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AC Power
For Business-Critical Continuity
Liebert® NXL
™
Operation and Maintenance Manual – 250 to 800kVA, 50/60Hz, Three Phase Single-Module and 1+N
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Dear Customer,
Please allow us to congratulate you on choosing a Liebert manufactured
Uninterruptible Power Supply (UPS) system.
If this is your first Liebert UPS, we cordially welcome you to a lifetime
relationship of post-sales support designed to keep your Liebert UPS and
your systems permanently at their peak performance.
If you already own and use a Liebert UPS, then we are doubly honoured by
your decision to continue this valued relationship.
It is our constant endeavour to partner you to ensure the growth & success
of your business;
our philosophy is reflected in our mission statement “Keeping Business
in Business”.
Please give us your valued feedback to help us realise our mission.
EMERSON NETWORK POWER
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© 2009 Emerson Network Power.
All Rights Reserved. No part of this document may be photocopied,
reproduced, stored in a retrieval system, or transmitted, in any form or
by any means whether, electronic, mechanical, or otherwise without the
prior written permission of Emerson Network Power.
No warranty of accuracy is given concerning the contents of the
information contained in this publication. To the extent permitted by
law no liability (including liability to any person by reason of
negligence) will be accepted by Emerson Network Power, its
subsidiaries or employees for any direct or indirect loss or damage
caused by omissions from or inaccuracies in this document.
Emerson Network Power reserves the right to change details in this
publication without notice.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
-----------------------------------------------
-----------------------------------------------Table of Contents
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Table of Contents----------------------------------------------
Table of ContentsTable of Contents
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1 INTRODUCTION.......................................................................................................... 11
1.1
General Description .................................................................................................................................... 11
1.2
Modes of Operation .................................................................................................................................... 11
1.2.1 Normal Mode ........................................................................................................................................... 11
1.2.2 Bypass Mode............................................................................................................................................ 12
1.2.3 Battery Mode ........................................................................................................................................... 12
1.2.4 Maintenance Bypass ................................................................................................................................ 12
1.3
Options......................................................................................................................................................... 13
2 OPERATION ................................................................................................................. 14
2.1
Features ....................................................................................................................................................... 14
2.2
Touchscreen Navigation ............................................................................................................................. 19
2.2.1 Main Display Screen ................................................................................................................................ 19
2.2.2 Help.......................................................................................................................................................... 19
2.2.3 Metering................................................................................................................................................... 19
2.2.4 Silence...................................................................................................................................................... 19
2.2.5 Reset......................................................................................................................................................... 19
2.2.6 Configurations Menu ............................................................................................................................... 20
2.2.7 Status Reports Menu ................................................................................................................................ 28
2.2.8 Startup Menu............................................................................................................................................ 29
2.2.9 Shutdown Menu ....................................................................................................................................... 29
2.2.10
Transfer Menu ..................................................................................................................................... 31
2.2.11
Battery Management Menu ................................................................................................................. 31
2.3
Modes of Operation .................................................................................................................................... 35
2.3.1 Load on Bypass........................................................................................................................................ 35
2.3.2 OK to Transfer ......................................................................................................................................... 36
2.3.3 Input Power Failure—Load on Battery.................................................................................................... 36
2.3.4 Off Battery ............................................................................................................................................... 37
2.3.5 Emergency Power Off (EPO) .................................................................................................................. 38
2.3.6 Remote Emergency Power Off (REPO)................................................................................................... 38
2.4
Manual Procedures..................................................................................................................................... 39
2.4.1 Startup Procedure..................................................................................................................................... 39
2.4.2 Load Transfer Procedures ........................................................................................................................ 42
2.4.3 Maintenance Bypass Load Transfers ....................................................................................................... 43
2.5
Shutdown Procedures................................................................................................................................. 45
2.5.1 Module Shutdown Procedure ................................................................................................................... 45
2.6
Automatic Operations ................................................................................................................................ 46
2.6.1 Overloads (Without Transfer) .................................................................................................................. 46
2.6.2 Automatic Transfers to Bypass (Overload Condition) ............................................................................. 47
2.6.3 Automatic Transfers to Bypass, UPS System Faults ............................................................................... 47
2.6.4 Automatic Retransfers to UPS ................................................................................................................. 48
2.7
1+N System Operating Procedures ........................................................................................................... 49
2.7.1 General..................................................................................................................................................... 49
2.7.2 Introduction.............................................................................................................................................. 49
2.7.3 Preliminary checks ................................................................................................................................... 49
2.7.4 System start-up......................................................................................................................................... 49
2.7.5 Cut off and separate one UPS module from the running parallel system................................................. 54
2.7.6 Recover the UPS module separated from parallel system........................................................................ 54
2.7.7 The steps of shutdown UPS and Load ..................................................................................................... 54
2.7.8 The steps of operation of maintenance bypass......................................................................................... 56
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3 MAINTENANCE ........................................................................................................... 57
3.1
Safety Precautions ...................................................................................................................................... 57
3.2
Liebert Services........................................................................................................................................... 58
3.2.1 Professional Start-up ................................................................................................................................ 58
3.3
Routine Maintenance.................................................................................................................................. 59
3.3.1 Record Log .............................................................................................................................................. 59
3.3.2 Air Filters................................................................................................................................................. 59
3.3.3 Limited Life Components ........................................................................................................................ 60
3.4
Battery Maintenance .................................................................................................................................. 61
3.4.1 Battery Safety Precautions ....................................................................................................................... 61
3.4.2 Batteries ................................................................................................................................................... 63
3.5
Detecting Trouble ....................................................................................................................................... 64
3.6
Reporting a Problem .................................................................................................................................. 64
3.7
Corrective Actions ...................................................................................................................................... 64
4 SPECIFICATIONS ....................................................................................................... 65
4.1
Battery Operation ....................................................................................................................................... 65
4.2
Environmental Conditions ......................................................................................................................... 65
5 APPENDIX A-UPS ALARM AND STATUS MESSAGES........................................ 70
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Figures
Figures
FiguresFigures
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---------------------------------------
----------------
-------------------------------
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Figure 1 Typical UPS system one-line diagram .................................................................. 11
Figure 2 Main component locations..................................................................................... 15
Figure 3 Main Display screen, typical.................................................................................. 16
Figure 4 Mimic display ......................................................................................................... 16
Figure 5 Monitor/mimic display example: Normal power flow ...................................... 17
Figure 6 Monitor/mimic display example: Utility fail....................................................... 17
Figure 7 Monitor/mimic display example: Load on bypass, UPS On.............................. 18
Figure 8 Monitor/mimic display example: Load on bypass, UPS module Off ............... 18
Figure 9 Menu tree ................................................................................................................ 19
Figure 10 Rating Parameters................................................................................................. 20
Figure 11 System Settings parameters ................................................................................. 21
Figure 12 Adjustable setpoints parameters ......................................................................... 22
Figure 13 Battery Equalize settings...................................................................................... 23
Figure 14 Battery Management Parameters ........................................................................ 23
Figure 15 Typical Event Management Parameters ............................................................. 25
Figure 16 Load Bus Sync screen ........................................................................................... 26
Figure 17 Input Contact Isolator Board screen ................................................................... 26
Figure 18 Programmable Relay Board screen ..................................................................... 27
Figure 19 Event Log............................................................................................................... 28
Figure 20 Shutdown menu ................................................................................................... 29
Figure 21 UPS shutdown popup .......................................................................................... 30
Figure 22 System shutdown popup ..................................................................................... 30
Figure 23 Transfer/retransfer commands ........................................................................... 31
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 24 Time remaining display ...................................................................................... 32
Figure 25 Battery cycle monitor........................................................................................... 33
Figure 26 Battery cycle monitor summary ......................................................................... 34
Figure 27 Battery cycle monitor—clear log ........................................................................ 34
Figure 28 Load on bypass (UPS not available)................................................................... 35
Figure 29 Load on bypass, UPS available........................................................................... 36
Figure 30 Load on UPS, bypass available.......................................................................... 36
Figure 31 Input power fail, load on battery ....................................................................... 37
Figure 32 Load on UPS, battery not available ................................................................... 37
Figure 33 Emergency Power OFF........................................................................................ 38
Figure 34 Remote emergency power off............................................................................. 38
Figure 35 Start-up commands ............................................................................................. 42
Figure 36 Maintenance bypass transfers............................................................................ 43
Figure 37 Current-versus-time curves of overload capacity............................................ 46
Figure 38 Manual Start to Bypass....................................................................................... 50
Figure 39 Manual Start to Bypass (one or more modules)............................................... 50
Figure 40 Rectifier ON command....................................................................................... 51
Figure 41 Load on Bypass, UPS available.......................................................................... 51
Figure 42 Load on Bypass, BCB closed .............................................................................. 52
Figure 43 Load on UPS........................................................................................................ 52
Figure 44 Parallel System view........................................................................................... 53
Figure 45 Starting 1+N System Shutdown ........................................................................ 55
Figure 46 1+N System Shutdown confirm ........................................................................ 55
Figure 47 1+N System Shutdown....................................................................................... 56
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Tables Index
Tables Index
Tables IndexTables Index
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Table 1: UPS component service life .................................................................................... 60
Table 2 Battery voltage, nominal and float.......................................................................... 63
Table 3: Environmental specifications (250-300-400kVA UPS).......................................... 65
Table 4: Electrical Specifications (250-300-400kVA UPS) ................................................... 66
Table 5: Specifications (800kVA UPS).................................................................................. 68
Table 6: Liebert NXL alarm and status messages ............................................................... 70
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This manual contains information concerning the operation and maintenance of the
Liebert NXL Series Uninterruptible Power System (UPS) and batteries.
All relevant parts of the manual should be read prior to commencing installation.
The UPS must be commissioned and serviced by an engineer approved by the
manufacturer (or his agent).Failure to do could result in personnel safety risk,
equipment malfunction and invalidation of warranty.
Do not apply power to this equipment before a Liebert approved engineer has
commissioned it. This information is required to substantiate any warranty claims that
might be made.
The Liebert NXL UPS has been designed for Commercial/Industrial use only, and is not
recommended for use in any life support applications.
The UPS is for indoor use only.
Warning: This is a product for restricted sales distribution to informed partners.
Installation restrictions or additional measures may be needed to prevent disturbance
(See EN 62040-2).
If you encounter any problems with the procedures contained in this manual you should
seek immediate assistance from the Liebert Sales Office from whom the equipment was
purchased. Alternatively, contact the Emerson Network Power's Customer Service &
Support department at the address shown below:
EMERSON NETWORK POWER srl
Customer Service and Support Department
Via Leonardo da Vinci, 8
35028 Piove di Sacco
Padova (PD) - Italy
Help Desk Telephone +39 049 9719311
Fax +39 049 9719053
Mail to : support.serviceEMEA@EmersonNetworkPower.com
Please visit our web site: http://www.eu.emersonnetworkpower.com
While every precaution has been taken to ensure accuracy and completeness in this
manual, Liebert Corporation assumes no responsibility and disclaims all liability for
damages resulting from use of this information or for any errors or omissions.
Liebert Corporation pursues a policy of continual product development and reserves the
right to change the equipment design without notice.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Requests the user to read the note
SUPPORT INFORMATION:
For repair or maintenance service, contact Liebert Services, if available in your
area. For areas not covered by Liebert Services, the authorized distributor is
responsible for providing qualified, factory-authorized service.
If you require assistance for any reason, please have the following information
available:
• Model and size
• Part number
• Serial number
• Date installed
• Location
• Voltage & Frequency
• Battery reserve time
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
installing, charging or
static
When the UPS system is under power, both the operator and any test equipment must
I
MPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important instructions that should be followed during
installation and maintenance of your Liebert NXL™ UPS and batteries.
Retain this manual for use by installing personnel.
WARNING
Risk of electrical shock. Can cause personal injury or death.
Exercise extreme care when handling UPS cabinets to avoid equipment damage or
injury to personnel. Refer to separate installation manual for equipment handling
information and installation procedures.
Follow all battery safety precautions in 3.0 - Maintenance when
servicing batteries. In addition to the hazard of electric shock, gas produced by
batteries can be explosive and sulfuric acid can cause severe burns.
