Cold Load (51C); Figure 2-4 Cold Load - Siemens 7SR21 Manual

2.4

Cold Load (51C)

Voltage Inputs:
Current Inputs:
Disable:
Map Pickup LED:
The CB must be open for more than the Cold Load Pick-up Time to allow testing of this function. It may be
convenient to reduce this setting to suit the test procedure. If the CB is open throughout the tests, the Cold Load
protection settings can be tested provided that the current is not allowed to fall below the level of the Reduced
Current Level for more than the Reduced Current Time during testing. It may be convenient to set the Reduced
Current setting to Disabled for the duration of the test. The Cold Load Active output is provided and can be used
as an indication during testing.
©2010 Siemens Protection Devices Limited
7SR21 & 7SR22 Argus Commissioning and Maintenance

Figure 2-4 Cold Load

V (V ), V (V ), V (V ) for directional elements
L1 A L2 B L3 C
I (I ), I (I ), I (I ),
L1 A L2 B L3 C
51V, 46, 49, 50CBF, 79
51-n - Self Reset
Chapter 6 Page 21 of 69