Liebert® EXM™ UPS User Manual

This manual provides detailed information for the Liebert EXM UPS, covering models from 20-kVA to 200-kVA with 208/120-V, 50/60-Hz configurations.

For technical support, visit VertivCo.com/en-us/support/. Please note that information in this document is subject to change without notice and may not be suitable for all applications. Vertiv assumes no responsibility for damages resulting from the use of this information.

Important Safety Instructions

This section contains critical safety information that must be followed during the installation and operation of the Liebert EXM UPS. Always read and understand these instructions before working with the equipment. Installation should be overseen by a trained and qualified electrical contractor. The UPS must be commissioned by the manufacturer or an authorized engineer before operation.

WARNING: Risk of moving heavy equipment and electric shock. Exercise extreme caution when handling UPS cabinets, as they can weigh between 684 lb (320 kg) and 1516 lb (688 kg). Always locate the center of gravity symbols before handling and test lift for balance. Never tilt the equipment more than 15 degrees from vertical. Use only CO2 or approved fire extinguishers for electrical fires. Be aware of high AC and DC voltages within the system and always check with voltmeters before making contact.

CAUTION: Risk of electric shock from high leakage current. Earth connection is essential before connecting the input supply. Earth leakage current exceeds 3.5 mA and is less than 1000 mA. Residual Current Circuit Breakers (RCCBs) must be sensitive to DC unidirectional pulses (Class A) and insensitive to transient current pulses.

NOTICE: Ensure proper grounding in accordance with local electrical codes. Maximum load must not exceed the rating label. This unit complies with FCC Part 15, Class A digital device limits and may cause interference if not installed and used as instructed.

Glossary of Symbols

This section defines various symbols used throughout the manual, including:

• Risk of electrical shock
• Caution
• AC input/output
• Consult the manual
• Valve-regulated lead-acid battery
• Recycle
• DC voltage
• AC voltage
• Equipment grounding conductor
• Bonded to ground

1.0 Introduction

The Liebert EXM UPS is a transformer-free, online, double-conversion uninterruptible power system available in capacities from 20-kVA to 200-kVA. It supports 208/120-V input and output and can operate with either a 50 or 60-Hz input frequency, providing matching output frequency conversion. The system is scalable in 20 kVA increments. It is designed to provide continuous, high-quality AC power to critical business equipment, protecting against utility power disturbances.

The Liebert EXM utilizes high-frequency, double-conversion pulse width modulation (PWM) technology and digital controls for enhanced reliability and ease of use. External batteries are required for extended runtime when utility power is unavailable.

2.0 Installation

This section covers the environmental requirements and mechanical considerations for installing the Liebert EXM UPS. Installation should be performed by a trained and qualified engineer.

NOTICE: Do not apply electrical power to the UPS equipment before the commissioning engineer arrives.

2.1 Initial Inspections

1. Inspect equipment and shipping containers for damage. Do not install if damage is apparent. File a claim with the shipping agency and contact Vertiv Services.
2. Compare shipment contents with the bill of lading and report any discrepancies.
3. Verify the product label matches the ordered UPS model, capacity, and main parameters.

2.1.1 Storing the UPS and Batteries for Delayed Installation

If installation is delayed, store the UPS and ancillary cabinets indoors in a clean, dry, and cool location. Batteries require specific storage conditions; unpack, install, and charge them as soon as possible. A “Charge Before Date” notice is affixed to units with batteries.

NOTICE: Failure to properly charge batteries can cause permanent damage and void the warranty.

2.2 Preliminary Checks

An identification tag on the back of the main door lists the UPS type and size.

2.3 UPS Location

Choose a location that offers:

• Easy access for input, output, and auxiliary equipment connections.
• Sufficient space for servicing.
• Adequate air circulation for heat expulsion.
• Protection from moisture, humidity, dust, and debris.
• Compliance with fire prevention regulations.
• An operating environment temperature of 74-80°F (23-27°C) for optimal battery life.

2.3.1 Positioning the UPS

Ensure the location meets environmental conditions specified in Section 7.2, particularly ambient temperature and air exchange. The UPS requires 24 inches (610mm) of clearance above the unit for proper airflow.

