How to choose the right model of current transformer?

1. Clarify the application scenario
Measurement purpose: If used to measure current or electric energy, a current transformer with higher accuracy should be selected, such as 0.2 or 0.5.
Protection purpose: If used for relay protection, a protection-level current transformer should be selected, such as 5P or 10P.
Metering purpose: For occasions where electric energy is measured, it is recommended to select a 0.2S or 0.5S current transformer.
2. Selection of rated current
The rated primary current should be selected according to the maximum load current during normal operation of the line, usually 1.0~1.3 times the load current.
If the load current variation range is large, a current transformer with multiple transformation ratios can be selected.
3. Selection of rated voltage
The rated voltage should not be less than the rated voltage of the line at the installation point.
4. Accuracy level
The accuracy level of the current transformer used for measurement can be selected as 0.5 or 0.2.
The accuracy level of the current transformer used for protection can be selected as 5P or 10P.
5. Installation method
Choose a suitable installation method according to the actual installation environment, such as through-type, pillar type, busbar type, etc.
If the installation space is limited, a through-type current transformer can be selected.
6. Rated capacity
The rated capacity of the current transformer should be greater than the actual secondary load, and the actual secondary load should be 25%~100% of the secondary rated capacity.
7. Environmental conditions
Considering factors such as ambient temperature and humidity, select a suitable insulation method and protection level.
8. Other precautions
The secondary circuit must be grounded to ensure safety.
When choosing, communicate with the manufacturer to understand the performance characteristics of the product.