76 Chapter 7 Parallel System & Dual Bus System
NX UPS Single Module And Parallel System 250kVA ~ 800kVA User Manual
7.4.2 External Protective Device
Refer to
3.1.7 External Protective Device.
7.4.3 Power Cable
The power cable wiring is similar to that of single module system. Refer to
3.1 Wiring Of Power Cable
.
The bypass and rectifier input sources must be referenced to the same neutral potential. The input earth leakage
monitoring device, if installed, must be located upstream of the common neutral sinking point.
7.4.4 LBS Cable
For 250kVA to 800kVA UPS dual bus system, the 250kVA ~ 400kVA and 600kVA ~ 800kVA UPS connect the optional
LBS cable (10m, 15m, 20m and 30m selectable) between the LBS ports (J34) of the two UPS systems, as shown in
Figure 7-8. The J34 port is provided on the front panel of the bypass control module, as shown in Figure 7-3.
The 500kVA ~ 600kVA E UPS connects the optional LBS cable (10m, 15m, 20m and 30m selectable) between the
LBS ports (J34, J38) of the two UPS systems, as shown in Figure 7-9. The J34 and J38 ports are provided on the
front panel of the bypass control module, as shown in Figure 7-4.
Note
You must use the shortest LBS cable to suit the application and must not coil excess. Meanwhile, separate the LBS cable from
the power cables to prevent electrical inteferences.
UPS 1 bypass cabinet
Control module
UPS 2 bypass cabinet
Control module
UPS 3 bypass cabinet
Control module
UPS 4 bypass cabinet
Control module
J26
J28
J28
J28
J26
J26
J26
J28
J34
J34
J34
J34
LBS cable
Figure 7-8 Connection of typical dual bus system (250kVA ~ 400kVA, 600kVA ~ 800kVA)
UPS 1 Bypass
control
module
J26
J28
J34
LBS cable
J38
J28
J26
J34
J38
J26
J28
J34
J38
J28
J26
J34
J38
UPS 2 Bypass
control
module
UPS 3 Bypass
control
module
UPS 4 Bypass
control
module
Figure 7-9 Connection of typical dual bus system (500kVA ~ 600kVA E)