2.3.2 Environmental Considerations

The UPS should be installed in a cool, dry, clean-air environment with adequate ventilation, maintaining an ambient temperature between 32°F and 104°F (0°C to 40°C). For optimal performance and service life, maintain 74-80°F (23-27°C).

2.4 Considerations in Moving the Liebert EXM

Ensure the UPS weight is within the surface weight loading capacity of handling equipment. The Liebert EXM can be rolled on its casters for short distances; use a forklift for longer distances. The UPS weight ranges from 684 lb (320 kg) to 1516 lb (688 kg).

WARNING: Risk of moving heavy unit. Ensure lifting equipment has sufficient capacity. The UPS presents a tipping hazard; do not tilt more than 15 degrees from vertical.

NOTICE: Casters are for even surfaces only. Shock loading can cause caster failure and unit tipping.

2.5 Mechanical Considerations

The Liebert EXM features a steel frame with removable panels and doors for access to power connections and switches. It includes an Operator Control Panel for status and alarm information. The wiring cabinet, available for 160-200 kVA models, provides space for conduit and power connections when a Liebert MBC is not used.

2.5.1 Dimensions

Refer to Figure 1 for UPS dimensions. Models range from 20-140 kVA and 160-200 kVA, with the latter including a wiring cabinet.

WARNING: Vertiv recommends lifting units using four eyebolts installed in factory-fabricated holes.

2.5.2 Clearances

Provide at least 36 inches (914mm) of front clearance for personnel access with the door fully open. Rear clearance depends on the anchoring system, up to 5 inches (127mm) may be required. A minimum of 24 inches (610mm) clearance is needed above the unit for air circulation.

Table 1 lists UPS weights by kVA rating.

2.5.3 Floor Installation

If installing on a raised floor, the UPS must be mounted on a pedestal that supports its point loading.

2.5.4 Cable Entry

Cables can enter from the top or bottom through removable metal plates. Conduit size and wiring methods must comply with all applicable codes and regulations, including NEC ANSI/NFPA 70. The UPS must be accessible from the front for connections and adjustments.

Figures 2 and 3 illustrate cable entry locations for different kVA models.

NOTICE: The customer must provide a disconnect with overcurrent protection at the UPS output.

2.6 Auxiliary Cabinets

The Liebert EXM system can be expanded with optional auxiliary cabinets:

• Battery Cabinets: Provide extended run time and bolt to the left side of the UPS. Refer to SL-25651.
• Maintenance Bypass Cabinet: Houses components for an external wraparound maintenance bypass switch. Bolts to the right side of the UPS. Refer to SL-25652.
• Parallel Cabinet: Provides components for parallel operation of two Liebert EXM units. Refer to SL-25654.

All cabinets are the same height and designed for side-by-side positioning.

2.7 Liebert Power Module Assembly

The Power Module Assembly includes a BATTERY START button, a Run LED (green), and a Fault LED (red). Table 2 details LED indications.

2.8 Control Module

The Control Module features three Liebert IntelliSlot™ interface card bays and connections for optional ancillary cabinets and other options.

2.9 Static Bypass Assembly

This assembly facilitates connections for various functions, including Liebert IntelliSlot bays and DB9/DB15 connectors.

3.0 Electrical Connections—UPS

After mechanical installation, the UPS requires power and control cabling. Control cables must be run separately from power cables in metal conduits or ducts.

3.1 Power Cabling

Cable sizing depends on voltage, current, room temperature, and installation conditions. Refer to ANSI/NFPA 70.

3.1.1 Lug Size and Cable Rating

• UPS input cables: Sized for maximum input current, including recharge current.
• UPS bypass and output cables: Sized for nominal output current.
• Battery cables: Refer to the Liebert EXM External Battery Cabinet manual (SL-25651).

WARNING: De-energize and lockout/tagout all power circuits before installing cables or making connections.

Table 3 provides busbar torque requirements, and Table 4 specifies terminal block torque for control wiring.

3.2 External Protective Devices

External circuit breakers or other protective devices are necessary for the UPS input AC supply. Connect only to circuits with branch circuit overcurrent protection per NEC ANSI/NFPA 70.

