The Tap Changer Analyzer & Winding Ohmmeter of the RMO-TT series is designed for winding resistance measurement of inductive objects, and for a tap changer analysis. The RMO-TT series is based on the state of the art technology, using the most advanced switch mode technology available today. The RMO-TT instruments are accurate (0,1%), powerful (up to 100 A) and still portable. The Instruments generate a true DC ripple free current with automatically regulated measurement and discharging circuit.
RMO-TT instruments can perform a simple, quick and reliable transformer on-load tap changer condition assessment. This series of instruments enable measurements of a winding resistance in every tap position, current ripple values (percentage of a current drop during a tap change) and transition times during the tap changes. Problems with a connection, contacts, and selector/diverter switch operation (tap change with interruption) can be detected with these measurements.
On-load tap changer dynamic resistance measurement
Three resistance measurement channels
Four temperature measurement channels
Vibration measurement
Automatic resistance/temperature measurement for the Heat Run test
Rapid automatic demagnetization
Tap changer motor current monitoring channel
Automatic discharge circuit
Three models: RMO40TT, RMO60TT, RMO100TT
Winding Resistance Measurement
Test currents:
5 mA – 40 A DC for RMO40TT
5 mA – 60 A DC for RMO60TT
5 mA – 100 A DC for RMO100TT
Output voltage: up to 55 V DC
Measurement range: 0,1 μΩ - 100 kΩ
Typical accuracy:
Up to 1Ω with the Resolution: 0.05 µΩ or better
Best accuracy: ± 0.1% rdg ±0.05 µΩ or better
Up to 10 Ω with the resolution: 0.5 µΩ or better
Best accuracy: ± 0.1% rdg ± 0.5 µΩ or better
Up to 100 Ω with Resolution: 5 µΩ or better
Best accuracy: ± 0.1% rdg ± 5 µΩ or better
Up to 2 kΩ with Resolution: 20 µΩ or better
Best accuracy: ± 0.1% rdg ± 20 µΩ or better
Up to 10 k Ω with Resolution: 200mΩ or better
Best accuracy: ± 0.2% rdg ± 200 mΩ or better
Resolution
0,01 μΩ – 999,99 μΩ: 0,01 μΩ
1,0000 mΩ – 9,9999 mΩ: 0,1 μΩ
10,000 mΩ – 99,999 mΩ: 1 μΩ
100,00 mΩ – 999,99 mΩ: 0,01 mΩ
1,0000 Ω – 9,9999 Ω: 0,1 mΩ
10,000 Ω - 99,999 Ω: 1 mΩ
100,00 Ω – 999,99 Ω: 0,01 Ω
1,0000 kΩ – 9,9999 kΩ: 0,1 Ω
Data Storage
1 000 internal memory positions
USB flash drive feature enables storage of a huge number of measurements
Printer (optional)
Thermal printer
Paper width 80 mm
OLTC Dynamic Resistance Measurement
Sampling rate: 0,1 ms
Automatic open circuit detection and warning
Transition current ripple measurement
Transition time measurement using DV-Win software
Timing measurement of different transition changes using DV-Win graph analysis tool
AC Current Measurement Channel
Resolution: 0,1 ms
Amplitude resolution: 16 bit
Current Clamp Meter Specifications
Measuring range: 30 / 300 A
Nominal current: 300 ARMS or 450 A DCPK
Frequency range: DC to 20 kHz (-3 dB)
Computer Interface
USB
Optional: RS232
Warranty
Three years
Environmental Conditions
Operating temperature: - 10 ºC to + 55 ºC / + 14 ºF to + 131 ºF
Storage & transportation: - 40 ºC to + 70 ºC / - 40 ºF to + 158 ºF
Humidity 5 % - 95 % relative humidity, non condensing
Dimensions and Weight
Device Weight Dimensions (WxHxD)
RMO40TT/RMO60TT 13,5 kg / 28.6 lbs 480 x 197 x 395 mm (18.9 x 7.8 x 15.6 in)
RMO100TT 15 kg / 33 lbs 550 x 215 x 420 mm 21.6 x 8.5 x 16.5 in
Vibration Measurement Channel
Resolution: 0,1 ms
ICP accelerometer, ±100 mV/g, ±50 g
Temperature Measurement
Four temperature measurement channels for RMO100TT
Mains Power Supply
Connection according to IEC/EN60320-1; UL498, CSA 22.2
Mains supply: 90 V - 264 V AC
Frequency: 50 / 60 Hz
Mains supply voltage fluctuations up to ±10 % of the nominal voltage
Input power: 2 250 VA
Fuse 15 A / 250 V, type F, not user replaceable
Applicable Standards
Installation/overvoltage: category II
Pollution: degree 2
Low voltage directive: Directive 2014/35/EU (CE conform); Applicable standards, for a class I instrument, pollution degree 2, installation category II: IEC EN61010-1
EMC: Directive 2014/30/EU (CE Conform) Applicable standard EN 61326-1
Safety: CAN/CSA-C22.2 No. 61010-1, 2nd edition, including Amendment 1
