Arc flash protection around electrical process equipment is paramount in any industrial setting, especially in the petroleum and chemical industries. Laboratory testing of motor terminal box structural integrity and rupture panel efficacy during a fault is carried out. Simple calculations are made to validate the design and are compared with the test results. Simulation results are then compared with both test data and the simple calculations. It is shown that more robust simulation techniques are needed to accurately capture the physics of an arc flash and make simulation a feasible tool for design. Recommendations are made for designing and testing future terminal boxes.