ABB Distribution Protection Unit 1500R
2-2
Configuration Settings
9/99
website:www.abb.com/papd
Slow Trip Time
At the time the DPU1500R issues a trip, the “Slow Trip Time” timer starts. This timer is used to determine a “sluggish”
breaker. This setting is adjustable from 5 to 60 cycles in 1-cycle steps. If the timer expires before the DPU1500R
determines an open breaker, a logical output “Slow Breaker” is asserted. If the DPU1500R determines an open breaker
within the “Slow Trip Time” setting, it will reset and re-enable when the breaker is reclosed. The Slow Trip Time is set by
factory default to 18 cycles.
Phase Rotation
Must be selected for proper sequence calculations for the metering. Options are ABC or ACB. This setting directly
affects all directional elements in the relay.
Protection Mode
Select “Fund” if the desired operating quantity for overcurrent protection is the 50 or 60 Hz fundamental current.
Select “RMS” if the desired operating quantity is the unfiltered RMS current which includes the fundamental and all
harmonics up to and including 11th harmonic.
Reset Mode
Select “Instant” if the desired overcurrent reset mode is instantaneous.
Select “Delayed” if the desired overcurrent reset mode is delayed as with electromechanical relays. The reset characteristic
equations are on page 1-9.
ALT1, ALT2 Setting
The Alternate 1 or Alternate 2 settings tables can be enabled or disabled with this setting. If enabled, the ALT settings will
only be active if the logical input ALT1 or ALT2 is mapped via programmable inputs and the logic is “true.” See section 6
for programmable Inputs.
MDT Mode
When the Multiple Device Trip Mode is enabled in the Configuration Settings Table, the DPU1500R’s TRIP and CLOSE
Output Contacts and Breaker Failure Alarm do not depend on the 52A and 52B contact input status. With this mode
enabled, the TRIP output is removed 3 cycles after the fault current drops below 90% of the lowest pickup setting. In the
reclose sequence, the open interval timer and subsequent CLOSE output are initiated only if an Overcurrent TRIP Output
has occurred and the current has dropped below 90% of the lowest pickup setting within the Trip Failure Time setting.
When the MDT mode is enabled, the lockout state is cleared when either of the following occurs:
1) The 52b contact input is open and currents in all three phases are greater than 5% of the 51P pickup setting and the
reset time has expired.
OR
2) The 52b contact input is open and the Targets are reset and the reset time has expired.
The 52b contact input is required for the 79S contact input (Single Shot Recloser Input) and the 79M contact input (Multi-
Shot Recloser Input) functions to initiate a reclosure when the MDT Mode is enabled. When the MDT Mode is enabled,
the Reset Mode is automatically switched to instantaneous.
The MDT mode is disabled in the factory default settings.