System Grounding, Control Wiring Connections | Liebert 100-1000A

Power and Control Wiring

5.3System Grounding

Equipment grounding — Grounding is primarily for equipment and personnel safety, although proper grounding also enhances equipment performance.

All input and output power feeds must include an equipment grounding means as required by the NEC and local codes.

An insulated equipment ground conductor is recommended to run with each input and output power feed. The equipment ground conductors should be at least the minimum size conductor per the NEC based on the upstream overcurrent protection device.

! WARNING

If conduit is used as a grounding means, adequate electrical continuity must be maintained at all conduit connections. The use of isolating bushings with a metal conduit can be a safety hazard and is not recommended.

4-Wire-Plus-Ground Systems — When 4-wire-plus-ground input feeds are utilized, the input power sources must be properly grounded. Because the neutral is not switched by the Liebert STS2, the neutrals of the two power sources are solidly interconnected. The NEC prohibits grounding a power source at more than one point. Connecting the neutrals of two grounded power sources together effectively grounds each of the sources at more than one point, which allows neutral current to flow on the ground system, defeats ground fault protection, creates a safety hazard, and violates the NEC.

Where possible, the two power sources should be located in close proximity and a single neutral-to-ground bond made (as shown in Figure 4 on page 12 or as is typical with a double- ended substation).

Figure 4 Typical one-line diagram of two PDUs and a Liebert STS2

SOURCE 1				SOURCE 2
	MICB1				MICB2
	ISOLATION				ISOLATION
	TRANSFORMER				TRANSFORMER
	CB1	STS1	STS2	CB2
	CB1			CB2
	K1			K2
K2 K3	CB4		CB3	K1 K3	CB5

225A

225A

225A

225A

225A

225A

5.4Control Wiring Connections

No control wiring is needed on the standard Liebert STS2. Only certain options require external control wiring. See 6.0 - Options on page 14 for details

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Image 20

Liebert 100-1000A System Grounding, Control Wiring Connections, Source MICB1 MICB2 Isolation Transformer, CB4 CB3, CB5

