ABB REF615 L User Manual

The user can define the delayed inverse reset time characteristics with the
following formula using the set Curve parameter D.
t s
D
I
I
k[ ] =
>






−














⋅
2
1
A060817 V3 EN (Equation 104)
t[s] Reset time (in seconds)
k set Time multiplier
D set Curve parameter D
I Measured current
I> set Start value
11.2.3 Inverse-timer freezing
When the BLOCK input is active, the internal value of the time counter is frozen at
the value of the moment just before the freezing. Freezing of the counter value is
chosen when the user does not wish the counter value to count upwards or to be
reset. This may be the case, for example, when the inverse-time function of an IED
needs to be blocked to enable the definite-time operation of another IED for
selectivity reasons, especially if different relaying techniques (old and modern
relays) are applied.
The selected blocking mode is "Freeze timer".
The activation of the BLOCK input also lengthens the minimum
delay value of the timer.
Activating the BLOCK input alone does not affect the operation of the START
output. It still becomes active when the current exceeds the set Start value, and
inactive when the current falls below the set Start value and the set Reset delay
time has expired.
Section 11 1YHT530004D05 D
General function block features
826 615 series
Technical Manual

ABB REF615 L Specifications

General

Type	Feeder Protection Relay
Rated Frequency	50/60 Hz
Weight	Approx. 1.5 kg
Communication Protocols	IEC 61850, Modbus RTU, DNP3
Protection Functions	Overcurrent, Earth fault, Thermal overload, Under/Over voltage, Under/Over frequency
Enclosure	IP20