Current Transformer Supervision (60Cts); Figure 3-3 Current Transformer Supervision - Siemens 7SR21 Manual

3.3

Current Transformer Supervision (60CTS)

Voltage Inputs:
Current Inputs:
Disable:
Map Pickup LED:
The presence of NPS current without NPS voltage is used to indicate a current transformer failure.
Apply normal 3P balanced current with a crossover of any two phases at a level above 60CTS Inps setting.
Measure the delay to operation.
Apply 3P balanced voltage with a similar phase crossover to the current. Increase the applied 3P voltage until the
CTS element resets.
Reduce the 3P voltage to cause CTS operation again. Gradually reduce the 3P current until the element resets.
©2010 Siemens Protection Devices Limited
7SR21 & 7SR22 Argus Commissioning and Maintenance

Figure 3-3 Current Transformer Supervision

V (V ), V (V ), V (V
L1 A L2 B L3
I (I ), I (I ), I (I ),
L1 A L2 B L3 C
51N, 46IT, 46DT, 46BC
60CTS - Self Reset
) for directional elements.
C
Chapter 6 Page 61 of 69