I am going to order a Generac Core Power (5837) to replace my 6KW portable unit.
1. I found a document from Generac regarding NFPA-37. This document indicates that ALL units can now be installed 18" from the wall. I have 96" to closest opening (garage door) and no windows on the wall where the unit will be located. Wall is brick, so fire rating is good. I was hoping to install the unit 24" from the wall.
Does the NFPA-37 document apply to this unit since it is composit housing?
2. Can I use a small inexpensive Air Conditioning disconnect on the outer wall.
You need to contact your local inspector. You may have amendments to code that will differ. Also the 18" Generac claims for installation has been disallowed by some states because the testing wasn't done by a recognized testing lab and Generac would not publish the results.
Yes, you can use a 60amp non-fuseable A/C disconnect.