In case of fire involving electrical equipment, use only carbon dioxide fire
extinguishers or others approved for use in electrical fire fighting.
Extreme caution is required when performing maintenance. Service and maintenance
work must be performed only by properly trained and qualified personnel and in
accordance with applicable regulations as well as with manufacturers’ specifications.
Be constantly aware that the UPS system contains high DC as well as AC voltages.
With input power off and the battery disconnected, high voltage at filter capacitors
and power circuits should be discharged within 5 minutes. However, if a power circuit
failure has occurred, assume that high voltage still exists after shutdown. Check with
a voltmeter before making contact.
AC voltage will remain on the system bypass, the UPS output terminals and the
bypass switch, unless associated external circuit breakers are opened.
Check for voltage with both AC and DC voltmeters prior to making contact.
be isolated from direct contact with earth ground and the UPS chassis frame by using
rubber mats.
Some components within the cabinets are not connected to the chassis ground. Any
contact between floating circuits and the chassis is a lethal shock hazard. Exercise
caution that the test instrument exterior does not make contact, either physically or
electrically, with earth ground.
This equipment contains circuitry that is energized with high voltage. Only
test equipment designated for troubleshooting should be used. This is particularly
true for oscilloscopes. Always check with an AC and DC voltmeter to ensure safety
before making contact or using tools. Even when the power is turned Off, dangerously
high voltage may exist at the capacitor banks.
Observe all battery precautions when near the battery for any reason.
ONLY properly trained and qualified service personnel should perform
maintenance on the UPS system. When performing maintenance on any part of
the equipment under power, service personnel and test equipment should be standing
on rubber mats. The service personnel should wear insulating shoes for isolation from
direct contact with the floor (earth ground).
One person should never work alone. A second person should be standing by to
assist and summon help in case an accident should occur. This is particularly true
when work is performed on the battery.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
1 INTRODUCTION
1.1 General Description
The Liebert NXL UPS provides continuous, high-quality AC power to your
business-critical equipment, such as telecommunications and data processing
equipment. The Liebert NXL UPS supplies power that is free of the
disturbances and variations in voltage and frequency common to utility power,
which is subject to brownouts, blackouts, surges and sags.
The Liebert NXL utilizes the latest in high-frequency, double-conversion pulsewidth modulation technology and fully digital controls to enhance its reliability
and increase the ease of use.
As shown in Figure 1, the AC utility source is input at Q1 and the rectifier
converts the AC utility into DC power. The inverter converts that DC power
from the utility—or DC power from the batteries— into AC power for the load.
The batteries power the load through the inverter in the event of a power
failure. The utility source can also power the load through the static bypass.
If maintenance or repair of the UPS is necessary, the load can be switched
without interruption in service to the maintenance bypass.
Bypass
Mains
Supply
Input
Mains
Supply
Battery
Maintenance Bypass Isolator Q3
Bypass Isolator Q2
DC Bus
RECTIFIER
Input
Isolator Q1
C.B.
Battery Circuit
Breaker
INVERTER STATIC SWITCH
UPS MODULE
Bypass Side
Output
Isolator Q4
UPS
Output
Figure 1 Typical UPS system one-line diagram
1.2 Modes of Operation
1.2.1 Normal Mode
Operating in normal mode, the Liebert NXL’s rectifier derives power from a
utility AC source and supplies regulated DC power to the inverter, which
regenerates precise AC power to supply the connected equipment. The rectifier
also uses the utility source power to charge the batteries.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
1.2.2 Bypass Mode
When the Liebert NXL is in bypass mode, the load is directly supported by
utility power and is without battery backup protection.
The Liebert NXL’s inverter and bypass static switch will shift the load from the
inverter to bypass mode without an interruption in AC power if the inverter is
synchronous with the bypass and any of the following occurs:
• Inverter fails
• Inverter overload capacity is exceeded
• Inverter is manually turned off by the user
NOTE:
If the inverter is asynchronous with the bypass, the static switch will transfer the
load from the inverter to the bypass WITH interruption in AC power to the critical
load. This interruption will be less than 20ms. This interruption time may be
modify through Bypass Transfer Setpoint Menu (for Service only).
1.2.3 Battery Mode
When utility AC power fails, the Liebert NXL protects the critical load by
instantaneously channelling battery power to the inverter, which continues
supporting the critical load without interruption.
When utility power returns and is within acceptable limits, the Liebert NXL
automatically shifts back to Normal mode, with the rectifier powering the
critical load.
1.2.4 Maintenance Bypass
The installation of a Maintenance Bypass Cabinet or Assembly is recommended
to allow you to totally isolate the UPS from all power sources. Use of the
Maintenance Bypass is described in 2.0 - Operation.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
1.3 Options
A number of options are available from Liebert for your UPS system. (Some
options are not available for all ratings.) Described below are the most
frequently provided options. The first three battery items are required to
complete the UPS system. The remaining options provide improved system
performance or convenience. Other options are available. Contact your Liebert
sales representative for more information.
• Battery and Racks—The batteries provide power in the event of a power outage.
The Liebert NXL UPS can use a variety of battery types, provided the battery plant
is designed for the UPS DC voltage range and the load requirements of your
application. This option is required to complete the UPS system.
• Battery Cabinets—Valve-regulated, lead-acid (VRLA) sealed batteries are
available in matching cabinets for convenient installation and maintenance in
otherwise unprotected space.
Depending on the UPS module rating, two or more cabinets may be connected in
parallel to provide the additional run time. This option is required to complete the
UPS system.
• Battery Breaker Disconnect—The UPS system utilizes a separate optional
switch for remotely located batteries. A sensing circuit in the UPS module, set at
the battery low voltage limit, trips the BCB to safeguard the battery from excessive
discharge. The BCB has an undervoltage release mechanism designed to ensure
that during any shutdown or failure mode all battery potential is removed from the
UPS system. This option is required to complete the UPS system.
• Input Current Distortion Filter—This filter reduces input current reflected
harmonic distortion THD at full load. The filter is factory-installed in the UPS. This
filter also improves the input power factor at full load.
• External Maintenance Breaker —This switchboard provides make-before-break
maintenance bypass. It includes: Maintenance Bypass Breaker (MBB),
Maintenance Isolation Breaker (MIB) and two Output Breakers (MOB).
• Load Bus Synchronization—The Load Bus Sync (LBS) option keeps two
independent UPS systems (and therefore their critical load buses) in sync, even
when the modules are operating on batteries or asynchronous AC sources. This
means that critical loads connected to both load buses can switch seamlessly
between the two.
• Customer Alarm Interface—This optional interface board allows the input and
display of eight alarms from customer-supplied contacts, each with a customerselected name of up to 19 characters.
The following attributes can be programmed for each alarm: latching, audible,
event log and time delay (0 to 99.9 seconds).
• Temperature-Compensated Charging—When the battery temperature exceeds
a preset limit (typically 25°C), this optional circuit proportionally reduces float
charging voltage to prevent overcharging the battery.
• Battery Load Testing—When activated, this option forces the battery string to
assume the load for a short period of time. The UPS then compares the test results
to data collected during the UPS commissioning to see if the battery system appears
to meet specifications.
The Liebert NXL will display status events for Battery Equalize, Battery Self-Test and
Battery Commissioning when those options are active.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2 OPERATION
The Liebert NXL UPS is equipped with a microprocessor-based display touchscreen
designed for convenient and reliable operation. The display is driven by an easy-tofollow, menu-prompted software.
2.1 Features
The Liebert NXL interface display enables the operator to perform such tasks
as:
• Quickly check operational status
• Monitor the power flow through the UPS system and all meter readings
• Execute operational procedures
• Check status reports and history files
• Adjustment programmable parameters (access limited by security access
function)
• Adjustment output voltage before performing a manual load transfer.
The touch screen is a white-background display with multicolor text. The display
turns on automatically, but after 15 minutes of inactivity the backlight will go out and
the display will appear very dim.
Touching the screen will reactivate the backlight; the backlight will again be active for
15 minutes. If any screen other than the mimic screen is accessed, that screen will be
displayed for 5 minutes without any interaction. If there is no activity for 5 minutes,
the display will revert to the basic mimic screen.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
1
2
3
4
5
6
: Input isolator
(Q1)
250-300-400kVA
800kVA
1
2: Bypass isolator (Q2)
3: Maintenance bypass isolator
(Q3)
4: Output isolator (Q4)
5: Options box (Intellislot
housings)
6: HMI Screen
: External interface board
(EIB)
: Emergency Power OFF
(EPO)
Figure 2 Main component locations
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Load
Battery block
Bypass
input
Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 3 Main Display screen, typical
UPS input
power
Bypass Input —Displays the bypass input voltage and the bypass input
frequency. The bypass isolator (Q2) is shown as open or closed.
UPS Input Power —Displays the UPS input voltage, current and frequency.
The input isolator (Q1) is shown as open or closed.
Battery Block —Displays the battery voltage and the charge or discharge
current to or from the battery. Pressing this icon switches among the connected
battery strings. The Module Battery Disconnect (BCB) is to the right of this
block. The circuit breaker status is shown as open or closed.
DC Bus —Displays the DC Bus voltage and the state of the battery charger.
Load —Displays the output line voltage, phase voltage, current, kVA, kW,
power factor and frequency. The critical load current per phase is also
displayed in this block. During an overload, the time remaining before transfer
is displayed at the bottom of the load box. After an overload transfer, retransfer
timeout is displayed at the bottom of the load box.
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Figure 4 Mimic display
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Line colour – means:
Green – Normal
Orange – Marginal
Gray – Absent
Black - Unknown
Figure 5 Monitor/mimic display example: Normal power flow
Figure 6 Monitor/mimic display example: Utility fail
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Line colour – means:
Green – Normal
Orange – Marginal
Gray – Absent
Black - Unknown
Figure 7 Monitor/mimic display example: Load on bypass, UPS On
Figure 8 Monitor/mimic display example: Load on bypass, UPS module Off
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2 Touchscreen Navigation
2.2.1 Main Display Screen
Several menu items can be accessed from the main display screen (see Figure 3).
These menu items are detailed in subsequent sections.
Figure 9 Menu tree
2.2.2 Help
This button will display the help menu.
2.2.3 Metering
This button will place the metering tables in the multipurpose window.
2.2.4 Silence
This button will silence the audible alarm.
2.2.5 Reset
This button will reset any non-active latched events.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Not available for SMS
2.2.6 Configurations Menu
2.2.6.1
2.2.6.1 Rating
2.2.6.12.2.6.1
This menu item will display a popup showing the following parameters (see Figure
10). These parameters are entered during commissioning when the UPS is
installed.
• Nominal Input Voltage
• Nominal Bypass Voltage
• Nominal Output Voltage
• Nominal Source Frequency
• Nominal Output Frequency
• Nominal Cell Count
•Output kVA
• Output KW
• Configuration Type
• Rectifier Type
• Input Isolation Transformer
•Unit Model
• Unit Serial
• Maintenance Bypass Model
• Maintenance Bypass Serial
• Battery Cabinet Model
• Battery Cabinet Serial
• Order Number 1
• Order Number 2
• Service Telephone Number
• Site ID Number
• Tag Number
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Figure 10 Rating Parameters
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.6.2
2.2.6.2 System Settings
2.2.6.22.2.6.2
User Settings
These display settings can be changed from the touchscreen. Press the box to the left of
each parameter to bring a popup window that will allow the parameter to be changed.
• Backlight Brightness—High or Low (default: Low)
• Time (24hr format)—Adjust Hour, Minute or Seconds
• Date (MM DD, YYYY format)—Adjust Month, Day or Year
• Password – Reset the password (4 characters, alphanumeric, case-sensitive)
• Language—English, Chinese, French, Spanish, German, Italian, Portuguese
• Audio level—Range 1 to 10 (default: 5)
• Phase labeling—Auto, ABC, RST, XYZ, RYB, RWB, UVW, 123, L1L2L3 (default:
Automatic)
• Unit Locator
• Location ID—Alphanumeric
• System Number—Alphanumeric
• Unit Number—Number (1 through 99)
• Unit Label—Alphanumeric
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Figure 11 System Settings parameters
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.6.3
2.2.6.3 Adjustable Setpoints
2.2.6.32.2.6.3
These warning and alarm settings can be changed from the touchscreen. Press the box to
the left of each parameter to bring a popup window that will allow the parameter to be
changed.
