The terms Class in reference to instrument transformers and meters is defined as the maximum continuous current the meter is capable of handling, abbreviated by the letters “CL.”
Common meter class ratings as defined by IEEE are below:
| Class | What it implies |
|---|---|
| CL 100 | 100 A—Self-contained |
| CL 200 | 200 A—Self-contained |
| CL 320 | 320 A—Self-contained |
| CL 480 | 480 A—Self-contained |
| CL 2 | 2 A—Transformer-rated |
| CL 10 | 10 A—Transformer-rated |
| CL 20 | 20 Amps—Transformer-rated |