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Looking to take advantage of price difference to import a washing machine from China - rated 220 volts 50 hertz to Kenya where we use 240 volts 60 hertz. Our supply also tends to be unstable with brownouts and surges. What would be the implication of using the device here?

  • The voltage is not a problem the frequency may be. I have quite a few motors that are listed for 50hz that run on 60hz, but it would be best to check with the mfg to make sure. – Ed Beal Dec 13 '17 at 14:15
  • @EdBeal depends on if he is talking a BLDC system Brushless DC or one that has AC motor. 240V could be a problem too - he has true 240Volts - generally 240 is the max volts for a household appliance in the USA to handle. – Ken Dec 13 '17 at 15:09
  • Most of the single phase motors I work on are rated from 208 to 240 v and yes I run them on a true 240 I have quite a few Euro motors designed for 50hz that do run on 60hz. If a brushless I would not be concerned at all. – Ed Beal Dec 13 '17 at 17:12
  • I see no Hiragana, Katakana, or even Hangul to give us hope this could be a quality product of those nations. It is also a supposed washing machine that weighs 8kg. Also washing machines are huge and bulky so shipping one halfway around the world to "save money" makes no sense. Super skeptical this thing is even real. – Harper Dec 14 '17 at 1:14
  • Realised that I had wrong information on our grid - after checking local appliances and checking with an utility employee, we actually have 240 V 50 Hz. So the only difference is 220 V and 240 V, which after enquiring from a power engineer, says should be within the range of any appliance designed for 220 Volts. – Dennis Kioko Dec 14 '17 at 8:37
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A BLDC motor is, by definition, electronically controlled, so frequency range is not a matter of the motor itself but of its control electronics and power supply. If the power supply is either a simple rectifier or a PSMPS (vulgo inverter), a slightly higher mains frequency should not matter much (a significantly LOWER mains frequency might, though!). HOWEVER, this is something to best ask the manufacturer about.

An explicitly 220V rated device on a 240V mains can be trouble, though - there are nominal minimum/maximum voltages for a given device, and also for a given power grid (often around +/- 10% - but that is up to your national grid). In a pessimal case (grid at maximum voltage allowed) the device can fail or wear more quickly than intended.

"Surges" and "Brownouts" are even more troubling, you would have to measure what the actual voltage during such events is and make sure the device can handle these (undervoltage in continued use can be bad for a PSMPS, not just overvoltage!). BTW, do not use small "plug in" surge protectors for that application: they are meant to deal with short surges from electrical storms and grid trouble, not constant overvoltag. The device you would need is called a voltage stabilizer and more large, complicated and expensive.

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BLDC ? Normally when talking BLDC my thoughts go to Motors you are talking Brushless Direct Current [Brushless DC] motor. Which means that motor is controlled differently - Voltage is converted to DC and you either have a direct connection where voltage controls RPM or a VFD style motor controller that determines RPM.

Now back to that BLDC motor - it would be using a Controller to operate that motor - and as such depending on what type of controller and how its supply circuits are it could over drive the motor - burn up both motor and controller.

In a washing machine the Motor is generally AC , but not always anymore.. Now on to the deal between 50Hz AC and 60Hz AC at 60 Hz your motor will run faster about 20% faster, you will use more power as well [see next paragraph for important information] - approximately 20% more.

You will also draw more current and might exceed the FLA [Full Load Amps] of the motor - what does that mean .. it means you will let the smoke out of the motor and the aroma will not be pleasant - nor the expense. They have yet to create any device to put the smoke back into a motor once it is blown and fried so you would need to buy a new motor. Now frying a motor if it goes up in flames while you went outside somewhere - perhaps your home burns with it.. is it worth saving a few pieces of silver IMO no.

Given that the unit you want is made in China I would imagine the FLA barely meets the requirements for the 50Hz threshold - so at 60Hz you would exceed the FLA.

In short - Don't do this..

EDIT 12/13/2017 If you insist on doing this : You can solve all the problems surges, brownouts and the voltage / frequency issue in another way.

Purchase a battery backup unit or Inverter of sufficient amperage to support operating your washer. 240VAC/60hz input 220VAC /50hz output.

Of course that might defeat your intent to save on costs..

  • Here's a link to the device detail.tmall.com/…. Also, saw a Samsung Variable Frequency Drive where the voltage and frequency isn't implied, wondering if that means it can take 240v 60 Hz – Dennis Kioko Dec 13 '17 at 20:35
  • @DennisKioko a Variable Frequency Drive is a motor controller. You supply it power and it controls the motor voltage, current AND frequency in order to provide the proper torque, rpm and braking. There is a rated input voltage for these drives and that depends on the drive as to how it is to be configured whether through wiring, configuration or automatically calculated or a combination thereof. As I was writing this - I have a better idea for you that solves both problems. See Edit in about 10 minutes. – Ken Dec 14 '17 at 2:04
  • So I checked what Bosch sell locally, and interesting enough, it is rated 240V 50Hz. So seems the only difference now is down to the voltage For surges and brownouts, we use some protectors on the socket that cuts out supply if it is outside a given range. – Dennis Kioko Dec 14 '17 at 6:19
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    A BLDC motor should run independent of mains frequency (unless some odd circuit uses the mains as a timebase) - since at some point in time, the supply voltage will be turned into .... wait for it ... DC before being modulated appropriate to each winding by power electronics. The power supply turning it into DC is what matters here. – rackandboneman Dec 15 '17 at 12:07
  • @rackandboneman Yes DC note my post outlines DC first and then for side note AC. The issue is not the conversion for his regular electronics, switching PS in modern world converts 240/220/130/120VAC 50/60hz AC to DC no problems; however all motor controllers do not not do this. I suspect the DC motor is controlled for speed, torque, braking and direction via a controller and that the motor is at least 48VDC. Since I don't have the service manuals or diagrams of the circuit I can not say if the motor controller will handle this (probably - but maybe not). – Ken Dec 15 '17 at 22:19

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