3.2.1 Rectifier and Bypass Input Supply of the UPS

Install suitable protective devices in the distribution unit. For split bypass, separate devices are needed for rectifier and bypass inputs. A shunt trip coil is required for the bypass input breaker if a Liebert Bypass Cabinet is not used.

Residual Current Detectors (RCDs) must be sensitive to DC unidirectional pulses (Class A) and insensitive to transient current pulses.

3.2.2 UPS Output

Protective device selection for external distribution panels must provide discrimination with input protective devices.

3.2.3 UPS Input Configuration

By default, the Liebert EXM uses internal links for a single input configuration. For a split bypass (single source dual-input), remove links and wire bypass and main feeds separately. Refer to Figures 8 and 9.

3.2.4 Cabling Guidelines

• Use wiring rated at 75°C or greater.
• Size the neutral cable carefully due to potential current from non-linear loads.
• Size the ground conductor based on fault rating, cable lengths, and protection type.
• Use separate conduits for control and power wiring, and for input and output cables.
• Consider paralleled smaller cables for heavy currents.
• Refer to SL-25651 for battery cable sizing.
• For distribution networks, UPS output cables can be rated for individual network demands.
• Avoid forming coils when laying power cables to minimize electromagnetic interference.

3.2.5 Cable Connections

Rectifier input, bypass, output, and battery connections are accessible from the front. They connect to busbars on the front of the Liebert EXM (Figure 10).

NOTICE: For single-input systems, connect only power wiring to the input busbars.

3.2.6 Accessory Fuses and Back-Feed Breaker Wiring

Two fuse blocks provide power for back-feed breakers and the BDSUi (optional). The back-feed breaker fuse block is rated for 8 amps. The Liebert EXM lacks internal back-feed protection; a 120V shunt trip coil is required in the bypass input breaker if a Liebert Bypass Cabinet is not used.

Figure 11 shows fuse-holder locations, and Figure 12 illustrates back-feed breaker wiring.

3.2.7 Safety Ground

The safety ground busbar is located below the neutral busbars. Connect the safety ground cable to this busbar and bond it to each cabinet. Grounding reduces problems caused by electromagnetic interference.

WARNING: Failure to follow proper grounding procedures can result in electric shock or fire.

3.2.8 Protective Devices

External circuit breakers are required for the input AC supply. Refer to Table 22 for overload capacity. For dual input single source systems, protect rectifier and bypass inputs separately.

The Liebert EXM’s main input and bypass input busbars have fuses (Bussmann 170M6466, 1250A).

3.2.9 Cabling Procedure

1. Ensure all power circuits are de-energized and locked out/tagged out.
2. Remove the front I/O panel for access.
3. Connect facility ground and ancillary ground bus cables to the copper ground busbar.
4. Make power connections according to steps 5-8, ensuring correct phase rotation.
5. For common bypass and main inputs, connect AC input supply to UPS input terminals.
6. For split bypass, connect AC input to rectifier terminals and AC bypass to bypass input terminals.
7. Connect system output cables between UPS output busbars and the critical load.
8. Refit all protective covers.

CAUTION: Operations must be performed by authorized electricians or qualified technical personnel.

3.3 Control Cables Details

3.3.1 Static Bypass Assembly Features

The static bypass assembly provides terminations for auxiliary connections, including battery management, PC communication, alarm signaling, and Remote Emergency Power Off (REPO).

3.4 Dry Contacts

Input and output dry contacts are available on the Auxiliary Terminal Block (ATB).

3.4.1 Input Dry Contacts

External input dry contacts are connected via the ATB for functions like environment detection and battery ground fault detection. The UPS accepts zero-voltage (dry) contacts. Cables must be separated from power cables and double-insulated.

Figure 16 shows input dry contacts, and Table 5 details the ports and descriptions for J26.

3.4.2 Output Dry Contacts

The ATB has three output dry contact relays. Figure 17 and Table 6 describe their functions.

3.4.3 Liebert MBC Interface

The Liebert MBC interface is located at J26 on the ATB.

3.4.4 Battery Cabinet Interface Connectors

The battery cabinet interface is at J22 on the ATB. Figure 18 and Table 8 provide details.

