Eaton Power Xpert 9395 Installation And Operation Manual page 63

UPS Installation Plan and Unpacking
3 3 . . 2 2 . . 6 6 D D i i s s t t r r i i b b u u t t e e d d B B y y p p a a s s s s P P o o w w e e r r W W i i r r i i n n g g P P r r e e p p a a r r a a t t i i o o n n
Read and understand the following notes while planning and performing the installation:
• All distributed bypass UPS rectifier inputs must come from one source and all bypass input feeds must
come from one source.
• All UPSs in the distributed bypass system must contain the same number of UPMs. Mixed UPS kVA
ratings are not permitted.
• 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
• If the load requires a neutral, a bypass source neutral must be provided. DO NOT install both a source
neutral and a bonding jumper. See
sizes. The bonding jumper must be copper wire.
• 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.
• 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.
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.
When selecting the most appropriate grounding scheme for your application, consider items such as:
– Ground fault detector settings
– Site specific specifications and requirements
– Local codes and regulations
• MOBs with dual auxiliary contacts are to be provided by the customer.
rating for the MOBs.
• The tie cabinet must contain Module Output Breakers (MOBs) with dual auxiliary contacts for control of
the system. Without dual auxiliary MOBs, UPMs are not allowed to go to bypass individually during
servicing. All UPMs will go to bypass instead of the just the UPM needing service, decreasing critical load
42 Eaton Power Xpert 9395 UPS Installation and Operation Manual 164201764—Rev 14
Table 5, Table 6, Table 7 or
Table 5, Table 6, Table 7 or
Table 8 for neutral bonding jumper wire
Table 18 lists the recommended
Table 8.