What 100 V appliances can I blow up at 110V?

Factual Questions
1

We’re going to be moving from Japan to Taiwan, and we’ve got a number of household appliances. Most consumer electronics are OK, but obviously anything with high wattage will require a transformer.

So that got me thinking. What would happen if one were to try to use 100 V appliances at 110V? Things with heating elements would run really hot, and may burn out sooner, I guess. What would happen with things with compressors such as refrigerators or AC units? Japanese use AC units for each room, not central air. I’ll check tomorrow on the wattage, but I can’t imagine it’s not tiny. The washing machine has a motor, so would this burn out quicker?

For what it’s worth, I’ve got a EE degree from a couple of decades ago, so I understand the concepts, just never studied blowing up appliances with the wrong voltage.

2

I don’t know if the following observations about American appliances is useful, but FWIW:

We have plenty of items labeled for 110 or 115 or 120 VAC, and AFAIK the 10 volt range between over these numbers is not meaningful, and the real meaning is to categorize the appliance as 1X or 2X or 4X the common household voltage, which hovers around 110 to 120. It isn’t unusual for it to go down to around 105 or a little lower, or up to around 125, where I live. If it does so quickly, we might notice the lights look a little different or the fans speed up or slow down just a bit. During brownouts, where the voltage goes substantially below say 100, some appliances just quit, and others still work albeit differently.

I have never heard of people doing much in residential settings to accommodate these differences. Perhaps one could ask the power company to change a transformer tap, or add one’s own buck/boost transformer. But these are things likelier to be done in an industrial setting.

If this situation is influencing appliance life, which seems possible and even likely, I don’t think we do anything about it. This makes me speculate if you just bring your appliances without adjusting anything you will probably be OK.

How about line frequency? Isn’t Japan unusual, with a 50 versus 60 Hz divide snaking through the country and even through Tokyo? I think I have heard that…

3

The AC frequency is of more concern than a difference of 10 volts. As Napier points out, the voltage on a power grid is more of an average, anyway. Mine regularly moves between 112 and around 123.

4

look at the operating ratings for each item.

line voltage is considered OK plus or minus 10% according to my utility, in USA 120V plus or minus 10 percent (108 to 132 V could be expected).

so things would likely be designed to work with voltage ranges of at least that size and likely greater for safety.

5

My ignorant Gaijin guess (or gaijin smash if you prefer) is that nothing will break with the difference from 100-110V and from 50/60 Hz. The tolerances for most appliances are way more than that.
Indeed I brought a bunch of electronics here from Australia that was designed for 240 Volts, 50 hz and every single thing has worked in Japan in Osaka with 100 volts 60 hertz.

Modern transformers are pretty forgiving.

6

Are you sure about that?

A 240V 50hz appliance worked well on 110V 60hz?!

7

I moved to Japan from Australia 18 months ago. I run a small software company and shipped 1 cubic meter of tech over here via sea. Literally not one thing has not worked, looking underneath my desk right now I have about 30 devices plugged in. Apple computers, audio mixers, monitors, speakers, ethernet hubs etc etc etc.

Every single device is dual switching 240/110 volts and 50/60 hertz, most devices sold in asia are.

8

Remember the old computer PSUs that had a big switch on the back to change the input current from 120VAC to 240? A lot of them can do that automatically now, as can power supplies for other electronics.

9

With motors, a lower voltage is typically worse, since they require higher current for the same power, which leads to higher resistive losses, and higher temperatures. Going from 100 to 110 volts should actually help motors run cooler.

For too high of a voltage, the danger would be the insulation not being good enough, and I can’t believe the tolerances are that tight. More likely, they’d be good up to at least 250 V. In this global economy, would anyone ever even make something that runs at 100 V, but couldn’t also run at 110 V?

10

I get the idea the OP is taking about things with motors and heating elements like toasters and blenders not things with mult-voltage power supplies like laptop computers.

My WAG matches the OP’s theory is that things with only heating elements will be kind of OK, while things with motors won’t be happy, especially if you’re from the half of Japan that uses 50hz.

11

I have no problem believing him for electronics. Things with large motors like a washing machine or an air conditioner, I’d be more skeptical. So it depends on what he brought.

12

If the OP is shipping fridges, washing machines, air conditioners or heaters from Japan to Taiwan I question their sanity. That kind of stuff you do a Sayonara sale and buy again at destination.

13

Appliances intended for US consumer use are rated at a nominal 120VAC, so most anything will be OK from 110 to 125v. Power lines aren’t regulated much more accurately at the home level, so there has to be some leeway.

14

Motors should be ok going from 100 vac to 110-120 vac. Their lives may be shortened a little.

I would be more concerned about the 50 to 60 HZ change. Going faster the motor will develope more power, meaning more current use. Get an Amp-prob and check the current draw to see if it exceeds the name plate.

15

Since it’s mentioned that the appliances have a range of operating points that handles variance in the US (and other) systems, do we know how much variance to expect in Taiwan?

Knowing that an appliance for the US is ok down to 110V because it’s within the allowed variance doesn’t mean it works in Taiwan at 110V, if Taiwan realistically has 100-120, for instance.