3.4.5 EPO Input—Optional

The UPS features an Emergency Power Off (EPO) function, activated by a control panel button or a remote contact. The J2 connector is for the remote EPO input. Do not apply more than 12V to the EPO input.

NOTICE: Exceeding 12V on the EPO input can damage internal circuitry and render the unit non-functional.

Figure 19 illustrates EPO wiring, and Table 9 details EPO input contact relays.

3.5 Parallel Cable Connections

Figure 21 shows the parallel cable wiring diagram for different configurations.

4.0 Installation Drawings

This section provides diagrams illustrating the mechanical and electrical characteristics of the Liebert EXM UPS cabinets.

Figure 22 shows UPS dimensions. Figure 23 identifies main UPS components. Figure 24 details UPS cable connections.

5.0 Option Installation

5.1 Liebert IntelliSlot™ Communication

The Liebert EXM has three Liebert IntelliSlot ports for optional communication cards that translate information into protocols like SNMP and Modbus, or provide dry contact signals.

5.2 Liebert IntelliSlot Web Card—SNMP/HTTP Network Interface Card

This card provides real-time data and status information via SNMPv1 traps and a web browser interface over a 10/100-baseT Ethernet connection.

5.2.1 Liebert IntelliSlot Unity Cards—IS-UNITY-LIFE, IS-UNITY-S, IS-UNITY-DP

• IS-UNITY-LIFE: For communication with Vertiv’s Trellis® NMS and LIFE™ services.
• IS-UNITY-DP: For communication with two third-party platforms (SNMP, 485) and Vertiv services.

Table 10 lists Liebert EXM communication options.

5.3 Liebert IntelliSlot™ Web Card—Optional

An optional web card offers remote access to UPS status and information via an Ethernet connection.

5.4 Liebert IntelliSlot™ Relay Card

The IS-RELAY card provides voltage-free contact closures for remote alarm monitoring (On Battery, On Bypass, Low Battery, Summary Alarm, UPS Fault, On UPS). It is rated for 24 VAC/DC at 1A.

5.4.1 Liebert IntelliSlot Relay Card Pin Configuration

The card has two terminal blocks, TB1 and TB2. Table 11 details the pin configuration and functions.

5.4.2 Liebert IntelliSlot™ Relay Card Jumper Setup

Five jumpers (P3-P7) are present on the card. By default, shunts are installed to tie relay commons together. Remove shunts if external voltage sources are present.

Table 12 shows jumper connections.

6.0 Operation

This section describes the Liebert EXM’s operating modes, including transfers between modes, settings, and startup/shutdown procedures.

WARNING: High AC and DC voltages are present. Check for voltage with voltmeters before contact. Only trained personnel should perform installation and maintenance.

6.1 Touchscreen Control Panel

The active touchscreen LCD allows logging in, customizing the interface, checking UPS status, silencing alarms, turning the UPS On/Off, resetting faults, and enabling Energy Saving Mode.

6.2 Access Level Log-In

Four access levels provide security:

• Observer: Viewing only.
• Operator: Start/shut down UPS, edit display, test battery, reset faults, enable/disable Eco Mode, acknowledge alarms.
• Administrator: All Operator functions plus changing PINs, configuring Status Gauge, setting energy saving mode, changing network protocols.
• Service: All Administrator functions plus altering system configuration.

6.3 Default PIN’s

Default PINs are Operator: 1234, Administrator: 2345. These should be changed immediately.

NOTICE: Change default PINs to prevent unauthorized changes.

6.4 Liebert EXM Operating Modes

The UPS operates in the following modes:

• Load on Inverter Mode
• Load on Battery Mode (requires optional external battery cabinet)
• Auto-Restart Mode
• Eco Mode (single-module UPS only)
• Load on Bypass Mode
• Module Redundancy Mode
• Maintenance Mode (Manual Bypass)
• Sleep Mode
• Paralleling Mode
• Output Voltage Adjustment
• Generator Mode

Load on Inverter Mode: Rectifier supplies DC power to the inverter, which generates AC power for the load. Rectifier also charges batteries.

Module Redundancy Mode: Load percentage is calculated based on available power module capacity. Up to one module can be set for redundancy.