Max Load Alarm
• Phase A (%)—10% to 105% (default: 100%)
• Phase B (%)—10% to 105% (default: 100%)
• Phase C (%)—10% to 105% (default: 100%)
• Delay (second)—0 to 60 (default: 5 seconds)
Manual Xfer Bypass Voltage Limits
• Manual Xfer Bypass Voltage Low Limit (%)—1% to
20% (default: 10%)
• Manual Xfer Bypass Voltage High Limit (%)—1% to 15% (default: 10%)
Figure 12 Adjustable setpoints parameters
Inlet Air Temp Warning
• Inlet Air Temp Warning—30°C to 40°C (default: 35°C)
NOTE
Temperature will display in both Celsius and Fahrenheit.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.6.4
2.2.6.4 Battery Management
2.2.6.42.2.6.4
These battery settings can be changed from the touchscreen. Press the box to the left of
each parameter to bring a popup window that will allow the parameter to be changed.
Battery Equalize
• Equalize Voltage, Vpc - 2.30 to 2.40 (default: 2.3)
• Equalize Time, hours - 0 to 200hours (default: 1)
NOTE
Battery Equalize must be enabled by service to be functional. If Battery Equalize is
disabled, the feature will not be available and the menu item will not be displayed.
Figure 13 Battery Equalize settings
Battery Test
• Auto Test—Enable/Disable (default: disabled)
• Test Cycle, weeks—1 to 26 (default: 13 weeks)
• Time of day, hh:mm—Set Hour and Minute; sets
the start time of the automatic battery test
• Start Date, mm dd, yyyyy—Set Month, Day and
Year
• Test Duration, minutes—0.5 minute to 30% of full
load Operating Time (default: 0.5 minute)
• Minimum Battery Voltage, lead-acid only—
1.75VPC to 1.95VPC (default: 1.75VPC); this is the
minimum voltage the battery test will stop.
Figure 14 Battery Management Parameters
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Low Battery Warning Time
• Low Battery Warning Time, minutes—2 to 15, depending on configured batteries (default:
5 minutes)
Battery Temperature
• Battery Temp Warning—30°C to 50°C (default: 40°C)
• Battery Temp Limit—35°C to 60°C (default: 50°C)
• Disconnect—Enable/Disable (default: disabled)
NOTE
If Disconnect is set to “Enable’ and the Battery Temp Limit is met, the Battery breaker
will open.
Cell Count Adjustment
• Cell Count Adjustment— -12 cells to +6
cells (default: 0)
Float Voltage
• Battery Float Voltage, Vpc—2.15 to 2.3 (default: 2.25)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.6.5
2.2.6.5 Event Management
2.2.6.52.2.6.5
This menu item permits changing how the Liebert NXL handles Alarms, Faults and Status
information. Each event can be configured for the following:
• Latch (yes/no)—Event stays active in the event window, even if the fault condition has
been cleared, until user acknowledges it by pressing the “Reset” button.
• Audible (yes/no)—Will set Audible alarm when event occurs
• Event log (yes/no)—Will display event in Event log when it occurs
NOTE
You must press “Save” for changes to take effect.
See Table 6 for a list of alarms, fault and status messages.
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Figure 15 Typical Event Management Parameters
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.6.6
2.2.6.6 LBS and Internal Options
2.2.6.62.2.6.6
NOTE
Load Bus Synch —Enable/Disable (default: disable)
These items must be enabled by service to be functional.
Figure 16 Load Bus Sync (not available on the display screen)
Input Contact Isolator Board
• Assignment—Custom, Pre-assigned (default: “Input Contact” XY)
• Delay, sec—0 to 99.9 (default: 0)
• Message—Custom: 0-19 characters
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Figure 17 Input Contact Isolator Board screen
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Programmable Relay Board
• Assignment—0 to 4 event (default: 0)
• Delay, sec—0 to 99.9 (default: 0)
Figure 18 Programmable Relay Board screen
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.2.7 Status Reports Menu
This menu accesses the events records.
2.2.7.1
2.2.7.1 Event Log
2.2.7.12.2.7.1
• Event Log—Up to 2048 time/date stamped events are captured in the log. The oldest
record will be overwritten with a new record once the buffer reaches 2048 events.
Figure 19 Event Log
2.2.7.2
2.2.7.2 System Status
2.2.7.22.2.7.2
•System Status
• Total Operating Hours—Total number hours the UPS has been operational
• Battery Operating Time—A running total of the battery discharge time for all
events since the log was last cleared
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2.2.8
2.2.8.1
2.2.8.1 Manual start-up
2.2.8.12.2.8.1
Manual—This will begin the UPS startup. See 2.5 - Manual Procedures for details.
2.2.8.2
2.2.8.2 Device control
2.2.8.22.2.8.2
Startup Menu
This menu is used to start the UPS and individual devices.
Devices
• Close Trap—This will start the Input filter, if installed
• Close BCB—The Close command will Enable the breaker UVR. The BCB must be
closed manually. If no BCB is selected, do not display this setting.
2.2.9 Shutdown Menu
This menu permits shutting down the UPS and individual devices.
2.2.9.1
2.2.9.1 Open Input Trap filter
2.2.9.12.2.9.1
Open Trap—Opens the input trap filter
2.2.9.2
2.2.9.2 Open BCB
2.2.9.22.2.9.2
Open BCB—Opens the associated BCB breaker
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Figure 20 Shutdown menu
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2.2.9.3
2.2.9.3 INV/RECT/BCB OFF
2.2.9.32.2.9.3
UPS—Turns off inverter, rectifier and trips all battery breakers. Transfers to bypass, if
available.
NOTE
The following popup window is displayed when the UPS is about to be shut down.
To shut down the UPS, an operator must press OK.
Figure 21 UPS shutdown popup
2.2.9.4
2.2.9.4 UPS OFF
2.2.9.42.2.9.4
System — Turns off inverter, rectifier, static switch and trips all battery breakers. Will
shutdown UPS completely.
NOTICE
NOTICE
NOTICE NOTICE
Risk of equipment damage. This command will result in the load being shut down.
The following popup window is displayed when the UPS is about to be shut down. To
shutdown the UPS, an operator must press OK.
Figure 22 System shutdown popup
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2.2.10 Transfer Menu
This menu permits switching between UPS and Bypass mode. A graph in the multipurpose
window shows if the UPS is in synch with the bypass. If the UPS and bypass are in synch,
pressing Bypass will switch the UPS to Bypass mode. Pressing UPS will switch back to
Normal (Inverter) Mode (see Figure 23).
Figure 23 Transfer/retransfer commands
2.2.11 Battery Management Menu
This menu permits configuring battery settings.
2.2.11.1
2.2.11.1 Time Remaining Graph
2.2.11.12.2.11.1
Time Remaining Graph —Displays the time remaining graph in the multipurpose
window; plot the battery voltage against elapsed time during a Battery Discharge Cycle
(see Figure 24).
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 24 Time remaining display
2.2.11.2
2.2.11.2 Manual Battery Test
2.2.11.22.2.11.2
Manual Battery Test — Start/Stop
2.2.11.3
2.2.11.3 Manual Battery Equalize
2.2.11.32.2.11.3
Manual Battery Equalize — For Service only.
2.2.11.4
2.2.11.4 Commissioning
2.2.11.42.2.11.4
Commissioning — For Service only.
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2.2.11.5
2.2.11.5 Battery Cycle Monitoring
2.2.11.52.2.11.5
Battery Cycle Monitor — Displays how many discharges have occurred for these time
periods: 0-30sec, 31-90sec, 91-240sec, 4-15min, 15-30min, 30-60min, 60-240min, 4-8hrs,
8hrs and up. Each discharge record will include: (see Figure 25)
•# •Max KW
•Date • AH
• Time • Start Temp °C
• Duration • End Temp °C
•Start kW •Battery CB Start
•Min kW •Battery CB End
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Figure 25 Battery cycle monitor
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Display summary (see Figure 26)
• Battery Commission Date/Time
• Last Battery Discharge Date/Time
• Active Battery Discharge Time
• Active Battery Amp Hours
• Active Battery KW
• Total Number of Discharges
Figure 26 Battery cycle monitor summary
Clear Log — This command resets the Date of First Discharge Cycle. A dialog box will
warn that the data will be permanently lost and should downloaded before proceeding (see
Figure 27).
Figure 27 Battery cycle monitor—clear log
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2.3 Modes of Operation
This section illustrates the flow of power through disconnectors, switches and UPS
components during various modes of operation. The same modes of operation apply to all
configurations of the Liebert NXL. Highlighted (thick) lines in the diagrams indicate power
flow and power availability.
These illustrations do not show an alternate power source (generator) and automatic
transfer switch (external to the UPS) that might be present at your installation.
2.3.1 Load on Bypass
Load on Bypass, with the UPS not available, is shown in Figure 28. The UPS system could
be in this mode of operation during either initial start-up or UPS shutdown.
NOTICE
NOTICE
NOTICE NOTICE
Risk of equipment damage. When the critical load is being supplied power from
the bypass line, it is exposed to utility failure and fluctuations.
Page 35
______________________________
Active line
Figure 28 Load on bypass (UPS not available)
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2.3.2 OK to Transfer
The OK to Transfer status message will be displayed when the bypass line and UPS output
power are both available, their voltage, frequency and phase synchronization are matched
within specifications, and the Static Switch Disconnects are closed (ON). An alarm message
may be displayed to indicate Load On Bypass (Figure 29). If no alarm is displayed, the
operating status is Load On UPS (Figure 30).
______________________________
Active line
Figure 29 Load on bypass, UPS available
When the OK to Transfer message is displayed, the load can be manually transferred from
the UPS to bypass or the load can be manually retransferred from the bypass to the UPS.
To perform a manual transfer, Use the Load Transfer Procedures screen. Refer to 2.4.2 Load Transfer Procedures.
The UPS control logic will initiate an automatic transfer to bypass if an overload condition
exceeds the system current versus time window or if a UPS fault is detected. The control
logic may initiate an automatic retransfer to the UPS system when the system is recovering
from overloads immediately. Refer to 2.6 - Automatic Operations.
2.3.3 Input Power Failure—Load on Battery
If the utility AC power source fails or is outside the acceptable range, the battery plant
becomes the power source for the UPS module inverters. The UPS continues to supply
power to the critical load and also to the UPS controls.
Page 36
Figure 30 Load on UPS, bypass available
______________________________
Active line
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Use the Battery Time screen at the UPS modules to monitor the present battery voltage
compared to the shutdown value. The time the battery can sustain the load depends on the
size of the load and the size and condition of the battery plant.
Alarm messages that indicate battery status are Battery Discharge, Low Battery and
Battery Shutdown.
The voltage limits for these alarms are displayed on the UPS module Alarm Limit Settings
screen. These limits were selected for your installation by Liebert Services during initial
start-up. The battery block in the UPS module Monitor/Mimic Display indicates Charge or
Discharge and the current in amperes.
______________________________
Active line
Figure 31 Input power fail, load on battery
2.3.4 Off Battery
The battery plant can be disconnected from the UPS, if required for battery maintenance,
by opening the module battery disconnect (BCB) circuit breaker. In this situation the UPS
module will continue to supply conditioned power to the critical load, but if input power
fails the UPS system cannot supply power to the load.
CAUTION
When the UPS system is operating with the module battery disconnect (BCB) circuit
breaker(s) open, the critical load is not protected from loss of the utility source power.
______________________________
Active line
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Figure 32 Load on UPS, battery not available
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2.3.5 Emergency Power Off (EPO)
The local Emergency Power Off (EPO) action shuts down the rectifier, inverter and static
bypass and trips the battery circuit breaker. It does not however internally disconnect the
input mains supply. Lift the cover and press the pad.
The EPO is a guarded pad next to the display touch screen (Figure 2). Refer to 2.5 Shutdown Procedures.
