Instruction manual

POWER WIRING INSTALLATION NOTES
093004B
164201535---5
DESCRIPTION:
DATE:
DRAWING NO: SHEET:
REVISION:
UPM 2
Battery
Bypass inputs to UPMs
UPM 1
Battery
UPM 3
Battery
UPM 4
Battery
Outputs from UPMs
1A
2A
3A
4A
1B
2B
3B
4B
17 of 17
Installation Information
A-27
EATON Powerware
®
9390 UPS (40–80 kVA) Installation and Operation Manual S 164201535 Rev E powerware.com
32. Required parallel system wiring length should be in accordance with the following rule, as
referenced to the diagram below, to ensure approximately equal current sharing when in
static bypass mode:
(Total length of 1A + 1B) ≅ (Total length of 2A + 2B) ≅ (Total length of 3A + 3B) ≅ (Total length of 4A + 4B)
This rule has a tolerance of approximately ±10% for the combined input and output wire
lengths.
If installing only two UPMs in a fully redundant system, this requirement is no longer
required, as each UPM is capable of supporting the full bypass requirement. However, this
would preclude future expansion.