Low Voltage
Inspection, Test and Measurement Procedures for LV and MV (up to 36kV) Switchgear
Installed in clean, well ventilated or air-conditioned locations, switchgear will require little routine maintenance. Major inspection should be scheduled for power plant shutdowns and concentrate for low voltage switchboards on identifying contact wear, correct operation of interlocks, correct overload settings and fuse… Read more
Jan 16, 2015 | By Edvard Csanyi
Cables
Test On 110kV Power Cable After Installation (3)
In previous two parts of this technical article first six procedures were explained. Now the last three (7, 8 and 9) will be explained in details: Phase indication test (part 1) DC conductor resistance measurement (part 1) Capacitance test (par 1)… Read more
Jan 02, 2015 | By Zafar Iqbal
Cables
Test On 110kV Power Cable After Installation (2)
In previous part of this technical article first three procedures were explained. Now the rest will be explained in details: Phase indication test (previous part) DC conductor resistance measurement (previous part) Capacitance test (previous part) DC Sheath test on outher sheath… Read more
Dec 26, 2014 | By Zafar Iqbal
Cables
Test On 110kV Power Cable After Installation (1)
Site test procedure covers all necessary electrical testing for the 110 kV cable and accessories to be carried out during and after installation of the cable system. This procedure is in line with the requirements of the contract suitable for… Read more
Dec 22, 2014 | By Zafar Iqbal
Testing and Commissioning
Transformer routine test – Partial discharge measurement
This routine test aims to measure the partial discharges which may occur in the transformer insulation structure during test. Partial-discharges are electrical arks which form the surges between electrodes of any area of the insulating media of a transformer between… Read more
Dec 15, 2014 | By Edvard Csanyi
Testing and Commissioning
Testing of Power Transformer – Measurement of Zero-Sequence Impedance
The zero-sequence impedance is usually measured for all star-connected windings of the transformer. The measurement is carried out by supplying a current of rated frequency between the parallell connected phase terminals and the neutral terminal. The zero-sequence impedance per phase… Read more
Jul 21, 2014 | By Edvard Csanyi
Power Substation
Why is continuous on-line monitoring of partial discharge in the switchgear necessary?
Not sure? You know that periodical maintenance test like partial discharge test can still leave switchgear in virtually unknown condition. Insulation defects and deterioration may very well develop in service within maintenance cycle. These defects are often not detectable with… Read more
Jun 16, 2014 | By Edvard Csanyi
Electric Motor
How to measure insulation resistance of a motor
If the motor is not put into operation immediately upon arrival, it is important to protect it against external factors like moisture, high temperature and impurities in order to avoid damage to the insulation. Before the motor is put into… Read more
Jun 09, 2014 | By Edvard Csanyi
Energy and Power
Erection of earthing arrangements (TNC, TN-S, TNC-S, TT)
The earthing arrangements (TNC, TN-S, TNC-S, TT) of low voltage networks is largely determined by the Low Voltage Supplies. However, if the incoming supplies are at 11kV and the transformers are in the ownership of the user, the LV supplies… Read more
Apr 07, 2014 | By Edvard Csanyi
Testing and Commissioning
Inspection and Test procedures for Instrument Transformers
Visual and Mechanical Inspection Electrical Tests: Electrical Tests – Current Transformers Electrical Tests – Voltage Transformers Electrical Tests – Coupling-Capacitor Voltage Transformers Electrical Tests – High-Accuracy Instrument Transformers (Reserved) Test Values: Test Values: Visual and Mechanical Test Values: Current Transformers… Read more
Apr 04, 2014 | By Edvard Csanyi
Testing and Commissioning
Testing of power transformer – Measurement of impedance voltage and load loss
The measurement is carried out to determine the load-losses of the transformer and the impedanse voltage at rated frequency and rated current. On Figure 1 above (Circuit for the impedance and load-loss measurement) there are following figures: G1 – Supply… Read more
Mar 12, 2014 | By Edvard Csanyi
Testing and Commissioning
Testing Procedures for HV Voltage Transformers
Equipment required for testing General inspection Insulation Resistance Test Polarity Test Transformer Turns ratio test Following equipment is necessary to perform testings: Polarity test kit Megger 500-5000V Ohmmeter Multimeter Autotransformers & Step-up transformers Go up to the Content General visual… Read more
Feb 28, 2014 | By Edvard Csanyi
Electric Motor
Inspection and test procedures for Rotating Machinery, Synchronous Motors and Generators
Visual and Mechanical Inspection Electrical Tests Test Values Visual and Mechanical Tests Electrical Tests Pictures: Electrical machine wired for electrical testing The Electrical Machines Laboratory TABLE 100.10 – Maximum Allowable Vibration Amplitude TABLE 100.12 – US Standard Fasteners Compare equipment… Read more
Feb 19, 2014 | By Edvard Csanyi
Testing and Commissioning
Power Transformer Capacitance and Dissipation Factor Test
The capacitance and dissipation factor test is an AC low voltage maintenance test and is very similar to the power factor test. While the transformer preparation is identical to the power factor test procedure, there is no requiremnts to make… Read more
Jan 22, 2014 | By Edvard Csanyi
Testing and Commissioning
How to perform a power transformer turns ratio test
Power transformer turns ratio test is an AC low voltage test which determines the ratio of the high voltage winding to all other windings at no-load. The turns ratio test is performed on all taps of every winding. The Transformer… Read more
Jan 17, 2014 | By Edvard Csanyi