Figure 33 Emergency Power OFF
2.3.6 Remote Emergency Power Off (REPO)
The Remote Emergency Power Off control is a user-provided switch, located remotely from
the UPS system. It usually is installed in the same room as the critical load equipment.
This mode can also be initiated by an automatic contact closure in the same external circuit
as the manually operated switch.
When the Remote Emergency Power Off switch is operated all power through the UPS is
removed from the load. Typically, the REPO circuit also opens the input circuit breakers
that provide power to the bypass lines and the UPS controls. Refer to 2.6 – System
Shutdown Procedures.
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Figure 34 Remote emergency power off
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2.4 Manual Procedures
The Liebert NXL UPS is designed to function while unattended by an operator. Many
important functions are handled automatically by the system control logic, as explained in
2.6 - Automatic Operations. Other procedures must be performed manually.
Manual procedures available to the operator include Start-up, Load Transfers and
Shutdowns. These procedures are performed by using the touch screen and some manually
operated isolators and switches.
The touch screen lists all steps required for each manual procedure. This section lists stepby-step controls to operate and conditions to observe in the following manual procedures:
• Start-up —including initial start-up, recovering from input power failure, recovering
from battery shutdown and recovering from shutdowns for emergencies or maintenance.
• Load Transfers —including transfers from UPS to bypass and retransfers from bypass
to the UPS system.
• Maintenance Bypass Load Transfers —including transferring from internal bypass to
maintenance bypass and transferring from maintenance bypass to internal bypass.
• Shutdowns —including module shutdowns for maintenance and emergency shutdowns.
NOTE
The following procedure assumes that the UPS installation inspection and initial startup have been performed by Liebert Services. A Liebert-authorized representative must
perform the initial system start-up to ensure proper system operation.
2.4.1 Start-up Procedure
CAUTION
CAUTION
CAUTION CAUTION
The following procedure provides power to the critical load distribution system.
Verify that the critical load distribution is ready to accept power. Make sure that
personnel and equipment are ready for the critical load distribution system to be
energized.
If your installation includes a Maintenance Bypass, you may already be supplying power to
the critical load equipment through the Maintenance Bypass. If there is no power to the
critical load, apply power through the UPS bypass line per the following procedure.
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During start-up, power is supplied to the critical load through the UPS (internal) bypass
line while the UPS system is being energized. Depending on the reason for the UPS system
shutdown, power may be present in the bypass line. To determine this, check the
Monitor/Mimic Display screen after control power is available.
1) Before you apply power to the UPS modules, determine the position of the following
isolators and switches:
• Input Isolator (Q1)—Verify that this breaker on the front of the UPS cabinet
(Figure 2) is in the Open position.
• Module Battery Disconnect (BCB)—Verify that this external breaker is open or
tripped. If battery cabinets are used, verify that breakers on all the cabinets are
open.
• Bypass Isolator (Q2)—This breaker (Figure 2) should be open.
NOTE
Power to the critical load may already be supplied through this breaker.
• Output Isolator (Q4) — This breaker (Figure 2) should be open.
NOTE
If the system was shut down in response to an “Emergency Off”, there may be alarm
messages on the touch screen that describe system conditions before (or at the time
of) the shutdown.
Some or all of the alarm conditions may have been resolved. To clear these alarm
messages, turn off control power (see Figure 2). Wait at least 10 minutes for the control
power circuitry to completely de-energize. After 10 minutes, turn control power back on
and wait two minutes before continuing.
WARNING
WARNING
WARNING WARNING
Risk of electrical shock and high short circuit current. Can cause equipment
damage, personal injury and death. If the UPS has been shut down for
maintenance, verify that all of the UPS system doors are closed and latched. All
test equipment must be removed from the system. All electrical connections
must be secure.
2) Power must be provided to the UPS controls so the operator can use the display touch
screen and so the system logic can function properly. The display touch screen may be
used to monitor UPS system status, even when the UPS modules are not operating.
This will be the usual condition unless you are recovering from a maintenance
shutdown.
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3) If the bypass line is not supplying the load, energize the bypass line by:
a) Closing the Bypass Input Breaker (BIB), external to the UPS. This breaker may
be in the Maintenance Bypass Cabinet.
The display touch screen should start up.
b) Pressing the “Start-Up” then “Manual Start” menu buttons (see Figure 35) the
"press Ok to start bypass, or skip into rectifier", if you press OK, then do the step
c, if you press Skip, then go to step ‘e’.
c) The “Close Q2” message appears in the multipurpose window. Close the Q2
isolator (see Figure 2).
d) A “Press OK to issue BPSS On Command” message appears. Press OK to continue.
This will energize the load on the UPS internal bypass.
e) The “Q1” message will appear. Close Q1 (see Figure 2)
f) The “Press OK to Issue Rectifier On Command” message will appear. Press “OK”
This will start the UPS’ rectifier. Load is still on internal bypass.
g) The “Press OK to Issue Inverter On Command” message appears. Press “OK”. The
inverter will be On and Load is still on internal bypass.
h) When the inverter start-up completed, then you can enabled the MBD (Module
Battery Device), if elec-trip breaker is enabled, when you press OK then the
battery connect into system, if set to manual breaker, after you press OK, the
system will show that "please close the BCB", Load is still on internal bypass.
i) The “Press OK to Issue Transfer Command” message appears. Press “OK” The
load is now energized from the UPS Inverter.
NOTICE
NOTICE
NOTICE NOTICE
Risk of equipment damage. If any abnormal situation occurs during this start-up
procedure, open the input circuit breaker and investigate the problem. Call
Liebert Services if help is required.
NOTE
The battery charge current may increase quickly, but then should slowly decrease. If
the system is recovering from a battery shutdown or an input power failure, the UPS
rectifier will be recharging the battery. Recharge current can be more than 100 Amps.
The maximum allowable recharge current for your unit will depend on the kVA rating
and your factory-set battery recharge current limit.
WARNING
WARNING
WARNING WARNING
Risk of electric shock, explosive reaction, hazardous chemicals and fire. Can
cause equipment damage, personal injury and death. Does not use equalize
charging with valve-regulated, lead-acid batteries. Refer to the battery
manufacturer’s manual, available on the manufacturer’s Web site, for specific
information about equalize charging.
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Figure 35 Start-up commands
2.4.2 Load Transfer Procedures
Changing the load from the UPS system to the UPS bypass is called a transfer. Changing
the load from UPS bypass to the UPS system is called a retransfer. Note that the UPS
system control logic can initiate automatic load transfers and retransfers. Refer to 2.6 Automatic Operations.
2.4.2.1
2.4.2.1 Transfer Procedure
2.4.2.12.4.2.1
1) Press the “Transfer” menu button on the touch screen.
2) The Transfer/Retransfer screen will appear in the multipurpose window (see Figure
23).
3) If the UPS output is with synchronization with the bypass, press the “Bypass” button.
This will transfer the load from UPS to Bypass.
2.4.2.2
2.4.2.2 Re-Transfer Procedure
2.4.2.22.4.2.2
1) Press the “Transfer” menu button on the touch screen.
2) The Transfer/Retransfer screen will appear in the multipurpose window (see Figure
23).
3) If the UPS output is with synchronization with the bypass, press the “UPS” button.
This will transfer the load from Bypass to UPS.
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2.4.3 Maintenance Bypass Load Transfers
To manually transfer the load between Maintenance Bypass and the UPS bypass line,
carefully follow these instructions. Do not transfer the load between Maintenance Bypass
and the UPS module (inverter) output. Use the Monitor/Mimic Display screen to verify the
UPS bypass line is available.
______________________________
Active line
Figure 36 Maintenance bypass transfers
NOTICE
NOTICE
NOTICE NOTICE
Risk of equipment damage. Failing to follow the proper operating sequence when
operating any circuit breaker may cause damage to the connected equipment.
Operating a Maintenance Bypass isolator out of sequence could cut off power to
the critical load.
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2.4.3.1
2.4.3.1 Maintenance Bypass Load Transfers—If Load is on UPS
2.4.3.12.4.3.1
1) Transfer the UPS system to bypass (see 2.4.2.1 - Load Transfer Procedures).
2) Close the Maintenance Bypass Isolator (Q3).
NOTE
Failure to close the Maintenance Bypass Isolator (Q3) will interrupt power to the
load.
CAUTION
The load is not protected from normal supply aberrations when operating in the
maintenance bypass mode.
3) Open the following isolators: Q1, Q2 and Q4. The UPS system is now isolated from the
critical load and the load is now on Maintenance Bypass mode.
2.4.3.2
2.4.3.2
2.4.3.22.4.3.2
Maintenance Bypass Load Transfers—If Load is on Maintenance Bypass
1) Close the Bypass isolators Q2 and Q4. Refer to 2.5.1 - Startup Procedure.
2) Check if load is on bypass then open Maintenance Bypass Isolator (Q3). Follows the
Startup Procedure.
NOTE
Failure to close Maintenance Isolation Breaker (Q3) will interrupt the load.
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2.5 Shutdown Procedures
2.5.1 Module Shutdown Procedure
Perform a Module Shutdown Procedure when you want to remove power from a UPS
module.
Read all warnings in 3.0 - Maintenance before performing any maintenance on your
Liebert NXL UPS. These warnings and cautions must be observed during any work on the
UPS.
NOTE
Service and maintenance work must be performed only by properly trained and
qualified personnel and in accordance with applicable regulations as well as with
manufacturers’ specifications.
Use the module Monitor/Mimic Display to determine the operating condition of the UPS
module.
2.5.1.1
2.5.1.1 UPS Shutdown Procedure
2.5.1.12.5.1.1
NOTE
This shutdown turns Off the inverter, rectifier and trips all battery breakers. Transfers to
bypass if available.
1) Press the “Shutdown” menu button on the touch screen.
The Shutdown screen will appear in the multipurpose window (see Figure 19).
2) Press the “UPS” button. This brings up a warning dialog box (see Figure 20).
3) Press OK to shut down the UPS
2.5.1.2
2.5.1.2 System Shutdown Procedure
2.5.1.22.5.1.2
NOTE
This shutdown turns Off the inverter, rectifier , static switch and trips all battery breakers.
Will shut down UPS completely.
1) Press the “Shutdown” menu button on the display touch screen.
The Shutdown screen will appear in the multipurpose window (see Figure 19).
2) Press the “System” button. This brings up a warning dialog box (see Figure 21).
3) Press OK to shut down the system.
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2.6 Automatic Operations
The Liebert NXL UPS system is designed to function while unattended by an operator. The
system control logic monitors the performance of the UPS, the availability of power sources
and the current required by the critical load.
The system control logic:
• Determines what overload conditions can be sustained without a transfer to bypass.
• Initiates an automatic transfer to bypass to sustain an overload or when selected
UPS faults occur.
• Can initiate an automatic retransfer to the UPS after an overload has been cleared.
• Initiates an automatic transfer to bypass and emergency module shutdown when
2.6.1 Overloads (Without Transfer)
The UPS system is capable of sustaining full output voltage (±2% of the nominal voltage)
for overload conditions that remain within (under) the current versus time curve of
overload capacity (Figure 37).
Note that the time scale is not linear.
For high current demands of short duration (momentary overloads) the critical load is
supplied simultaneously by both the UPS system and the bypass line. Whenever an
overload condition occurs, you should determine the cause of the overload. If an overload
condition exceeds the overload capacity, the UPS system initiates an automatic load
transfer to the bypass line.
specified UPS faults occur.
85 min
60 min
10 min
1 min
110%
105%
125%
150%
Figure 37 Current-versus-time curves of overload capacity
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2.6.2 Automatic Transfers to Bypass (Overload Condition)
The UPS system will initiate an automatic load transfer to the bypass line if an overload
condition exceeds the current-versus-time curve of overload capacity or if specified UPS
system faults occur.
Load On Bypass is illustrated in Figure 29.
The Overload Transfer alarm message will initiate an automatic transfer to bypass and the
Load On Bypass message will be displayed. The active event window will display the
Automatic Transfer to Bypass message. Other UPS system faults will initiate an automatic
transfer to bypass followed immediately by the shutdown and isolation of the UPS system.
Refer to 2.6.3 Automatic Transfers to Bypass, UPS System Faults.
