When in doubt, get an inexpensive digital volt meter. Harbor Freight has them for 3 or 4 dollars. Measure across the poles you are planning on wiring up. If you get 220 or close to it then you know you have the right setup. My breaker box has the old "pushmatic" breakers. The configuration on my breaker box has the power from the electrical meter going to the two main breakers in a doublebreaker configuration at the top of the box. Those two main breakers each feed a separate power bar. You can draw 110 off of either of the two bars via pushmatic breakers attached to each bar. To draw 220 you have a doublebreaker just like the Main breakers. You tap off of both sides of the double breakers to get a properly breakered 220 volt line, often used for electric clothes dryers and whole house air conditioners. As stated earlier it is wise to use wiring and outlets made to fit 220 volt appliances so you cannot accidentally plug an 110 volt appliance into a 220 volt connection. The power cord for the miner power supply will probably need to be customized to fit the 220 volt outlet while maintaining the connector that fits into the power supply, which is the same for both 110 and 220 volt power supplies, at least in the USA. If you are not familiar with house wiring then it is wise to get the help of an electrician. There may be codes that require certain electrical boxes to be used when adding a circuit. I typically use metal junction boxes with a properly grounded safety ground going to the ground , not neutral, connections in the breaker box. Some cities have other ideas about what is safe, but I prefer a junction box that will not burn and is grounded so any short circuit will trip the breaker as it is supposed to.
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