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KESS Power Solutions Gmbh / www.kess.at / info@kess.at
Models 4 to 6 kVa:
•
As the device has class i protection against electric shock, it is essential
to install a protective earth conductor (connect earth). Connect this
conductor before supplying voltage to the input terminals.
•
Connect the power cables to the input terminals respecting the order of the
phase (R) and the neutral (N) indicated on the labelling of the device and
in this manual. Pay particular attention when connecting the power cables
to the input terminals and do not reverse the connection to the output
terminals or vice versa. Non-compliance may result in faults. when there are
discrepancies between the labelling and the instructions in this manual,
then the labelling on the device applies.
•
in accordance with the safety standard EN-iEC 62040-1, the installation must
be equipped with an automatic backfeed protection system. for example a
contactor which prevents the appearance of hazardous voltage or power on
the UPS input line during a mains failure (see fig. 9). The standard applies to
both, individual units as well as parallel systems.
•
warning labels should be attached to all primary power switches installed next
to the device, so that the maintenance personall is informed about the exis-
tence of an UPS. The label should contain the following or an equivalent text:
Before working on the circuit
● Isolate the uninterruptible power
supply system (UPS).
● Check the voltage between all terminals,
including the protective earth.
Return voltage risk of the UPS.
fig.9: „backfeed Protection“
fig. 9 shows:
1) Automatic backfeed protection system external to the UPS (EN-iEC 62040-1).
2) fuse holder and general purpose fuse 250V AC / 3A type f.
3) 230V AC bipolar contactor with minimum contact spacing of 1,4 mm and coil
with the same voltage and the minimum current indicated on the nameplate of
the UPS (input or bypass, as appropriate).
for parallel systems, each device must have its own separate backfeed
protection.