NOTE
A load transfer to the bypass line will be completed whenever an automatic transfer to
bypass is initiated. If the OK to Transfer condition is present, the load transfer will be
uninterrupted. If the Static Switch Unable alarm message is present for any reason, the
automatic transfer will be interrupted for 20 to 120 milliseconds. Because of the
reliability of the UPS components, an interrupted load transfer is a very unlikely
occurrence.
2.6.3 Automatic Transfers to Bypass, UPS System Faults
For specified UPS system faults, the control logic will initiate an automatic transfer to
bypass followed immediately by a shutdown and isolation of the UPS system.
The following UPS system faults will initiate an automatic transfer to bypass:
• DC Overvoltage Shutdown
• Hardware Shutdown
• Inverter Fault
• Low-Battery Shutdown
• Output Overvoltage
• Overload Shutdown
• Overtemperature Timeout
• Rectifier Fuse Blown
• Reverse Power
Refer to Table 6 for more information about these alarm messages.
NOTE
A load transfer to the bypass line will be completed whenever an automatic transfer to
bypass is initiated and the bypass line is available. If the OK to Transfer condition is
present, the load transfer will be uninterrupted. If the Static Switch Unable alarm
message is present for any reason, the automatic transfer will be interrupted for 20 to
120 milliseconds. Because of the reliability of the UPS components, an interrupted
load transfer is a very unlikely occurrence.
Some installations may include a Remote Emergency Power Off mode that can be initiated
automatically by a contact closure in the critical load equipment. Refer to 2.3.6 - Remote
Emergency Power Off.
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2.6.4 Automatic Retransfers to UPS
The following critical bus conditions must be present to initiate an automatic retransfer of
the critical load from the bypass source to the UPS inverter:
1) Critical load was initially transferred to the bypass source due to a system overload
only. A manual retransfer from bypass is required if the transfer to bypass was caused
by any condition other than output overload.
2) Both output power and current have since dropped below 101% of the rated load.
3) Both the Input isolator and the Battery (BCB) circuit breaker have remained closed
since the overload transfer.
4) OK to Transfer signal received from the control logic.
5) Cyclic-type overloads, which occur up to five (select range is 0 to 5) times in 60
minutes, are automatically returned to the inverter for each event including the Nth
overload.
NOTE
If you do not want the UPS system to initiate any automatic retransfers, this can be set
during the initial commissioning or by calling your local Liebert Services representative.
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2.7 1+N System Operating Procedures
WARNING
If the input of UPS use RCD, only use the public electric devices in the system when
bypass is utility. At the instant of electrical connection, the current may not be split
instantaneously and this may cause the residual current circuit breakers (RCCB) to trip
separately.
2.7.1 General
The 1+N system has two or more (up to a maximum of eight) modules of the
same size (kVA). The load is equally divided between the units that form the
system. The system can be of two types:
Parallel power: All the UPS's are able to provide the full power requested for
the load.
Parallel redundant: The system comprises a higher number of UPS's able to
provide the full power required for the load.
2.7.2 Introduction
Installation and commissioning must be performed by properly trained and
qualified service engineer. This chapter describes the various procedures
available for the operator to intervene with the 1+N system mode operations
including starting up, transferring load to bypass and shutting down.
Perform each step of the procedure in every UPS module before proceeding to
the next step.
2.7.3 Preliminary checks
Be sure that the modules are the same rating and with the same firmware
release.
2.7.4 System start-up
This procedure should be followed when turning on the UPS from a fully
powered down condition - i.e. where the load is not being initially supplied at
all. It is assumed that the installation is complete, the system has been
commissioned by Liebert Services and the outside power sources are closed.
Refer to figures in Chapter 2 for corresponding isolators Q1 to Q4.
WARNING
WARNING
WARNING WARNING
The following actions will apply utility power on the UPS output terminals.
If want needing, please open the subordinate load breaker and put a warning label on the
load.
The following procedures are performed by using the touch screen (refer to Par. 2.2) and
manually operated breakers.
1) Verify the Q3 Maintenance Bypass Breaker and BCB are opened, then close Q2
(Bypass breaker), Q1 (Input breaker) and Q4 (output breaker).
2) Using the touchscreen to operate:
3)
Start the bypass: On the LCD, press the STARTUP button, choose Manual Start, then
choose OK (into process of start bypass) or Skip (into process of start Rectifier), as
shown in figure below.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 38 Manual Start to Bypass
4) After pressed the OK button, then can choose this module (only start this module on
bypass) and all modules (start all modules on bypass), as shown in figure below.
Figure 39 Manual Start to Bypass (one or more modules)
5) Press either “All Modules” or “This Module”, then the load is on bypass, as shown in
figure below.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 40 Rectifier ON command
6) Start rectifier: After bypass started, then enter the process of starting
rectifier on the LCD, as shown in figure above (Rectifier section will be green).
Press Ok button, then rectifier start as shown in figure below.
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Figure 41 Load on Bypass, UPS available
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
7) Connect battery: After inverter started, you can enable the BCB (named
MBD1) through the LCD, as shown in figure above. If an elec-trip breaker is used,
when you press OK button the battery will be connected into UPS system. Otherwise
if manual breaker is used, when you press OK button the system will show that you
can manually close the BCB. After that the battery is connected successful, as shown
in figure below.
Figure 42 Load on Bypass, BCB closed
8) The parallel system transfer to UPS: After inverter started and the battery
is connected into system and all module’s voltage and frequency of inverter output
sync with the bypass of this parallel system, the LCD shows the figure above (if don’t
sync the ‘Ok button’ colour remains gray). Press Ok, the parallel system transfers to
UPS mode, as shown in figure below.
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Figure 43 Load on UPS
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
9) After that, you can press the ”System View” button located on the top right
corner of LCD and view the whole parallel system status. In the figure below are
shown the breakers of the System Paralleling cabinet option (the figure below is for
‘1+1’ parallel system).
Figure 44 Parallel System view
10) Add new module into the parallel system: if a module need to be added after
the parallel system is running, enter the process of start-up rectifier and inverter
directly so this module can be added.
UPS on the mode that inverter supply the power
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
2.7.5 Cut off and separate one UPS module from the running parallel system
1) Open all breakers of battery.
2) Open all UPS breakers one by one, Q4 (output breaker), Q1 (input breaker), Q2
(bypass breaker).
For separate this module completely, open the input breaker of AC line power (both circuit
breakers if separate supplies are provided for rectifier and bypass) and the output breaker
of distributed cabinet.
WARNING
If individual UPS output isolation circuit-breaker (and assistant contact) are not installed on the
power distribution switchboard, remember that voltage supplied by the others UPS which remains
in service will still be present on the output terminals of the shutdown UPS.
WARNING: Wait five minutes until there are no power on the capacitances of DCBUS.
2.7.6 Recover the UPS module separated from parallel system
This step can recover the module into the parallel system again.
In case of fixing completed and have tested by authorization of Liebert Services engineer,
all of the power breaker outside were closed.
1) Open (confirm opened) the breaker of maintenance bypass Q3 and BCB.
2) Close the breaker of bypass Q2, Q4 (output breaker) and the outside output
breaker (if exist).
3) Close the breaker of input Q1, start-up rectifier and inverter directly (refer the
operations of SMS).
4) Connect the battery (refer the operation of connect battery in 1+N start-up).
5) When of local module output synchronises with the parallel system, then press
Ok button, this module can transfer to UPS and into the parallel system (refer
the operations of SMS).
2.7.7 The steps of shutdown UPS and Load
Please accord to this step when want let the UPS shutdown at all and load drop. All of
breaker of power and switch must be opened; UPS don’t supply power to load.
The next steps will cut off the input power of load and load will be drop
1) Press the “SHUTDOWN” menu on LCD. If you choose “This module”, then refer
to the operation of SMS: the steps of shutdown system (Shutdown all of UPS
and Load), as indicated in Par. 5.2. If you choose “all modules” then refer to next
figure.
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WARNING
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Figure 45 Starting 1+N System Shutdown
2) If press“1+N UPS” button and press Ok then shutdown all of the UPS modules
and parallel system transfer to bypass, as shown in next figure.
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Figure 46 1+N System Shutdown confirm
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3) If press “1 N System” button and press Ok then shutdown all of the UPS and
load drop occur as shown in next figure.
Figure 47 1+N System Shutdown
2.7.8 The steps of operation of maintenance bypass
The maintenance bypass procedure transfers the load supply from being protected
by the UPS into AC input bypass supply through a maintenance bypass breaker.
This breaker is either:
• Internal (Q3 located within UPS) for single module system (SMS) or 1+1
redundant multimodule UPS applications.
• External (located in the SPC) for 1+1 capacity and 1+N redundant
multimodule UPS applications.
IMPORTANT
With configurations consisting of two UPS's 1+1 capacity or 1+N redundant systems integrated
with more than two UPS's, where the load level is above the rated power of the single UPS, it is
necessary to install an adequate external maintenance bypass. It is also necessary to adopt all
the measures required to prevent the internal manual bypass breaker of the UPS (Q3) from
being used.
The steps of operation show in operation of SMS. The steps of operation of
maintenance bypass (the steps of operation for UPS shutdown).
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3 MAINTENANCE
3.1 Safety Precautions
Observe the safety precautions inside the UPS front cover.
NOTE
Service and maintenance work must be performed only by properly trained and
qualified personnel and in accordance with applicable regulations as well as with
manufacturers’ specifications.
Observe ALL of the WARNINGS below before performing ANY maintenance on the UPS
System and associated equipment. Also observe the manufacturer’s safety precautions
pertaining to the battery, along with the battery safety precautions in this section.
WARNING
Risk of electrical shock and high short circuit current. Can cause equipment damage,
personal injury and death.
Extreme caution is required when performing maintenance.
Be constantly aware that the UPS system contains high DC as well as AC voltages. With
input power off and the battery disconnected, high voltage at filter capacitors and power
circuits should be discharged within 5 minutes. However, if a power circuit failure has
occurred, you should assume that high voltage may still exist after shutdown. Check with a
voltmeter before making contact.
AC voltage will remain on the bypass and output isolators and the static bypass switch,
unless associated external circuit breakers are opened.
Check for voltage with both AC and DC voltmeters prior to making contact.
When the UPS system is under power, both the operator and any test equipment must be
isolated from direct contact with earth ground and the UPS chassis frame by using rubber
mats.
Some components within the cabinets are not connected to chassis ground.
Any contact between floating circuits and the chassis is a lethal shock hazard. Use
differential oscilloscopes when measuring a floating circuit.
Exercise caution that the test instrument exterior does not make contact, either physically
or electrically, with earth ground.
In case of fire involving electrical equipment, use only carbon dioxide fire extinguishers or
others approved for use in fighting electrical fires.
Risk of electrical shock and high short circuit current. Can cause equipment damage,
personal injury and death.
Always identify connecting wiring prior to disconnecting any wiring.
Do not substitute parts except as authorized by Liebert Corporation.
Maintain the UPS cabinets free of foreign materials such as solder, wire cuttings, etc.
Contact Liebert Services if you are not sure of the procedures to follow or if you are not
familiar with the circuitry.
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WARNING
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3.2 Liebert Services
Startup, UPS maintenance, battery maintenance and training programs are available for
the Liebert NXL UPS through your Liebert sales representative.
3.2.1 Professional Start-up
UPS Start-up — Liebert’s Customer Engineers perform a thorough non-powered
inspection of the units and will then conduct a complete electrical checkout. The battery
installation is also inspected and placed on an initialization charge to ensure cell
equalization. Customer Operation training will be conducted during battery charge time.
Load bank testing and full site acceptance testing are additional services that can be
performed during a UPS start-up. One preventive maintenance service call can be added to
the initial UPS start-up agreement.
Battery Installation/Start-up — When purchased with a UPS Start-Up, this Agreement
provides consistent, professional service for your entire UPS system. This one-source
approach avoids conflicts that may occur during a multi-source installation. Note that
Liebert requires a mandatory installation inspection for all batteries not installed by
Liebert Customer Engineers.
The Battery Specialist will perform a detailed inspection of the entire battery system to
ensure it meets current standards.
