Buy Quality and Durable Current Instrument Transformer

Current Instrument Transformer is very important for complex power systems and undertakes the task of converting high primary current into standardized low secondary current. Ceho's products are structurally robust and highly accurate, meeting international standards such as IEC 61869 and ANSI/IEEE C57.13.

Can the Secondary Side of Current Transformer Be Open Circuit During Operation?

We can tell you very directly, absolutely not. Secondary side open circuit is extremely dangerous. When the primary side current flows in the case of an open circuit on the secondary side, the current transformer is equivalent to a high-rate step-up transformer. The excitation impedance becomes the only load, resulting in deep core saturation. This induces extremely high voltages at the open secondary terminals, posing a serious electric shock and arc flash hazard to personnel and possibly permanently breaking down the insulation. If the secondary-side terminals are not connected to the load, they must be short-circuited using short-circuit blocks or special terminals.

How to Determine the Correct Load of Current Transformer?

The total load on the secondary side is the sum of the loads of all connected equipment plus the load of the interconnecting conductors. Ceho can help you calculate this, or you can calculate it yourself based on the following terms.

First, add up the volt-ampere requirements of all devices.

The conductor load is then calculated using the following formula: Load = Isn² * Rwire, where Rwire is the total loop resistance of the cable. For the 5A secondary side, wire loads can be considerable when routed over long distances.

To ensure accuracy, the rated output of the current transformer must be greater than the calculated total load.