what is the purpose of current transformers on electrical services?

Question

what are the ct's on electrical sevices for

Answer 1

Current transformers can be used to supply information for measuring power flows and the electrical inputs for the operation of protective relays associated with the transmission and distribution circuits or for power transformers. These current transformers have the primary winding connected in series with the conductor carrying the current to be measured or controlled. The secondary winding is thus insulated from the high voltage and can then be connected to low-voltage metering circuits.

Current transformers are also used for street lighting circuits. Street lighting requires a constant current to prevent flickering lights and a current transformer is used to provide that constant current. In this case the current transformer utilizes a moving secondary coil to vary the output so that a constant current is obtained.

Answer 2

Since it is practically impossible for the National electricity grid to supply to each and everyone's home only the amount needed for each device, there is a national standard and a voltage which is delivered the same all over the country.

If anyone has has and electrical device (or is building one) that uses more or less current than the national standard, then you require a transformer to either step up or step down the voltage to the required level

Answer 3

Generally they are for lowering the voltage to a usable level, while at the same time raising the amperage.

Example: If you take a 480VAC 100 Amp main trunk line and run in thru a 2 to 1 transformer you end up with 240VAC @ 200 Amps.

Answer 4

....since electricity is delivered at much higher voltage than a residence can use, it is STEPPED DOWN by the transformer up on the pole.

Answer 5

to increase or reduce the line voltage
ie. 120 volt line voltage but you device needs 24 volts, use a stepdown transformer to do this!

Answer 6

To change the voltage