Precautions for capacitor selection and installation

When confirming the use and installation environment, as a capacitor used within the rated performance range specified in the product sample design manual, it should be avoided under the following conditions:
a. High temperature (the temperature exceeds the operating temperature);
b. Overcurrent (the current exceeds the rated ripple current). After the applied ripple current exceeds the rated value, it will cause the capacitor body to overheat, reduce the capacity, and shorten the life;
c. Overvoltage (the voltage exceeds the rated voltage). When the voltage applied to the capacitor is higher than the rated working voltage, the leakage current of the capacitor will increase, and its electrical and oxygen properties will deteriorate in a short time until it is damaged;
d. Apply reverse voltage or AC voltage. When the DC aluminum electrolytic capacitor is connected to the circuit with the reverse polarity, the capacitor will cause a short circuit of the electronic circuit, and the resulting current will cause the capacitor to be damaged. If it is possible to apply a positive voltage to the negative lead in the circuit, use a non-polarized capacitor;
e. It is used in circuits with repeated rapid charging and discharging, such as rapid charging, and its service life may be reduced due to the decrease in capacity and the sharp rise in temperature;
f. In environments that are in direct contact with water, salt water, oil, or condensation, environments full of harmful gases (sulfide, ammonia, etc.), environments that are exposed to direct sunlight, ozone, ultraviolet rays, and radioactive substances, vibration and shock conditions It is forbidden to use capacitors in harsh environments that exceed the scope of the samples and instructions;
g. When installing the capacitor, leave a space above the explosion-proof valve of the capacitor, avoid wiring and installation of other components above the explosion valve, and avoid installing heating components around the capacitor and the circuit board.
2. Precautions for capacitor installation
a. The used capacitor can not be used again, but it can be removed as a periodic inspection to test the electrical performance;
b. If the capacitor has been charged, use a resistor of about 1kΩ to discharge it before use;
c. If the capacitor is stored under the condition of more than 35°C and humidity greater than 70%, its leakage current may increase, and the rated voltage can be applied through a resistance of about 1kΩ before use;
d. Confirm the rated capacity, voltage and polarity of the capacitor before installation;
e. Do not use capacitors dropped on the ground;
f. Do not use deformed capacitors;
g. The spacing between the positive and negative leads of the capacitor should match the position of the solder holes on the PC board. If the capacitor is forcibly inserted into a circuit board with an unmatched hole pitch, stress will be applied to the lead wire, which will cause the capacitor to short-circuit or increase the leakage current;
h. Insert the capacitor pins or solder pins into the PC board when installing, until the bottom of the capacitor is attached to the surface of the PC board;
i. Do not apply mechanical pressure exceeding the specified. When a pulling force is applied to the capacitor lead wire, the pulling force will act on the inside of the capacitor, which will cause a short circuit inside the capacitor, an open circuit or an increase in leakage current. Solder the capacitor to the circuit board without shaking the capacitor strongly.