Specialists of Irkutsk HPP (hydro power plant) have been using the SKB EP instruments for several years. The PKV/M7 instruments were used for measuring time characteristics of moving parts of such circuit breakers as ABB HGI-3 (13.8kV), AREVA HGF-1012 (110kV), SIEMENS 3AP1DT-145 (110kV, 220kV), and 3AP1DT-245 (220kV); the MIKO-2.3 and MIKO-7 instruments are used on electric motors (0.4kV) and the RVR(Z)-20/2000 M-U3, RGNP-110/2000-50UHL1, RDZ-1-110-2000UHL1, and RNDZ-220/2000U1 (13.8/110/220kV) disconnecting devices.
The PKV/M7 instrument meets all our needs in HV circuit breaker diagnosis. It provides convenient control of poles time difference using the PC software that shows defects in a circuit breaker long before they may cause a heavy failure.
The MIKO-2.3 milliohmmeter provides quick output of the results of measurements; it is a universal instrument that integrates four modes in one. The instrument is rather convenient and mobile. But for some circuit breaker models the length of a cable for the milliohmmeter mode is not quite sufficient for convenient instrument manipulation. Battery charge for ‘microohmmeter with account of a current transformer’ mode is sufficient for one measurement only, which extends the diagnosis time, but the instrument has an option of fast battery charge.
The MIKO-7 in the course of operation proved to be rather efficient. The only drawback is non-reliable "crocodile" clips. The instrument has a robust shock-proof housing that “saved” the instrument many times.
The updated software of the milliohmmeter allowed us to save time and eliminate personnel’s mistakes. When we used a voltampermetre we had to carry several instruments, and a battery; their assembly took time, and measurements on a transformer took two hours minimum. Time of measurements using the MIKO-7 is halved or even makes one third of that.
Benefits of the PKV/M7 include: information on the results of measurements and ability to operate the circuit breaker from the instrument. The MIKO-2.3 is rather mobile; the MIKO-7 has a large set of functions and automatic mode of operation.
During the SKB EP instruments operation on the main electric equipment of the plant we did not face any problems, the instruments worked properly, without failures. On the auxiliary equipment the problems with electric motors were timely revealed (inter-winding short circuit, break of windings end).
Specialists of Irkutsk HPP recommend the PKV/M7, MIKO-2.3 and MIKO-7 to all the companies as they are cost-effective analogues of the instruments of foreign manufacture.