Capacitors can Explode?! 🤯

Two types of failure in electrolytic capacitors...

1. Venting:
Electrolytic capacitors are designed with safety vents on the top or bottom - these are scored lines or rubber bungs that allow the capacitor to relieve pressure. Venting occurs when the internal pressure within the capacitor builds up, typically due to overheating, reverse polarity or overvoltage conditions. This can cause the electrolyte to boil and produce gas, increasing the internal pressure. The vent is a safety feature that allows this pressure to be released in a controlled manner, preventing the capacitor from exploding. When a capacitor vents, it may emit electrolyte, which is a messy failure, but it's a preferable alternative to an explosion.

2. Explosion:
If an electrolytic capacitor is subjected to excessive power, such as extreme overvoltage or reverse polarity, it can explode violently even if it has proper venting, due to the rapid buildup of pressure that the vents cannot relieve quickly enough. This is a catastrophic failure where the capacitor casing ruptures violently, potentially ejecting pieces of the casing and spewing out electrolyte. This can damage other components in the vicinity and is a serious safety hazard.

In both cases, the capacitor will no longer function as intended, and the circuit it was a part of will likely fail. To minimize the risk of such failures, it's important to ensure that capacitors are not subjected to conditions that exceed their rated tolerances and that they are installed correctly. Regular inspection and timely replacement can also help prevent such failures, especially in applications where capacitors are subjected to harsh conditions or continuous operation.

[hameh_chiz_az_hameh_jah]

who says the pictures doesn't have smell

[danek_hren]

"Capacitors can explode?!"
YES, IMAGINE

[junkyardjimmyriversiderecy]

The part the mystery blue smoke comes from 😊

[schaltnetzteil]

Bad quality chinese capacitors sometimes have non-working safety vents, even the larger ones. I've already had a 470uF 35V chinese cap explode violently even though it had a safety vent.