Load on Battery Mode: In case of utility power failure, batteries instantly power the inverter to support the load. Automatically reverts to Load on Inverter Mode when utility power returns.

Auto-Restart Mode: After an extended AC utility failure, the UPS can be programmed to auto-recover after a delay time if the AC utility recovers and the battery reaches End of Discharge (EOD).

Load on Bypass Mode: Load is directly supported by utility power without battery backup. Transfers occur without interruption if the inverter is synchronous with bypass.

Eco Mode: Switches inverter power to bypass to save energy. Bypass is the preferred source; load transfers back to the inverter if bypass voltage/frequency limits are exceeded.

Maintenance Mode: For maintenance, the UPS can be operated in maintenance mode. Refer to Section 6.6.

Output Voltage Adjustment: Allows adjustment of output voltage by -5% to +5% of nominal.

Generator Mode: Requires setup by a Vertiv Services engineer by connecting J26 Pin 2 to Pin 4.

NOTICE: Load on Bypass Mode offers no protection against supply aberrations.

WARNING: In maintenance mode, input and output busbars remain energized.

6.5 UPS Startup

The UPS must be fully installed and commissioned before startup. External power isolators must be closed.

NOTICE: If feeding a downstream transformer, use maintenance bypass to energize the UPS to mitigate in-rush current.

6.5.1 Startup Procedure

1. Log in as Operator, Administrator, or Service.
2. Ensure Liebert Power Module Assembly ready switches are latched.
3. Close the external input circuit breaker and connect input power.
4. The rectifier starts, and the bypass static switch activates.
5. Close the external output circuit breaker.
6. Touch OPERATE, then Inverter On. Confirm when prompted.
7. Power module run lights flash green during inverter startup, then turn solid green.
8. Close the battery breaker.

WARNING: Output terminals become live during this procedure. Ensure connected load is ready for power.

6.5.2 Startup in Eco Mode

For single-module Liebert EXM systems:

1. Log in.
2. Touch OPERATE, then Energy Saving Mode Activation Setup.
3. Select Enable from the drop-down menu.
4. Touch Save. The status bar will indicate ENERGY SAVING MODE ACTIVE.

6.5.3 Switching Between UPS Operation Modes

To switch from Load on Inverter to Static Bypass:

1. Log in.
2. Touch OPERATE, then Inverter Off. Confirm when prompted.

NOTICE: Load on Bypass Mode offers no protection against supply aberrations.

To switch from Load on Bypass to Load on Inverter:

1. Log in.
2. Touch OPERATE, then Inverter On. Confirm when prompted.

6.6 Switching the UPS from Normal Operation to Maintenance Bypass

This procedure transfers the load from the UPS inverter to the Maintenance Bypass system. It must be performed by trained personnel.

NOTICE: Ensure bypass supply is regular and inverter is synchronous with it to avoid interruption.

1. Log in.
2. Touch OPERATE, then Inverter Off. Confirm.
3. Open the Liebert MBC door to access breakers.
4. Press and hold the push button, then remove the key (K0).
5. Insert the key into the MBB lock and close the MBB.
6. Verify MBB is closed.
7. Open the MIB.
8. Remove the key from MIB, insert into K0 and turn.
9. The UPS is now isolated from the critical load.
10. For single-input systems, the BIB remains closed. For dual-input systems, BIB can be opened.

NOTICE: Load is not protected in maintenance bypass mode.

WARNING: Wait 5 minutes for DC busbar capacitors to discharge before removing internal barriers.

WARNING: Portions of the UPS remain energized even when in maintenance bypass and Off.

6.7 Switching the UPS from Maintenance Bypass to Normal Operation

This procedure transfers the load from the Maintenance Bypass system back to the UPS inverter output. It must be performed by trained personnel.

Conditions: UPS operating normally, BIB closed, UPS in Maintenance Bypass mode.

1. Verify UPS is in Load on Bypass Mode.
2. Open the Liebert MBC door.
3. Press and hold the push button, remove key (K0).
4. Insert key into MIB lock and close MIB.
5. Verify MIB is closed.
6. Open MBB. Remove key from MBB.
7. Insert key into K0 and turn. The UPS is now supplying power.
8. Log in.
9. Touch OPERATE, then Inverter On. Confirm.

