Functionality - ABB 615 series Technical Manual

Section 5
Protection related functions
5.8.3
5.8.4
832

Functionality

The switch onto fault function SOTF provides an instantaneous trip or a time delayed trip
when closing the breaker while a fault exists.
SOTF is activated when the CB_CL_CMD circuit breaker closing command is set high.
The function has PICKUP and PICKUP_DLYD inputs for immediate or delayed pickup
operation respectively.
The function contains a blocking functionality. It is possible to block function outputs and
the reset timers, if desired.
Operation principle
The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are "Enable" and "Disable".
The operation of SOTF can be described by using a module diagram. All the modules in
the diagram are explained in the next sections.
CB_CL_CMD
PICKUP
Trigger
PICKUP_DLYD
BLOCK
GUID-E9DDE27C-C5BA-46BA-B508-A4147781CC75 V1 EN
Figure 424: Functional module diagram
Trigger
This module is used for detecting possible fault immediately after closing the circuit
breaker. An external protection function for example, 51P, 50P, 50P-3 or 51N, 51G, 50N,
50G, 50N-3, 50G-3 is used for fault indication. The PICKUP and PICKUP_DLYD inputs
are available for feeding the detected fault.
• PICKUP input is used when it is required to enable SOTF control immediately after
protection function indicates a fault.
• PICKUP_DLYD input is used when time delayed SOTF control enabling is needed.
In this case, the delay can be set with a Trip delay time setting.
SOTF
TRIP
control
1MAC059074-MB A
615 series ANSI
Technical Manual