Silencer Spa Blower

Spa Blower 1hp shuts off after 5 mins when running in the sun. Runs 30 mins early morning without the sun on it, Unit is brand new and replaced same size blower. Do I need an enclosure around the unit?

Spa Blower 1hp shuts off after 5 mins when running in the sun. Runs 30 mins early morning without the sun on it, Unit is brand new and replaced same size blower. Do I need an enclosure around the unit?
 
Spa Blower 1hp shuts off after 5 mins when running in the sun. Runs 30 mins early morning without the sun on it, Unit is brand new and replaced same size blower. Do I need an enclosure around the unit?
Talked to Air Supply tech. Said unit is on the edge of overheating trip. Drill 1/4 inch hole in return pipe under check valve. No success. Pulled fish eyes in spa (4). Unit runs fine. Replaced fish eyes with larger opening. Runs fine (30 mins) now.