design a automatic swicth for genset

Do you mean A) "design a switch" from scratch, i.e. designing the individual metal and plastics parts to make the switching elements, or B) "design a switching circuit", using commercially-available component parts?

Does "project work" have anything to do with school?

Are you a student, hobbyist or employed to produce the switch as part of your job?

See previous threads on CR4 for your answer as we have covered this a number of times.

how can design a swicth for a genset as part of my project work

You can start the process by defining exactly what you want the switch to do. Once you've done that, then you will want to search the web to see if a switch already exists which will do what you want. Chances are very high that such a switch exists. If you can find nothing, then assess your educational level to determine if you are the best person to design the switch.

UR right，the best way is find a switch already exists

Hi Giovaaani,

First, I think we must know you and your intension on this question. To design a switch for a genset has some factors for consideration. If we can give you an idea on simple and concise one, let say the generator start perfectly based on that design, what next? how your load gonna be switching over to the generator. To give you diagram for auto start up is too easy, however it will be too funny when we don't know where you will be using it. Is the generator voltage and frequency output is correct and reliable as this is very important things to ensure before loading.

Kind regards

Roman

This one works well.

http://web.thomsontechnology.com/index.php?option=com_content&task=view&id=68&Itemid=8

I assume you mean an automatic transfer switch (ATS) to switch between the mains and the generator when the power fails. Google Automatic Transfer Switches and study various schematics. Do not try to design one, just buy it. They are very complex and sophisticated. Not for 'hobby' designing. There are a lot of setting to prevent nuisance starting and various timers for reconnection to the mains under full load. An ATS also provides the start contacts to start up the generator automatically. If you try an interlocked breaker scheme you may injure yourself or case a fire if you are not VERY experienced with such matters. If you have more questions than answers, it is best to stay away from designing electrical things and 'making' things from simple cheap components..... at least that is what will be said at your funeral.

Having designed a few, I found the regulations and bureaucrats the most difficult.

Before the local authorities will allow a system to be connected it has to be (CSA)certified and inspected system. That process takes more time and money than the hardware and design time takes. It is far cheaper and less hair pulling to purchase an approved system, especially as a one off.