The differences between Current Transformer (CT) and Potential Transformer (PT) are given below:
| S.No. | Current Transformer (CT) | Potential Transformer (PT) |
| 1. | It is connected in series with the power circuit. | It is connected in parallel with the power circuit. |
| 2. | Its secondary is connected to an Ammeter. | Its secondary is connected to a Voltmeter. |
| 3. | Its secondary work always in short circuit condition. | Its secondary work always in open circuit condition. |
| 4. | CT primary current depends on power circuit current. | PT primary current depends on the Secondary burden. |
| 5. | CT primary current and excitation vary over a wide range with the change of power circuit current. | PT primary current and excitation are restricted to a small range. |
| 6. | In this transformer, one terminal of the secondary is earthed to avoid the insulation break down. | In this transformer, one terminal of secondary can be earthed for safety. |
| 7. | Its secondary never be open circuited under operation. | Its secondary can be open under operation. |