The only area I’d be confident enough to make a firm statement: I’d expect that a modern cell phone charger will be ok…and may be able double check if you want to provide me information about what you use. But you probably understand enough of that world to check that yourself, even based on an old degree.

-D/a

16

It can, if it’s designed to do so. Most (but not all!) modern devices using switch-mode power supplies can take pretty much any AC mains voltage/frequency in the world w/o modification. If the info label on the device/power supply says “Input voltage 100-250 VAC, 50/60 Hz” it’ll work anywhere in the world, you just might need a plug adapter.

Single-voltage equipment is still out there, though it either tends to be specialized equipment (like my Audio Precision analyzer which requires you to manually configure the fuses for the intended AC mains power) or older stuff which have linear unregulated power supplies. When I worked at Sony, we had some older amplifiers and CD players brought over from Japan which were clearly marked “100 VAC only” so we had to use step-down transformers with them.

As for things with motors, appliances like refrigerators, clothes washers/dryers, and A/C units tend to use induction motors which run at a speed determined by the mains frequency. An induction motor will run slower on 50 Hz AC than it will on 60 Hz AC. I would expect a motor intended for 100 VAC 60 Hz to be OK on 120 VAC 60 Hz, but if it’s intended for 100 VAC 50 Hz it might not be a good idea. And of course this doesn’t account for any electronics which might be present in the appliance. If in doubt, see if you can contact the manufacturer.

things like vacuum cleaners, blenders, food processors and the like usually have series universal motors, which don’t really care about mains frequency but are sensitive to voltage differences. a 100 V universal motor will run faster on 120 V.

17

This is the proper response. I doubt it makes much difference in the life of small appliances, and the cost of shipping large ones is a greater loss than the shortened life span of a small voltage and frequency change.

18

A personal anecdote - I once took a computer (one off the street, so no big deal if it blew up, though the parts in the power supply are among those I desire more), plugged into 120 v, and flipped the voltage switch to 240 v while it was running - and it continued to run as if nothing happened (although it wouldn’t start up if set before turning on). Note, don’t try this the other way around - because it WILL blow up (voltage doubler produces 600+ volts into a ~300 v circuit).

Also of note, modern power supplies don’t actually have any automatic voltage switch (a few older power supplies did use a voltage sense circuit to control a relay or TRIAC); switch-mode power supplies can run off of a wide input voltage range, or they use a power factor correction circuit (another SMPS) which produces a set output voltage, usually around 380-400 volts (higher than the highest peak AC voltage), which enables higher efficiency (often even after including PFC losses) since operating off a fixed voltage allows more optimization of components (that aside, PFC isn’t an issue with residential power, but industry does have to pay more for low power factor).

19

We took all of our small appliances overseas with us, which meant they had to run on 50hz for about six years, and had to be powered through auto-transformers to convert the voltage. Transformers don’t correct voltage, they just (in this case) reduced the input voltage by exactly half (give or take a couple of loss points). For two years the input voltage in our house was up past the 10% tolerance, for whatever reason. The result was: nothing. No problems. We continued to use these items over the next four years, and in fact still have some of them which continue to work just fine 16 years later. That doesn’t mean there wasn’t some stress on the motor parts, brushes, windings, etc., but the effect was obviously minimal. I wouldn’t worry much about it.

20

Thanks all for the responses. I found some good news today. Although I’m on the 50Hz (Eastern) side of Japan, I confirmed with the manufacturer today that household appliances made in Japan are designed to handle either 50 or 60 Hz.

This is probably the same reason that most consumer electronics are built to handle all voltages worldwide. It may cost a tiny bit more, but saves by not having the build and keep inventory for all the different products. I do want to thank people who mentioned the frequency though, as it reminds me why I wouldn’t have been a particularly gifted engineer. I’ve been much better served by interfacing between engineers and the customers. My customers have also benefited by not having products designed by me, but that’s another story.

Also very aware of fluctuations in actual line voltage. Do remember that from school and actual experience. The point is that the fluctuation we need to be aware of is the upper side of Taiwan’s voltage, since it’s downside would be closer to Japanese voltage. Taking the generally given plus or minus 10%, worse case would be 120 V, which I would anticipate would be outside of the range which makes the machine happy. How much that would cause the machine to age faster would be a great question to ask a household appliance design engineer, but they are probably in relative short supply.

The manufacturer’s salesman gave the party line that they don’t recommend it, which of course they don’t. I don’t expect or even want them to design products to cover the whims off all customers, including those insane enough to ship them overseas.

This being the Net in general and the I had anticipated two lines of responses which really didn’t apply. First, electronic equipment, (e.g. not electrical equipment, things with motors) should be fine. I understand that well.

Second, for the question of shipping or buying new. It’s less a question of “sanity” than economics. We’re shipping by boat a household and the additional cost of a refrigerator and the other things is less than the replacement cost of purchasing new. Yup, I’ve calculated it.

When you send over a certain amount of stuff, you pay XX yen for YY cubic meters. Sending over a ZZ sized fridge costs WW yen and if you can still use for fridge for 5 to ten more years, it’s worth it.

Good transformers cost about $100 so that’s part of the calculation.