10 Chapter 2 Installation
Liebert ITA 16kVA/20kVA User Manual
Battery module
(4 pcs)
UPS (1 piece)
Figure 2-5 UPS installation diagram of battery modules included
2.5 External Protective Device
The circuit breaker or other protective devices must be installed at the external AC input port of the UPS. This section
provides general guidance for the qualified installing engineers. The qualified installing engineers should learn about
the related knowledge about the local wiring regulations for the equipment to be installed.
2.5.1 Rectifier And Bypass Inputting
Overcurrent
The appropriate overcurrent protective device should be installed on the mains input distribution, and you should take
the current capacity of power cable as well as the system overload requirements into account in installation (see
Table 1-2). It is generally recommended to use the thermomagnet circuit breaker of IEC60947-2 tripping curve C
(normal), following the 125% of current value listed in Table 2-2.
Bypass disconnection: When the system uses bypass disconnection, the protective devices should be respectively
installed at the mains input distribution for main input and bypass input.
Main/Bypass reflected protection
When using the main/bypass reflected protection function, the gross mains input needs to be equipped with the
protective devices with auxiliary contact function. The recommended model: S1N125 R125 TM FFC 4P + 1A + 1B +
YO (220Vac).
Note
The same neutral line must be used for the rectifier and bypass input power.
For IT power grid system, the protective device with four poles must be installed at the UPS external I/O distribution.
Earth leakage current
The residual current detector device (RCD) for the UPS upstream input distribution should:
z
Be sensitive to the DC unidirectional pulse (level A) in distribution network
z
Be insensitive to the transient current pulse
z
Be the general sensitivity type, settable: 0.3A ~ 1A
