A commercial fridge is heavy, tall, and has a compressor that hates being tipped. The single most important rule is keep it upright, then let it settle before you ever plug it back in.
Pro tip: If the unit was tipped at all, wait 24 hours upright before restarting to be safe, rather than the minimum settle time.
Watch out: Laying a commercial refrigerator on its back or side pushes compressor oil into the refrigerant lines and can destroy the compressor.