A short circuit situation in an electric vehicle can lead to several undesirable occurrences. One of such is the formation of high temperature electric arcs between the contacts of the high voltage direct current (HVDC) relays in the circuit. These arcs significantly vaporize the contacts within a few milliseconds. As a result, the pressure of the gas within the relay chamber significantly increases. Depending on the magnitude of the short circuit current, the pressure increase may lead to an explosion of the relay. To understand and quantify the pressure increase, a Panasonic AEV14012 relay is investigated. A short circuit experiment is conducted on the relay. The test results are compared with a numerical model established in COMSOL to simulate the electric arcing process. The temperature of the arcs is used to estimate the resulting vaporization. The simulation results show the arcing process and the resulting pressure increase within the relay chamber.