Arrived at location on 8/12/21 - To check front cookline Vulcan convection ovens. Found top convection oven is operational. Found bottom convection oven shorted and tripping breaker. Proceeded to troubleshoot bottom Vulcan convection oven. Cleaned and removed excessive aluminum foil buildup in blower wheel. Troubleshot and found power switch and light switch broken internally and shorted. Replaced both power and light switch. Rechecked resistance to ground- none. Brought oven into operation. Oven no longer tripping breaker. Oven in operation and heating.