When I select a Current Transformer for a 10kV or 35kV system, the first step is nailing the transformation ratio. You want the primary rated current to be just above the maximum load current—usually about 1. Correct CT selection and application directly influence: Billing accuracy: Misapplied ratio or accuracy class can cause revenue leakage or disputes. 10 (not exceeding 65K or 105 degrees C for bare busbars). How do I check busbar short circuit withstand? Busbar short circuit withstand has two components: thermal and electrodynamic. Thermal withstand ensures the busbar temperature does. Beckhoff®, TwinCAT®, TwinCAT/BSD®, TC/BSD®, EtherCAT®, EtherCAT G®, EtherCAT G10®, EtherCAT P®, Safety over EtherCAT®, TwinSAFE®, XFC®, XTS® and XPlanar® are registered trademarks of and licensed by Beckhoff Automation GmbH. Other designations used in this publication may be trademarks whose use by. This is the ratio of secondary to primary winding turns: K n = N s /N p = I pr /I sr Go back to Content Table ↑ This is the highest level of rms primary fault current which the CT can endure, both thermally and dynamically, for 1 second without damage. It's configured with 5 multi-function energy meters (2VA/phase each), 3 busbar protection and control devices (0.
