Siemens 7SR224 - Section 3: Supervision Functions; CB Fail (50 BF)

7SR224 Argus Commissioning & Maintenance Guide
©2010 Siemens Protection Devices Limited Chapter 6 Page 53 of 73
Section 3: Supervision Functions
3.1 CB Fail (50BF)
Figure 3-1 CB Fail
Voltage Inputs: n/a
Current Inputs: I
L1
(I
A
), I
L2
(I
B
), I
L3
(I
C
),
Disable:
Map Pickup LED: 50BF-n - Self Reset
The circuit breaker fail protection time delays are initiated either from:
A binary output mapped as Trip Contact in the OUTPUT CONFIG>BINARY OUTPUT CONFIG menu,
or
A binary input mapped as 50BF Ext Trip in the INPUT CONFIG>INPUT MATRIX menu.
Apply a trip condition by injection of current to cause operation of a suitable protection element. Allow current to
continue after the trip at a level of 110% of the 50BF Setting current level on any phase. Measure the time for
operation of operation of 50BF-1 Delay and 50BF-2 Delay. Repeat the sequence with current at 90% of the 50BF
Setting current level after the element trip and check for no CB Fail operation.
50BF Setting (xIn) Test Current 50BF-1 Delay…………… 50BF-2 Delay……………….
(110%)………….
(90%)…………... No Operation □ No Operation □