The Secondary Burden test is used to analyze the effect of a resistive burden on the behaviour of the CT. Within the ST-3/XT3 is an array of high accuracy resistors that can be, with the use of electromechanical relays, added to the secondary path of the CT to cause burden.
How does it work?
There are no prerequisites for running the Secondary Burden test.
By applying a resistance in series with the CT, the tester can analyze the maximum burden under which CT can still operate efficiently.
- The available burden values are 0.1, 0.2, 0.5, 1.0, 2.0 and 4.0 Ohms.
- The Secondary Burden test steps through the available burden values and measures the primary (if an accessory is connected) and secondary current values.
- This process is repeated for each of the service lines (A, B and C).
- The test automatically stops when it reaches the maximum burden value that can be applied on the CT, as configured in the CT setup interface prior to starting the test.
