How do you calculate current transformer ratio?
Recommended is a ratio slightly beyond the measured / defined maximum load current (In). Example: In = 1,154 A; selected transformer ratio = 1,250/5.
What is the nominal ratio for current transformer?
In instrument transformers, the nominal ratio is the ratio of rated primary winding quantity to the rated secondary winding quantity.
What is electrical ratio?
A CT ratio is simply the primary and secondary currents being expressed as a ratio where the secondary is either 1 or 5 amps. A 100/5 ratio CT means that the primary current is 20 times greater than the secondary current.
What is P1 and P2 in current transformer?
P1 indicates the side on which the current source is located, whilst P2 indicates the load side.
What are CTs and PTs?
CTs stands for Current Transformers. They are the devices that measure the current in a circuit. PTs stands for Potential Transformers. They are devices that measure the voltage and frequency in a circuit.
What is ratio error in CT?
Explanation: Ratio error of a C.T. is defined as the ratio of the magnitude of the difference between the nominal and actual ratio with respect to the actual ratio.
How can you tell CT from PT?
Important is connection, as C.T is having thick bar primary connected in series, between transformer secondary and bus bar, can easily be judged, while P.T place is on side, looks having only low current, input wired connection, and connected in parallel.
What are the errors in CT?
The ratio (primary to secondary current) error of a Class 1 CT is 1% at rated current; the ratio error of a Class 0.5 CT is 0.5% or less. Errors in phase are also important, especially in power measuring circuits. Each class has an allowable maximum phase error for a specified load impedance.
What is meant by transformer ratio bridge?
A transformer ratio bridge consists of voltage transformer whose performance approaches that of an ideal transformer.An ideal transformer is one that has no resistance, no core loss and no leakage flux (i.e., there is perfect coupling between the windings).