Critical Power
Modifications reserved
Page 47/146
GE_UPS_OPM_TLE_SCE_M60_M80_1GB_V020.docx
User Manual
TLE Series 600 & 800 CE S1
5.8.2
Input/output over current protection and wire sizing
NOTE !
The UPS is designed for TN System.
The input neutral shall be grounded at source and shall never be disconnected.
4 pole breaker shall not be used at the UPS input (see also IEC 60364, IEC 61140, IEC
61557).
The cabling of the UPS system has to be sized according to the UPS power rating.
Exceptions are only allowed to suit local prescriptions.
Sizing of circuit
breakers
,
fuses
and
cables
for
Mains Input
,
output load
and
battery
must meet the
requirements of local and national electrical codes.
Before connecting the UPS, verify that the
mains voltage
and
frequency
, the o
utput load voltage
and
f
requency
and
battery data
(cells number, floating voltage, autonomy) are according to the required
data.
The protection of the UPS mains input must be exclusively with 3 pole breakers.
Disconnection of the Neutral is not permitted.
The UPS needs the connection of the Neutral to the input, to guarantee the function in TN mode
(Neutral-Earth).
Caution when using
four-pole circuit breakers
as protection to the
UPS Load
.
A potential problem exists for situations with
non-linear Loads
, causing the
neutral current
to be higher
than the
phase current
.
Avoid to run the
input cables
in parallel with the
output cables
to prevent them from noise induction.
The
three-phase Mains power
supply must be symmetrical with respect to earth, due to the existence of
voltage surge protection devices inside the UPS.
The connection of the
Battery
to the UPS must be protected with
fuses
or similar devices according to
technical specifications and in accordance with local standards.
NOTE !
If you use
ELCB breakers
to protect the input connections, consider the high leakage
current towards the earth generated by the noise suppression capacitors.
If these
ELCB breakers
are strictly necessary, we suggest to use the largest type
suitable for non-linear current and for delayed operation.
To ensure the circuit selectivity in case of
short- circuit in the load equipment
, special care must be
taken in choosing the
fuse or circuit breaker ratings
installed in the output distribution circuits.
Due to the relatively low short-circuit capability of the
UPS Inverter
, a short-circuit in the
Load
will cause
an immediate transfer to
Mains
.
The
largest fuse
in the output distribution should be
at least 1.6 time
smaller than the
fuses
supplying
the
bypass line
.
If circuit selectivity is required while the
Load
is fed from the
Inverter
(
Bypass Mains
not available), the
largest fuse
or
circuit breaker
should be rated at no more than
20%
of the
UPS output current rating
.
