Testing and Commissioning
Transformer no-load loss and excitation-current measurements
A transformer dissipates a constant no-load loss as long as it is energized at constant voltage, 24 h a day, for all conditions of loading. This power loss represents a cost to the user during the lifetime of the transformer…. Read more
Mar 27, 2019 | By Edvard Csanyi
Testing and Commissioning
Six system requirements of HV and EHV circuit breakers
With the phenomenal growth of the power system (EHV and HV) the duties that a circuit breaker is called upon to perform, besides the ability to handle short circuits, have become complex. Recent studies in this field have thrown much… Read more
Mar 20, 2019 | By Edvard Csanyi
High Voltage
Inspection and maintenance of capacitor banks (recommended practices)
Capacitor banks generally require very little maintenance because they are static type of equipment, but don’t be fooled by this statement. Capacitors are well known for their dangerous reaction when something goes wrong. Standard safety practices should be followed during… Read more
Feb 13, 2019 | By Edvard Csanyi
Testing and Commissioning
Transformer pre-commissioning tests and after-receipt checks you MUST perform
Once oil filling is completed, various pre‐commissioning checks and tests are performed to ensure the healthiness of the transformer (or reactor) prior to its energization. Various electrical tests must be performed and their significance and short description are given below…. Read more
Dec 26, 2018 | By Edvard Csanyi
Power Substation
Power transformer combined differential and restricted earth fault protection schemes
This technical article explains very important transformer protection methods and schemes: combined differential and REF, overfluxing, tank-earth and oil/gas protection. In previous article we described how overcurrent, restricted earth fault (REF) and differential protection of a transformer can be applied… Read more
Nov 14, 2018 | By Edvard Csanyi
Energy and Power
8 practical applications of testing ground system using clamp-on tester
First of all, it is extremely important that the operator/engineer understand the ground system that is being tested. The clamp-on measurement works well in many situations, but it has limitations and is not applicable in some configurations. Clamp-on ground testing… Read more
Aug 08, 2018 | By Edvard Csanyi
Medium Voltage
The Most Important Tests For Medium Voltage Metal-Enclosed Switchgear (You SHOULD Perform)
The design of the insulation system for metal-enclosed switchgear is based upon life expectancy of about 30 years. However, environmental conditions such as dirt, moisture, and corrosive atmosphere can shorten the design life. Moisture combined with dirt is the greatest… Read more
Mar 28, 2018 | By Edvard Csanyi
Low Voltage
Good Practice Rules For In-Process Inspection Of Low Voltage Switchboard
The purpose of in-process inspection is to ensure product conformity after each manufacturing operation. This process concerns all the manufacturing operations done by the workshop operators. Inspection during the manufacturing stage could be described by the following process: Inspection during… Read more
Mar 21, 2018 | By Edvard Csanyi
Power Substation
What does a good grounding of the power substation and switching station really mean?
Provision of adequate grounding in a substation and switching stations are very important for the safety of operating personnel as well a electrical devices do not rise above tolerable thresholds and that the earth connection is rugged to dissipate the… Read more
Dec 18, 2017 | By Edvard Csanyi
Protection
Primary injection testing of protection system for wiring errors between VTs / CTs and relays
This type of test involves the entire circuit – current transformer primary and secondary windings, relay coils, trip and alarm circuits, and all intervening wiring are checked. There is no need to disturb wiring, which obviates the hazard of open-circuiting… Read more
Dec 13, 2017 | By Edvard Csanyi
Protection
Secondary injection tests for checking the correct operation of the protection scheme
Secondary injection tests are always done prior to primary injection tests. The purpose of secondary injection testing is to prove the correct operation of the protection scheme that is downstream from the inputs to the protection relay(s). Why done prior… Read more
Nov 22, 2017 | By Edvard Csanyi
Protection
Commissioning Numerical Protection and Procedure For Carrying Out Performance Tests
Numerical protection is based on a number of microprocessors that can be programmed to reproduce virtually any type of protection and relay. It represents important advantages in reliability, space and economics compared to conventional protection arrangements. The method of calculating… Read more
Oct 30, 2017 | By Edvard Csanyi
Power Substation
3 greatest enemies to the transformer operation (and how to prevent them)
The principal object of transformer maintenance is to maintain the insulation in good condition. Moisture, dust and excessive heat are the main reasons of insulation deterioration and avoidance of these will keep insulation in good condition. Heat and contamination are… Read more
Jul 28, 2017 | By Edvard Csanyi
Maintenance
How do faults develop in a HV transformer and why condition monitoring is important
Condition monitoring equipment that can be used to extend the life of a transformer or to prevent catastrophic failure could pay for itself many times over. However, condition monitoring does not come free of charge, and tight budgets are to… Read more
Jul 10, 2017 | By Edvard Csanyi
Protection
Pre-commissioning tests and in-service checks of protection system
The pre-commissioning tests need to be carefully programmed so that they take place in a logical and efficient order, in order that no equipment is disturbed again during subsequent tests. Before starting the tests, it is essential to ensure that… Read more
Jun 14, 2017 | By Edvard Csanyi
