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Hoping I can get some feedback here. I've been bought a really nice Kitchenaid mixer (110v/60hz) from the US as a gift...However, I live in South Africa where the voltage/frequency is 220-240v/50hz.

The mixer has a 1 HP DC motor, and based on my limited research this equates to 746 watts (although this site claims the output power is really 350 watts).

I'm going to purchase a step down transformer, but considering they are already hefty beasts, I'd prefer to get the smallest one possible for the job. I've read one should allow for roughly a 20% buffer for appliances with motors, so I'm thinking that a 1000w 220v-110v transformer should be good enough.

Is anyone able to confirm if this should be safe or are there other things I should consider? Thanks.

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    \$\begingroup\$ The mixer probably states the electrical power needed, somewhere on the manual or on the body itself, possibly near where the power cable is connected. Check that to size your trasformer. \$\endgroup\$ Feb 13, 2017 at 14:28
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    \$\begingroup\$ If the motor plate says 350W, it's 350W electrical and a few watts less mechanical. The gear eats up another 10-20%. There may be some excess rating on the motor for intermittent use (can be up to 3 times the continuous rating) but all the other statements are marketing BS and plain ignorance of physics. If you aren't planning to use your kitchen aid to make ground beef yourself, you don't ever need more than 300W. \$\endgroup\$
    – Janka
    Feb 13, 2017 at 14:40
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    \$\begingroup\$ Definitely ignore the HP rating. Look for a discrete label that lists input power or current, and use that to size the transformer. \$\endgroup\$
    – user57037
    Feb 13, 2017 at 16:24

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There are two types of transformer (amongst the other types).

You can buy an isolating transformer, the sort that's used for most applications. As the name suggests, these have a mains winding, and a secondary winding, with no electrical connection between the two.

Or you can buy a non-isolating auto transformer. This shares a winding between input and output. While a no-no for applications needing isolation, powering appliances that are designed to be direct connected to the mains is just fine. Because it shares a winding, it's about 50% lighter and smaller (but I doubt as much as 50% cheaper) than an equivalently rated isolating transformer.

What size to get?

If you assume that 350watt rating is the output power of the motor, then it sounds quite reasonable that 1HP (~750 watts) could be the input power.

So 750 watts is a safe size to go for.

However, transformers can be overloaded for a while, and if turned off before they get too hot, that's OK. Does the mixer draw full power all the time, or only when making ground beef? Take those two together, and you may get away with a lower rated transformer that you use intermittently, and keep an eye on the temperature.

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