MIKO-8M(A) milli-ohmmeter is developed to measure DC resistance in the range of 1 µΩ - 10 kΩ with test current up to 10А of:
Windings of power and instrument transformers, windings of electric motors, generators, linear compensators and windings of other high-inductive equipment;
Contacts of circuit breakers, resistors, buses and other non-inductive circuits;
Compensatory, current limiting and other resistors of high-voltage circuit breakers;
Сables.
Test current range is specified both in automatic and manual modes; resistance measurement range is set automatically. The instrument ensures fully automated resistance measurement under highly inductive load and thermal EMF balancing in external circuit.
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MIKO-8M(A) implements specialized measurement modes for various configurations of 11 objects (resistive object, inductive object, voltage transformer, current transformer and power transformer, generator, electric motor, reactor, compensator, connection filter and magnet), taking into account their specific features, while the user can select a standard object from the list, or create his own object.
The instrument automatically takes into account the configuration of the object to adjust the measuring modes.
Depending on the object type, you can select special measurement modes. For example, for a resistive object:
AUTO: the measurement starts automatically by the circuit closing.
SINGLE: the measurement starts upon the user's command (by pressing the START button).
PERIOD: the measurement starts automatically in prespecified time intervals.
For an inductive object, the user can also select one of two modes:
MANUAL: start and stop of the measurement are conducted manually by pressing the START button.
AUTO 1Ph: the measurement is initiated by pressing the START button and stopped automatically, if criterium specified is reached.
AUTO 1Ph mode has SKB EP patented automatic measurement method that guarantees results with the highest accuracy.
It is achieved by setting the max test current in the measurement circuit not on a staggered basis (depending on the value of the measured resistance), but continuously w/o fixed measurement ranges in a wide load range.
This measurement mode provides high signal level in a complex electromagnetic environment of industrial production or substation. Moreover, in AUTO modes of the measurement process the instrument produces the highest test current that enables guaranteed saturation of the transformer magnetic system.
MIKO-8M(A) has a built-in archive of up to 1,000 measurements for viewing, copying or deleting data. And due to the possibility of choosing an object at the measurement stage, the results are presented more systematically. This feature facilitates interaction with the archive.
The group of MIKO-7M(A), MIKO-8M(A) and MIKO-9(A) instruments has a number of automatic recalculation functions:
Auto δ calculation of Rphasebetween one another.
Auto conversion of Rlinear to Rphase. Linear windings are Delta or Star without neutral connected.
Auto correction of R measured at t° to R at t°p taking into account the winding material.
Auto δ calculation between Rcorrected and Rp.
Auto calculation of t° by its R.
OLTC non-demountable check mode allows the user to assess the state of the switching OLTC equipment with current limiting resistors without removing contactor tank cover.
This mode involves measuring of instant test current values. Test current firstly passes through the transformer winding and then through OLTC contacts while switching from one tap to another. The DRM graph is built on the basis of the measurement results and shows current change during tap changing. This graph enables to check tap changing time and general object state.
Analysis of the acquired graphs enables not only to sort out OLTC by fault-free/faulty criteria, but also to define the nature of the defect eliminating the opening of fault-free OLTCs. Milli-ohmmeter mode and DRM test complement each other and provide the user comprehensive information about the transformer state.
MIKO-8М(A) has the safety certificate IEC 61010-1. The instrument also meets the requirements of electromagnetic compatibility that are applied to class A instruments according to IEC 61326-1.
The instrument has a high degree of protection against:
test cable or mains cable breakdown;
excess of test current;
EMF of self-induction;
overheat of the test block.
At disconnection of the test cable from transformer bushings or from the instrument as well as at disconnection of the mains cable from the mains in the course of measurement, EMF of self-induction of up to several kV is generated in the disconnected circuit and the electric arc appears in the break point.
MIKO-8М(A) is characterized by the redundant protection against EMF of self-induction in case of involuntary disconnection of the test cable or mains cable protecting users from electric shock and the instrument from being damaged.
MIKO-8M(A) is equipped with a color graphic touch screen display of high brightness and an intuitive interface, which facilitates interaction with the device.
Management can be carried out through the keyboard, touch screen or from a special mobile application that allows you to maintain and synchronize the enterprise measurement database from the instrument, and also makes it possible to control the device remotely.
None of the test cables is included to the standard complete set of MIKO-8M(A) device. This allows the customer to choose exactly required cables.
