Whether the single phase asynchronous capacitor starter motor burns out and how it can be repaired

Fault phenomenon caused by capacitor damage in single-phase asynchronous motor and maintenance method.

1. Motor failure caused by capacitor damage.

1.After the single-phase asynchronous motor is added to the rated voltage of 220V, the motor can not be started, check that the wiring and fuse are good, the motor is normal, and the fault is caused by the damage of the capacitor.

2 When the single-phase motor is in use, it is found that the motor speed decreases. This is caused by the capacitor being broken down or the capacitance is reduced.

3. During the use of the single-phase motor, it is found that it does not move when it is under a large load, and the fault is the decrease in motor torque caused by the damage of the capacitor.

4 When the capacitor is damaged, it can also cause the motor to emit a "hum" noise.

Second, the common method of detecting faulty electric cellars.

1 Multimeter test method.

Suspect faulty capacitors are first shorted and discharged at both ends with a screwdriver or wire, and then removed. Use the R 10K or R 1K block of the universal meter to measure, and the two meter pens are connected to both ends of the capacitor respectively, and judge according to the swing of the watch hand

1) The pointer swings sharply towards the zero level of the resistor, and then slowly returns to the position of hundreds of dry ohms, indicating that the capacitor is intact.

2) If the pointer does not move, it means that the capacitor is open.

3) The pointer does not return after swinging to the zero level of the resistor, indicating that the capacitor has been broken down and short-circuited.

4) The pointer swings to a small resistance on the dial and cannot be returned, indicating that the leakage current of the capacitor is large.

5) The pointer can swing and return, but the first swing is small, indicating that the capacitor capacity has been reduced.

6) Turn the transfer switch of the multimeter to R 100 gear, and measure the resistance of the two leads of the capacitor to the shell with a meter pen, if the resistance is zero, the capacitor electrode and the shell have broken down and grounded.

2 AC discharge method.

The two pins of the capacitor are directly in contact with the single-phase AC power supply for a short time (1-2 seconds), and then immediately disconnect from the power supply (note that the power-on time should be as short as possible, if it exceeds 4 seconds, the capacitor may be burned). Then use a screwdriver or wire (do not touch it with your hands, pay attention to safety) to short the two leads of the capacitor, if there is a spark discharge, it means that the capacitor is good. If there is no spark or the spark is small, the capacitor is damaged or the capacitance has decreased significantly and should be replaced.

3 New product substitution method.

During maintenance, if the quality of the capacitor cannot be judged, the original capacitor can be replaced with a capacitor with sufficient withstand voltage and the same or similar capacitance, if the fault disappears, it indicates that the capacitor is faulty. Then replace it with a capacitor with the same capacitance and withstand voltage.

Your motor is not burned out, it is your incoming circuit that causes the fuse to burn out, and if you connect the wrong wire on the 4 terminals, it will never burn out in an instant. As for whether U1, Z1, U2, and Z2 are all conducted, and if there are continuous pieces, it is normal to connect the single-phase live wire and the neutral wire on the two continuous pieces respectively. If there is no continuous piece, it is recommended to find a repair department and check that it may be able to deal with it.

All conduction is not equal to burn-out, it depends on the resistance value.

How long does it take to connect the wrong wire? It doesn't burn out the motor in a few minutes.

Motor burn-out process Heating - > smoke - > very smelly burnt paste - > motor breakdown.

If it really burns out, you can only rewind the wire.

If all four interfaces are turned on, there is a high possibility that the motor will burn out.

Solution: Unreasonable capacitor selection. Choose a higher withstand voltage value. Take the overall parameters up a notch.

There are two reasons, one is a short circuit in the secondary winding, and the other is a problem with the quality of the capacitor. the amount of charge stored in a capacitor at a given potential difference; Denoted as c, the SI unit is farad (f).

Generally speaking, the charge will move under force in the electric field, and when there is a medium between the conductors, it hinders the movement of the charge and causes the charge to accumulate on the conductor; The most common example of an accumulation of electric charges is two parallel metal plates.

The operation of a single-phase motor requires a starting capacitor and a running capacitor. Both the starting capacitor and the running capacitor are designed to help the motor start and keep the speed stable.

