60 hz to 50hz?

The RMS (root mean square) value changes with the frequency.

If it is transformer based, the turns to iron ratio is 'ideally' for a frequency.

Similarly a switching type may be more efficient at a design frequency.

Meaning it just may be more efficient at 50Hz than 60.

Would help if you said what the device was.

if i just use the adapter into the wall... is that ideal? not ideal? im still confused on how i would calculate the power consumption @ 50hz.

Depends on the type of device it is and whether there is any internal conversion of the input power.

Consider an ohmic device like an incandescent light bulb. A 120 W light bulb would put out 480 watts if if were connected to a 240 V source; though not for very long since it would burn out much quicker.

so is there a way to calculate how much power a 60hz device would consume on a 50hz source?

Yes, there is a way to calculate how much power a device designed to operate on 120VAC 60 Hz power will draw when attached directly to 220VAC 50 Hz power. But which calculation one should use to produce an accurate value will depend solely on identifying the input impedance of the device. Without knowing what the device is or the input impedance then no equation can be offered.

I forgot to mention that the key factor that you are missing that will permit us to calculate the input impedance from the data you've provided is the phase angle between the 1 ampere of current and 120VAC power. Oh, your power calculation is not correct without knowing this information. Without knowing this, all that you can say is that you have 120VA which means the maximum power you can draw is 120 Watts.

i dont see the impedance on the device... so lets say its 2.2 impedance

Electrical impedance requires two numbers.

it depends on the nature of your device,

if it is a resistor(heater) frequency dont matter too much, just the voltage,

you cannot apply a voltage over than the nominal voltage of the device whatever this device is,

you cannot apply a 230V-50Hz supply to a 120V-60hz device, you will burn, it you need an adapter..

BTW, what is this device? a shaving machine by any chance?

ok what if i forget about using the 60hz device on 50hz service... but a spec sheet states It says 120V 1.4A @ 60hz 220 to 230V 95W @ 50Hz so is there normally a drop in power?

Not in Power, in Power factor

again it depends of the device....what is this device/?

Face it, he/she's not going to tell us. No matter how many ways or how politely we ask this is going to stay a "device."

its a sewing machine.... page 4 http://www.juki.co.jp/household_en/pism/img/tl98q/download/98pqsm.pdf is what i am referring to

As per this catalog, the same machine can not be plugged on both 120v-60 hz or 220v-50 hz

these are 2 different units, 120V 60HZ unit part number is TL-98Q while the 5oHz 220/230V part number is TL-98P

Cheers

Now I see what you have.

You have a very fine sewing machine here.

Reviewing the manual it appears that the only difference between the two different voltage models is the line cord plug assembly. This is not surprising since in Japan the power grid voltage and frequency will be different depending on location. So many machines are built to utilize both power distributions. I would verify this with a manufacturer's representative about my assumption before plugging the 120V model into 220V power grid though.

Now the reason that the power changes depending on which grid connection you happen to be using is that the dominant but not sole electric load is the electric motor. The motor on this model is likely an AC induction motor that gets only 100VAC after coming from your filter board assembly. In an induction motor the rotor's magnetic field is generated by inductive coupling like a transformer so there are no brushes required to connect to the rotor windings and also one less part to fail. The natural resonant speed of the motor will be related to the frequency of the AC source providing the power so the fastest speed this motor can produce will be with a 60Hz. This is part of the reason that more power will be drawn by a 60Hz usage. The compounding reason is that even though the rotor will spin faster, the amount of coupled current (to the rotor) will increase to be able to make a sufficiently large rotor magnetic field since the stator field is changing faster.

Now you may remember that I mentioned earlier that the angle between the current and the voltage will determine the real power that you use. So with a 120V and 1.4A with a 55° angle between these two you could still be producing the same real power of 95 watts.

I hope that this helps to explain what is going on here. As I said earlier, you have a very nice industrial machine with this sewing machine.

I hope that you didn't mind the gentle barbs to find out what machine you were using.

RedFred, Titan

I still believe the same unit rated 120V-60hz cannot be plugged into 220V-50Hz,

those are two different units.

If you get an answer from the representative, please post it here .

Titan, I add my voice to redfre

I hope that you didn't mind the gentle barbs to find out what machine you were using.

Hi Redfred,

When you read the manual did you see all the line diagrams as well?I only got script from a google translation.

If you have a link for pdf without translation I would like to see it .

Thanks Garth.

What device ?

Have you come from The american continent to Europe ?

The machine will require the same amount of wattage to run it whatever voltage you are using providing it is designed to use that voltage.

However 120V at 1.4A does not relate to 95W, so I do not see what the figures you have given have any relationship.

The power on maximum input to your motor will increase slightly when on 50Hz all other things being equal as the impeadance is lower, assuming it is a series brush motor.

