An electronic megaohmmeter is a specialized device that allows you to control the insulation resistance, which determines the correct operation of electric power equipment. Using the device, you can check the suitability for operation of power transformers 10/6 / 0.4 kV, as well as cable lines of 0.4 kV, machines and more.
The advantages of an electronic megaohmmeter
Compared to analog products, this type of product has a number of advantages, which are expressed in the following:
- Compact and lightweight. Devices are easier to carry, which ensures maximum operating comfort on the part of maintenance personnel.
- No need to twist the lever to achieve the required performance. An independent source allows you to get the same result much faster.
- The measurement accuracy is slightly higher, which ensures the correct implementation of the tasks.
Along with the pluses, there is also a minus, which lies in the difficulty of pickup due to the strong electromagnetic field.
Note that the measurement and operability of the device are no different from analog.
Operating principle
An electronic megohmmeter involves the use of the following mechanism:
- Any device of this type has three components that can be combined into a single unit or delivered separately. The first is a generator that generates increased voltage, the second and third are chains and scoreboards.
- Measurements are based on Ohm's law. The current strength will be directly proportional to the voltage and inversely proportional to the resistance. From this it follows that at a fixed voltage and current strength, the insulation resistance must have a certain value.
- The study is carried out in several ways. First of all, it is necessary to check the circuit for an open, and then go to the insulation test.
Details of use can be found in the manufacturer's instructions for each specific device.
How to take measurements?
Usually, an instrument for an electronic megohmmeter is included with the device, which determines the sequence of actions for measurements.
The first stage involves the preparation of the workplace. It is important here not only to de-energize, but also to ground the electrical installation whenever possible. It should be noted that for a home network such measures may be unnecessary, especially since the voltage supply will not exceed 500 V.
After connecting the terminals, it is necessary to start the generator, which will display certain values on the electronic display. The latter can be saved, and the numbers themselves are the main indicator of the health of the wiring or power equipment. Please note that connected cables in electrical installations require disconnection. For the study, it is necessary to short the cable conductors.
The same operation is carried out for a transformer, which is expandable, and the tires are shorted with wire or ground. When specifying the characteristics of transformers, it is necessary to carry out at least four measurements for an open circuit and for the integrity of the insulation on each side in a closed and open state.
Security measures
Measurement of insulation resistance by a megohmmeter belongs to a special category of work that should be performed by two workers by order of the management. With regard to basic security measures, it is important to highlight the following:
- You can use only a proven and serviceable device. Before each use, make sure that the product is in good condition.
- It is only necessary to connect the megaohmmeter to the disconnected equipment, having previously removed the residual charge by turning on the grounding knives (if any).
- Removing the terminals and performing additional measurements requires preliminary removal of the charging current, which is done by grounding knives or special rods.
- It is possible to apply voltage only after people leave the electrical installation. This operation can only be performed using primary and secondary security features.
The processes involved in the measurement should be clearly understood. This will remove the human factor and help to properly complete the task.
Electronic megaohmmeter E6-24 / 1
After watching the video, you better understand the device and its measuring capabilities.
Thus, the device in question is a specialized device that helps to measure insulation resistance, that is, its suitability for operation. The main advantages of the electronic megaohmmeter are: ease of use, low weight and ease of use.
In order to properly cope with the tasks, it is necessary to follow the manufacturer's instructions, as well as observe safety measures. Remember that the device produces an increased voltage, which requires special care on the part of service personnel.