What does an electrical transformer do?
Transformers step voltage up and down depending on the application. Step up is used to reduce the losses during transmission and step down is to required closer to the load, as higher voltages are dangerous and insulation and protection is expensive.
What is the difference between power and distribution transformers?
Power transformers are used in transmission networks of higher voltages for step-up and step down application (400 kV, 200 kV, 110 kV, 66 kV, 33kV) and are generally rated above 10MVA.
Distribution transformers are used for lower voltage distribution networks as a means to facilitate end user connectivity (11kV, 6.6 kV, 3.3 kV, 440V, 230V) and are generally rated less than 2.5 MVA.
What is a kVA rating?
All transformers have a kVA rating. It tells the user how much apparent power can flow through a transformer without exceeding a temperature rise associated with the rating.
What is a dry type transformer?
A dry type transformer has no moving parts and is a completely static solid state device. Unlike liquid fill transformers which are cooled with oil or fire resistant liquid dielectric, dry type units typically utilise resin based insulation systems.
What are the benefits of using dry type transformers?
Dry type transformers require minimal maintenance and can provide years of trouble free service. They provide a safe and reliable power source that does not require fire proof vaults, catch basins or the venting of toxic gases. This allows the installation of dry type transformers inside buildings close to the load, which improves overall system regulation and reduces costly secondary line loss.
What is an electrical kiosk substation?
Kiosk substations are an integral part of a complete electrical network. They convert high voltage into useable lower voltage within a safe, protected unit. A kiosk typically has switching devices on both the high and low voltage side of the transformer.
What are the main types of electrical transformers?
Power Transformers: are used in the transmission and reticulation network for long distance transmission at higher voltages.
Distribution Transformers: are used in the distribution network to provide voltage transformation in the power system by stepping down the voltage level where the electrical energy is distributed and utilized at the consumer end.
Current Transformers: are used for measuring and for protection, current transformers transform a high current into the desired value of the current required in a circuit.
Potential Transformers (a.k.a Voltage Transformers): are used to step down voltage levels to a safe limit or value for metering and protection purposes. They have a very low VA rating and cannot be used to power large devices.