ABB Distribution Protection Unit 1500R/2000R
13-15
Applications Notes
9/99
website:www.abb.com/papd
Breaker
Position
Open
Down-line
DPU1500R/2000R
Closed
Closed
Backup
DPU1500R/2000R
L
O
C
K
O
U
T
79-1
Delay
79-2
Delay
79-3
Delay
79-4
Delay
(50)
(50)
(51)
(50 or 51)
(51)
(50)
(50)
(51)
Time
Open
Enabled Protective
Element
Enabled Protective
Element
shown in Figure 13-22.
Figure 13-21. Down-line and Backup Recloser Operations without ZSC