Emerson 10-30kVA, 208V 2.1.5Safety Ground, 2.1.6Protective Devices, System Output, Dual Input

Electrical Connections

2.1.5Safety Ground

The safety ground busbar is located below the neutral input and output busbars as shown in Figure 5 below. The safety ground cable must be connected to the ground busbar and bonded to each cabinet in the system.

All cabinets and cable conduit should be grounded in accordance with local regulations.

! WARNING

Failure to follow proper grounding procedures can result in electric shock hazard to personnel or the risk of fire, should a ground fault occur.

NOTE

Proper grounding significantly reduces problems in systems caused by electromagnetic interference.

NOTE

The ground and neutral busbars are easily accessible when the left protective cover plate is removed. Cable connections should be made before a cabinet is attached to the left side of the NX or before the UPS is placed where another obstruction, such as a wall, is against the NX’s the left side.

Figure 5 Ground and neutral busbar connections

Output neutral busbar

OUTPUT	INPUT
NEUTRAL	NEUTRAL

Ground busbar

Input neutral busbar

2.1.6Protective Devices

For safety, it is necessary to install circuit breakers in the input AC supply and external battery bat- tery cabinets, external to the UPS system. Given that every installation has its own characteristics, this section provides guidelines for qualified installation engineers with knowledge of operating prac- tices, regulatory standards and the equipment to be installed.

UPS Rectifier and Bypass Input Supply

•Protection from excessive overcurrents and short circuits in power supply input

External overcurrent protection for the AC output circuit is to be provided. See 6.4 - UPS Elec- trical Characteristics and Table 12 for overload capacity.

High-speed fuses and SCRs are used for internal battery circuit overcurrent protection. When an external battery supply is used, overcurrent protection for the battery circuit is to be provided by the customer.

•Dual Input

When wiring the UPS with dual inputs, the Rectifier input and the Bypass input must be pro- tected separately. Size the breakers according to the input currents shown in Table 10.

System Output

When using an external distribution panel for load distribution, the output neutral and input neutral must be separated at the input to the UPS.

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