Application Guide - NP900 Series
61 (504
)
A996A
3.2.2.4
O
PERATING TIME CHARACTERISTICS FOR TRIP AND RESET
The operating timers’ behavior of the function can be set for trip signal and also for the
release of the function in case the pick-up element is reset before the trip time has been
reached. There are three basic operating modes available for the function. Instant
operation gives the trip signal with no additional time delay simultaneously with start
signal. Definite time operation (DT) will give trip signal with user given time delay
regardless of the measured current as long as the current is above the Iset value and thus
pick-up element is active (independent time characteristics). Inverse definite minimum
time (IDMT) will give the trip signal in time which is in relation of the set pick-up current
Iset and measured current Im (dependent time characteristics). For the IDMT operation is
available IEC and IEEE/ANSI standard characteristics as well as user settable
parameters. Inverse operation time delay also includes minimum pick-up delay which is
similar to definite operation time. The minimum pick-up delay for IDMT is freely
configurable and the operation time will never go below this.
In the following table are presented the setting parameters for the function time
characteristics.
Table 3.2.2.4-47 Operating time characteristics setting parameters.
Name
Range
Step
Default
Description
Delay Type
DT
IDMT
-
DT
Selection of the delay type time counter.
Selection possibilities are dependent
(IDMT, Inverse Definite Minimum Time)
and independent (DT, Definite Time)
characteristics.
Definite operating
time delay
0.000…1800.000 s 0.005 s
0.040 s
Definite time operating delay. Setting is
active and visible when Delay Type is
selected to DT.
When set to 0.000 s the stage operates as
instant (PIOC, 50) stage without added
delay. When the parameter is set to 0.005
– 1800 s the stage operates as
independent delayed (PTOC, 51).
Delay curve series IEC
IEEE
Non standard
-
IEC
Setting is active and visible when Delay
Type is selected to IDMT.
Delay curve series for IDMT operation
following either IEC or IEEE/ANSI
standard defined characteristics.
Non-standard characteristics include RI
and RD type characteristics
Delay
characteristics
IEC
NI
EI
VI
LTI
Param
-
NI
Setting is active and visible when Delay
Type is selected to IDMT.
IEC standard delay characteristics.
Normally Inverse, Extremely Inverse, Very
Inverse and Long Time Inverse
characteristics. Param selection allows the
tuning of the constants A and B which
allows setting of characteristics following
the same formula as the IEC curves
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...
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