Section 4 1MDU07212-YN Rev. D
Protection and Control Function
36 REF601 / REJ601 / REM601
Application Manual
4.13.2 Principle of operation
This module counts the operation time. When current in any phase exceeds 0.12xIn
the counter is activated and starts counting. The count is continuously added to the
time duration until all current drops below 0.12xIn. The unit of time duration count
for RUN_TIME is hour. The value is available through the monitored data view.
The RUN_TIME output is a continuously increasing value and it is stored in a non-
volatile memory.
Resetting of the counter can be done by changing the setting value. As soon as
new setting is saved the counter will get reset and will be registered as an event.
The counter will count up to 2
16
after which counter will overflow and restart from
0.
Table 21: Setting ranges counter
Initial value of the counter at the start
of IED, ‘Value’
Binary input configured at
PULSE_INPUT, ‘BIconf’
1…4 (1=BI1, 2=BI2, 3=BI3, 4=BI4)
‘-‘ no selection if counter selection not needed
4.14 Protection characteristics
4.14.1 Time / Current characteristics
Relay offers three-stage overcurrent and two stage earth-fault protection functions.
The low-set stage of overcurrent protection and earth-fault protection are equipped
with standard Inverse Definite Minimum Time (IDMT) characteristics – (Normal
Inverse (NI), Extreme Inverse (EI), Long Inverse (LI), and Very Inverse (VI))
along with definite time (DT) characteristics for better co-ordination with rest of
the network. Additionally special characteristic curve RI is also provided. The
high stage and instantaneous stage for over current protection and high stage earth
fault protection come with DT characteristics.
When IDMT characteristic has been selected, the operating time of the stage will
be a function of the current; the higher the current, the shorter the operating time.
The stage includes ten different time/current curve sets – four according to the BS
142 and IEC 60255 standards namely normal inverse, very inverse, extremely
inverse, longtime inverse, four according ANSI C37.xxx standard namely moderate
inverse, normal inverse, very inverse, extremely inverse and one special curve,
named RI type curve along with DT characteristics.
4.14.2 IEC 60255-3 IDMT characteristic
The relationship between current and time for standard normal inverse, very
inverse, extremely inverse and long-time inverse complies with the BS 142.1966
and IEC 60255-3 standards and can be expressed as follows:
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