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 is a protection CT?
The protection current transformer is used to reduce the currents in power systems, producing proportional currents in the unit’s secondary windings that remain isolated from the main circuit. … In doing so, the protection current transformer allows the unaffected areas of the circuit to continue in operation.
Why is CT used?
CT scans can detect bone and joint problems, like complex bone fractures and tumors. If you have a condition like cancer, heart disease, emphysema, or liver masses, CT scans can spot it or help doctors see any changes. They show internal injuries and bleeding, such as those caused by a car accident.
What is PS class CT?
PS Class CT is also known as PX Class or simply Class X Current Transformer. It is special type of current transformer meant for protection purpose. … Deviation in characteristics of CTs may lead to spill current in the secondary and even lead to actuation of protection element even under through fault condition.
What will happen if we interchange protection CT with metering CT?
Metering current transformers are designed to be within quite accurate values up to say two x rated current, and down to <0.01 x rated. Consequently a protection relay connected to a metering current transformer will get a heavily saturated waveform during fault conditions and it won’t work properly.
What is the difference between CT used for protection purpose?
The burden of protection CTs is quite high when compared with a metering class CT, which means that voltage drop across the burden will be high. Therefore, the knee point voltage of a protection class CT must be more than the voltage drop across the burden to maintain the CT core in its linear zone.
What is the difference between CT is used for protection and used for instrumentation?
Current transformers are used for both metering and protection purposes. By reduce the power system primary current to lower value CT is used for measuring or metering purpose. By permit the use of standard current rating for secondary equipment CT is used for Protection purpose.
What is CT calculation?
Definition: 1) The ratio of primary amps divided by secondary amps. For example, a CT that is rated to carry 200 Amps in the primary and 5 Amps in the secondary, would have a CT ratio of 200 to 5 or 40:1. …
How is CT calculated?
To calculate CT, multiply the free chlorine residual concentration (C) measured at the end of the contact time by the time (T) the water is in contact with free chlorine. To get the required CT value of 6, adjust the free chlorine residual concentration or the contact time.
How do you read a CT rating?
The CT ratio is the ratio of primary current input to secondary current output at full load. For example, a CT with a ratio of 300:5 is rated for 300 primary amps at full load and will produce 5 amps of secondary current when 300 amps flow through the primary.
What are the side effects of a CT scan?
Possible side effects of an abdominal CT scan
- abdominal cramping.
- nausea or vomiting.
What are the side effects of contrast dye after a CT scan?
Iodine-based Contrast Materials
- nausea and vomiting.
- mild skin rash or hives.
How much does a CT scan cost?
In general, you can expect to see CT scan costs that range from $270 on the very low end to nearly $5,000 on the high end. The cost varies depends on the facility, your location, and factors such as whether you pay in cash or bill your insurance provider.