I bought a small 220v/300 watt tool from ebay that came from either china or Australia. I am worried that the 20 amp breaker on my 220v line in my shop will fry the motor. do I need a step down transformer to make it work or will it work as is?


The 20 A breaker is the maximum the circuit can provide. Your motor is rated 300 W so it should use less than 2A and be fine. The concerns are frequency - 50 vs. 60 hz can affect the speed, and by extension safety and efficiency, of the motor, depending on design. In addition any used or "unknown" device, particularly if not rated /tested by a reputable source, might turn out to be a safety hazard even under normal use due to issues with insulation, grounding, or other problems.

  • By "tested by a reputable source" I presume you mean Underwriters' Laboratories (UL) listing, or equivalent? Australia has one, China does not lol. Dec 21 '18 at 18:11
  • @Harper I am well aware of that. I found it quite funny to see China & Australia lumped together. Except for longitude, they have very little in common... Dec 21 '18 at 18:54
  • @Harper -- Where does CCC (China Compulsory Certification) fit into that? AIUI, that's the Chinese domestic product safety certification mark... Dec 21 '18 at 23:37
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    I don't know, but given the country's long history of behavior in intnational trade, I would not trust it at all. Dec 21 '18 at 23:49

As far as the voltage goes, you're OK to hook up that tool to a 220 volt circuit. However, if the tool has a motor that is designed for a 50 hz system, it may not work or it may run poorly and overheat. That could be a fire hazard.

  • it has a variable speed rheostat on it so I think the frequency issue should be okay? at least at a lower load speed. Dec 22 '18 at 16:44

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