Precautions for capacitor selection and installation

When confirming the use and installation environment, the capacitor used within the rated performance range specified in the product sample design specification should be avoided under the following conditions:

A. High temperature (the temperature exceeds the service temperature);

B. Overcurrent (the current exceeds the rated ripple current). When the ripple current exceeds the rated value, the capacitor body will overheat, the capacity will drop, and the service life will be shortened;

C. Overvoltage (the voltage exceeds the rated voltage). When the voltage applied on the capacitor is higher than the rated working voltage, the leakage current of the capacitor will rise, and its electro-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 according to the reverse polarity, the capacitor will cause short circuit of the electronic circuit, and the resulting current will cause damage to the capacitor. If it is possible to apply positive voltage to the negative lead in the circuit, non-polar capacitor shall be selected;

E. It is used in circuits with repeated and repeated rapid charging and discharging. For example, its service life may be reduced due to capacity reduction and rapid temperature rise;

F. It is forbidden to use the capacitor in the environment that is in direct contact with water, salt water, oil or dew, the environment full of harmful gases (sulfide, ammonia, etc.), the environment with direct sunlight, ozone, ultraviolet ray and radioactive substances, and the vibration and impact conditions exceed the limits specified in the sample and the instructions;

G. During the installation of capacitor, space shall be reserved above the explosion-proof valve of capacitor, wiring and other elements shall be avoided above the explosion-proof valve, and heating elements shall be avoided around the capacitor and circuit board.

2、 Precautions for capacitor installation

A. The used capacitor cannot be reused, but it can be removed for periodic inspection to test the electrical performance;

B. If the capacitor has been charged, discharge it with a resistance of about 1k Ω before use;

C. If the capacitor is stored at a temperature of more than 35 ℃ and humidity of more than 70%, its leakage current may rise, and the rated voltage can be applied through a resistance of about 1k Ω before use;

D. Confirm the rated capacity, voltage and polarity of the capacitor before installation;

E. Do not use capacitors that fall on the ground;

F. Do not use the deformed capacitor;

G. The distance between the positive and negative leads of the capacitor shall be consistent with the position of the PC board welding hole. If the capacitor is forcibly inserted into the circuit board with mismatched hole spacing, there will be stress on the outgoing line, which will lead to short circuit or leakage current rise of the capacitor;

H. During installation, insert the capacitor pin or soldering pin into the PC board until the bottom of the capacitor sticks to the surface of the PC board;

I. Do not apply more than the specified mechanical pressure. When the pulling force is applied to the outgoing line of the capacitor, the pulling force will act on the inside of the capacitor, which will cause the internal short circuit, open circuit or leakage current of the capacitor to rise. When the capacitor is welded to the circuit board, do not shake the capacitor strongly.