Emerson 10-30kVA Manuel D’Utilisation

Figure 2 illustrates the NX in a split bypass (dual-input) configuration. In this configuration the 

Static Bypass and the Maintenance Bypass lines are supplied from a separate feed from the Main 

input. Both sources must be protected externally with properly sized protective devices. By default, 

the unit ships with internal links installed between the Bypass input and Main input (Single Input 

configuration). To wire the unit as a dual input UPS, remove the links and wire the bypass to the 

input bus bars, then wire the Main input directly to CB1 (see Figure 3).

The following are guidelines only and are superseded by local regulations and codes of practice where 

applicable.
1. Take special care when determining the size of the neutral cable, as current circulating on the 

neutral cable may be greater than nominal current in the case of non-linear loads. Refer to the 

values in 6.4 - UPS Electrical Characteristics.

2. The ground conductor should be sized according to such factors as the fault rating, cable lengths 

and type of protection. The ground cable connecting the UPS to the main ground system must 

follow the most direct route possible. Control wiring and power wiring must be run in separate 

conduit. Output and input cables must be run in separate conduit.

3. Consider using paralleled smaller cables for heavy currents—this can ease installation.
4. When sizing battery cables, a maximum voltage drop of 4VDC is permissible at the current 

ratings in Table 10. For terminal connection sizing, see Table 10.

5. In most installations, especially parallel multi-module systems, the load equipment is connected 

to a distribution network of individually protected busbars fed by the UPS output, rather than 

connected directly to the UPS itself. When this is the case, the UPS output cables can be rated to 

suit the individual distribution network demands rather than being fully load-rated.

6. When laying power cables, do not form coils; this will help avoid increasing formation of 

electromagnetic interference.

NOTE
If more load is added to the distribution panel, the unit’s cabling must be resized.

NOTE
Left-side access may be required when making power connections. Cable connections should be