If the single-phase motor continuously burns out the operating capacitor, it may be caused by the following reasons:

1.The quality of the operating capacitor is not good. Poor quality of the running capacitor may cause damage to the capacitor, which will prevent the motor from functioning properly. Therefore, it is recommended to choose a capacitor with reliable quality for replacement.

2.The motor is overloaded. If the motor is overloaded, it will cause the motor to overheat, overheating the operating capacitor, which will cause the capacitor to burn out. In this case, the load of the motor needs to be evaluated to ensure the normal operation of the motor.

3.The power supply voltage is unstable and resistant. If the power supply voltage is unstable, it will cause the motor to work in an overload state, and the capacitance is also susceptible to damage.

4.Aging of the motor. If the motor has been used for a long time, it may cause the internal parts of the motor to deteriorate, which will affect the operating state of the motor and even lead to capacitor damage.

Therefore, if the single-phase motor continuously burns out the operating capacitor, it is necessary to conduct a comprehensive inspection of the capacitor and other components to find out the cause of the problem and take corresponding measures to solve the problem.

If the operating capacitor of a single-limb attack phase motor burns out, the following situations usually occur in Zen Bu:

Motor Won't Start: The running capacitor calendar provides extra current to keep the motor running steadily, and if the capacitor is damaged, the motor won't function properly and therefore won't start.

Motor Failure to Achieve Rated Speed: If the capacitance value of the running capacitor is incorrect or the capacitor is damaged, the motor may not reach the rated speed because the additional current is not sufficient to maintain the motor operating speed.

Motor overheating: If the running capacitor is damaged, the motor will operate under high load conditions, and the motor will generate too much heat, causing the motor to overheat.

In single-phase motors, the operating capacitor is used to create a phase difference that allows the motor to start and run. Sometimes, if the operating capacitor fails or is not selected properly, the motor may run continuously and eventually cause the capacitor to burn out. This is because overheating of the capacitor will cause damage to its internal medium, and then short circuit, resulting in high-temperature, high-voltage arcing, and incineration of the capacitor.

In addition, if the motor is overloaded with nuclear keys, harsh use environment, or other reasons, it may also cause the capacitor to burn out. Therefore, when using the motor, you should pay attention to the selection and installation of capacitors, ensure that the stove can operate normally, and carry out regular inspection and maintenance.

Possible causes:

1) Whether the motor runs at low speed for a long time, and the centrifugal switch inside cannot reach the rated speed, it is not separated.

2) Frequent starting, centrifugal switch stickiness, resulting in the capacitor on the circuit can not be separated.

3) The voltage is too low.

4) The quality of the capacitor is not good.

5) The motor is overloaded and the heat is serious, and the capacitor is too close to the heat source.

First, the power supply voltage is high for a long time.

The second is the quality of capacitors.

When purchasing capacitors, mark the same capacity, and buy them with a large weight. I buy it with high pressure.

1. Whether the capacitor is placed in a very dry place at high temperature, then the capacitance may disappear automatically due to the drying up of the electrolyte. 2. The voltage is too high, 3. The working time is long, and 4. The capacitance of the configuration is not too small!

The capacitor withstand voltage must be higher than 40ov, it is best to use 450V or 500V, if the withstand voltage is enough, how bad, the problem is that the quality of the capacitor is not good.

1) Single-phase dual-value capacitor asynchronous motor, centrifugal switch working time is short, usually within 1 second, if the time is too long, the starting capacitor will be damaged, its principle.

2) Single-phase dual-value capacitor asynchronous motors, the wire diameter, turns and wiring methods of the starting winding and the running winding are different.

The first is that the voltage capacity is not enough, and the motor is small in power and large in load, and the motor is overloaded. The relay can not be used instead of the centrifugal switch, because the starting winding is not the same as the running winding, the motor starts by the capacitor phase split, and the capacity of the capacitor has an impact on the motor.

The common reasons for burning the starting capacitor of single-phase dual-value capacitor motors are:

1) The quality of the starting capacitor is poor and the withstand voltage is low;

2) The motor is stuck or the starting time is too long.

