ABB DPU 1500R Instruction Book page 171

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Programming the Bus DPU1500R/2000R
The bus DPU1500R/2000R provides high-speed tripping for bus faults, and local backup protection for feeder faults not
cleared by their primary protective relays. The bus fault protection is accomplished with the 50-1 phase and ground
instantaneous elements. A 50 ms time delay is added to coordinate with the blocking signal from the feeder DPUs.
This blocking signal is from the pickup alarms (PUA) of each down stream feeder. Each PUA is isolated by an auxiliary
relay, PA.
Local backup for feeder faults is accomplished with the 50-2 phase and ground instantaneous elements. A 0.3 second
time delay is recommended to coordinate with the down stream feeder instantaneous elements. The 50-2 element
should not be used for backup protection with feeder schemes (such as fuse saving schemes) that disable instantaneous
elements in a multi-shot recloser sequence.
Follow these steps to program MDT mode on the DPU1500R/2000R on the bus breaker:
1. Enable Multiple Device Trip mode (MDT Mode) in the Configuration Settings.
2. Set the 50P-1 and 50N-1 functions in
the Primary Settings table as follows
(see Figure 13-10):
a. Set the curve to "Definite Time."
b. Select the desired pickup.
c. Set the Time Delay to 0.05 sec.
d. Disable the 79 reclosing function
by setting the 79-1 open time to
"Lockout".
3. To allow the feeder DPU1500R/2000R
relays to control the high-speed
instantaneous functions of the bus
relay, map the 50-1 element to a
physical input in the Programmable
Inputs screen (Figure 13-12). Remove
the 50-1 elements from the Master Trip
settings and map it to a physical output
(Figure 13-13 and 13-14). This is
required because the 50-1 elements
are supervised by the 74 auxiliary relay. Next, wire a normally closed contact from the PA auxiliary relay to the
selected physical input on the Bus DPU.
4. The 50-2 provides local backup protection for failed feeder breakers. If this feature is desired, set the time delay in
the Primary Settings (Figure 13-10) to 0.3 seconds. The 50-2 element should not be used for backup with feeder
Applications Notes
ABB Distribution Protection Unit 1500R/2000R
Figure 13-10. Typical Primary Settings for the Bus DPU1500R/
website:www.abb.com/papd
2000R
13-9