Maintenance Agreements: The Signature Program
UPS Service Agreements — Liebert Services (LGS) has a variety of available
maintenance agreements, depending on specific site needs. Choose the level of support
appropriate for each installation.
Mission-critical sites can have the standard parts-and-labor, around-the-clock coverage for
their UPS, with or without scheduled preventive maintenance visits. Other sites can benefit
from a variety of money-saving options.
Liebert recommends two preventive maintenance visits per year for the UPS. The first can
be conducted with the UPS operational and includes an infrared scan of key UPS
components.
The annual visit will require taking the UPS off-line for a thorough non-powered
inspection.
These visits are in addition to the general housekeeping tasks (changing air filters, etc.)
that can be performed by customer personnel.
Battery Service Agreements — The same flexible Signature Program can also be applied
to contracts for battery maintenance. Again, the coverage needed will depend on the type of
battery purchased and the degree of support required from Liebert Services.
Training
Customer training courses include the proper operation of the system, emergency
procedures, preventive maintenance and some corrective maintenance.
Warranties
Contact Liebert Services if you have any questions regarding the warranty on your Liebert
NXL UPS or the batteries.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3.3 Routine Maintenance
You should become thoroughly familiar with the equipment, but at no time should you go
beyond the specific procedures in this manual while performing maintenance or correcting
a malfunction.
If you have any doubt as to what must be done, call Liebert Services for further instructions
at the address shown in the beginning of this manual.
NOTE
Service and maintenance work must be performed only by properly trained and
qualified personnel and in accordance with applicable regulations as well as with
manufacturers’ specifications.
The UPS is designed for unattended operation, but does require some common-sense
maintenance.
• Keep good records — Troubleshooting is easier if you have historical background.
• Keep it clean — Maintain the UPS free of dust and any moisture.
• Keep it cool — Battery systems must be kept in the range of 22-26°C in order to
meet design specifications for capacity and longevity.
The UPS will reliably meet all performance specifications and design life at
temperatures up to 40°C (30°C for 800kVA UPS). However, performance and longevity
will be optimized when the UPS is operated at the same temperature as the batteries.
Contact Global Service Support for further details.
• Keep connections tight — Tighten all connections at installation and at least
annually thereafter.
• Keep it inspected — Periodically inspect external upstream switches and
downstream isolators to assure that the trip current settings are correct.
Become familiar with typical ambient conditions surrounding equipment so that
abnormal conditions may be more quickly recognized. Know what typical meter
readings are and where adjustable settings should be.
3.3.1 Record Log
Set up a maintenance log to record scheduled checks and any abnormal conditions.
The log should have space for all metered parameter indications including phase readings,
alarm messages, UPS mode of operation, air filter replacement date and observation notes.
A second log should be maintained for the battery module as directed by the battery
manufacturer.
A periodic walk-through inspection of the UPS and battery rooms is advised to check for
visible and audible indications of problems. Log the inspection, metered parameter
indications and any discrepancies.
3.3.2 Air Filters
The air filters must be inspected and serviced on a regular schedule. The period between
inspections will depend upon environmental conditions. Under normal conditions, the air
filters will require cleaning or replacement approximately every two months. Abnormal or
dusty conditions will require more-frequent cleaning and replacement of air filters. Inspect
installations in new buildings more often, then extend the inspection period as experience
dictates.
All NXL models have a replaceable air filter located inside the front doors. These filters can
be changed while the UPS is in operation.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3.3.3 Limited Life Components
The Liebert NXL UPS has a design life well in excess of 10 years. Well-maintained units
can continue to provide economic benefits for 20 years or more. Long-life components are
used in the UPS wherever practical and cost-effective. However, due to the currently
available component material, manufacturing technology limitations and the general
function and use of the component, a few components in your Liebert UPS will have a
shorter life cycle and require replacement in less than 10 years.
The following components utilized in your UPS system have a limited life cycle and are
specifically exempt from warranty. To prevent a wear-out failure of one of these
components affecting your critical load operations, Liebert recommends these components
be periodically inspected and replaced before the expected expiration of their life cycle. The
expected life of each component listed below is simply an estimate and is not a guarantee.
Individual users may have site-specific requirements, maintenance and other
environmental conditions that affect the length of the component's useful life cycle.
Component Expected Life Replace in:
Power AC filter capacitors > 7 years (~62,000 hours) 5 to 6 years
Power DC filter capacitors > 7 years (~62,000 hours) 5 to 6 years
Low-profile fans > 7 years (~62,000 hours) 5 to 6 years
Air filters 1 to 3 years Check four times per year
Battery, lithium logic memory
backup
Battery, storage
Lead-acid wet-cell (user
selection)
(VRLA)
10 years (~87,600 hours) 8 to 9 years
10 to 20 years 1 to 2 years before end-of-life
5 years 3 to 4 years Valve-regulated, lead-acid
10 years 6 to 8 years
Table 1: UPS component service life
In most cases, replacement components must exactly match the original component
specifications.
These replacement components are not readily available from third-party component
distributors.
For assistance with your specific component specifications, replacement component
selection and sourcing, call Global Service Support. For customers using Liebert Services’
preventive maintenance services, periodic inspection of these components is part of this
service, as well as recommending component replacement intervals to customers to avoid
unanticipated interruptions in critical load operations.
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3.4 Battery Maintenance
WARNING
Risk of electrical shock and high short circuit current. Can cause equipment damage,
personal injury and death.
These maintenance procedures will expose hazardous live parts. Refer servicing to properly
trained and qualified personnel working in accordance with applicable regulations as well
as with manufacturers’ specifications.
DC fuses operate at the rated battery voltage at all times. A blown DC bus fuse indicates a
serious problem. Serious injury or damage to the equipment can result if the fuse is
replaced without knowing why it failed. Contact Liebert Services for assistance.
3.4.1 Battery Safety Precautions
Servicing of batteries should be performed or supervised by personnel knowledgeable of
batteries and the required precautions. Keep unauthorized personnel away from batteries.
When replacing batteries, use the same number and type of batteries.
WARNING
Risk of electric shock, explosive reaction, hazardous chemicals and fire. Can cause
equipment damage, personal injury and death.
Lead-acid batteries contain hazardous materials. Batteries must be handled, transported
and recycled or discarded in accordance with federal, state and local regulations. Because
lead is a toxic substance, lead-acid batteries must be recycled rather than discarded.
Do not dispose of battery or batteries in a fire. The battery may explode.
Do not open or mutilate the battery or batteries. Released electrolyte is harmful to the skin
and eyes. It is toxic.
WARNING
Risk of electrical shock and high short circuit current. Can cause equipment damage,
personal injury and death.
The following precautions must be observed when working on batteries:
• Remove watches, rings and other metal objects.
• Use tools with insulated handles.
• Wear rubber gloves and boots.
• Do not lay tools or metal parts on top of batteries.
• Disconnect charging source prior to connecting or disconnecting battery terminals.
• Determine whether the battery is grounded. If it is grounded, remove source of ground.
Contact with any part of a grounded battery can result in electrical shock. The likelihood of
such shock will be reduced if such grounds are removed during installation and
maintenance.
Lead-acid batteries can present a risk of fire because they generate hydrogen gas. In
addition, the electrical connections must be protected against accidental short circuits
which can cause sparks. The following procedures should be followed:
• DO NOT SMOKE when near batteries.
• DO NOT cause flame or spark in battery area.
• Discharge static electricity from body before touching batteries by first touching a
grounded metal surface.
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• After replacing battery jars in a battery cabinet, replace the retaining straps that hold the
jars in place on the shelves. This will limit accidental movement of the jars and connectors
should the cabinet ever need to be repositioned or relocated.
Regular maintenance of the battery module is an absolute necessity. Periodic inspections of
battery and terminal voltages, specific gravity and connection resistance should be made.
Strictly follow the procedures outlined in the battery manufacturer’s manual, available on
the manufacturer’s Web site.
Valve-regulated lead-acid (sealed-cell) batteries do require periodic maintenance. Although
maintenance of electrolyte levels is not required, visual inspections and checks of battery
voltage and connection resistance should be made.
NOTICE
NOTICE
NOTICE NOTICE
Risk of equipment damage. Batteries should be cleaned with a dry cloth or a cloth lightly
moistened with water. Do not use cleaners on the batteries. Solvents can make the battery
cases brittle.
Because individual battery characteristics are not identical and may change over time, the
UPS module is equipped with circuitry to equalize battery cell voltages. This circuit
increases charging voltage to maintain flooded type battery cells at full capacity.
WARNING
Risk of electric shock, explosive reaction, hazardous chemicals and fire. Can cause
equipment damage, personal injury and death.
Do not use equalize charging with valve-regulated, lead-acid batteries. Refer to the battery
manufacturer’s manual, available on the manufacturer’s Web site, for specific information
about equalize charging.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
3.4.2 Batteries
Although the individual battery cells are sealed (valve-regulated) and require only minimal
maintenance, the rack mounted batteries should be given a periodic inspection and
electrical check. Checks should be performed at least annually to ensure years of troublefree service.
Voltage Records: With the battery DC circuit breaker closed and the connected UPS
operating, measure and record battery float voltage. With the DC circuit breaker open,
measure and record the nominal (open circuit) voltage. Both these measurements should be
made across the final positive and negative terminal lugs. Compare these values with those
shown below. The recorded nominal voltage should be no less than the value shown; while
the recorded float voltage should be within the range shown. If a discrepancy is found,
contact Liebert Services.
Table 2 Battery voltage, nominal and float
Battery Voltage, VDC
UPS (kVA) Number of
Cells@400V
250-300-400 198 396 446
800 240 480 540
Nominal Float
Power Connections: Check for corrosion and connection integrity. Visually inspect wiring
for discolored or cracked insulation. Clean and/or retighten as required. Refer to torque
specifications in the Installation Manual.
Battery Cell Terminals: Check for discoloration, corrosion and connection integrity.
Clean and tighten if necessary. Note that when installing a new battery, the initial torque
value is higher than the re-torque value.
Rack-Mounted Batteries
If the UPS system uses a rack mounted batteries perform maintenance on the battery as
recommended in the battery manufacturer’s maintenance manual, available on the
manufacturer’s Web site.
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3.5 Detecting Trouble
It is important that the operator check the instrument readings if abnormal equipment
performance is suspected. Any metered value that differs appreciably from normal could
mean an impending malfunction and should be investigated.
Items to check include:
• If the UPS has not operated on battery power during the last 10 hours, the batteries
should require little charging current. Battery mimic should indicate normal DC voltage
with the battery charge current no more than 1% of maximum discharge current.
• Input current on each phase should be within 10% of the average input current.
• Alarm messages indicate malfunction or impending malfunction. A daily check of the
Display Screen will help to provide an early detection of problems. Refer to Table 6 for
information about interpreting alarm messages.
• Tracing a problem to a particular section is facilitated by alarm messages and the
metered parameter indications.
NOTICE
NOTICE
NOTICE NOTICE
If the UPS system has an open fuse, the cause should be determined before replacing the
fuse.
Contact Liebert Services for assistance.
3.6 Reporting a Problem
If a problem occurs within the UPS, review all alarm messages along with other pertinent
data. Contact Liebert Global Services Support to report a problem or to request assistance.
3.7 Corrective Actions
For each alarm message on the Display Screen, you can find the recommended corrective
action in Table 6.
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4 SPECIFICATIONS
4.1 Battery Operation
The separate battery manufacturer’s manual, available on the manufacturer’s Web site,
provides the necessary information for the installation, operation and maintenance of the
battery. Use the battery manual in conjunction with this manual.
The float charge voltage for a battery is equal to the number of cells in series making up the
battery multiplied by the charge voltage for each cell.
Because the charging voltage level is critical to proper battery operation, refer to your
battery manual, available on the manufacturer’s Web site, for information about your
system.
For models with nominal 198-cell battery, the DC bus nominal float voltage range is 425 to
460VDC (516 to 552VDC @ 240 cells).
Maximum equalize voltage is 485VDC (581VDC @ 240 cells). Battery voltage at end of
discharge is 327VDC at the UPS terminals (396VDC @ 240 cells). The number of battery
cells required will range from 192 to 204 (250-300-400kVA), depending on the application.
