OMD10078 rev F
32
4.6
BACKFEED PROTECTION DEVICE
The back-feed protection device, as indicated by the EN 62040-1 Standard, is
optional and can be installed during the UPS production phase; the installation on site
can only be carried out by skilled personnel.
The device is a contactor that automatically disconnects the bypass line in case of
failure of the static switch, in order to avoid voltage feed-back on the input terminals
during the a mains failure.
The use of a device installed inside the UPS allows a higher flexibility of use, as only
the bypass line is cut leaving the rectifier battery charger in operation.
The use of an external device forces the user to separate the UPS supply lines
(rectifier and bypass) if the flexibility and availability of the UPS are supposed to be kept
unaltered.
The following table shows the main electrical characteristics of the external
sectioning device in case this solution is chosen.
Backfeed protection device
UPS power (kVA)
60 80 100 125 160
Maximum operating voltage (Vac)
690
Minimum rated current (A)
130 180 220 270 350
Category AC-1
