Testing Instruments for Condition Monitoring

1. Automatic Insulation Analyzer

• Laptop with latest configuration with all licensed software.
• User friendly windows Software for operation, data collection.
• Measuring range of bridge for Tan d : 0 to 100 %, Resolution 0.001% accuracy +1% of the reading.
• Measuring range for capacitance: 1pF to 5mF and Resolution 0.01pF on lowest range and accuracy + 0.25 % of the reading.
• Calibration unit for validating accuracy at site.
• Induction cancellation unit for energized switchyard operation.
• 0-12 kV AC, 100 mA.
• Resonating Inductor with current rating up to 5 Amps. This facilitates the generator testing up to a 600 MW rating.
• The test set has Temperature, Humidity measurement and inbuilt charts for tan delta value automatic correction.

Capacitance and Tan Delta Measurement Test Set

2. Partial Discharge Measurement Equipment

• The test Instrument detects Partial Discharges in the high voltage insulation.
• The Unit of measure is apparent charge pico coulomb (pC)
• The ndb make XDP IIB test instrument can be used :
    1. To check the insulation quality of HT equipment at the time of       manufacturing.
    2. To have the base footprint values before commissioning.
    3. To check the discharge values during every maintenance cycle       to check the ageing of the insulation.
    4. Depending upon the measured values every six or twelve       months, to trend monitor the insulation.

PD Measurement Test Set

3. Sweep Frequency Response Analyzer (SFRA)

• The best diagnostic instrument for detecting "hidden" transformer defects
• The M5200 detects mechanical failure or movement of windings due to short circuits, mechanical stresses, or transportation. Used to ensure transformer performance, reduce maintenance cost, reliability and increase the service life of transformers.
• The M5200 can "see" inside transformers and can detect problems early, before they become costly failures. This test is used :
    1. To improve the quality of your regular inspection program.
    2. To eliminate unnecessary detanking and costly internal        inspections.
    3. To check new transformers to verify good condition on site.
    4. To inspect for damage if the 'transformer' has experienced        mechanical stress during transportation or in service.
    5. In case of system problems, like short-circuit faults that can      damage transformers.
    6. After earthquakes, lightning, or other environmental events.
• The entire set is operated with a software which can be used for analyzing SFRA plots.

Sweep Frequency Response Analyzer (SFRA)

4. MV / HV Power Cable testing by: Very Low
Frequency (VLF) test method: Quantity: 3 Nos.

• The VLF (Very Low Frequency) test method tests power cables by AC sinusoidal waveform.
• Achieved by reducing test frequency to 0.1 Hz.
• The VLF test set detects ageing of the Power cable, defects in insulation by measuring the dielectric loss of the insulation.
• Compatible for Partial Discharge Detection in Cable. Combined Tan Delta and Partial Discharge can identify and locate faults in Power Cable
• The test set can carry out following tests :
    1. Insulation Resistance measurement.
    2. Leakage current measurement.
    3. Capacitance value measurement.
    4. Tan delta value measurement.
    5. Partial Discharge Measurement.
    6. DC (+ and - Polarity) HV testing
• This test is used :
    1. To check the cable insulation during the Installation / Acceptance and Maintenance stage.
    2. To check the condition of joints, end termination and sheath.
  

VLF Tan Delta measuring Test Set

Power Cable ‘PD’ measuring Test Set

5. Lightning Arrester Test Set: For ON Line Testing of Lightning Arresters

• Online testing of Lightning Arrester is carried out by harmonic analysis of leakage current. The harmonic analysis is used as a tool to diagnose the health / reliability of the Lightning Arrester in online.
• This test set has an inbuilt voltage compensation circuit which is useful in charged switchyards where 3rd harmonic voltages if present will cause error in harmonic current measurement.

ON LINE LA Test Set

6. RSO Test Set: For main Rotor Winding Earth Fault and Inter Turn Fault Detection : Quantity: 2 Nos.

• This is a world renowned, highly accurate Rotor Reflectometer for Recurrent Surge Oscillograph test.
• There are several modes in which the rotor can be tested. These are,
    1. Testing of stationary rotor within generator,
    2. Testing of the rotor at speed within unexcited generator and
    3. Testing of rotor when removed from generator.
• The test set can be used for detecting,
    1. Fault between winding and rotor body (earth fault).
    2. Inter turn fault.
    3. High resistance joint in rotor.
  

RSO Test Set

7. Digital Dual Channel Storage Oscilloscope

8. Digital Megger

Kyoritsu Megger Model No. 3128

Sonel Megger Model No. MIC-10K1

9. Winding Resistance Meter

• High stability, high voltage compliance and extremely low ripple source.
• Meter is protected against inductive load for all ranges.
• Test current can be selected.
• Suitable for live switchyard.
• Obtains Fast and stable readings for inductive loads.
• Four-wire system of measurement.
• High resolution
• Direct reading of resistance is available on display

Winding Resistance Meter