How To Tell If The Capacitor Is Burned Out? Cause Analysis And Repair Method OF Capacitor Burnout

In many electronic products, capacitors are essential electronic components, which act as smooth filtering of rectifiers in electronic devices, power supply and decoupling, AC signal bypass, AC coupling of AC and DC circuits. Capacitor is a necessary component in board design, and its quality has become a very important aspect for us to judge the quality of board. What happens when the capacitor burns out? Let's take a look at the cause analysis and repair methods of capacitor burning with little goo.

Capacitor Fault Phenomenon

1. If the capacitor shell is deformed and the bulge is found, the insulating medium or electrode inside the capacitor must be damaged, and the operation should be scrapped immediately and replaced with new products.

2. If the capacitor high voltage porcelain bottle is found to flash and burst or there has been oil injection and overflow of the internal insulation medium, it should also be immediately judged as capacitor damage, and the damaged products should be properly handled and recovered and replaced with new products.

3, the capacitor in normal operation, should not have any sound. If you hear an abnormal "snap", "snap" discharge sound or "buzz" dull sound, indicating that the capacitor must be faulty inside, should be immediately shut down for further inspection or replacement of new products.

Cause OF Capacitor Burnout

1, the capacitor itself product quality problems, such as manufacturing process, material unqualified, the marked capacity is not consistent with the actual capacity, the use of long time leading to aging will cause burnout.

2, the impact of the external environment, such as installed in a place where heat dissipation is not good or near the heat source, capacitor wiring is not good, poor contact, etc., is also easy to cause burn out.

3, harmonic problems, harmonics make the filter capacitor resonant, resulting in capacitor overcurrent, burned out.

4, the voltage is too low; Centrifugal switch adhesion.

5, overload; Low speed and repeated start; Or the startup time is long. It is necessary to analyze and judge the scene of the capacitor burning, and gradually investigate the cause of the failure, sometimes small details may also be the cause of its burning.

Repair Method After Capacitor Burn

1, because the two poles of the capacitor have the characteristics of remaining residual charge, so we should first try to discharge its charge, otherwise it is prone to electric shock.

2. When dealing with faulty capacitors, the circuit breaker of the capacitor bank and its upper and lower isolation switch should be opened first. If the fuse protection is used, the fuse tube should be removed first.

3. At this time, although the capacitor bank has been self-discharging through the discharge resistance, there will still be some residual charge, so it must be manually discharged. When discharging, the grounding end of the grounding wire should be fixed with the grounding network first, 

and then the grounding rod should be used to discharge the capacitor several times until there is no spark and discharge sound, and finally the grounding wire should be fixed.

4, at the same time, it should also be noted that if the capacitor has an internal break, fuse fuse or poor lead contact, there may be a residual charge between the poles, and these residual charges will not be discharged when the automatic discharge or artificial discharge.

5, so the operation or maintenance personnel in contact with the faulty capacitor, should also wear insulation gloves, and use a short route to short-circuit the poles of the faulty capacitor to discharge. In addition, the capacitor using the series connection mode should also be discharged separately.

In summary, the capacitor itself is a start-up operation protection of electrical appliances, and many electrical appliances use different types of capacitors for start-up and operation. It is assumed that if there is no capacitor, unstable voltage and large current load will easily affect the service life of electrical appliances.

Ac Motor Capacitance Damage Performance is

1, look: see whether the capacitor is bulging, swelling is capacitor damage;

2, listen: connected to the motor listen to the motor has a humming sound, with the hand to move the rotor speed is slow and weak;

3, smell: some capacitors because the current is too large to burn the surface has a burning smell (limited to plastic shell capacitors);

The Causes OF Capacitor Damage Are

1, capacitor quality problems, the voltage can not reach the rated value;

2, the starting line (secondary winding) ring smashing short circuit or ground (shell);

3, the power supply voltage is too high;

4, starting capacitor capacity is not enough;

5, centrifugal switch separation is not complete (secondary winding) has been running; Capacitance damp, grounding (shell), etc.