Testing and Commissioning
Procedure for transformer lightning impulse test
The purpose of the impulse voltage test is to secure that the transformer insultations withstand the lightning overvoltages which may occur in service. Where: C1 – Impulse capacitor Rc – Charging resistor Rs – Series resistor Ra – Low-ohmic discharging resistor for… Read more
Jun 12, 2015 | By Edvard Csanyi
Maintenance
Maintenance and testing of overcurrent protective devices
When designing electrical distribution systems, required maintenance and testing of the overcurrent protective devices is a very important consideration. The electrical system reliability, component and circuit protection, and overall safety are directly related to the reliability and performance of the… Read more
May 04, 2015 | By Edvard Csanyi
Testing and Commissioning
What to check when commissioning variable speed drives
The main purpose of commissioning VSDs is to ensure that: The AC converter and motor have been correctly installed and meet the wiring and safety standards such as IEC 60364 or Australian standard AS 3000. The power and motor cables… Read more
Apr 22, 2015 | By Edvard Csanyi
Cables
General guidelines for online partial discharge testing of power cables
Online PD testing is becoming the topic of interest for power cable owners to ensure the safe and continuous operation of power cables. Partial discharge is a localised discharge in the insulation medium due to high voltage stress that does… Read more
Mar 30, 2015 | By Ammar Anwar KHAN
Energy and Power
Impulse withstand voltage test performed on assemblies
Only optional in the past, the impulse test which allow defining the rated impulse withstand voltage Uimp, is now a necessity thus demonstrating the strategy of the Standards directed to increasing the importance of such performance. In addition to the… Read more
Mar 02, 2015 | By Edvard Csanyi
Testing and Commissioning
Do Not Energize Oil-Filled Transformer Without Performing These 15 Tests and Checks!
The following tests and checks should be performed at a minimum to ensure that the transformer is ready to be energized. Do not energize the transformer without performing these tests and checks. If any of below explained tests fail and… Read more
Feb 23, 2015 | By Edvard Csanyi
Testing and Commissioning
Basic Transformer Routine Test – Measurement of Winding Resistances
The resistance between all pairs of phase terminals of each transformer winding are measured using direct current. Furthermore the corresponding winding temperature is measured. The measured resistances are needed in connection with the load loss measurement when the load losses… Read more
Feb 20, 2015 | By Edvard Csanyi
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
