losses or even dangerous operation conditions for the process itself. Solution is to
connect a standby power supply for the installation.
The HSABTC function monitors the voltage and frequency of the available supply
feeders and the busbar. Function continuously keeps track on the allowed transfer
direction and the standby incomer(s) readiness for transfer. Bus transfer can
be initiated internally by the function, based on drop on voltage or frequency.
Alternatively external initiation can be used. Once transfer is initiated, sequence for
busbar transfer is executed according to the allowed and enabled transfer modes.
HSABTC also provides support for load shedding as a part of the transfer sequence.
9.12.4
Analog channel configuration
HSABTC has five analog group inputs which must be properly configured.
Table 1600: Analog inputs
Input
Description
U3P1
Voltage from feeder 1
U3P2
Voltage from feeder 2
U3P_BB
Voltage from busbar
I3P1
Current from feeder 1
I3P2
Current from feeder 2
Recommended number of measured voltages is following:
• U3P1: all three phases, can be phase-to-phase or phase-to-ground voltages
• U3P2: all three phases, can be phase-to-phase or phase-to-ground voltages
• U3P_BB: one phase-to-phase voltage
Minimum requirement is to have one voltage connected to each voltage group.
In this case all measurements must be made with the same connection type,
meaning all measurements must be either phase-to-ground or phase-to-phase
voltages. Mixing between different connections types in this case is not allowed.
Measurements must also be made from same phase (phase A or phase AB), mixing
between phases is not allowed.
shows supported voltage connections.
Table 1601: Supported voltage connections
U3P1
U3P2
U3P_BB
Note
3 phase-to-phase
3 phase-to-phase
1 phase-to-phase
Recommended
3 phase-to-ground
3 phase-to-ground
1 phase-to-phase
Recommended
3 phase-to-phase
3 phase-to-phase
1 phase-to-ground
Not recommended
Table continues on the next page
Control functions
1MRS759142 F
1760
REX640
Technical Manual