NOTICE: Pressing Alarm Silence cancels audible alarm but leaves message displayed.

6.8 De-Energize Liebert EXM with Maintenance Bypass Cabinet

This procedure removes power from the critical bus and must be performed by trained personnel. Provide backup power or shut down equipment beforehand.

1. Log in.
2. Touch OPERATE, then Inverter Off. Confirm.
3. Open all battery circuit breakers.
4. Open the Maintenance Isolation Circuit Breaker (MIB) if using a Vertiv MBC.
5. Open the Rectifier Input Circuit Breaker and Bypass Input Breaker (if dual input).
6. Allow 5 minutes for DC circuits and capacitors to discharge.
7. Open the external feeder breaker to the MBC.
8. Apply Lockout/Tagout to the external feeder breaker.
9. Verify no AC or DC voltage is present at UPS input, output, and bypass busbars using a multimeter.
10. Verify no AC or DC voltage is present at MBC BIB, MIB, and MBB breakers.

6.9 De-Energize Liebert EXM Without Maintenance Bypass Cabinet

This procedure removes power from the critical bus and must be performed by trained personnel. Provide backup power or shut down equipment beforehand.

1. Log in.
2. Touch OPERATE, then Inverter Off. Confirm.
3. Open all battery circuit breakers.
4. Open the UPS output circuit breaker(s).
5. Open the UPS input and bypass circuit breakers (dual input systems only).
6. Allow 5 minutes for DC circuits and capacitors to discharge.
7. Use a digital multimeter to verify no AC or DC voltage is present at the UPS input, output, and bypass busbars.

6.10 Parallel Operations—Determine Control Panel Firmware Version

Parallel operation procedures vary by firmware version. Check the firmware version via the touchscreen menu (Context Menu > About).

6.11 Parallel Operations—Software Version 1.1

6.11.1 De-Energize a Liebert EXM Parallel System—Software Version 1.1

1. Log in.
2. Prepare system and load for shutdown.
3. Touch OPERATE, then Inverter Off. Select System.
4. Power module run lights flash yellow during shutdown; inverters turn off, static bypass closes.
5. Check parallel switchgear.
6. Open MIB (Vertiv cabinet) or relevant breakers. Open all Module Output Breakers (MOB).
7. Open input breakers for each UPS and the breaker feeding the MBB.

NOTICE: Shut down load or transfer to independent supply before de-energizing.

6.11.2 Re-Energize a Liebert EXM Parallel System—Software Version 1.1

1. Log in.
2. Close input breakers for all UPSs.
3. LCDs activate, rectifiers start, bypass and output icons illuminate green. Battery LED is red.
4. Close Module Output Breakers (MOB) for each UPS.
5. Close MIB breaker.
6. Touch OPERATE, then Inverter On. Select System.
7. Inverters start, static bypass opens, icons turn solid green.
8. Close all battery breakers.

6.12 Parallel Operations—Software Version 1.0

6.12.1 De-Energize a Liebert EXM Parallel System—Software Version 1.0

1. Log in.
2. On each UPS, touch OPERATE, then Inverter Off.
3. All units transfer to bypass.
4. Open all battery circuit breakers.
5. Check parallel switchgear. Open MIB (Vertiv cabinet) or relevant breakers. Open all MOBs.
6. Open input breakers for each UPS and the breaker feeding the MBB.

NOTICE: Shut down load or transfer to independent supply before de-energizing.

WARNING: Notify personnel that input power is being supplied.

6.12.2 Re-Energize a Liebert EXM Parallel System—Software Version 1.0

1. Close input breakers for all UPSs.
2. Rectifiers start.
3. Close MOB circuit breakers for each UPS. Static switch turns on.
4. Close MIB breaker.
5. Verify K0 light illuminates.
6. Log in on UPS 1, touch OPERATE, then Inverter On.
7. Repeat for UPS 2 and others.
8. All UPSs synchronize and transfer online.
9. Close all battery circuit breakers.
10. Verify green Run lights and green status indicators.

WARNING: Notify personnel that input power is being supplied.

