What is the class of current transformer?
What is the class of current transformer?
Current transformers are divided up into classes according to their precision. Standard precision classes are 0.1; 0.2; 0.5; 1; 3; 5; 0.1 S; 0.2 S; 0.5 S. The class sign equates to an error curve pertaining to current and angle errors. The precision classes of current transformers are related to the measured value.
What is a protection current transformer?
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.
What is protection class CT?
Protection CT The secondary current is used to operate a protective relay which can isolate part of the power circuit experiencing a fault condition. Core material for this type of CT has high saturation level and is normally made from silicon steel.
What is class of CT and PT?
The standard accuracy classes of current transformer as per IS-2705 are 0.1, 0.2, 0.5, 1, 3 and 5 for metering CT. Here in the protection current transformer, 5 P means 5%, 10 P means 10 %, and 15 P means 15 % error and ′P′ stands for protection.
What is main purpose of current transformer?
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.
How do I choose a transformer?
- Step 1: Determine the KVA, Amperes or wattage required by the load. Determine the KVA, Amperes or wattage required by the load.
- Step 2: Find out the supply voltage.
- Step 3: Determine the voltage required by the load.
- Step 4: What is the frequency of the supply source?
- Step 5: Determine the Marcus transformer model number.
What are the different types of protection current transformers?
The classes are defined as class 0.1, class 0.2,class 0.5,class 1, class 3, class 5. There are two types of Protection current transformers available. One is the Normal protection CTs and the other is Special Purpose Protection CTs.
What are the protection class ratings of Transformers?
Typical protection class CT ratings are 5P10, 5P15, 5P20. A 200/1 A CT has a protection class rating of 5P15. The secondary current is guaranteed to be linear up to 15 times the rated primary current.
What is the difference between class PS Transformers?
Class PS transformers are the special purpose protective current transformers. These are used where the required characteristics of the current transformers cannot be conveniently expressed in terms of the ordinary protection current transformers like Class 5P, 10P and 15P current transformers.
Which is the best class of current transformers?
Class PX is the definition in IEC 60044-1 for the quasi-transient current transformers formerly covered by class X of BS 3938, commonly used with unit protection schemes. Class PX type CTs are used for high impedance circulating current protection and are also suitable for most other protection schemes. IEC 60044-6