SECRSYN has two analog group inputs which must be properly configured.
| Input | Description |
|---|---|
| U3P1 | Three-phase voltages (bus side) |
| U3P2 | Three-phase voltages (line side) |
There are a few special conditions which must be noted with the configuration.
| Condition | Description |
|---|---|
| U3P1 connected to real measurements | The function requires that at least two voltage channels from the bus side are connected. i.e. UL1; UL2, UL1; UL2; UL3 for UTVTR function block |
| U3P2 connected to real measurements | The function requires that one voltage channel from the line side is connected to Analog 4. i.e. UL1, UL1; UL2, UL1; UL2; UL3 for UTVTR function block |
When a single voltage channel is connected on the line side, the VT connection setting of the U3P2 source UTVTR defines whether ph-to-earth or ph-to-ph voltages are used from both sides in checking the conditions. If at least two voltage channels are connected on line side, ph-to-ph voltages are used from both sides in checking the conditions regardless of the VT connection settings of the source UTVTRs.
Improper analog channel configuration causes a validation error if the analog channels are not completely configured or they do not match with certain settings.
For troubleshooting, check the contents of this chapter and also the preprocessing blocks in this document. The configuration can be written to the protection relay once the mismatch is corrected.