6.12.3 De-Energize and Isolate a Single Liebert EXM in a Parallel System—Software Version 1.0

This procedure removes power from one UPS in a parallel system. Ensure remaining UPSs can handle the load.

1. Determine system setup (capacity or redundancy).
2. Verify remaining UPSs can support the load.
3. Log in on the UPS to be de-energized.
4. Touch OPERATE, then Inverter Off.
5. Open the MOB for the isolated UPS.
6. Open all battery circuit breakers for the UPS.
7. Open the input breaker feeding the UPS.

The isolated UPS is Off. Other UPSs will display communication alarms.

6.12.4 Re-Energize a Single Liebert EXM in a Parallel System—Software Version 1.0

1. Close the input breaker feeding the Liebert EXM to be re-energized.
2. The isolated UPS LCD activates, and the rectifier starts.
3. Close the MOB for the isolated UPS.
4. Log in on the isolated UPS, touch OPERATE, then Inverter On.
5. Close all battery circuit breakers.
6. Verify green Run lights and status indicators.

WARNING: Notify personnel that input power is being supplied.

6.12.5 Place a Liebert EXM Parallel System with SKRU Interlock in Maintenance Bypass—Software Version 1.0

This procedure places the UPSs in bypass. The load will not be protected from utility failure.

1. Log in on the UPS to be bypassed.
2. Touch OPERATE, then Inverter Off. Repeat for all UPSs.
3. All UPSs transfer to bypass.
4. Open all battery circuit breakers.
5. Check parallel switchgear.
6. If a Kirk key interlock is present, follow steps a-d to close MBB and open MIB.
7. If a Kirk key interlock is present, follow steps g-h to lock MIB and K0.
8. Open all MOBs.
9. Open the input breakers feeding each UPS.

6.12.6 Re-Energize a Liebert EXM Parallel System with SKRU Interlock Online from Maintenance Bypass—Software Version 1.0

1. Close input breakers feeding all UPSs. Rectifiers start.
2. Close MOB for all UPSs. Output LED turns solid green.
3. If a Kirk key interlock is present, follow steps a-d to close MIB.
4. Open MBB.
5. If a Kirk key interlock is present, follow steps f-g to lock MBB and K0. The load is now powered by the UPS static switch.
6. Log in on UPS 1, touch OPERATE, then Inverter Off. Repeat for all UPSs.
7. Close all battery circuit breakers.
8. Verify green Run lights and status indicators.
9. Check LCDs for alarms.

The system is now online and supporting the load.

6.13 Emergency Shutdown With EPO

The Emergency Power Off (EPO) circuit shuts down the rectifier, inverter, and bypass immediately. The battery stops charging or discharging. Output is turned Off if utility is present. Open external feeder breaker to remove all power.

6.14 Auto Restart

After battery depletion during a utility failure, the UPS shuts down at End of Discharge (EOD). It can be programmed to auto-restart when utility power is restored, if “Auto Recovery after EOD Enabling” is active, and after the “Auto Recovery after EOD Delay Time” expires (default 10 minutes). During the delay, batteries charge.

If auto-recovery is disabled, manual restart is required.

6.15 Reset After Shutdown for Emergency Stop (EPO Action) or Other Conditions

After correcting an alarm condition (e.g., Inverter Overtemperature, Overload, Battery Overvoltage), follow these steps to restore normal operation:

1. Log in.
2. Touch OPERATE, then the yellow Reset button.
3. Press and hold Inverter On for over 2 seconds (after rectifier qualification).

If input utility is removed after EPO, the UPS shuts down completely. Upon utility restoration, the EPO condition clears, static bypass restores output.

6.16 Battery Protection

6.16.1 Battery Undervoltage Warning

A low-battery warning is displayed before EOD, providing approximately 5 minutes of full-load discharge time (user-configurable from 3 to 60 minutes).

6.16.2 Battery End-of-Discharge (EOD) Protection

If battery voltage drops below EOD, the battery converter shuts down.

6.17 Operation

The Liebert EXM operates in various modes as detailed in Table 13. The AC utility powers the rectifier, which converts AC to DC for the inverter and battery charging. The inverter converts DC to AC for the load. Batteries power the load via the inverter during power failures. The static bypass can also power the load.

