Methods for troubleshooting electrical equipment

Troubleshooting electrical equipment failures is an important task for maintenance personnel. To completely eliminate the failure, it is necessary to clearly understand the cause of the failure. More importantly, it is necessary to be able to analyze and solve the failure theoretically. This requires certain professional theoretical knowledge and the ability to master troubleshooting methods.

1. Resistance test method

Resistance test method is a commonly used measurement method. It usually refers to a method of using the resistance range of a multimeter to measure whether the motor, circuit, contact, etc. meet the nominal value and whether they are on or off, or using a megohmmeter to measure the insulation resistance between phases and between phases and ground. When measuring, pay attention to the accuracy of the range and calibration table used. Generally, when using the resistance method to measure, the general practice is to use a low range first. At the same time, pay attention to whether the measured circuit has a loop, and it is strictly forbidden to measure with power on.

(II) Voltage test method

Voltage testing method refers to a method of measuring the voltage value in the circuit using the corresponding voltage range of the multimeter. When measuring, sometimes the voltage of the power supply and load is measured, and sometimes the open circuit voltage is measured to determine whether the circuit is normal. When measuring, you should pay attention to the gear of the meter and select the appropriate range. Generally, when measuring unknown AC or open circuit voltage, the highest voltage gear is usually selected to ensure that the meter is not damaged by operating at high voltage and low range; at the same time, when measuring DC, pay attention to the positive and negative polarity.

(III) Current test method

The current test method is a method that usually measures whether the current in the circuit meets the normal value to determine the cause of the fault. For weak current circuits, an ammeter or a multimeter current range is often connected in series in the circuit for measurement; for strong current circuits, a clamp ammeter is often used for detection.

(IV) Instrumental testing method

Various parameters are measured with the help of various instruments, such as using an oscilloscope to observe the changes in waveforms and parameters in order to analyze the cause of the fault. It is mostly used in weak current lines.

5. Routine inspection method

Relying on human sensory organs (such as: some electrical equipment has a burning smell, sparks, discharges, etc.) and with the help of some simple instruments (such as: multimeter) to find the cause of the fault. This method is the most commonly used and the first one to be adopted in maintenance.

(VI) Replacement of original parts

That is, when you suspect a device or circuit board is faulty but cannot be sure, and there are substitute parts, you can replace them and test to see if the fault disappears and returns to normal.

7. Direct Inspection Method

If you know the cause of the fault or have determined the location of the fault based on experience, you can directly check the suspected fault point.

8. Gradual elimination method

If a short circuit occurs, some lines can be gradually cut off to determine the fault range and fault point.

9. Adjustment Parameter Method

In some cases, when a fault occurs, the components in the circuit are not necessarily bad and the circuit contact is also good. It is just that some physical quantities are not adjusted properly or have been running for a long time. External factors may cause the system parameters to change or the system values ​​cannot be automatically corrected, resulting in the system not working properly. At this time, adjustments should be made according to the specific situation of the equipment.

(X) Principle Analysis Method

According to the control system's composition diagram, by tracking the signals associated with the fault, analysis and judgment are carried out to find the fault point and the cause of the fault. Using this method requires maintenance personnel to have a clear understanding of the working principle of the entire system and unit circuits.

11. Comparison, analysis and judgment

It is based on the working principle of the system, the action procedures of the control links and the logical relationship between them, combined with the fault phenomenon, to compare, analyze and judge, reduce the measurement and inspection links, and quickly determine the scope of the fault.

The above commonly used methods can be used alone or in combination. When encountering actual electrical equipment failures, they should be applied flexibly according to the specific circumstances.

There are many kinds of fault phenomena in electrical equipment. The same type of fault may have different fault phenomena. Different types of faults may have the same and diverse fault phenomena, which will bring complexity to fault finding. However, the fault phenomenon is the basic basis for finding electrical faults and the starting point for finding electrical faults. Therefore, it is necessary to carefully observe and analyze the fault phenomenon, find out the most important and typical aspects of the fault phenomenon, and find out the time, place, environment, etc. of the fault. To eliminate many electrical faults, you must rely on professional theoretical knowledge to truly understand them. Compared with other types of maintenance personnel, electrician maintenance personnel are more theoretical. Sometimes, without theoretical guidance, many tasks cannot be carried out at all. Therefore, they must have certain professional theoretical knowledge. In order to better improve their ability to effectively solve practical problems and their maintenance level in actual work, maintenance personnel should continuously strengthen their own professional theoretical knowledge learning and improve their operating skills. When an electrical fault occurs, they can accurately find the fault, thereby eliminating the fault and enabling electrical equipment to operate normally and stably.