| Model | Functional Details | Cabinet Style |
| A21T | Transformer Protection Relay | CSE |
| ANSI Code | Description |
| 46 | Negative Phase Sequence Protection |
| 49 | Thermal Overload Protection |
| 50 | Instantaneous/Definite time phase over current Protection |
| 51 | Inverse Time Phase Over current Protection |
| 50N | Instantaneous/Definite Time Ground Over current Protection |
| 51N | Inverse Time Ground Over current Protection |
| 64G | High Impedance Restricted Earth Fault Protection |
| 50BF | Breaker Failure |
| 86 | Lockout (Trip command) |
| 87T | Two Winding Phase Differential Protection |