I'd like a nice safe step down transformer so I can buy US appliances sometimes. Would this be safe? Could someone point out a safe model or brand? Economical and reliable would be nice too but safety is the most important thing to me.
Are 240v to 120v Step down Transformers Safe?
bargain huntress on 29/07/2023 - 14:57
Comments
You haven't said what kind of appliance, or any associated power draw requirements.
Something rated at 100w is going to be very different to one that's rated for 1000w or more, for example.Oh i see.
So i need to look for the right wattage too not just the step down voltage?So i need to look for the right wattage too not just the step down voltage?
It sounds like you are wanting to do something that you don't know enough about to be able to do safely.
Electrical stuff is measured in volts and watts. You've got to have the right volts, and enough watts, or something goes bang.
It usually works out that unless the device is designed to run on both US 120V and Australian 240V, like computer power supplies are, which means it doesn't require a step down transformer, the cost of a transformer is more than you save by buying an overseas product.
You should probably just explain what you are trying to plug in.
Wattage matters, and also things with motors will be affected (US runs at 60Hz, rest of world mostly runs at 50Hz). Depending on what it is, hertz might not matter.
So i need to look for the right wattage too not just the step down voltage?
As you're performing a voltage transfer, the components and circuitry are going to be rated to/capable of a certain current (and therefore wattage).
Once you work out the size and how expensive a 1000w plus step down transformer is, for something that's not likely to burn your house down, you'll likely work out why using one for random appliances isn't generally a done think.
(and you would normally buy a transformer suitable for at least 1.5x the appliances rated wattage for overhead and any startup current etc)1000W tranformers also continuously consume power regardless of what the end device is doing. Mine draws about 30W just plugged into the wall.
Voltage, wattage AND HERTZ !
For, say, a mix-master Kitchen Aid or anything similar will require the correct cycles. Domestic US Kitchen Aid will not run well, need to buy the Australian 50Hz version.
Are knives safe? What about forks?
I recommend not using 240v cutlery. Your meal might end up being shockingly bad.
240V knives were the height of fashion a few decades ago, for slicing bread of carving meat.
Why did people stop using them?Because people like my mother were shockingly stupid using them. Like the time she was using the electric carver, with the twin reciprocating serrated blades, to cut the roast while simultaneously watching TV, and cut straight down to the bone.
I'd like a nice safe step down transformer so I can buy US appliances sometimes. Would this be safe?
Yes/No/Maybe.
It will depend on the appliance, as in the amount of 'watts' it uses and if the step down transformer can handle that etc.
Lots of appliances are 110/220v anyhow. So some won't even need it.
As safety is the most important then make sure the appliances have an Australian electrical certification, which they will not have.
A step down transformer will not make the appliances safe to use in Australia and some appliances will not work with "just" a step down transformer.
Google "using a safety switch with a step down transformer" and have good read.
Any affordable step down transformer will mitigate the safety functionality provided by the RCD in your switchboard. That is, you will have no RCD protection on any devices connected to the output of the transformer. So if there is a fault with the appliances you are using, you could receive a shock, and not be protected by your RCD. Use with caution…
So they stop the safety switch from working?
That sounds very unsafe.You will still have overcurrent protection to a degree (but remeber the transformer will step down voltage, but step up current, so it may be possible to overload the appliance on the output side, without tripping your circuit breaker). You will lose leakage current protection however, which is more concerning.
That sounds very unsafe
As does your whole plan. Since you don't actually know what you're doing, and still haven't told us what you want to use it for, then you should forget any preconceived idea about buying international 'appliances'.
Google "using a safety switch with a step down transformer" and have good read.
Any affordable step down transformer will mitigate the safety functionality provided by the RCD in your switchboard. That is, you will have no RCD protection on any devices connected to the output of the transformer. So if there is a fault with the appliances you are using, you could receive a shock, and not be protected by your RCD.
Hmm, it's actually the other way round. There are two types of stepdown transformers - an isolated transformer and an autotransformer. The autotransformers are much more affordable than the isolated ones.
A device connected through an autotransformer will trip the RCD as the input and output earth and neutrals are common.
A device connected through an isolated transformer will not trip the RCD as the load is completely isolated. However that also means in the case of an earth fault you will not get a shock because the output is not referenced to earth. You can however get a shock if you touch both active and neutral outputs.
