Toshiba GR200 Series Instruction Manual page 1275

10.2.17 Supervision of voltage in negative-sequence (V2 error)
Applying the voltage in negative-sequence is calculated regularly using three-phase voltages
measured in the IED. If Equation (10.2-3) is satisfied over 10 seconds, the supervision function
determines that a failure occurs in the input circuit.
The voltage in negative sequence can be used to detect a failure within the voltage input
circuit in high sensitivity. It facilitates the detection of the incorrect phase sequence if cables
are connected irregularly.
1.
where,
a = Phase shift operator of 120
Error level
(i)
Generally, the default error level has been set at level 3 (Minor error), but the user can program
the level using setting [CHK_V2:LVl]; then, set On for the setting [CHK_V2:Sw]. The time for
the detection can be set using [CHK_V2:Timer], which is set for 15 seconds as default. After
the error is cleared, resetting will be performed after the elapse of setting time.
Error message
(ii)
When the function operates and detects error, an error message can be shown at the LED and
the LCD screen.
Table 10.2-35 Error messages provided by the supervisor in CHK_V2
Message and level
V2 error
Error level
Table 10.2-36 Detailed information in Hexadecimal in CHK_V2
Display area
N/A
2
| V |
+ �� V + aV
a b c
3
Meaning of the information
Detection of the negative-sequence voltage
Minor error (Level 3)
Meaning of the detailed information
(No information is displayed)
- 1252 -
≥ 6.35 (V)
6F2S1914 (0.49)
(10.2-3)
GRL200 (Soft 033 & 037)