1 Answer
The CT (Current Transformer) ratio is a way to describe the relationship between the primary current (the actual current in the power circuit) and the secondary current (the current produced in the secondary winding of the transformer).
It's typically expressed as a ratio like **100:5** or **200:5**, which means that for every 100 (or 200) amperes of current flowing through the primary winding, the secondary winding will produce 5 amperes of current.
### Formula:
\[
CT \, \text{ratio} = \frac{\text{Primary Current}}{\text{Secondary Current}}
\]
### Example:
If the CT ratio is **100:5**, and 100A is flowing through the primary, the secondary current will be 5A. This makes it easier to measure and monitor high current values by scaling them down to a safer, manageable level (like 5A) for measurement instruments or protection devices.
The CT ratio is important for proper meter reading, protection, and control in electrical systems.
It's typically expressed as a ratio like **100:5** or **200:5**, which means that for every 100 (or 200) amperes of current flowing through the primary winding, the secondary winding will produce 5 amperes of current.
### Formula:
\[
CT \, \text{ratio} = \frac{\text{Primary Current}}{\text{Secondary Current}}
\]
### Example:
If the CT ratio is **100:5**, and 100A is flowing through the primary, the secondary current will be 5A. This makes it easier to measure and monitor high current values by scaling them down to a safer, manageable level (like 5A) for measurement instruments or protection devices.
The CT ratio is important for proper meter reading, protection, and control in electrical systems.