Secm Air Compressor Wiring, External Tap

[MatthewH]

Id like to wire a short pigtail, or a junction box into the SECM so I can power the air compressor either by the generator or by plugging it into a wall outlet.
I've heard of guys doing this, however I'm not positive how they wired them without back feeding to the generator. There is a large "breaker" on-off box in the back, that turns on the compressor once you fire up the generator and flip the switch on the panel. Not sure if I can wire a short pigtail to the compressor side of that box, or if I needed to go threw some sort of switch box to insure nothing backfeeds?
Any insight would be great
Thanks
Here's my setup for clarification

 

[nattieleather]

You would have to install another switch box in line to the compress so that when you are on pig tail you cut the power going back to the generator. Kinda of like wiring your house to run off or generator or power line. You have to disconnect one from the other.

 

[MatthewH]

After looking around online, a 30amp, 110v single circuit transfer switch should be what I need to make this happen