Emerson 610 installation manual Configuring Your Neutral and Ground Connections

Page 19

Configuring Your Neutral and Ground Connections

6.0CONFIGURING YOUR NEUTRAL AND GROUND CONNECTIONS

Improper grounding is the largest single cause of UPS installation and start-up problems. This is not an easy subject, since grounding techniques vary significantly from site to site, depending on several factors. The questions you should ask are:

• What is the configuration of the input power source? Most of the recommended schemes for UPS grounding require grounded-wye service. The UPS system requires a bypass neutral for sensing and monitoring the quality of the bypass input. If the building service is anything other than a grounded wye system (corner grounded delta or impedance grounded wye), contact your Liebert representative for details about the Isolated Neutral kits for the System Control Cabinet and UPS modules.

! WARNING

If the building service feeding the UPS is any configuration other than those mentioned above, contact your Liebert representative or Liebert Global Services immediately.

A Power-Tie or distributed redundant system has different grounding requirements from stand- alone UPS modules. If using one of those systems, refer to Liebert’s Power-Tie configuration user manual, SL-30030.

•What are the UPS input and output voltages? Systems with 480 VAC input and output have sig- nificantly different needs from systems with 208/208 VAC.

•What is the connected load? Does the critical load consist of one or more Power Distribution Units (PDUs)? Do the PDUs have isolation transformers?

Proper grounding should be based on NEC Section 250, but safe and proper equipment operation requires further enhancements. The following pages detail Liebert’s recommendations for grounding various system configurations to ensure optimal UPS system performance.

NOTE

Some UPS modules are equipped with input isolation transformers. However, these transformers have no effect upon any system grounding considerations. These modules will be grounded exactly as shown in Figures 4 through 10.

! CAUTION

The UPS ground lug must be solidly connected to the service entrance ground by an appropriately sized wire conductor per NEC Article 250. Each conduit or raceway containing phase conductors must also contain a ground wire, both for UPS input and output, which are solidly connected to the ground terminal at each termination point. Conduit-based grounding systems tend to degrade over time. Therefore, using conduit as a grounding conductor for UPS applications may degrade UPS performance and cause improper UPS operation.

13

Page 18 Page 20
Image 19
Page 18 Page 20
Contents Liebert Series 610 UPS Contacting Liebert for Support Battery Cabinet PrecautionsTable of Contents Figures Iii Tables Important Safety Instructions Page Installation Considerations Multi-Module 500 to 750kVA UPS System Control Cabinets Types of System Control CabinetsUnloading and Handling Internal Inspections and Shipping Material Removal External InspectionsInspections Equipment Location Battery Installation Battery Safety PrecautionsAvertissement Battery Safety Precautions in French Per CSA RequirementsBattery 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 Abbreviations for circuit breakers Control WiringBattery Wiring Specific Connections Wiring ConnectionsWiring Connections Power wiring terminals, factory supplied Wiring InspectionField-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
Top Page Image Contents