ABB DPA UPScale ST120 - 8 Options; System; Backfeed Protection

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8 Options
8.1 System
8.1.1 Backfeed protection
The UPS backfeed protection prevents any hazardous voltage or energy from being present on the
UPS input AC terminals after interruption of the input AC power.
The backfeed protection is implemented in the DPA UPScale ST by internal backfeed protection
contactors (K1 and K2) as shown in the wiring diagram below.
Fig 8.1.1-1: Backfeed protection
K1
Mains backfeed contactor
(option)
In the event of an AC failure, prevents the occurrence of any
hazardous voltage at the rectifier mains terminal due to
backfeed from the power modules sourced by the battery
K2
Bypass backfeed contactor
(option)
In the event of an AC failure, prevents the occurrence of any
hazard voltage at the bypass input terminal due to backfeed
from the power modules sourced by the battery
Order Number
04-0727
Backfeed protection ST40
04-0728
Backfeed protection ST60
04-0729
Backfeed protection ST80
04-0730 Backfeed protection ST120
04-3229
Backfeed protection ST200