Application Guide - NP900 Series
270 (504
)
A996A
3.3.5
U
NDER CURRENT
I<
(37)
Undercurrent function (NUC) is used for monitoring motor loading especially in conveyor
type of applications. If the motor load is suddenly lost it indicates problems in the actual
load rather than in the motor itself. In conveyor application this may indicate broken belt
and the motor should be turned off quickly in order to avoid further problems. Other
reasons may be mechanical breakdowns of the motor used apparatus. In some cases this
undercurrent function output may be also used for the automation system to indicate that
the device has finished work load and is ready for next batch. To operate this function
needs the internally connected motor status running signal. This is due that the operation
is blocked when the motor is not running.
Outputs of the function are Start Trip and Blocked signals. Setting parameters are static
inputs for the function which are changed only by user input in the setup phase of the
function. Non-directional undercurrent function utilizes total of eight separate setting
groups which can be selected from one common source.
The function can be operating on instant or time delayed mode. In time delayed mode the
operation can be set to operate on definite set time delay.
Inputs for the function are setting parameters and measured and pre-processed current
magnitudes and binary input signals. Function outputs START, TRIP and BLOCKED
signals which can be used for direct IO controlling and also for user logic programming.
The function registers its operation into 12 last time-stamped registers and also generates
general time stamped ON/OFF events to the common event buffer from each of the three
output signal. In instant operating mode the function outputs START and TRIP events
simultaneously with equivalent time stamp. Time stamp resolution is 1ms. Function
provides also cumulative counters for START, TRIP and BLOCKED events.
Содержание NP900 Series
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Страница 49: ...Application Guide NP900 Series 49 504 A996A Figure 3 2 1 3 25 Definite time operating characteristics...
Страница 50: ...Application Guide NP900 Series 50 504 A996A Figure 3 2 1 3 26 IEC predefined characteristics NI VI LTI and EI...
Страница 52: ...Application Guide NP900 Series 52 504 A996A Figure 3 2 1 3 28 IEEE predefined characteristics EI MI and VI...
Страница 243: ...Application Guide NP900 Series 243 504 A996A Figure 3 3 2 1 122 NPS biased thermal trip curves with kNPS values 7 and 10...
Страница 491: ...Application Guide NP900 Series 491 504 A996A 3 7 5 6 SETTING EXAMPLE...
Страница 504: ...Application Guide NP900 Series 504 504 A996A A996A...