4.2 Environmental Conditions
Liebert NXL Model Size 250-300-400 kVA
Parameter Specification
Enclosure The UPS is housed in a IP20 enclosure. The enclosure is designed for
indoor use only and is not to be subjected to falling objects or precipitation.
Recommended Operating
Temperature (°C)
Maximum Operating
Temperature (°C)
Minimum Operating
Temperature (°C)
Storage Temperature
(°C)
Typical Battery
Temperature
Requirements
Relative Humidity 0 to 95% without condensation
Operating Elevation Sea level to 1500m without derating
Storage Elevation Sea level to 15.000m
Audible Noise(1.5m) from
Unit
Table 3: Environmental specifications (250-300-400kVA UPS)
25 ambient
(40) ambient (design temperature) without derating; (see Notes 2 and 3).
0°C
-25 to 70
Average annual temperature must not exceed 27°C. Peak temperature
must not exceed 43°C. See battery manufacturer’s recommendations.
≤69 dBA
Notes on Environmental Specifications
1. This category of electronic equipment is agency rated for use in an atmosphere free of
conductive particles. Some industrial facilities may require a room air filtration system
to keep the UPS free of excess moisture and contaminants.
2. The UPS system is designed to operate continuously at 40°C. However, design
equipment life expectancy will be extended with lower temperatures (25°C is
recommended).
3. Ambient temperature is the maximum ambient temperature during any 24-hour period.
For operation at higher temperatures or elevations, consult Liebert Global Services
Support.
4. Exercise care during installation to ensure unimpeded airflow through the UPS.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Liebert NXL Model Size
Units
250 300 400
Input Parameters
Input Voltage to Rectifier Vac 380/ 400 default/ 415 - 3-phase, 3-wire plus ground
Input Voltage to Bypass Vac 380/ 400 default/ 415 3-phase, 4-wire
+/-10%
Input Voltage Range (Vac) %
(*) -15% to -20%
(**) -20% to -30%
(***) <-30%
Input Frequency Hz 50
Permissible Input Frequency Range Hz 47 to 63
Input THDi at nominal voltage at
full load
%
<10% with 6-pulse and passive filter
<5% with 12-pulse and passive filter
Flexi Power Walk-In sec 3 to 30 sec (selectable) in 1 sec. increments
Battery & DC Parameters
Battery Type
-
VRLA (Valve Regulated Lead Acid) or
FLA (Flooded Lead Acid)
Nominal Battery Bus Vdc 396V @400Vac
Battery Float Voltage Vdc 446V
End-Cell Voltage Vdc/
cell
DC Ripple Voltage in Float and
Const V Ch. Mode
Temperature Compensated Battery
Charging
% <1 (RMS value) < 3.4% Vpp
- Standard (with optional temperature probe)
Selectable from 1.6 to 1.9 (for VRLA / Wet cells)
Output Parameters
Inverter Type - IGBT-based Sine-Sine PWM Controlled
Output Power kW 225 270 360
Output Voltage Vac 380/ 400 default/ 415 , 3-ph, 4-wire plus ground
Output Voltage Regulation (%) % < 1% (3-phase RMS average)
Output Voltage Regulation (100%
Unbal. Load)
% < 2% (3-phase RMS average)
Output Frequency Hz 50
Output Frequency Regulation % ± 0.1
Output THDu at Nominal Voltage
(Linear Load)
% <2
Output THDu at nominal voltage
Including a 100kVA Non Linear
% 2.5% (max)
Load per EN 62040-3
Capacity to Handle Step Load % 0-100 or 100-0
Transient Recovery (Linear Loads)
%,
Capacity to Handle Leading PF
Load:
%,
msec
within 5% peak to peak in one-line cycle
0.9 lag to Unity Subject to maximum kW rating
at 0.95 Lead Subject to maximum. kW rating
at 0.9 Lead Subject to 12,5% kW derate or same rating and 10°C temp. derate
Voltage Displacement ° el 120° ±1° el (with 100% unbalanced load)
Compliance to EMC Class-A Optional
Overload Conditions, 3 phase
% FL
100% continuous
110% for 60 minutes
125% for 10 minutes
150% for 1 minute
(*) The UPS will operate at full load, but the battery charge will be either reduced or Off (depending on input current).
Table 4: Electrical Specifications (250-300-400kVA UPS)
(**) The UPS will operate at full load, but UPS may source share with the batteries (depending on input current).
(***) UPS will be in Battery mode
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Liebert NXL Model Size
Units
250 300 400
System Parameters
UPS Efficiency AC-AC 100%
Load (w/o any power option)
UPS Efficiency AC-AC 40÷80%
Load (w/o any power option)
%
%
≥ 93.5 (depends on rating & operating conditions)
≥ 92.5 (depends on rating & operating conditions)
Physical Parameters&Standards
Width 6 Pulse mm 1430 1600 1600
Width 12 Pulse mm 2045 2215 2385
Depth mm 850 990
Height mm 1950
Weight 6 Pulse (approx.) kg 1700 1880 2370
Weight 12 Pulse (approx.) kg 2420 2710 3490
Colour - RAL 7021
Front Door Opening (for
serviceability)
Degree of Protection for UPS
Enclosure
More than 180°
IP 20 even with front door in opened condition
Acoustical Noise dBA 67 69
Standards & Conformities
The above mentioned product standards incorporate relevant compliance clauses with
EN 62040-1-1 (2003), EN 62040-2 (2006), EN 62040-3 (2001)
CE MARK
generic IEC and EN standards for safety (60950), electromagnetic emission and
immunity (61000 series) and construction (60529)
Electrical Specifications - 250-300-400kVA UPS (continued)
Disclosures with Regard to Embedded Software Licensed from TrollTech, Inc.,
(“Sublicensed Software”)
1. Limits on Use, Distribution and Derivative Works: User is not given any rights to modify or
create derivative works based on Sublicensed Software, or reproduce Sublicensed Software, or
distribute any copies of Sublicensed Software, or disclose any Sublicensed Software to any third
party, or decompile, disassemble or otherwise reverse engineer Sublicensed Software, or use
any information learned therefrom. User acknowledges that TrollTech, Inc., and its licensors
own the copyrights and other intellectual property in and to the Sublicensed Software.
2. Responsibility of User: The Sublicensed Software is not designed, intended or licensed for use
in or with systems, devices or products intended for surgical implant into the body or other
applications intended to support or sustain life or for any aviation or nuclear reactor. It is
User's responsibility to ascertain the suitability of Sublicensed Software for any situation or
application.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Model Name
100 continuous
Liebert NXL UPS SPECIFICATIONS
Liebert NXL
Nominal Power Rating at 0.9 PF Load kVA
800
Input Parameters
380V 400V 415V
Input Voltage to Rectifier Vac
Rated Input Current (12P rectifier) @400V
Rated Inp Current (12 P + inp filter) @400V
Permissible Input Rectifier Voltage Range
Input Voltage to Bypass
Bypass Input Current @400V- 110% LOAD A
Permissible Bypass Input Voltage Range
Input Frequency Hz
Permissible Input Frequency Range Hz
Input THDi at nominal voltage at full load
Input Power Factor at nominal voltage
Flexi Power Walk-In sec
Vac
Vac
A
A
%
%
%
-
-
-
380 / 400 / 415 (400V : default) 3-phase, 3-wires plus ground
1393
1238
291 (-23%) to 438 (+15%) 300 (-25%) to 460 (+15%) 310 (-25%) to 477 (+15%)
380 / 400 / 415 (400V : default) 3-phase, 4-wires plus ground
1270
320 (-20%) to 460 (+15%)
50 or 60
45 to 66
<10% with 12-pulse
<5% with 12-pulse & Passi ve Filter
<3% with 12-pulse & Passi ve Filter + Active Filter
≥ 0.80 with 12-Pulse
≥ 0.90 with 12-Pulse w ith Passive Filter
≥ 0.98 with 12-pulse & Passive Fil ter + Active Filter
3 to 30 (selectable) in 1 sec. Increments
Battery & DC Parameters
Battery Type
Number of battery cells N°
Nominal Battery Bus Vdc
Float Voltage
End Of Discharge (EOD)
Equalize Charge
DC Ripple Voltage in float & Const V Ch.mode
Temperature Compensated Battery Charging
Vdc/Cell
Vdc / Cell
Vdc/Cell
%
VRLA (Valve Regulated Lead Acid) or Wet or NiCd
228 ~ 246 @ 380/ 400/ 415Vac
540 Vdc @ 380/ 400/ 415Vac
Selectable from 1.60 to 1.88 (for VRLA / Wet Cells)
2.30 (adjustable in 0.01 volt increments from 2.3-2.45 V/cell)
2.15-2.3
<1 (RMS value) < 3,4% Vpp
Optional
Output Parameters
Inverter Type
Output Power kW
Output Voltage
Output Voltage Regulation (loss&return of utility)
Output Voltage Regulation (100% Unbal. Load)
Output Frequency
Output Frequency Regulation
Output THDu at nominal voltage %
Output THDu at nominal voltage Including a 100kVA
Non Linear Load per EN 62040-3
Capability to handle High Crest Factor Load
Capability to handle Step Load
Transient Recovery msec
Capability to handle Leading PF Load
c) at 0,95 Lead
d) at 0,9 Lead
e) at 0,8 Lead
Voltage Displacement
Inverter Overload rating, 3 phase % FL
a) 0,5 lag to 0,9 lag
b) 0,9 lag to Nominal
Vac
%
Hz
%
%
%
d) Subject to 12,5% kW derate or same Rating and 10°C ambient derate
e) Subject to 25% kW derate or 12,5% kW derate and 10°C ambient derate
º
el
While specifying the parameters here, it is assumed that, extremes of all the condition s do not apply simultaneously.
IGBT-based Sine-Sine PWM Controlled
380 / 400 / 415 (400V : default) 3-phase, 4-wires plus ground
< % 1 (3-phase RMS average)
< % 2 (3-phase RMS average)
3 : 1 (compliant with IEC 62040-3)
20 (recovery to 95% of the voltage level)
Up to 0.8 with the following rating s:
a) Subject to Max. kVA rating
b) Subject to Max. kW rating
c) Subject to Max. kW rating
120deg +/- 1 deg electrical (with 100% unbalanced load)
720
50 or 60
+/- 0.1
<2%
2,5% (max)
0-100 or 100-0
110 for 60 minutes
125 for 10 minutes
150 for 1 minute
Page 68
Table 5: Specifications (800kVA UPS)
Page 69
Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Model Name
UPS Efficiency AC-AC
110 continuous
Liebert NXL UPS SPECIFICATIONS
Liebert NXL
Nominal Power Rating at 0.9 PF Load kVA
(without any power option) 100% Load
UPS Efficiency AC-AC
(without any power option) 40%-80% Load
System Parameter
%
%
Bypass Parameters
≥ 93.5% (depends on rating & operating conditions)
≥ 92.5%
(depends on rating & operating conditions)
800
Bypass Overload rating, 3 phase % FL
125 for 10 minutes
150 for 1 minutes
1000%, 10 cycles
Physical Parameters & Standards
Cabinet section
Width
Total Width ***
Depth mm
Height mm
Weight (without packing material) kg 2850 3080 460
Total Weight (without packing material) kg
Colour
Front Door Opening (for better Serviceability)
Degree of Protection for UPS Enclosure
Standards & Conformities
kVA
mm
mm
Rectifier Inverter Bypass/ Output
1585 1570 800
IP 20 even with front door in opened condition
IEC 62040-1-1, IEC 62040-2, IEC 62040-3
EN 62040-1-1, EN 62040-2, EN62040-3, EN 60950
The above mentioned product standards incorporate relevant compliance
clauses with generic IEC and EN standards for safety (60950), electromagnetic
emission and immunity (61000 series) and construction (60529)
3955
1090
1950
6390
ZP 7021
More than 180
CE Mark
°
Environmental Parameters
°
Operating Temperature Range
UPS Temperature de-rating
UPS Storage Temperature Range
Battery Storage Temperature Range
Relative Humidity %
Acoustical Noise
Maximum Altitude above MSL with full rating m
Altitude de-rating
°
°
°
dBA
C
C
C
C
***with OR without input harmonic filter
While specifying the parameters here, it is assumed that, extremes of all the condition s do not apply simultaneously.