The single capacitor starting and running asynchronous motor is a product of unified design in the country, and has the advantages of similar products at home and abroad. The structure is reasonable and simple, the appearance is beautiful, the operation is reliable, the technical and economic indicators are excellent, the maintenance is convenient, and in line with the relevant provisions of the IEC standards of the International Electrotechnical Commission, can be used in plastic machinery, agricultural machinery, food machinery and other equipment.

This is inconvenient, not synchronized, if you want to synchronize, increase complex circuits, the gains outweigh the losses, often burn the capacitor, generally the capacitor withstand voltage is not enough, you can use 630V capacitor with the same capacity instead.

The capacitor withstand voltage is not enough, especially when the motor load is very light, it is easy to burn, centrifugal switch, it does not cost much to replace one, and it is durable.

According to the information you provided, it should be that the motor generates an overcurrent during use, and the motor is seriously overheated and smoked, resulting in a short circuit. The following causes may arise

1.Overload causes overcurrent.

2.The failure of the operating capacitor in the double capacitor causes an overcurrent in the main winding.

3.The power supply voltage is low or the cross-section of the power line is too small, and the line is too long, causing overcurrent.

4.Bearing damage causes overcurrent.

The hand does not move because the motor is seriously overheated, causing the insulation of the stator groove to melt and flow out of the stator cavity and sticking to the rotor, or the high temperature causes the loss of bearing lubricating grease and stuck.

Replace the capacitor first, if it doesn't work, the motor will be overhauled.

1. You can run a single unit first, if it is stable, it means that the motor is no problem, each one is tried separately, if it is normal, it will be added one by one, and finally it will trip if the switch capacity is not enough;

2. If you use a leakage switch, consider where the leakage is, find it in sections, use a multimeter with a high resistance level, a meter pen to connect the motor lead-out line, and a meter pen to connect to the motor shell, to see how big the resistance is, to determine whether the leakage to the ground, the multimeter voltage is low, and it can only be roughly judged;

3. You can also use a dry wooden board and a floor mat to open the motor, run the motor, and test the shell with a test pen.

Single-phase motor generally refers to a low-power single-phase asynchronous motor powered by a single-phase AC power supply (AC220V). This type of motor usually has a two-phase winding on the stator, and the rotor is a normal squirrel cage type. The distribution of the two-phase windings on the stator and the power supply can produce different starting and running characteristics.

Run a single unit first, if it is stable, it means that the motor is fine, and try each one separately. If it's all OK, add them one by one. If you trip in the end, your switch capacity is not enough. If you use a leakage switch, consider where the leakage is and find it in sections.

Use a multimeter with a high resistance level, a meter pen is connected to the motor lead-out line, and a meter pen is connected to the motor shell to see how much resistance there is to determine whether it leaks to the ground. The voltage of the multimeter is low, so it can only be roughly judged.

You can also use a dry wooden board and a floor mat to open the motor, run the motor, and test the shell with a voltage tester. If the test pen does not light up, the power supply can be replaced with a zero live wire and then tested, and the motor can also be roughly judged whether the motor is leaking.

Possible reasons: (1) Whether the motor runs at the bottom speed for a long time, and the centrifugal switch inside cannot reach the rated speed, it is not separated.

2) Frequent starting, centrifugal switching, sticky conductive capacitance, can not be separated on the circuit.

3) The voltage is too low.

4) The quality of the capacitor is not good.

5) The motor is overloaded and the heat is serious, and the capacitor is too close to the pyrogen.

Solution: Unreasonable capacitor selection. Choose a higher withstand voltage value. Take the overall parameters up a notch.

Generally, the operating capacitor is selected according to the micromethod per 100 watts, and the starting capacitor can be selected in a wide range because it is disconnected after starting, and the motor within 1kw is selected as 200 micromethod 450V. The motor within 2000W can be selected according to 300-400 micro-method, yours is 750 watts, choose 35, or 40 micro-method as the running capacitor, and the starting capacitor can be selected from 150 to 200, because after starting, the starting capacitor will be disconnected. If you burn the running capacitor, it may be that your running capacitor is too large, and the motor is also prone to heating.