ABB RELION REF615R, Technical Manual

Page: 577 / 664

immediately when the current exceeds the set Pickup value and the
PICKUP
output is
activated.
The
TRIP
output of the component is activated when the cumulative sum of the integrator
calculating the overcurrent situation exceeds the value set by the inverse-time mode. The
set value depends on the selected curve type and the setting values used. The curve scaling
is determined with the
Time multiplier setting.
There are two methods to level out the inverse-time characteristic.
• The Minimum trip time setting defines the minimum operating time for the IDMT
curve, that is, the operation time is always at least the Minimum trip time setting.
• Alternatively, the IDMT Sat point is used for giving the leveling-out point as a
multiple of the Pickup value setting. (Global setting: Configuration/System/IDMT
Sat point ). The default parameter value is 50. This setting affects only the overcurrent
and ground-fault IDMT timers.
IDMT operation time at currents over 50 x In is not guaranteed.
1MRS240050-IB C
Section 12
General function block features
REF615R 571
Technical Manual