Eaton Power Xpert 9395 550/275, Installation And Operation Manual

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UPS Installation Plan and Unpacking
Power Xpert
TM
9395 550/275 UPS (225–550 kVA) Installation and Operation Manual 164201716—Rev 8 www.eaton.com/powerquality 3-19
CAUTION
On all 9395 models that will be fed by a site generator at any time it is recommended to have an “On
Generator” sensing input connected and proven functional. This allows the UPS to optimize its operation
with the generator. This function includes reduced input current and battery current limits, slower walk-in
to ease the load step on the generator initially, and HIGH ALERT mode for ESS and VMMS operation.
HIGH ALERT mode is desired because any loads with a leading power factor will not be seen by the
generator. Rectifier operation will be much softer while on generator thereby increasing overall system
stability.
3.2.5 Distributed Bypass Power Wiring Preparation
Read and understand the following notes while planning and performing the installation:
l
All distributed bypass UPS rectifier inputs must come from one source and all bypass input feeds must
come from one source.
l
All UPSs in the distributed bypass system must contain the same number of UPMs. Mixed UPS kVA ratings
are not permitted.
l
Distributed bypass UPS input wiring size requirements and output wiring size requirements from the UPSs
to the tie cabinet or distribution panel are the same as listed in Table 3-4 and Table 3-6.
l
If the load requires a neutral, a bypass source neutral must be provided.
l
In the case of parallel Distributed Bypass configurations, wiring for the common system neutral reference
will also be connected to E12 of each module and this common system neutral reference wiring will be
routed to the output switchgear cabinet and connected to an isolated / ungrounded bus which is common
with the wiring from the E12 terminal of all other paralleled modules of the Distributed Bypass system.
l
DO NOT install both a source neutral and a bonding jumper. See Table 3-9 for neutral bonding jumper wire
sizes. The bonding jumper must be copper wire.
l
Eaton UPS systems are designed to operate with two optional ground schemes. Both configurations comply
with international safety regulations (as seen on the UPS name plate).
1. Internal reference generated through an earth reference. Ground current will be equal to or less than 5%
of the unit rating. This takes the form of a UPS N bus to ground bond wire.
2. Internally generated reference which avoids ground current. By locating the center reference inside the
three phase conductors, the relationship between the UPS source and the UPS output is maintained. This
is an internal UPS function and requires no additional work on the part of the installer or user.
CAUTION
SINGLE HIGH IMPEDANCE GROUND SOURCE - In North American installations, the neutral conductor
from the high impedance ground source of supply CANNOT be used. DO NOT bond the inverter center
point (E12) to ground: this is an internal UPS function and requires no additional work by the installer or
user.
DUAL HIGH IMPEDANCE GROUND SOURCE - In North American installations, the neutral
conductor from the high impedance ground source of supply CANNOT be used. DO NOT bond the
inverter center point (E12) to ground: this is an internal UPS function and requires no additional
work by the installer or user. Please contact the Eaton help desk listed in Chapter 1 for additional
guidance regarding dual high impedance ground sources.
NOTE For full-rated operation of a Distributed Bypass System when in Bypass or ESS mode,
the line frequency impedance of all conduction paths must be equal when assessed
from the point where the Bypass Power Source connects to the System Switchgear to
the point where the Common Load connects to the System Switchgear.