Whole sewing machine : 120V 1.4A 60Hz 220 to 230V 95W 50Hz

Lamp : 12V 3W (Halogen lamp)

Well, now we know it's this device - all above may be largely irrelevant as generally they use a 'universal motor' _{(which is frequency independent) ^{(given such a small Hz difference).}}

So the power consumption "difference" is because the higher voltage enables more "amp turns" on the motor and a lesser resistance in the speed controller - so less Watts loss in the system.

So though the higher frequency brings a slight torque improvement, the lower voltage brings significantly greater losses.

Or "efficiency" in this 'device' is far more about motor and controller than Hz

I'll buy that.

It cannot be a universal motor as a previous poster have already pointed out two different catalogue entries for the different voltages

Good grief - and you got 2 votes?

"universal" is a configuration that applies to all the AC brush motors that run like a DC motor because the armature and field are frequency synchronous.

It was clear in my post, by "more "amp turns" on the motor" that the 120 Vac winding and the 240 Vac winding are different. As you cannot - to my knowledge - re-wind 'on the run' - logically they are separate motors and different controllers.

Further proof GA's misdirect.

To the best of my knowledge, Power is function of Voltage & Current. It has nothing to do with frequency. Whereas, if frequency changes the speed of the motor. Synchronous speed of the Motor = 120*Freq. in Hz/no. of poles. So, if your equipment is of 50 Hz and you are using it in 60 Hz area then the motor speed will increase by 1.2 times (60/50). Now, the power rating of motor (HP) = 71620 * torque/r.p.m. This means that for particular motor, if r.p.m. increases, the torque reduces and power remains constant.

Please NOTE in my previous e-mail: Motor HP = 71620 * torque (kg.cm.) / rpm. This is same as HP = Force (kg) * velocity (m/sec)/75.

From the wiring diagram in the manual at the link, it appears that either 120VAC or 230VAC goes from the cord, through a filter board to a transformer. The voltage of the transformer secondary is either 22 or 19.8 volts. There could be either one multi-tap transformer that must be rewired for depending on input voltage or the machine is built with one of two different transformers depending on the input voltage.

The difference in the secondary out put voltage accounts for the difference in input power, there is simply more power available at the 120VAC input voltage due to the turns ratio of the transformer creating a higher available voltage for the motor. The motor overcurrent protection appears to be the same for either input voltage since the main control board is common to both voltages. The motor is most likely a DC motor given the low voltage and wide RPM range.

Do not plug the 120V version of this machine into 230V without doing something with the transformer, maybe you would just blow the internal fuse, or maybe you would fry the control board. Either way would not be good.

Jim

Depends.

If it has a transformer at the input, which you have to reconfigure for the different voltage, this may be a warning not to make the device consume as much when run on 230V 50Hz. The transformer will run hotter at 50 Hz, because the transformer core magnetising current is higher, and may need to run with a lower rating.

Otherwise, no idea.

Still do not know what the device is but if the spec sheet say's it will run on these voltages it probably will maybe it is just a switch mode device.

V=I.R and W=I.V

Sigh. This relationship is true only when the load is purely resistive with an Alternating Current (AC) source. Since this entire thread is about the power difference that happens with a change in the AC source then this law cannot be applied. Instead one should use the equation for real power of P=V*I (Bold variables are vectors) → |P|=|V|*|I|*cosφ. (φ is the angle between current and voltage.) To calculate the current one must use the complex impedance equations instead.

You may need some more accurate measurements for the device than the manufacturers rating plate averaged maximums too.

Perhaps the question could be; will the 3 Watt lamp be brighter or duller?

(assuming a transformer, the taps are V perfect and the iron ratio is say for 55 Hz)

_{(the other question, of why people comment having not read the thread, I suspect is forever un-answerable)}

You are not right in your viewpoint, sorry, but still true.

The maths are slightly different for AC......thats the law!!

Unless its a purely resistive load as Redfred mentioned......few AC loads are PURELY (100%) resistive......its usually inductance.....a coiled heater element for example.....

Motors and transformers for example have quite large and important inductances relative to the power used....

You need to read up on AC electrics a lot more.......

Leading and lagging currents - out of phase with the voltage, wattless power etc etc etc....

The specs that the OP gave actually relate to two different motors that can be fitted to the sewing machine.

The proposition that it is a dual voltage motor has given rise to most of this forums speculation.

EXACTLY!!!

GA from me!!!

All these comments are nothing than speculations

The specs talk about two different models with two different motors for 2 different suply voltage....

I thing you boys have "Bad mouthed" each other enough.

Portugal Phillip and Redfred.

We all need both of you on CR4 but for different reasons, so please just agree to not agree, OK?

No need to reply, just both stop posting right now on this particular blog please.

Hopefully something new will come up on CR4 where you are both of the same opinion!

(AND I WILL BE THE ONE WITH AN OPPOSITE OPINION AND A LOUD BAD MOUTH, AS IT WILL BE MY TURN TO BE A BIG KID!! OK???)

So please forgive me if and when that happens!!

Have a great day Guys in spite of me......