Other Considerations: Potential Transformer nameplate details and other details are discussed here.
In the previous example the CT was accurate to within 0.3% from 600 amps all the way to 1200 amps. Accuracy classes of measuring instruments CHAPTER I 1 General 1.1. Cahier Technique Schneider Electric no. We can use a Class 0.15S, 600:5 CT with rating factor of 4 to create another example. Selecting ANSI Class Metering Current Transformers 142 H B0.1 B0.2 B0.5 B0.9 B1.8 0.3 0.6 0.9 1.2 2.4 ANSI METERING CLASS @ 60 Hz CURRENT RATIO 50:5 PERCENT ACCURACY BURDEN IN OHMS TURNS RATIO One of the most common uses of current transformers are … 194 / p.2 Lexicon If: maximum through current crossing a protected area. For a given accuracy class, the PT characteristics need to lie within the bounds shown on the table above from all voltages between 90% to 110%. Accuracy: ±1.0% at 100% and 120% of rated primary current; Accuracy: ±1.5% at 20% of rated primary current; Accuracy: ±3.0% at 5% of rated primary current; Phase angle: ±1.0 degrees (60 minutes) at 100% and 120% of rated current This characteristic makes them suitable for use with overcurrent protection relays. Is: current threshold setting. RE: CT ratios randyman (Electrical) 20 Apr 09 18:55 I assumed it was a window type by the class designation alone, 2.5L, which indicates low reactance design with distributed turns.
Class Rating. CT Accuracy Classes CT4 ANSI Accuracy Classes Current Transformers are defined by Accuracy Classes depending on the application.
The CT accuracy class is comprised of a number-letter-number combination as set forth in ANSI C57.13 and is broken into three parts: rated ratio accuracy rating; class rating; maximum burden • Metering Accuracy CT’s are used where a high degree of accuracy is required from low -load values up to full-load of a system. IEEE C57.13-2016, Table 8: Standard accuracy class for metering service and corresponding limits of transformer correction factors* Accuracy class Voltage Transformers Current Transformers 90% to 100% rated voltage 100% rated current+ 10% rated current 5% rated current Min Max Min Max Min Max Min Max 0.15S - - 0.9985 1.0015 - - 0.9985 1.0015 2. For example, a CT with an accuracy class of 0.3B0.1 is certified by the manufacturer to be accurate to within 0.3 percent of its rated ratio value for a primary current of 100 percent of rated ratio. The second part of the CT Accuracy Class is a letter that designates the application for which the CT … 2.3. Pn: (=Rn 2In).Accuracy power of the CT. The standard grade CT meets or exceeds the accuracy class 1.0 limits. what is current transformer accuracy class (iec61869-2, iec60044-1, ieee/ansi c57.13)?
And below 60 amps there was no guaranteed accuracy.