Electrical short circuits are a common cause of relay burnout. This can result in excessive current passing through the relay, causing it to overheat and burn. Relays burn out for several reasons. Other causes include poor ventilation, which traps heat, and. Relay burnout may have been caused by overcurrent, overvoltage, vibration, or short circuit. I notice when switching it under the 24V load that when I close the switch again, it delays before completing the circuit. Relays must be modeled correctly, and contacts must be chosen wisely to prevent. Some of the most common reasons why relays fail are: We will now take a look at some of the common failure modes of relays in more detail.