Arcteq AQ-S215, Instruction Manual

Page: 83 / 289

In the current-dependent mode the function constantly measures phase current magnitudes and the
selected residual current. In the signal-dependent mode any of the device's binary signals (trips, starts,
logical signals etc.) can be used to trigger the function. In the digital output-dependent mode the
function monitors the status of the selected output relay control signal. The blocking signal and the
setting group selection control the operating characteristics of the function during normal operation,
i.e. the user or user-defined logic can change function parameters while the function is running.
The outputs of the function are CBFP START, RETRIP, CBFP ACT and BLOCKED signals. The circuit
breaker failure protection function uses a total of eight (8) separate setting groups which can be
selected from one common source. Additionally, the function's operating mode can be changed
via setting group selection.
The operational logic consists of the following:
• input magnitude processing
• input magnitude selection
• threshold comparator
• block signal check
• time delay characteristics
• output processing.
The inputs of the function are the following:
• operating mode selections
• setting parameters
• digital input signals
• measured and pre-processed current magnitudes.
The function' output signals can be used for direct I/O controlling and user logic programming. The
function generates general time-stamped ON/OFF events to the common event buffer from each of the
two (2) output signals. The time stamp resolution is 1 ms. The function also provides a resettable
cumulative counters for RETRIP, CBFP, CBFP START and BLOCKED events.
The following figure presents a simplified function block diagram of the circuit breaker failure protection
function.
Figure. 5.3.1 - 68. Simplified function block diagram of the CBFP function.
A AQ Q-S215 -S215
Instruction manual
Version: 2.04
82