For user's choice and the convenience of connecting to the object, there are special test cables designed of different lengths and different types of clamps/fasteners:
10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 80 mm);
10A Kelvin C-clamp test cable 1 x 8.5 m (jaw up to 103 mm) for connection to transformer;
10A Kelvin Clamp test cable 1 x 4 m (jaw up to 25 mm) for resistance measurement of CT and VT windings;
10A Kelvin test cable 1 x 3 m (0.5 kg) with 2 probes and 4 crocodile clips (jaw up to 25 mm) (length: 70 mm, plug: 3 mm) for contact resistance measurement of CT and VT contact joints and windings.
For customer’s choice the MIKO-8M milli-ohmmeter has two modifications: with a built-in battery (MIKO-8MA) and without a built-in battery (MIKO-8M). The device can also be powered from the mains (AC 90-253 V, 47-63 Hz // DC 127-354 V).
Specifications
Value
Resistance range
1 μΩ - 10 kΩ
Resolution capability
0.1 μΩ
Accuracy
±(0.1%+0.5 μΩ)
Test current output
0,001 A - 10 A
Test current range in DRM mode
0.1 A - 10 A
Measurement display resolution
5 digits
MIKO-8MA: Power supply (built-in battery)
Li-ion battery
MIKO-8MA: Battery charge time
3 hours
MIKO-8MA: Battery runtime (in continuous operation) with output capacity 1W
8 hours
Built-in memory
up to 1,000 measurements
PC connection
USB cable and Bluetooth (optional)
Display
Color graphic TFT touch, 800 x 480 pixels
Power consumption
120 W
Output capacity, W
60 W
Power supply (mains voltage)
90-253 V AC, 47-63 Hz 127-354 V DC
Dimensions
270 х 250 х 130 mm
MIKO-8MA: Main instrument weight with battery
4.0 kg
MIKO-8M: Main instrument weight without battery
2.7 kg
Operating temperature range
-20ºС - +55ºС
Environmental protection with open cover
IP40
Environmental protection with closed cover
IP67
Interface and user manual language
English
Testing period
3 years
Calibration period
3 years
Warranty period
3 years
Standard complete set
Photo
Item, Index
Application
MIKO-8M or MIKO-8MA main instrument
049.00.00.000 or 049.00.00.000-01
MIKO-8M or MIKO-8MA main instrument
049.00.00.000 or 049.00.00.000-01
Instrument and documents: User Manual and a Log Book.
Test cables on order
Test cables on order
As a matter of convenience for the user, test cables are not included to the standard complete set. Each user can select a cable to his/her own requirements. Please, select at least one test cable (see "additional complete set on order" below).
Mains cable
018.09.00.000
Mains cable
018.09.00.000
Mains cable 1 x 2 m. Weight 0.24 kg. For connecting the instrument to the power line. Temperature range -25°С - +120°С. Rubber insulation.
Ground cable
010.01.00.000
Ground cable
010.01.00.000
Ground cable 1 x 2 m. Weight 0.08 kg. For instrument grounding. The cable is equipped with a ground clamp and a screw end cap. Nominal test current – 50А.
Zero resistance standard
023.15.00.000
Zero resistance standard
023.15.00.000
Resistance zero point accuracy check. Value – 0.000 µOhm.
Shunt
Shunt
Type: 75ShSM M3 (75ШСМ М3). For checking MIKO-8M(A) operability. Value – 1 mΩ ±0.5%.
Fuses
Fuses
Type: VP2B-1V-2A (ВП2Б-1В-2А) (2 pcs). For the power source protection.
USB 2.0 A-B Cable
USB 2.0 A-B Cable
USB cable 1 x 1.8 m. For computer connection and data transfer.
Attachment devices set kit
126.06.02.000
Attachment devices set kit
126.06.02.000
Additional complete set (on order)
Photo
Item, Index
Application
Test cable
041.18.00.000
Test cable
041.18.00.000
10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 70 mm) with for connection to transformer bushings. Weight 1.72 kg.
Elastic silicone tube resistant to low and high temperatures and corrosive media.
Test cable
041.22.00.000
Test cable
041.22.00.000
10A Kelvin Clamp test cable 1 x 8.5 m (jaw up to 70 mm) with for connection to transformer bushings. Modification of the 041.18.00.000 cable. To be used on transformers with bushings located close to each other. Weight 1.72 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable
041.30.00.000
Test cable
041.30.00.000
10A Kelvin Clamp test cable 1 x 3.5 m (jaw up to 50 mm) for connection to transformer bushings. To be used on transformers with bushings located close to each other. Weight 0.76 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable
041.26.00.000
Test cable
041.26.00.000
10A Kelvin C-clamp test cable 1 x 8.5 m (jaw up to 103 mm) for connection to transformer. Weight 2.26 kg.
