWIW, the oven frequency (say 2.45GHz) needs to closely controlled and might well be tied to the line frequency (50 or 60 Hz) rather than by a seperate crystal oscillator - again all supposition.