Contents

Liebert STS2 Page Table of Contents Alarm and Faults Theory of Operation Communication Interfaces Liebert STS2 Touch Screen Display Specifications Event Message Help Text 17.0 Maintenance Figures Tables Important Safety Instructions Overview of Manual Safety Precautions Unpacking and Inspections External InspectionsUnloading and Handling Unit Preparation Internal InspectionsHandling Considerations Recommended Minimum Service Clearances Operating Temperature Range 0 to 40C 32 to 104FHeat Output Operating Environment Altitude Recommended derating for high altitude operation Leveling of the Static Switch Without Anchoring Leveling and Anchoring the Static Switch Using Floor StandLeveling and Anchoring the Unit to the Floor Locating the Liebert STS2 Input And Output Power Connections Power and Control Wiring Rating Max. number and size Input Junction Box Installation-OptionalInput/output conduit plate specifications Input junction box dimensions Input junction box terminal wire size rangeLength Width Height Switch Rating Inches mm Switch Rating Power and Ground Lug Wire Range Control Wiring Connections System GroundingSource MICB1 MICB2 Isolation Transformer CB4 CB3 Remote Source Selection Wiring Power SupplyTerminal block 1 and terminal block 2 wire connections Remote source selection terminal block Programmable Relay Board Optimized TransferOptions Programmable relay board pinout Liebert IntelliSlot SNMP/Web/Modbus 485 Card Input Contact Isolator BoardComms Board Key Lockout Switch LED DisplayRemote Source Selection Redundant Output Breaker Seismic Floor Stand Input Junction Boxes and CablesSeismic Floor Anchors Installation Drawings Detail a Rev PS211800 Rev PS211101 Rev PS211401 PS211801 Seismic anchor Liebert STS2 STS2 Front System Seismic ANCHORING, Figure ONE-LINE Diagram Rev Section A-A ONE-LINE Diagram PS212401 Single output Drawing 800 1000 amp Liebert STS2 withBreaker PS212801 Liebert STS2 non-automatic circuit breaker schedule ABB Control connection location diagram 100 600 amp Liebert STS2 See Option Location Detail Control Wiring Front View with Front Door Removed Option Location Detail See Note J71 J72J73 J74 Control wiring for the input contact isolator board option Table J51 02-810015-XX Connection No customer ConnectionDB-9 No customer Control wiring for the RS-232 port TXD RXD GND Input Junction BOX Mimic Symbol Description Installation drawing, seismic floor stand 100-250A Installation drawing Seismic floor stand 100-250A Installation drawing, seismic floor Stand 100-250A PS215003 Rev Height Table Hardware Torque ChartDrawing, seismic floor stand 400-600A PS216001 Rev Seismic floor stand 400-600A PS216002 Rev PS216003 Rev Installation drawing, seismic floor stand 800-1000A Seismic floor stand 800-1000A Front Right Isometric View Rear Right Isometric View Right Side View Side View RightFront View View Redundancy System DescriptionIntroduction to Liebert STS2 Operations Modes of Operation Operator Controls Bypass General Description Theory of Operation Emergency Transfer Load Current Transfer InhibitSCR Failure 7 On/Off Sequence Detailed Component Description Controls Operator InterfaceHardware Firmware Audible Alarm Circuit BreakersSCRs Logic Modules Operating Instructions for the Touch Screen Interface Normal System Startup Manual Transfer / Preferred Source Selection Source transfer screen To manually select the preferred source Maintenance BypassEnabling Remote Source Selection Viewing Slot for the Source 2 Gate Drive Board Touch Screen Viewing Slot for the Source 1 Gate Drive Board To return to normal mode Bypass Procedures for SourceTo bypass the switch for Source Normal System Shutdown Shutdown in Static Transfer Switch ModeShutdown in Maintenance Bypass Mode Alarm and Faults Event Mask History Log Event and History LogsEvent Log Alarm Notes List of Messages Alarm Message Description/Cause Action Event messages See Configuring the Input Contact Isolator Settings on Using the RS-232 Port Communication Interfaces Keys Function Connecting and Using a TerminalTerminal commands Item Parameter Configuring the Liebert STS2 via the TerminalGroups Parameter Value types Group settings and valuesValue Parameter User Event Mask Comms Options Setting Bitpacked Options with the TerminalOptions1 Critical Option Enabling Non-Critical Option EnablingBinary-hexadecimal conversions Hex Putting the Terminal Command Together Setting Event Masks with the Terminal Examples of Event Mask Settings Display Overview Liebert STS2 Touch Screen Display Menu Overview Backspace Using the Optional Key Lockout Switch Using the PasswordTo set or reset the password Changes disabled Changes enabled Configuration Menu Mimic DisplayEvent Controls Event Display To set the event masks User SettingsTo access the User Settings dialog box User settings dialog box Source Set Points Sepoint parameters To configure the setpoints for each sourceButton Range Default Comments Liebert STS2 Touch Screen Display System Settings To access the System Settings menuComm Options Option buttons Configuring the Modem To configure the modem Configuring Pager Support Configuring the Input Contact Isolator Settings To configure the Input Contact Isolator relays Relay Setting Definition Configuring the Programmable Relay Board SettingsStandard settings for programmable relays Configuring the Liebert IntelliSlot SNMP/Web/Modbus 485 Card Liebert SiteScan Configuration Saving Your Communications ConfigurationsSystem Options Dual Output Breaker Pole Transfer Switch System IDShunt Wye Output Transformer Logs 13.11.1Event Log13.11.2History Log To use the Event Log Startup Procedure Bypass ProcedureCleaning the LCD Touch Screen Source Transfers Front Panel Controls LEDs and Buttons and Key Lockout SwitchOperating the Liebert STS2 LED Display LED and Push Button Description LED and push button descriptionDescription Action Cause. See 12.0 Communication Interfaces for PC terminal Key Lockout Switch Event Controls Operations Normal System Startup Manual Transfer / Preferred Source Selection Maintenance Bypass 109 When the Liebert STS2 is operating on bypass Normal System Shutdown System Configuration SpecificationsFrequency Input/Output Voltage Grounding Electrical RequirementsInput Surge Suppression Response Time System Components Frame and EnclosureCasters, Leveling and Seismic Anchoring Cooling Access Cable EntranceDoors Color Graphical Display or LED Display Pin Signal Name Function / Comments 15.2.9 RS-232 PortTerminal Port Connections MTA plug pinout RS-232 settings Parameter Setting15.2.11 RS-232 Interface Parameters Fuseless Design Event Message Help Text KeyS1 SCR Short S2 SCR Short S2 SCR Open 119 120 S1 SCR Sense Fail S1 Volt Sense FailS2 Volt Sense Fail S2 SCR Sense Fail S1 Curr Sense FailS2 Curr Sense Fail S1 Gate Drive Fail S2 Gate Drive Fail Heat Sink Overtemp S1 OV S1 UVS1 UV RMS S2 UV S1 OF/UFS1 Fail S2 UF/OF S2 UV RMSS2 OV S2 Fail S1 I-PEAK S2 I-PEAK 130 CB5 S1 BYP Closed 132 133 134 135 136 137 Testing the Liebert STS2 MaintenanceProper Tightening of Nuts and Bolts Changing the Air Filter Support Information Programmable Relay Board Settings Record Channel Channel PRB Notes Input Contact Isolator Settings Record Page Ne t Is tTwor k Care