Alternative version of 041.18.00.000 test cable. Elastic silicone tube resistant to low and high temperatures and corrosive media.
Test cable
041.19.00.000
Test cable
041.19.00.000
10A Kelvin test cable 1 x 3 m. Weight 0.5 kg.
With 2 probes and 4 crocodile clips (jaw up to 25 mm) (length: 30 mm, plug: 3 mm) for contact resistance measurement of CT and VT contact joints and windings.
Test cables for CT and VT
041.21.00.000
Test cables for CT and VT
041.21.00.000
10A Kelvin Clamp test cable 1 x 4 m (jaw up to 20 mm) for resistance measurement of CT and VT windings. Weight 0.61 kg.
Cable is used for CTs and VTs which are stand-alone or built into transformers / circuit breakers.
Test cable
041.29.00.000
Test cable
041.29.00.000
10A Kelvin Clamp test cable 1 x 3.5 m (jaw up to 70 mm) for connection to transformer bushings., to be used on transformers with bushings located close to each other. Weight 0.92 kg. Elastic silicone tube resistant to low and high temperatures, and corrosive media.
Test cable extension
031.20.00.000
Test cable extension
031.20.00.000
Extension cable 1 x 6.5 m. Weight 1.18 kg.
Elastic silicone tube resistant to low and high temperatures and corrosive media. To be used together with test cables 041.18.00.000, 041.22.00.000 and 041.26.00.000.
Test cable
041.28.00.000
Test cable
041.28.00.000
10A Kelvin test cable 1 x 3 m, 0,54 kg, with spring-loaded probes. To be used for electrical resistance measurement in hard-to-reach places.
Short-circuiting cable (set of 3 pcs.)
041.23.00.000
Short-circuiting cable (set of 3 pcs.)
041.23.00.000
Short-circuiting cable set 3 x 3 m with crocodile clips (jaw up to 70 mm). Set weight 1.89 kg (0.63 kg + 0.63 kg + 0.63 kg).
The set is used for applying the DRM-test by short-circuiting secondary circuits. This cable is for OLTCs of power transformers.
Furthermore, this cable is needed for connecting the high-voltage and low-voltage windings when 2 windings mode is applied.
Short-circuiting cable (set of 3 pcs.)
035.31.00.000
Short-circuiting cable (set of 3 pcs.)
035.31.00.000
Short-circuiting cable set 3 x 12 m with crocodile clips (jaw up to 50 mm). Set weight 0.8 kg (0.27 kg + 0.27 kg + 0.27 kg).
The set is used for applying the DRM-test by short-circuiting secondary circuits. This cable is for OLTCs of power and auto transformers.
Additional resistor
032.25.00.000
Additional resistor
032.25.00.000
For in-place OLTCs monitoring at total resistance of the winding of no more than 0.5 Ω.
Length 0.11 m + 0.35 m. Weight 0.23 kg.
Adapter for a reference coil
023.12.00.000
Adapter for a reference coil
023.12.00.000
For testing laboratories: inspection / calibration of the instrument. Length 0.025 m + 0.16 m. Weight 0.04 kg.
Tool bag
126.06.00.000
Tool bag
126.06.00.000
Convenient, robust, wear proof bag for transportation of cables, documentation and other accessories to MIKO-8M or to MIKO-8MA instrument.
Weight 0.6 kg.
Manipulating rod
010.41.00.000 010.41.00.000-01 010.41.00.000-02
Manipulating rod
010.41.00.000 010.41.00.000-01 010.41.00.000-02
Manipulating rod is designed for test cables connection from the ground or from the tank cover to the bushings of high-voltage circuit breakers, and to the structural elements of high-voltage disconnecting switches and earthing devices, without the use of ladders or elevated platforms.
The manipulating rod is completed with special extension cables. There is a Kelvin clamp with current and potential contacts to connect to the object on one side, and a contact pad on the other side. The device test cable is connected to the contact pad from the ground or a tank cover.
Manipulating rod extension cable is made according to a four-wire (Kelvin) scheme with the test current capacity of 100 A in the presence of a good contact.
Manipulating rod - 2.2 (length 2.2 m / weight as an assembled set 3.4 kg);
Manipulating rod - 3.7 (length 3.7 m / weight as an assembled set 4.0 kg);
Manipulating rod - 5.1 (length 5.1 m / weight as an assembled set 4.6 kg).
Official reviews from customers based on the results of operating SKB EP instruments are available upon request. Please, fill out the form on the website.