Emerson 610 installation manual Preferred Grounding Configuration, Wye-Connected Service

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Configuring Your Neutral and Ground Connections

6.1Preferred Grounding Configuration, Wye-Connected Service

The most common configuration of Series 610 UPS Multi-Module Systems is with 480 VAC input, 480 VAC output and a connected load consisting of multiple Power Distribution Units (PDUs) with isolation transformers in the PDUs to produce 208 VAC. For Canadian customers, the UPS modules usually have 600 VAC input and output. The same principles apply if the connected load is an isola- tion transformer feeding various loads. Figure 4 shows a typical installation. The Maintenance Bypass Switchgear is shown separately for clarity, but may be contained within the System Control Cabinet (SCC)/switchgear.

Notice that the UPS module input and the system bypass input are connected to a grounded-wye ser- vice. In this configuration, the UPS module is not considered a separately derived source.

All of the UPS module output neutrals are solidly connected to the SCC neutral. A parity-sized neu- tral is recommended between the UPS module and the SCC for best system performance. The SCC neutral is solidly connected to the building service neutral, which is bonded to the grounding conduc- tor at the service entrance equipment.

The isolation transformers in the PDUs are considered a separately derived source. Therefore the PDU neutral should be bonded to the PDU grounding conductor and connected to a local grounding electrode in compliance with NEC 250-26. (PDUs are connected to the critical load output of the SCC, but are not shown in Figure 4 for clarity.)

Figure 4 Preferred grounding configuration, wye-connected service

NOTE

UPS MODULE N, N=2-6

Impedance-grounded wye sources require an Isolated Neutral Kit in addition to the grounding and neutral conductors shown above—see 6.5 - Grounding Configuration, Corner- Grounded Delta or Impedance-Grounded Wye.

NOTE

If there is a 4-pole Automatic Transfer Switch (ATS) between the service entrance and the UPS, this configuration cannot be used. Refer to 6.2 - Alternate Grounding Configuration, Wye- Connected Service or 6.3 - Preferred Grounding Configuration With Isolated Bypass to determine a suitable configuration.

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Contents Liebert Series 610 UPS Battery Cabinet Precautions Contacting Liebert for SupportTable of Contents Figures Iii Tables Important Safety Instructions Page Installation Considerations Multi-Module 500 to 750kVA UPS Types of System Control Cabinets System Control CabinetsUnloading and Handling Inspections External InspectionsInternal Inspections and Shipping Material Removal Equipment Location Battery Safety Precautions Battery InstallationBattery Safety Precautions in French Per CSA Requirements AvertissementBattery Cabinets Open-Rack Batteries Configuring Your Neutral and Ground Connections Preferred Grounding Configuration, Wye-Connected Service Preferred grounding configuration, wye-connected serviceAlternate Grounding Configuration, Wye-Connected Service Alternate grounding configuration, wye-connected servicePreferred Grounding Configuration With Isolated Bypass Preferred grounding configuration with isolated bypassAlternate Grounding Configuration, Non-Isolated Alternate grounding configuration, non-isolatedConfiguring Your Neutral and Ground Connections Preferred grounding configuration, impedance-grounded wye Preferred Grounding Configuration, Battery Systems Preferred grounding configuration, battery systemsWiring Considerations Power Wiring Scct Control Wiring Abbreviations for circuit breakersBattery Wiring Wiring Connections Specific ConnectionsWiring Connections Wiring Inspection Power wiring terminals, factory suppliedField-supplied lugs 16, National Electrical Code Reprint Installation Drawings 97-797600-176 Rev 88-797658-84 Rev 88-797658-94 Rev 88-797657-26 Rev 88-797657-95 Rev Outline drawing, 500kVA Multi-Module UPS, 12-pulse rectifier 88-797657-92 Rev 88-797668-84 Rev 88-797668-90 Rev 88-797665-29 Rev 88-797665-90 Rev 88-797656-66 Rev 88-797656-86 Rev 88-797668-66 Rev 88-797668-86 Rev 88-797664-68 Rev 88-797664-88 Rev 88-797677-65 Rev Base mounting patterns, 500kVA module, 6-pulse rectifier Base mounting patterns, 500kVA module, 12-pulse rectifier 88-797613-28 Rev Base mounting patterns, 625-750kVA module, 6-pulse rectifier 88-797613-29 Rev 88-797613-19 Rev 88-797613-27 Rev Shipping split detail, 500kVA, 12-pulse rectifier 88-797612-08 Rev Shipping split detail, 625-750kVA, 6-pulse rectifier 88-797612-09 Rev Shipping split detail, 625-750kVA, 12-pulse rectifier 88-797612-07 Rev Battery power pack system Battery power pack, Size a 88-797607-63 Rev Outline drawing, System Control Cabinet SCCT, 200-1200A 88-797613-71 Rev Outline drawing, System Control Cabinet SCCT, 1600-2000A 88-797613-78 Rev Outline drawing, System Control Cabinet SCCT, 2500-3000A 88-797613-73 Rev Outline drawing, System Control Cabinet SCCT, 4000A Base mounting patterns, System Control Cabinet SCCT, 4000A 96-797619-58A Rev 96-797619-66A Rev Control connection location diagram, Scct 96-797619-51A Rev 96-797619-60 Rev 96-797619-19A Rev 96-797619-20 Rev 96-797619-21 Rev 96-797619-130 Rev 96-797619-28 Rev 96-797619-128 Rev 96-797619-62 Rev 96-797619-90 Rev 96-797619-91 Rev 96-797619-52A Rev 96-797619-53A Rev 96-797619-54A Rev 96-797619-55A Rev 96-797619-56A Rev 96-797619-57A Rev 88-797616-09 Rev 88-797616-13 Rev 88-797616-07 Rev Outline drawing, remote status panel, surface mount Installation Drawings Data, Series 610, 500-750kVA, Multi-Module Systems Site planning data-600V input Site planning data-480V input System Control Cabinets Page Page Page Environmental Systems 800-543-2778 Outside the United States