Change output voltage of transformer with taps
Most power transformers have taps on either primary or secondary windings to vary the number of turns and, thus, the output voltage. The percentage of voltage change, above or below… Read more
Apr 20, 2011 | By Edvard Csanyi
Current transformers (CTs) in a few words
A current transformer is defined as as an instrument transformer in which the secondary current is substantially proportional to the primary current (under normal conditions of operation) and differs in… Read more
Mar 18, 2011 | By Edvard Csanyi
How to choose transformer rating?
When an installation is to be supplied directly from a MV/LV transformer and the maximum apparent-power loading of the installation has been determined, a suitable rating for the transformer can… Read more
Mar 12, 2011 | By Edvard Csanyi
Transformer Winding Temperature Thermometer
These devices are supposed to indicate hottest spot in the winding based on the manufacturers heat run tests. At best, this device is only accurate at top nameplate rated load… Read more
Feb 25, 2011 | By Edvard Csanyi
Risk and Consequences Of Transformer Fire
The risk of a catastrophic fire with a properly inspected, tested, and maintained transformer is small. Proper maintenance and thorough testing of the transformer will prevent or detect many events… Read more
Feb 07, 2011 | By Edvard Csanyi
How To Connect Current Transformers?
The primary of a current transformer typically has only one turn. This is not really a turn or wrap around the core but just a conductor or bus going through… Read more
Jan 29, 2011 | By Edvard Csanyi
Price Of A Transformer
Today the production of transformers is characterised by a large variety of designs, manufactured in relatively short batches to meet the demands of a variety of customers with ever-changing expectations…. Read more
Jan 26, 2011 | By Edvard Csanyi
What Are Partial Discharges On Cast Resin Transformers?
Partial discharges are electrical discharges occuring in insulating materials. The electrical discharge’s path only spans part of the insulating distance separating the conductors. The problem of partial discharges, whilst not… Read more
Jan 17, 2011 | By Edvard Csanyi
NEMA TP1 Energy Efficiency Standard
Most commercial and industrial facilities require several low-voltage transformers to decrease the voltage received from the utility to the voltages used by various loads such as lighting, computers and other… Read more
Jan 08, 2011 | By Edvard Csanyi
Transformer Losses Standards
Unlike many countries around the world, Europe has no mandatory standard on energy efficiency of distribution transformers. The two main documents which describe losses in transformers are: the European Standard… Read more
Jan 07, 2011 | By Edvard Csanyi
Parallel Operation Of Transformers
Most transformers installed in parallel have the same kVA, turn ratios, and impedances, which can make it difficult for power engineers in industrial and commercial facilities to understand circulating currents… Read more
Jan 05, 2011 | By Edvard Csanyi
Types and Origins of Substation Fires
The risk of fire in substations has been historically low, but the possible impacts of a fire can be catastrophic. Fires in substations can severely impact the supply of power… Read more
Dec 26, 2010 | By Edvard Csanyi
Transformer Cooling Classes
Since no transformer is truly an “ideal” transformer, each will incur a certain amount of energy loss, mainly that which is converted to heat. Methods of removing this heat can… Read more
Nov 28, 2010 | By Edvard Csanyi
Oil-Filled, Inert-Gas System
A positive seal of the transformer oil may be provided by an inert-gas system. Here, the tank is slightly pressurized by an inert gas such as nitrogen. The main tank… Read more
Nov 08, 2010 | By Edvard Csanyi
Aluminum vs. Copper: Conductors in Low Voltage Dry Type Transformers
In North America, aluminum is the predominant choice of winding material for low-voltage, dry-type transformers larger than 15 kilovolt-amperes(kVA). In most other areas of the world, copper is the predominant… Read more
Oct 27, 2010 | By Edvard Csanyi