Liebert UPS System - Manual (Page 97)

Chapter 8 Parallel System
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Maintenance mode: The condition to transfer to maintenance mode is same with
that of single module UPS system. The maintenance switches should be switched
on synchronously as possible. Thus the system can be repaired without interrupting
the power supply to load.
8.2 Installation
The installation method of parallel operation system is the same with that of single
module UPS system. The following contents only introduce the installation
procedures relating to parallel operation system.
8.2.1 Cabinet installation
1. Parallel operation system with two UPS units
The layout of 40/60 kVA UPS system is shown in Fig.8-5. Two UPS units are placed
in the middle side by side. Each battery cabinet is placed next to the UPS unit. The
battery cabinet should be placed in front of or behind the UPS cabinet if considering
capacity expansion.
The layout of 20/30 kVA UPS system is the same with that of 40/60kVA UPS.
battery cabinet 1 UPS cabinet 1 UPS cabinet 2 battery cabinet 2
Fig. 8-5 40/60KVA UPS Layout
2. Parallel operation system with multi UPS units
Please place the battery cabinet in front of or behind the UPS cabinet for shorten
the battery cables and battery temperature sampling cables and for convenient
capacity expansion.