A fifth or sixth ton condensing unit is typically a very large unit, however the standard requirements are relatively small. So, if you intend to own one of these units it is important to know your electrical requirements first. In order to do this, it is best to have your electricity supply put in through a local supplier. However there are companies that can deliver power through the mains, if you are using a mains feeder. That said, if you intend to use your mains feeder to create your own power, you will need to get a second source of power for the condensing unit itself.
Once you have your electrical requirements known you are in a position to decide whether to use your own power source, or to buy a second unit. A third option is to use the power of the mains supply of the home in which you live, and then use the condensing unit as an independent source of power, saving on installation and all those other headaches. Obviously this last option is a more expensive option, but might be worth it if you do not have your own mains supply, or if you want a huge power output.
Some considerations when buying a condensing unit include the size of the space, if it will be used outside, how much heat it will produce, and how large your space will be when it is working. A single person living space will need a smaller unit, while larger families will require a larger unit. Also consider the costs involved with installing a new unit, and whether or not you can afford to pay for it yourself, or if you would rather employ a professional electrician to come and fit the unit for you. Finally, consider whether you are going to live in the condensing unit for the foreseeable future, as you may need to take it down and take it with you, or perhaps it will be part of a building that you move. There are many factors to consider when making such a decision.