IV432E Rev.01 SIEL S.p.A.
Installation and user manual
Date of issue: 2021-05-05
Pag.
17
of
50
+ FR
3.9
UPS parallel Installation
The following sections introduce the installation procedures specified to the parallel system.
3.9.1 Cabinet installation
Connect all the UPS needed to be put into parallel system as below picture.
Make sure each UPS input breaker is in
“
off
”
position and there is no any output from each
UPS connected. Battery groups can be connected separately or in parallel, which means the
system itself provides both separate battery and common battery.
WARNING!
Make sure the N, A (L1), B (L2), C (L3) lines are correct, and
grounding is well connected.
3.9.2 Parallel cable installation
Shielded and double insulated control cables available, 5 meters standard length, must be
interconnected in a ring configuration between UPS units as shown below. The ring configuration
ensures high reliability of the control.
3.9.3 Requirement for the parallel system
A group of paralleled UPS behaves as one large UPS system but with the advantage of
presenting higher reliability. In order to assure that all UPS are equally utilized and comply with
relevant wiring rules, please follow the requirements below:
1) All UPS must be of the same rating and be connected to the same bypass source.