Milli-ohmmeter MIKO-8M(A) with integrated check of OLTCs

Yamalo-Nenets enterprise of the main power networks the branch of FGC UES, PJSC thanks your company SKB EP, LLC for the fruitful cooperation in the supply of measuring instruments for the diagnostic of high-voltage equipment. We also thank you for prompt, professional work and individual approach, as well as for the high quality of instruments and its components.

Our company operates such instruments as MIKO (10 pcs.), and PKV (10 pcs.) manufactured by SKB EP, LLC.

These instruments are used to determine repair quality of high-voltage circuit breakers and disconnecting switches. The contact resistance of the current-carrying circuit, the time and speed characteristics of HV circuit breakers are checked with a help of them.

The instruments are very convenient, they give an opportunity to identify the worsened condition of contact connectors on HV circuit breakers and of disconnecting switches. They reduce the time for detecting a defect and prevent accidents and technological disturbances. The defects are periodically identified. That fact allows us to schedule a necessary repair work on time and maintain the equipment in a good working condition.

We recommend these instruments for use in organizations, which operate high-voltage equipment.

Thank you for your help in solving our production tasks and sincerely hope for further mutually beneficial cooperation.

S.I.Kandiano
Acting Chief Engineer-Deputy Director

Since 2017 Electrotechnical laboratory of the Urengoy branch of Gazprom Energo, LLC has been operating MIKO-10 and MIKO-21 micro-ohmmeters and also MIKO-8M(A) milli-ohmmeter. These devices are used to measure the resistance of switching devices, power and measuring transformers, and electric motors.

The advantages of the operated devices include small dimensions and weight, the presence of built-in power sources in MIKO-10 and MIKO-21 micro-ohmmeters, a simple and intuitive interface.

[Manufacturer note]: MIKO-8M(A) milli-ohmmeter also has a built-in power supply. It can be supplied both without a battery: MIKO-8M version, and with it: MIKO-8MA version.

During the operation, all devices have proven themselves on the good side, there are no malfunctions or failures. In comparison with the previous versions of measuring devices, MIKO-10, MIKO-21 and MIKO-8M(A) have become more efficient, which allows, in addition to the high accuracy of the measurements obtained, to reduce the work time due to the simpler assembly of the measurement circuit.

Our plant has been using MIKO-8 milliohmmeter since 2016. The device is built into a good strong case that is convenient for transportation. During the time of use, with the help of MIKO-8 were diagnosed more than 100 units of electrical equipment (transformers, electric motors of various capacities and other equipment). One of the main advantages for our staff was the ability of automatic recalculations of deviations with indication of parameters and their saving into the device memory. The second advantage is the possibility of further processing of measurement results on a PC using specialized software. Also, among the advantages we can highlight the measurement speed, intuitive operation of the device, and its small dimensions.

Among the disadvantages, we note the use of non-standard connectors on the test cables and the inability to use third-party cables, the lack of auto power selection of the device.

[Manufacturer note]: Cable connectors that are implemented in our devices actually involve the use of the cables only of our production. Thereby we guarantee the reliability of the devices that you use, and we are responsible for the results that you get during measurement process. Unfortunately, when using third-party cables, we cannot guarantee the correctness of the data obtained.
The possibility of auto power selection is implemented in the upgraded versions of our milliohmmeters, more information about their characteristics can be found via the link. In addition, in modern milliohmmeters, the power can be set both automatically and manually.

MIKO-8 copes well with the assigned tasks. We can recommend it to other companies.

We allow you to post this review on the website and to use it for advertising purposes.

In May 2018, MegionEnergoNeft LLC received a pilot operation of the MIKO-8 device for measuring the direct current resistance of windings of oil and dry transformers from 0.4 to 110 kV of various types and designs. The device was operated both during the repair of electrical equipment during the repair of power transformers, and at transformer substations in the course of acceptance tests of electrical equipment serviced by MegionEnergoNeft LLC.

During exploitation, the advantages of the instrument were revealed, for example: small dimensions, a convenient housing for transportation and operation, an intuitive menu, a built-in measurement archive that allows you to speed up the measurement, simplify the processing of the results and automatically recalculate the data. Measurements are carried out in a short time, which in comparison with other devices significantly reduces the time of measurements. A positive feature of MIKO-8 is the ability to measure the resistance of the windings of power transformers with on-load tap-changers without disconnecting the device from the network and the equipment being measured, which significantly reduces the time it takes to take measurements.

Information is displayed on a large contrast screen that allows readings without voltage. During operation, no shortcomings were detected, the device works flawlessly.

As wishes for additional equipment, there is not enough portable compact battery pack with a built-in charger and a plug for connecting in the field [Manufacturer comment: The MIKO-8 millimeter is discontinued – in its place is a new modification of the MIKO-8M / MIKO-8M(A) (with built-in battery)].

According to the results of trial operation, it was found that this instrument meets the declared characteristics and significantly superior to instrument of a similar purpo

We have been operating MIKO-8M(A) milliohmmeter for two years, and the advantages of the device are the following:

• portability;
• compact size;
• informative menu;
• availability of the DRM test;
• possibility of use on high-inductive equipment.