Of course all that is moot if the appliance you're using is double insulated and has no earth pin anyway.
Transformers are heavy and outdated. Most voltage converters now are switch-mode.
But appliances are also switch-mode, which makes it easy to support a wide voltage range.
What appliances are you wanting? In some cases it is easier to replace a 110V part, typically a heating element, with a 240V one, and the rest will work fine.
Transformers are heavy and outdated. Most voltage converters now are switch-mode
That's simply not true at all for the type of transformer that the OP was asking about.
"Transformer" refers to an old-style iron-core 50/60Hz inductive converter. Perhaps OP was using the word incorrectly?
And these are the ones that can isolate the input and output, thus rendering the safety switch ineffective.
OTOH, if they are isolated from earth, you don't need a safety switch, no?"Transformer" refers to an old-style iron-core 50/60Hz inductive converter.
There's no other realistic way to convert 240v to 110v to power appliances.
For AC switch mode PS do not care ( assuming they are 90 to 260 V input).
50 v 60 hertz sync issues still cause issues if the appliance needs AC to sync with the input.
Yes transformer is safe. I bought a Giantz brand from ebay.
If you know what a step down transformer actually does from a safety point of view, which OP does not understand. Safety != < 10mA through the pump in you can decipher.
Safety != < 10mA through the pump in you can decipher
What does that sentence mean?
just buy appliances designed for australian voltages
Ive always used a plain adapter never had a problem.
You would if you'd used a device that didn't support 220-240v.
<facepalm>
100% misses point of the thread.
Don't go there. Nothing but complications and risk of blowing up equipment. They are clumsy and you're bound to plug your USA device into 240v accidentally and damage it. Most appliances run on both voltages. I had an expensive coffee machine from the USA which i eventually toasted with 240V, and my medical nebuliser wouldn't work on 110V making me have to buy one in usa (which wouldn't run in 240V) before i got there…. voltages and frequencies are a pain! Stick to Australian certified equipment!
Some appliances would not work even if you use a transformer to step down the voltage.
This is because the US power network is 60 Hz and Australia's is 50Hz
Unless you fully understand the volts, watts and frequency issues that will occur with each different appliance and the transformer then you may not be able to do it safely.
Someone that's electrically or technically savvy would have no problems though.Sometimes you may not even need a STT if you can just convert the internals from 110v to 220v. I did so with a few things I bought from USA, cost was reasonable for components, just plug and go. But I guess it also depends on what appliance you're looking at, you're not trying to import fridges and washers are you?
You will find that 230 / 110 transformers (not autotransformers which are also available) are floating on the 110V side. So, safety differently.
Sooooo, what is it for?
Different random things - kitchen appliances, crafting tools, even science equipment - from time to time i cant find something here or its cheaper overseas and i thought maybe a transformer was an option. But now im not keen. Will have to do a lot more research first.
For those asking for an example use what about this one here you go: https://www.amazon.com.au/Star-Wars-Death-Popcorn-Maker/dp/B…
Would it work with a transformer and if so which one and would it be safe? Getting electrocuted for some star wars popcorn is probably not worth it.
Well there's reviews of that mentioning 220v so whether you'd receive one needing a power transformer is questionable (as is dropping $200 on a novelty popcorn maker :) )
try it and report back
I searched it up, it's a pretty fancy 120v 1100watts popcorn maker. The one I use at home is called the microwave. I plan to order some starwars decals from eBay to immitate.
Anyway it seems to be a simple device with a heating element so the power factor will be 1 so you dont have to worry about power surge or anything so a 1200w(just to be safe) will work for you. There are plenty cheap a 2000w will be fine for a wide range of goods except for those with a huge motor that has funny power factor rating. Definitely don't try anything with inverter motor like a washing machine or fridge.
https://www.amazon.com.au/Giantz-Stepdown-Transformer-Voltag…
What about the US model of this machine?
https://alternativebrewing.com.au/products/coffee-tech-df64v…
Would using a transformer be ok?
It looks like a posh coffee grinder with a DC 300watts brushless motor. The US spec is 110V only. In this case, a voltage converter above will work properly.
If you want something safe then get one that is certified for Australia and not from an eBay dropshipper or from AliExpress.
Have a look at the step down range from Tortech for example: https://www.tortech.com.au/product/voltage-converters/step-d…