1027212
UPS 225 - 275 kVA/300kVAPF0.8
21
Revision E
User’s and Installation Guide
3.2.4 Distributed bypass power wiring preparation
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.
•
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 on page 16.
•
The UPS can be installed in a high-resistance ground application only by using a factory-installed
neutral forming kit.
•
MOBs with dual auxiliary contacts are to be provided by the customer. Table 3-8 on page 18 lists
the recommended 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, UPSs are not allowed to go to bypass individually during
servicing. All UPSs will go to bypass instead of the just the UPS needing service, decreasing critical
load protection. With dual auxiliary MOBs, one UPS can be bypassed while the remaining UPSs
support the load as long as the remaining UPMs have the capacity to do so.
