I have just purchased a split mini 13000btu air conditioner, I asked the question to the reseller if the unit would run on 110 volts ac 60hz and said that it was this that I wanted.
received the unit and it says on the board its 220volts 60hz, its got three wires, brown=live, blue=neutral, green/yellow=earth.
they told me it would work with the 110volts 60hz as normal but don't want to wire it up with out asking if it would work and if I'm missing something.
thank you in advance.

Given the color code of the wires it sounds like a European or British wiring method, which would use 220-240 volts. You may want to double check the manual or contact the manufacturer.

I agree with the previous post. Don't assume that the seller is truly knowledgeable about the unit - or honest. They wanted you to purchase it, and wouldn't want to discourage you. If you can provide the brand & model #'s, someone may be able to further assist you here.