emergency generator

During a power failure is it save to connect my portable generator as follows: turn off all circuit breakers and the main breaker; plug my generator 220 VAC output into my 220 VAC compressor outlet; turn on the 200 VAC compressor circuit breaker as my main and switch on only the circuit breaker I need (sump pump). I think this will work but, is it savely isolated from the power lines repair crew?

 

This is not allowed by the NEC and is probably illegal where you live. An approved transfered switch properly installed is the safest way, and legal. This could be expensive, so the next best thing is to just plug the devices you want to power directly into the portable generator.

 

This is not really a safe way of doing this backfeeding power from the generator into the panel is a very risky thing to do. Emergency generators connected to a system is suppose to have an approved transfer switch that will break contact should power be restored to the circuits the generator is controlling.
If all you want to control is the sump pump put a disconnect in the circuit. It might be as easy as mounting a box and installing a receptacle there, at which the sump pump can be disconnected and plugged into your generator then there is no chance of the power being restored to that circuit without you knowing about it.

 

Aside from being illegal the compressor probably doesn't have a neutral so what you want to do won't work anyway.

 

Just plug your pump into an extension cord, and into the generator, simple as that.