Selecting the correct 11kV current transformer is essential for accurate metering, electrical monitoring, and relay protection.
For switchgear manufacturers and electrical contractors, voltage rating alone is not enough to determine the right CT.
Six Parameters to Check
Before purchasing an 11kV current transformer, verify:
- Rated system voltage and insulation level
- Primary and secondary current ratio
- Metering and protection accuracy classes
- Rated secondary burden (VA)
- Short-time thermal and dynamic current ratings
- Mounting dimensions and terminal arrangements
For example, a 600/5A CT has a nominal current transformation ratio of 120:1.
However, the required primary current should be selected according to the actual circuit design.
VABO LZZBJ9-11 Current Transformer
The VABO LZZBJ9-11 is designed for suitable indoor 11kV power distribution applications.
According to VABO product documentation, the series offers:
- Rated secondary current: 5A or 1A
- Documented insulation level: 12/42/75kV
- Metering and protection accuracy configurations
- Indoor installation
The final configuration must be verified against the approved product datasheet.
Why Installation Dimensions Matter
Switchgear manufacturers should verify the CT's mounting dimensions, conductor arrangement, and secondary terminal accessibility before confirming an order.
A correct electrical rating does not guarantee mechanical compatibility.
Work With VABO
Established in 1985, Zhejiang VABO Transformer Co., Ltd. supplies instrument transformers for power distribution applications.
Send VABO your switchgear drawings, current ratio, accuracy class, and quantity to request technical selection support and a quotation.
