Relay burnout may have been caused by overcurrent, overvoltage, vibration, or short circuit. (It does not mean that the relays burn continuously with flames, because flame-retardant materials are used for the relay components. ) Contact vibration (ultra-frequent switching) causes continuous arcing. An installed relay burned out and no longer operates. Other causes include poor ventilation, which traps heat, and. Failure of the Coil- The relay coil can burn due to overheating, high voltage, or continuous use. Examine Contacts- Periodically inspect the pitting, burning, or oxidation of contacts. The contacts need to be cleaned or replaced. Measure Coil. Relay protection forms a critical part of electrical power network transmission and distribution systems. However, relay malfunctions can occur, which can lead to incorrect. The testing and verification of protection devices and arrangements introduces a number of issues.