3 Phase generators are basically three (times) single phase generators combined to make one machine. Oscillating voltage is induced when a permanent rotating magnet swings past three stator magnets that are non-permanent. This will be able to give you some kind of idea of what to find when finding manufacturers selling these generators. You will also be able to find these generators in petrol and diesel, so if you are looking for the cheaper alternative you have two options to choose from. Honda and Yamaha are two big names in generators, and if you are looking for quality and machines that will get the job done, then you should definitely choose Honda or Yamaha.
You should also know that there are a couple of connections types when it come to connecting coils on 3 phase generators and those two connections are delta and star. Make sure that when you are researching the diesel or petrol generator from the manufacturers that you know what you are going for. There are many companies out there that sell these types of generators, but you should only go with those well-known companies that know generators.
If you are looking for a generator to deliver the required amount of power you are looking for, then it is important that you research the generators. Anybody can buy a generator and use it to complete a few jobs, but only those that know generators will know that you will be able to get a lot of power out of a 3 phase. Research the well-known generator companies on the Internet and see what they have available. If there is something that concerns you when it comes the 3 phase, you should visit online stores where these are sold and see what others have to say about 3 phase generators.