Power Cables; Figure 32 Hot Standby Configuration - Emerson Liebert NX 400V User Manual

3.3.3

Power Cables

The wiring of power cables is similar to that of single module system except that the output of the
upstream UPS is fed into the bypass input of the downstream UPS, and the load is fed by the down-
stream UPS through its inverter or bypass. The bypass and the main input sources must be refer-
enced to the same neutral potential and input earth leakage monitoring devices, if installed, must be
located upstream of the common neutral sinking point. Refer to the instructions in 1.0 - Single Mod-
ule UPS Installation.
No control wires other than those specified for the single module configuration are required.

Figure 32 Hot standby configuration

Upstream
Mains L1,
L2, L3, N
UPS1
Charger
Input Distribution
Bypass L1,
L2, L3, N
Q1
Rectifier
Inverter
Q2
Q3
Q5
L1, L2, L3, N
UPS1 Output
Mains L1, Bypass L1,
L2, L3, N L2, L3, N
Q1
UPS2
Rectifier
Charger
Inverter
Q5
L1, L2, L3, N
49
UPS Multi-Module Installation
Downstream
Q2
Q3