What makes capacitors blow

See Technical Bulletin Continued operation of the capacitor can result in increased end termination resistance, additional heating, and eventual failure.

The "open" condition is caused by a separation of the end-connection of the capacitor. This condition occurs more often with capacitors of low capacitance and a diameter of less than. This is why care must be taken when selecting a capacitor for AC applications.

Mounting capacitors by the leads in a high vibration environment may also cause an "open" condition. Military specifications require that components weighing more than one-half ounce cannot be mounted only by their leads. The lead wire may fatigue and break at the egress area if a severe resonance is reached.

The capacitor body must be fastened into place by use of a clamp or a structural adhesive. The following list is a summary of the most common environmentally "critical factors" with respect to capacitors. The design engineer must take into consideration his own applications and the effects caused by combinations of various environmental factors. The service life of a capacitor must be taken into consideration.

The service life decreases as the temperature increases. Capacitance will vary up and down with temperature depending upon the dielectric. Changes in capacitance can be the result of excessive clamping pressures on non-rigid enclosures.

See Technical Bulletin 4. However, applying a voltage can reduce the leakage current. This is the principle behind reconditioning an electrolytic capacitor by applying a voltage. The the same reason, circuit designers should consider the initial increases in cap current when designing the equipment.

The usual technique is to put a guard circuit in parallel with the cap. The packaging of the cap itself can cause problems. Note there is no isolation between the capacitor case and the cathode terminal. The cap outer sleeves are also susceptible to damage.

The sleeve may crack if exposed to high temperatures. Generally the outer sleeves are made from PVC, but the PVC is there for labeling, not to provide electrical insulation.

Electrolytic caps typically also incorporate pressure vents that take the form of a thin area on the outer case, put there to handle pressure build-up if the cap is mistreated. Finally, slight differences in capacitors wired in series or parallel can lead to issues. For example, electrical current may not balance evenly among capacitors in parallel. In power supplies, one outcome can be excessive ripple current one or more of the caps.

Similarly, when two or more capacitors connect in series, the balance of the applied voltages must be taken into account so the voltages applied to each of the individual capacitors stay below the rated voltages. The usual approach is to install voltage divider resistors in parallel with each of the capacitors.

The first was a power supply for a monitor. Doing so gave it a few more years of life. If a high voltage greater than rated is applied across capacitor, its dielectric strength will break down and eventually capacitor will explode. Electrolytic capacitors fail due to leakage or vaporization of the electrolyte inside.

This can be caused due to heating in operation. Heating can be caused by either wrong connection or the use of under-rated capacitors. Electrolytic and Tantalum capacitors have polarity. The leads are marked positive and negative. Wrong polarity connections of these capacitors can cause explosion or failure.

Connect Positive terminal of Voltage Source to positive terminal of the Capacitor. Adobe d simulation click here. Don't forget to subscribe my YouTube channel [ Subscribe ].

Reply 5 years ago. Capacitors can fail overtime due to old age and normal wear and tear. What are the signs of a blown capacitor? A burning smell.

Whenever an electrical component overheats, it tends to give off a burning smell. This can happen when your capacitor is overheating. Hard starts. Blown capacitors are the number one reason for hard starts in an air conditioner. A humming or clicking sound.