Allen-Bradley Rockwell Automation 857 User Manual page 115

Table 3.39 – Measured and recorded values of synchrocheck stages SyC1, SyC2 (25)
Parameter
Measured df
values
dU
UState
SState
ReqTime
f
fy
U12
U12y
Recorded ReqCntr
values
SyncCntr
FailCntr
f
fy
U12
U12y
dAng
dAngC
EDly
Please note that the labels (parameter names) change according to the voltage selection.
The following signals of the both stages are available in the output
matrix and the logic: "Request", "OK" and "Fail". The "request"-
signal is active, when a request has received but the breaker is not
yet closed. The "OK"-signal is active, when the synchronizing
conditions are met, or the voltage check criterion is met. The "fail"-
signal is activated, if the function fails to close the breaker within the
request timeout setting. See below the figure.
Protection Functions
Values Unit
- Hz Measured frequency
difference
- % Un / deg Measured voltage amplitude
and phase angle difference
- - Voltage status (e.g. DD)
- - Synchrocheck status
- - Request time status
- Hz Measured frequency
(reference side)
- Hz Measured frequency
(comparison side)
- % Un Measured voltage (reference
side)
- % Un Measured voltage
(comparison side)
- - Request counter
- - Synchronising counter
- - Fail counter
- Hz Recorded frequency
(reference side)
- Hz Recorded frequency
(comparison side)
- % Un Recorded voltage (reference
side)
- % Un Recorded voltage
(comparison side)
- Deg Recorded phase angle
difference, when close
command is given from the
function
- Deg Recorded phase angle
difference, when the circuit-
breaker actually closes.
- % The elapsed time compared to
the set request timeout
setting, 100% = timeout
3-65
Description
857-UM001A-EN-P – July 2009