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
Medium Voltage
Field Inspection and Testing of Medium-Voltage Motor Control Centres (MCCs)
Check MCC equipment for: alignment, levelness, and tightness of all bolting. Check all equipment for: removal of blocking, supports, temporary ties, and temporary wire jumpers. Check that all protective barriers are properly installed. Check door alignment of individual starter units… Read more
Oct 28, 2013 | By Edvard Csanyi
Testing and Commissioning
Eight important checks to do before powering up the dry-type transformer
The transformer should be powered up only after checking the following items: name plate ratings, parallel operation, connections: cables, busbars, tap change connections, grounding connection, thermal protective device, impurities removal and insulation resistance test. Make sure the name plate ratings… Read more
Oct 23, 2013 | By Edvard Csanyi
Electric Motor
Testing and commissioning procedure for electric motors
It should be noted that the scope of motor testing depends upon the motor type and size, this being indicated on the inspection forms. Motor vibration shall be measured in a tri-axial direction, i.e.: Point x axis – side of… Read more
Sep 20, 2013 | By Edvard Csanyi
Testing and Commissioning
Identifying The Primary And Secondary Phasor Polarities Of Transformer – Polarity Test
This is needed for identifying the primary and secondary phasor polarities. It is a must for poly phase connections. Both a.c. and d.c methods can be used for detecting the polarities of the induced emfs. The transformer is connected to… Read more
Aug 26, 2013 | By Edvard Csanyi
High Voltage
Commissioning of HV Panel – Operational and Functional Checkup
The main objective of the test is to check the proper operation function of the circuit breaker; in this test we do the following: This test is conducted by manual, Local and Remote. For the manual Operation test, we will… Read more
Jul 17, 2013 | By Edvard Csanyi
High Voltage
High voltage testing – Direct current (DC)
DC tests are used mainly to do “pressure tests” on high voltage cables. Although the cables operate with AC, AC testing is not practical. The high capacitance of the cables necessitates AC test sets with a high kVA rating to… Read more
Jun 01, 2013 | By Edvard Csanyi
Testing and Commissioning
Condition Monitoring of Transformers
It is possible to provide transformers with measuring devices to detect early signs of degradation in various components and provide warning to the operator in order to avoid a lengthy and expensive outage due to failure. The technique, which can… Read more
May 24, 2013 | By Edvard Csanyi
Testing and Commissioning
Transformer Routine Dielectric (Insulation) Test
The following insulation tests are performed in order to meet the transformer insulation strength expectations. Unless otherwise requested by the customer, the following test are performed in the following order (IEC 60076-3) : To confirm the insulation of the transformer terminals… Read more
May 23, 2013 | By Edvard Csanyi
