ABB Relion 670 series - Password Policies and Requirements

The DeadbandtDiff setting range is ±200-1000 μs. If the accumulated time delay of
up to four changes is greater then the set value for DeadbandtDiff but below the set
value for MaxtDiffLevel, no action is taken. When the fifth time delay change
occurs, the protection function is blocked even if the maximum deviation is not
reached. This restriction is included because of measuring inaccuracy with too
many consecutive, accumulated time delay changes. After blocking, the
communication set-up must be checked before restarting.
IEC10000062 V1 EN-US
Figure 6: Setting DeadbandtDiff in PCM600
Figure 7 shows an oscillogram example of deadband, measured change in time
delay and scattering (deviation in calculation) within the set DeadbandtDiff value.
D
dt
IEC07000226-1-en.vsdx
IEC07000226 V1 EN-US
Figure 7: An oscillogram example showing deadband (D), measured change
in time delay (dt) and scattering
D
DeadbandtDiff = ±200 μs
dt Measured time delay change = ±200 μs
1MRK 505 382-UEN B Section 2
Telecommunication networks and line differential protection
Communication set-up 670/650 series 2.2 19
Application Guide