ABB UNITROL 1020 - Page 34

Chapter 3 - Device Overview 
26 3BHS335648 E82 UNITROL 1020 User Manual
Input Function
Description
Secondary Net 1
Selects the Secondary Net for VDC operation.
Binary coding to select 4 net IDs or left side breaker in ring structure.
(Requires Voltage Droop Compensation (VDC) SW)
Secondary Net 2
Selects the Secondary Net for VDC operation.
Binary coding to select 4 net IDs or left side breaker in ring structure.
(Requires Voltage Droop Compensation (VDC) SW)
Reset Alarm
Clear the following alarms: (Requires Double Channel SW)
- Supervision Alarm 1 and 2
- Supervision Trip
- Switch over
- Monitor Alarm 1 and 2
Standby
When the AVR is in Standby mode:
- The excitation output of the AVR is turned off
- Boost is disabled
- Field flashing is off
- Integrator is kept in 1/Kceiling
- All limits are disabled
- No VDC data is transmitted via RS-485.
- The AVR displays Standby as Operation Mode.
- DCH Follow-up
1
operates, only if DCH communication is active; otherwise
the Channel Follow-up operates instead. For more information see
Chapter 3.4.4.4.8 - DCH Follow-Up and 3.4.1.5 - Channel Follow-up.
- Alarm and Trip statuses
1
output their values via digital outputs only if they
are configured to behave like that. For more information see Chapter
3.4.4.4.2 - DCH Supervision.
RC Fieldbus Block
It disables the Fieldbus communication in local operation.
All control registers are reset to default, excitation is switched off if
controlled over Modbus
(Requires Modbus Option)
FCB closed Status
Field circuit breaker closed status active.
External Alarm
Input to use as External Alarm input.
EmergencyExcitationOff
Excitation OFF command, overwrites Excitation ON input and Modbus
control input
PSS enable
Enables PSS. In case digital IO is selected, PSS is blocked when digital
input is not activated
(Requires PSS Option)
Gain Reduction
Reduces the gain of PID tuning (AUTO and PF/VAR) by factor 2
Sync Dead Bus Enable
Enables dead bus synchronization, Unet < 5%
Synchrocheck
Enables synchrocheck function, voltage matching is disabled
Unload VAR
Regulates VAR to 0, command must be activated until VAR reaches 0
Line Charging
Second parameter set for soft start, activated with new digital input "Line
Charging"
3.3.5.1 Polarity
Polarity can be configured for all digital input/output ports separately, and each one has a
separate polarity configuration when configured as input or output. Each DIO port can be
configured as only input or only output at the same time.