WARNING: Internal components carry high voltages. Only trained service personnel should remove protective covers.

6.18 Static Bypass Switch

The static bypass switch connects the critical load to either the inverter output or a bypass power source. It automatically transfers the load in case of UPS overload or inverter failure. For a seamless transfer, the inverter output and bypass supply must be synchronized.

NOTICE: Load on Bypass Mode offers no protection against supply aberrations.

7.0 Specifications and Technical Data

7.1 Conformity and Standards

The Liebert EXM conforms to UL 1778, CSA 22.2 107.3-14, IEC 61000-4-5, IEC 61000-3-4, IEC 61000-4-4, IEC 61000-4-2, FCC Part 15 Class A, IEC 61000-4-3, IEC 61000-4-6, IEC 61000-2-2, ISTA Procedure 1H, ISO 9001, OSHA, ASME, and NEMA PE-1. It is UL and c-UL approved.

7.1.1 ENERGY STAR® Certification

The Liebert EXM UPS is ENERGY STAR certified.

7.2 UPS Environmental Requirements

The UPS operates within specified environmental conditions without damage or degradation. Table 14 lists requirements for acoustical noise, operating altitude, relative humidity, operating temperature, and storage/transport temperature.

7.3 UPS Electrical Characteristics

Tables 16-24 provide detailed electrical specifications, including input/output currents, voltages, frequencies, power factor, THD, and battery DC intermediate circuit parameters. Table 25 lists recommended lug sizes.

8.0 Maintenance

8.1 Safety Precautions

Maintenance must be performed by trained and qualified personnel. Observe all warnings and cautions, including those pertaining to batteries.

WARNING: High AC and DC voltages are present. Always identify wiring sources before disconnecting. Do not substitute parts. Keep cabinets free of foreign materials. Contact Vertiv Services if unsure.

WARNING: Extreme caution is required. High voltages may persist after power is Off. Use rubber mats for isolation. Use differential oscilloscopes for floating circuits. Use only approved fire extinguishers.

8.2 Limited-Life Components

The Liebert EXM has a design life exceeding 10 years. Certain components have a shorter life cycle and require periodic inspection and replacement to prevent failure. Contact 1-800-LIEBERT for assistance with component specifications and sourcing.

Table 26 lists components with limited expected life: Air filters (5 years), Power Modules & Static Bypass Assembly (20 years), Frame Fans (10 years).

8.3 Routine Maintenance

Keep good records, maintain a dust- and moisture-free environment, keep the UPS cool (batteries 72-77°F / 22-25°C, UPS optimal at battery temperature), and keep connections tight.

8.3.1 Record Log

Maintain a log for scheduled checks, abnormal conditions, metered data, alarm messages, UPS mode, and filter replacement dates. A separate battery module log is recommended.

8.3.2 Air Filters

Inspect and service air filters regularly, approximately every two months under normal conditions. Replaceable filter elements are located behind the grille on the front of the unit and can be changed while the UPS is operating. Filters are washable and reusable.

Replacing Air Filters: Requires a Phillips screwdriver. Open the front door, locate filters, remove brackets, replace filter, and reassemble.

8.3.3 Torque Requirements

All electrical connections must be tight. Tables 27 and 28 provide torque values for busbars and terminal blocks.

8.4 Detecting Trouble

Monitor instrument readings for deviations from normal. Check output voltage, output currents (for balance), battery charging current, and input current. Alarm messages indicate malfunctions. Refer to Appendix B for status messages.

8.5 Reporting a Problem

Review alarm messages and pertinent data before reporting a problem to Vertiv Services at 800-543-2378.

8.6 Corrective Actions

Recommended corrective actions for alarm messages are found in Appendix B.

8.7 Recommended Test Equipment

Table 29 lists recommended test equipment and tools for maintenance and troubleshooting.

APPENDIX A – HAZARDOUS SUBSTANCES OR ELEMENTS ANNOUNCEMENT

Table 30 lists hazardous substances present in various parts of the UPS. Vertiv is committed to reducing hazardous substances in its products.

APPENDIX B – UPS STATUS MESSAGES

Table 31 provides a list of event messages, their descriptions, and suggested actions for troubleshooting.