Dell DELL10KWEBM, Getting Started

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Installation and Startup
CAUTION:
If the UPS does not have an automatic protection device against current backfeed, install an
external isolating device. After the device is installed, you must add a warning label with the following
wording or the equivalent on the external AC contactor: RISK OF VOLTAGE BACKFEED. Isolate the UPS before
operating on this circuit, then check for hazardous voltage between all terminals.
External Distribution Panel
UPS
L/L1
L/L1
N/L2 N/L2
Legend
Coil Remote Switch
Magneto-Thermal Input
Main Switch
AC Contactor
Neutral/L2
L1 Line Input
B
Q
T
N/L2
L/L1
B
Q T
The following table lists backfeed protection devices (AC contactors) that can be used as an external
isolating device for backfeed protection. Only use AC contactors listed in the table.
Manufacturer Type Rating
ABB France (E12527)
A75-30
220–240 Vac, 105A
25 HP at 208V, 30HP at
240V
Tianshui 213 Electrical Apparatus Co., Ltd.
(E203071)
(alternative)
GSC1(CJX4-d)-6511
220–240 Vac, 68A
25 HP
Tianshui 213 Electrical Apparatus Co., Ltd.
(E203071)
(alternative)
GSC1(CJX4-d)-8011
220–240 Vac, 80A
30 HP
NOTE:
Although the UPS does not contain anti-backfeed (ABF) relays, some backfeed protection is provided.
For example, if some components are damaged in battery mode, the output voltage may feed back to the input.
In this case, a current transformer (CT) is used to detect the bypass current feedback voltage. If a current
backfeed fault condition is detected, the UPS will terminate the inverter output to avoid the personal injury.