Arcteq AQ-M255, Инструкция по эксплуатации

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The function can operate on instant or time-delayed mode. In the time-delayed mode the operation can
be selected for definite time (DT) or for inverse definite minimum time (IDMT); the IDMT operation
supports both IEC and ANSI standard time delays as well as custom parameters. The function includes
the checking of CT saturation which allows the function to start and operate accurately even during CT
saturation.
The operational logic consists of the following:
• input magnitude selection
• input magnitude processing
• saturation check
• threshold comparator
• block signal check
• time delay characteristics
• output processing.
The inputs for the function are the following:
• operating mode selections
• setting parameters
• digital inputs and logic signals
• measured and pre-processed current magnitudes.
The function's outputs are START, TRIP and BLOCKED signals which 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 three (3) output signals. In the instant operating mode the
function outputs START and TRIP events simultaneously with an equivalent time stamp. The time stamp
resolution is 1 ms. The function also provides a resettable cumulative counter for the START, TRIP and
BLOCKED events.
The following figure presents a simplified function block diagram of the non-directional earth fault
function.
Figure. 5.3.3 - 35. Simplified function block diagram of the I0> fucntion.
A AQ Q-M255 -M255
Instruction manual
Version: 2.06
68 © Arcteq Relays Ltd
IM00020