Eaton 93PR - Page 52

Eaton 93PR 500 kW UPS
User's and Installation Guide 42
Dual Source
The Input Feed and Bypass feed may be separate sources. The sources must share a common neutral.
Battery connection
A separate battery shall be connected to each UPS, and the battery capacity for each UPS must be identical.
A common battery for all UPSs is not supported.
Parallel system wiring
CAUTION
• Parallel system combined input and output cable length should be in accordance with the following rule.
It should be designed to ensure that wiring impedance from point of supply to UPS input and from UPS
output to load connection for each UPS module in a multi-module system is equal, or within a tolerance of
approximately ±10%. This is to ensure approximately equal current sharing when in static bypass mode and
restrain input/output high frequency loop current of parallel system. Suggest that parallel system combined
input and output cable length no less than 10m, 5m for input and 5m for output.
Total length of 1A =2A=3A=4A
1B=2B=3B=4B
1C=2C=3C=4C
• If installing only two UPS modules (redundant), this requirement is no longer required as each UPS is
capable of supporting the full bypass requirement. However, this would preclude future expansion.
• Ensure that each UPS static bypass is fed from a single common source, as is an external bypass switch if
installed. If each UPS is fed with a separate rectifier source, please consult Eaton for advice on compatibility.