The disadvantage is a small internal memory for information storing.

MIKO-8M(A) milliohmmeter deserves a high rating according to its characteristics. We are looking forward to new developments.

We have been using MIKO-8M(A) for two months. And the following positive advantages were revealed during the operation process:

1. Built-in rechargeable battery allows to make measurements without connecting the device to the network.
2. Checking the continuity of the measurement circuit of the object allows you to make sure that the device is connected correctly.
3. The presence of the multi-touch screen and buttons ensures reliable control of the device.
4. Extended resistance range up to 10 kΩ (comparing to MIKO-7) allows to measure resistance of the voltage transformer windings.
5. The presence of the archive ensures convenient processing of the numerous measurement results in various objects.

Revealed remarks:

1. The inscription "Measurement in progress, do not break the circuit" is too small, hardly noticeable in sunlight (it is worth increasing the font of all inscriptions).
2. It is necessary to increase the volume of the sound signal, because in conditions of heightened noise level it is not audible (in MIKO-7 the sound signal is much stronger).
3. For the convenience of typing on the keyboard, please add a virtual QWERTY keyboard.

Our company has been using MIKO-8M ohmmeter since 2018.

The device is built into a good robust case that is convenient for transportation in the extreme conditions of Russian roads. Device is equipped with comfortable-to-use control via buttons and multi-touch screen. The key point when choosing a device was the upper board of resistance range, as we are faced with the measurements of voltage transformers, and the price. MIKO-8M seemed to be an ideal choice. One more advantage is that test cables are not included to the complete set of the device because we were able to choose the most suitable one and not to overpay for cables that we would not use in our work.

The device is doing well with the assigned tasks:

1. resistance measurements of voltage transformers 15-220 kV;
2. resistance measurements of generators and electric motors windings;
3. winding resistance measurements of power transformers 6-220kV.

We would like to recommend MIKO-8M(A) milliohmmeter to other companies that are involved in the energy industry.

Our company has been using MIKO-8M milliohmmeter since 2019.

The device is built into a good robust case. It is convenient in working process on production sites. Device is convenient to be operated via buttons or touch screen. An important point when choosing the device was that the measured transformer winding was quite quickly saturated and the EMF appeared was balanced. Previously we have been using Vitok ohmmeter, but it significantly inferiors in the above-mentioned parameters to the MIKO-8M milliohmmeter. Several more advantages are the upper range of the resistance measurement, as we have to deal with the measurements of voltage transformers, and the price. The correlation of all the requirements and possibilities turned out to be the most optimal with MIKO-8M. One more advantage of this device is that none of the measurement cables is included to the complete set of the device. We were able to choose the most suitable one for us and not to overpay for cables that we would not use in our work.

The device copes with the assigned tasks very well (DC resistance measurement of the windings of power, tapped, auxiliary, voltage transformers). We could definitely recommend it for other companies in the energy industry.

With the following review we would like to tell you about the experience of use of the devices manufactured by Russian company SKB EP, LLC. We have been working with MIKO-8, MIKO-9A and PKV/M6N in Omskenergo the branch of Rosseti Siberia, PJSC.

MIKO-8 and MIKO-9A milliohmmeters have proven themselves well during DC resistance measurements of the windings of power and measuring transformers up to 110 kV inclusive, both in the lab and in the field. PKV/M6N circuit breaker analyzer allows to control the required time, travel and speed parameters of moving parts of oil, vacuum, SF6, and electromagnetic circuit breakers 6-10 kV.

No malfunctions were found during the use of the above-mentioned devices.

S.V.Kapitonov
Deputy Director for technical issues -
Chief Engineer

2 measurement devices manufactured by SKB EP, LLC are used in the Western section of the diagnostics service of Kurskenergo the branch of Rosseti Centre, PJSC: PKR-2M transformer OLTC analyzer and MIKO-8M milliohmmeter. PKR-2M device has been used since 2018, and MIKO-8M device has been used since 2019.

These devices are used for diagnostics of power and measuring transformers of voltage 110, 35, 10 kV (MIKO-8M) and OLTCs of power transformers of 110, 35 kV (PKR-2M).

In practice, both devices have proven themselves from the best side: compact, robust case, convenient and easy-to-use interface, the ability to select the necessary schemes and groups of winding connection. The ability to create and maintain an archive, including the ability to enter factory test data that allows you to carry out the primary analysis of diagnostics results directly at the workplace. High-quality of test cables and clamps, the possibility of adjusting the scope of the complete set. All this greatly reduces the time and labor costs when carrying out equipment diagnostics in comparison with the previously used fleet of devices. It should also be noted that there is software for analyzing and storing diagnostics results on a PC. Furthermore, there is the ability to obtain the necessary information or consultation directly from the device developers.

The use of PKR-2M and MIKO-8M devices manufactured by SKB EP, LLC brought the diagnostics of power and measuring transformers to a new, higher quality level.

PKR-2M and MIKO-8M devices manufactured by SKB EP, LLC are recommended to be used by enterprises and companies engaged in the repair and diagnostics of power and measuring transformers.

I.V. Shirlin
Head of the Western Section of the Diagnostics Service