What is TPS Class CT?
Class TPS low leakage current transformer performance is defined by the secondary excitation characteristic and turns ratio limits. However, the CT is classified by the voltage across the burden impedance at the limit current of 100 A. Hence, the voltage standard classifications are 100, 200, 400, and 800.
What is TPS current transformer?
TPS – low leakage with performance defined by secondary excitation and turns ratio error. TPX – defined by peak instantaneous error during specified transient duty.
What is the main purpose of current transformers?
A Current Transformer (CT) is used to measure the current of another circuit. CTs are used worldwide to monitor high-voltage lines across national power grids. A CT is designed to produce an alternating current in its secondary winding that is proportional to the current that it is measuring in its primary.
What are types of current?
There are mainly two different types of current: Direct current and alternating current.
What is knee point voltage?
The knee point is defined as the voltage at which a 10% increase in applied voltage increases the magnetizing current by 50%. For voltages greater than the knee point, the magnetizing current increases considerably even for small increments in voltage across the secondary terminals.
Why CT secondary is grounded?
Why CT secondary is grounded? Why CT secondary is grounded? The one pole of the CT is earthed to avoid voltages being present due to capacitive coupling between the CT secondary and the line being monitored (CT Primary). At low voltages CT Secondary is not earthed but this is always the case with 11Kv and above.
What happens if the CT is grounded at multiple locations?
If the current transformers are grounded at multiple ground points, the normal current does not create any problem. However, during a fault condition, the magnitude of potential rise at the different ground points of the current transformer will be different.
What happens when a transformer secondary is shorted?
A shorted secondary results in a very large secondary current but little or no load current since the short is connected across the load (see Figure 3). The primary current is also much greater than normal since the reflected impedance is very low. If there is a short, the meter will read 0 Ω.
Is PT is always step down or step up?
Potential transformers are also known as voltage transformers and they are basically step down transformers with extremely accurate turn’s ratio. Potential transformers step down the voltage of high magnitude to a lower voltage which can be measured with standard measuring instrument.
Why is PT connected in parallel?
PT needs to be connected in parallel because we need to measure the voltage. These are similar to voltmeter and Ammeter.
What are the two types of transformer?
The different types of transformer are step up and step down transformer, power transformer, distribution transformer, instrument transformer, single phase and three phase transformer, auto transformer, etc.