Figure. 5.3.23 - 137. NPS-biased thermal trip curves with k
NPS
value of 10.
Function inputs and outputs
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 machine thermal overload protection function uses a total of eight (8) separate setting groups
which can be selected from one common source.
The operational logic consists of the following:
• input magnitude processing
• thermal replica
• comparator
• block signal check
• output processing.
The inputs for the function are the following:
• setting parameters
• measured and pre-processed current magnitudes.
The function's 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
output signals. The time stamp resolution is 1 ms. The function also provides a resettable cumulative
counter for the TRIP, ALARM 1, ALARM 2, INHIBIT and BLOCKED events.
The following figure presents a simplified function block diagram of the machine thermal overload
protection function.
A
AQ
Q-M255
-M255
Instruction manual
Version: 2.06
240
© Arcteq Relays Ltd
IM00020
Summary of Contents for AQ-M255
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