0 to 30 (UPS) without derating
20 +/-5 (Battery)
1,5% Max kW derate / °C up to 50°C Max.
-25 to 70
-20 to 30
0 to 95 non-condensing (Operating and non operating)
78
1500 (as per IEC 62040-3)
1% Max kW derate per 100m rise above 1500 m or
temp derate of 1° C/ 100m between 1500-3000 m
Page 69
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
5 APPENDIX A-UPS ALARM AND STATUS MESSAGES
Table 6 shows alarm and status messages as they appear in Liebert NXL’s touch-screen
and in the history log, along with a description and recommended actions, if any.
If the recommended action fails to correct the condition, contact your factory-authorized
service provider.
The “Service Telephone Number” can be found by pressing “CONFIG,” “Ratings,” “More>>”
on the menu bar.
Event Message Event Definition Recommended Action
Auto Restart
Fail
Auto Rexfer
Failed
Batt CB “#”
Open
An Automatic Restart was enabled but
has failed to complete. With Automatic
Restart enabled, the unit automatically
restarts after an End of Discharge
(EOD) event. This alarm means that
one of the auto restart requirements
was true, but failed before the restart
sequence completed. For example, one
conditional requirement for Automatic
Restart to occur is that the Rectifier
Input Voltage must be within acceptable
limits. If, during the restart sequence,
the input voltage drops out of tolerance,
the Automatic Restart will fail. This
alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The condition that caused an automatic
transfer to bypass failed to clear within
a specified time delay. An example of a
recoverable transfer (one which the
controls may attempt to recover from
automatically) is an overload that
exceeded the overload time curve.
Battery Circuit Breaker “#” is open.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal. (The Liebert NXL has eight
battery circuit breakers.)
Table 6: Liebert NXL alarm and status messages
Press “SILENCE” to silence the audible
alarm. Check the active events to
determine the status of the UPS. If “Auto
Restart Fail” is the only alarm present,
attempt a manual start of the unit by
pressing “Startup,” “Manual Start,” then
following the prompts to attempt to place
the unit back online.
If the manual start fails, or if there are
other alarms present that won’t clear,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm. Press “RESET” to attempt to clear
active events This does not clear the
“Auto Retransfer Failed” alarm.. If all
other alarm conditions clear, attempt a
manual transfer back to Inverter by
pressing “Transfer,” “UPS.”
If the transfer is successful, press
“RESET” to clear this alarm from the
Active Event Window. If the UPS fails to
transfer and the active messages do not
explain the reason, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm. Check the status of Battery
Circuit Breaker “#”. If it is open, the
alarm is normal.
If Battery Circuit Breaker “#” is closed,
contact your factory-authorized service
provider.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Batt Discharging
Batt Equalizing
Batt Ground
Fault
The UPS is on battery.
The most common reason for going to
battery is a loss of rectifier input power
(power outage).
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The batteries are being equalized.
Battery equalization stops
automatically based on the Equalize
Time Setting. This status message is
self-clearing. When the condition is no
longer present, the message and any
control activity tied to the status event
reverts to normal.
Detected battery ground current exceeds
the trip setting. A possible symptom
that could cause this alarm is a leaking
battery. This alarm has a higher
detection setpoint than “Battery Ground
Fault Current Warning,” and if present,
means that the Battery Ground Fault
Current is excessive. This alarm could
cause Battery Breakers to trip if the
“Battery Ground Fault Trip Enable”
setting is enabled.
Press “SILENCE” to silence the audible
alarm.
Observe the One-Line Display. If the
input line is orange, black, or gray, the
battery discharging condition is normal.
If the input line on the One-Line Display
is green, check the Active Event Window
for potential fault conditions that could
explain why the UPS is on battery. An
example of this could be “Rectifier Fault.”
Monitor the UPS during the battery
discharge. The display shows the
discharge curve of the battery.
When the Battery Voltage Line touches
the End of Discharge Line, the UPS shuts
down.
Check the bypass line on the One-Line
Display. If the line feeding the Static
Bypass Switch (BPSS) is green, the unit
can be transferred to bypass by pressing
“Transfer,” “Bypass” to transfer the load
to the bypass source. Note that
transferring to bypass could expose the
load to an outage if the bypass source
fails.
If the battery is discharging because of a
fault such as “Rectifier Fault” in the
Active Event Window rather than an
actual power outage, transfer to bypass if
available, and contact your factoryauthorized service provider.
In normal operation, no user response is
required.
Equalize charge can be terminated at any
time by pressing “Battery Management,”
“Manual Battery Equalize,” “Stop.”
Press “SILENCE” to silence the audible
alarm. Are any Battery Circuit Breakers
tripped? Perform a visual inspection of
the batteries in the tripped string(s).
Look for signs of leaking battery acid or
excessively corroded battery terminals.
If there are no visible signs of defective
batteries, press “RESET” to try and clear
the alarm.
Close any open breakers one at a time,
pressing “RESET” after each one to see
which string is causing the alarm. The
string reporting the fault, when online,
will not allow the alarm to reset.
Once the location is identified, or if the
battery string tests are inconclusive,
contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Batt Ovtemp
Limit
Batt Ovtemp
Warning
One or more of the Battery Temperature
Sensors is reporting a temperature
above the limit setpoint. There are two
user-adjustable Battery Temperature
Setpoints: Battery Over Temperature
Warning and Battery Overtemperature
Limit. The temperature in one or more
battery compartments has risen above
the limit setpoint. Depending on user
settings, the controls may trip the
battery breaker associated with the over
temperature condition.
One or more of the Battery Temperature
Sensors is reporting a temperature
above the warning setpoint. There are
two user adjustable Battery
Temperature Setpoints: Battery Over
Temperature Warning and Battery
Overtemperature Limit. This alarm
means the temperature in one or more
battery compartments has risen above
the warning setpoint.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Observe the One-Line Display. To
identify which battery cabinet is
reporting the temperature condition,
press the “Battery Box” on the One-Line
Display to cycle through each battery
compartment or string. The temperature
display is located under the voltage
reading in the Battery Box.
If the Common Battery Disconnect and/or
the individual battery cabinet or string
reporting the over temperature condition
is tripped, check the following settings.
Press “User Settings,” “Battery
Management,” “Battery Temperature” to
check the current Battery Temperature
Setpoints. If none of the Battery Boxes on
the One-Line Display exhibit a
temperature in excess of the temperature
setpoint in the user settings, contact your
factory-authorized service provider.
If the overtemperature limit is being
reported correctly, investigate potential
causes such as faulty air conditioning, or
air flow blockage and resolve.
Otherwise, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm. Observe the One-Line Display. To
identify which battery cabinet is
reporting the temperature condition,
press the “Battery Box” on the One-Line
Display to cycle through each battery
compartment or string. The temperature
display is located under the voltage
reading in the Battery Box.
Press “User Settings,” “Battery
Management,” “Battery Temperature” to
check the current Battery Temperature
Setpoints. If none of the Battery Boxes on
the One-Line Display exhibit a
temperature in excess of the temperature
setpoint in the user settings, contact your
factory-authorized service provider. If the
overtemperature warning is being
reported correctly, investigate potential
causes, such as faulty air conditioning or
air flow blockage and resolve. Otherwise,
contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Batt Self Test
Batt Sensor Fail
Batt Temp
Imbalance
Batt Test Failed
The UPS is performing a battery self
test.
The battery self test terminates
automatically at the end of the test.
Battery test settings are adjustable and
can be accessed by pressing “Config,”
“User Settings,” “Batt Mgt,” “Battery
Test.”
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
The controls are sensing a failed Battery
Temperature Sensor.
If a sensor reports a value outside the
normal operating range of the sensor, it
is considered failed.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
With more than one Battery
Temperature Sensor installed, the
controls are detecting too great a
temperature difference between the
individual sensors.
An Automatic or Manual Battery Test
Failed. The battery “Test Duration” is
adjustable. The battery test fail criteria
were met before the end of the timed
battery test.
For example, there must be at least 25%
load to run the battery test. If, during
the battery test the load drops below
25%, the test fails.
During normal operation, no user
response is required.
The battery test can be terminated at any
time by the user by pressing “Batt Mgt,”
“Manual Battery Test,” “Stop.”
Press “SILENCE” to silence the audible
alarm.
Try to identify which sensor has failed by
observing the temperature reading inside
the Battery Box on the One-Line Display.
Cycle through all connected batteries by
pressing the Battery Box on the display.
Contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
To attempt to identify which sensor is
reporting an inconsistent temperature or
an overheating battery, observe the
temperature reading inside the Battery
Box on the One-Line Display. Cycle
through all connected batteries by
pressing the Battery Box. If it appears
this alarm is due to a specific cabinet or
battery string being warmer than the
others, verify through investigation
whether the string is actually getting
warmer than the others, or if the sensor
appears to be reporting incorrectly.
Contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Batt Test Inhibit
Batt Test Passed
Q2 Open
BPSS Ovld
Exceeded
The conditions required to perform an
automatic battery test are not met.
When the battery test is inhibited, the
system delays the test for 7 days. If
conditions are satisfied after 7 days, the
UPS performs the battery test at that
time.
Examples of conditions required to run
the automatic battery test are at least
20% load, all battery breakers closed,
normal operation, etc.
The Battery Test passed. None.
The Bypass isolator is open.
The Bypass isolator feeds the Static
Bypass Switch (BPSS).
The purpose of this isolator is to prevent
leakage current through the bypass
circuit during an outage.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
The Bypass Static Switch (BPSS) was
turned off due to an extended overload.
While the BPSS can sustain an overload
greater than the Inverter and for a
longer period of time, there are still
limits on the amplitude and duration of
overload that the BPSS can handle. This
alarm indicates the overload was
greater in amplitude and time than the
BPSS can handle, and therefore shut off
to prevent damage to the equipment.
Check the Active Event Window and
investigate other events to further
analyze.
If there are other active events in the
Active Event Window, press “RESET” to
clear the events.
Check the One-Line display to verify the
UPS is online.
Check the Module Output Meter and
verify the kW load is between 20%-100%.
Press the Battery Box on the One-Line
Display and verify all battery strings
show at least 90% charged and all battery
breakers are closed.
If the issue cannot be resolved, contact
your factory-authorized service provider.
This status message is informational. If
the isolator was not opened intentionally,
or if the isolator is actually closed and
this message is active, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
If Q3 is available (visible if present on the
One-Line Display), close it to restore
power to the load.
DO NOT ATTEMPT TO CLOSE Q3
UNTIL THE SOURCE OF THE
OVERLOAD IS IDENTIFIED AND
ISOLATED.
Once the overload source is isolated,
restart the UPS by pressing “Startup,”
“Manual Start” and follow the prompts.
If the overload condition does not clear, or
the overload is cleared but the UPS does
not restart, contact your factoryauthorized service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
BPSS Unable
Breaker Close
Fail
Breaker Open
Fail
Byp Overload Ph
A
Byp Overload Ph
B
Byp Overload Ph
C
A problem has been detected in the
Bypass Static Switch.
This is a summary event that informs
the user that a isolator that was either
signaled to close or was manually closed
failed to report a closed status.
The Breaker Close Fail event indicates
a mismatch between the expected state
of a isolator and the reported state of
the isolator.
This is a summary event that informs
the user a isolator that was either
signaled to open or was manually
opened failed to report an open status.
The Breaker Open Fail event indicates a
mismatch between the expected state of
a isolator and the reported state of the
isolator.
The critical load is greater than 110%
while the UPS is on bypass. The
controls may shut the unit down if the
overload condition does not clear within
the allotted time. Allotted time is
variable, and is inversely proportional to
the amplitude of the overload, i.e., the
greater the amplitude of the overload,
the less time the unit continues to
support the load.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to attempt to clear the
fault.
Contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display and the
Active Event Window to determine which
isolator or switch is open.
If the open isolator cannot be reset or
closed, or if all isolators are closed but the
One-Line Display does not agree, or the
alarm cannot be cleared, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display and the
Active Event Window to determine which
breaker or switch that should be open is
still closed.
If a breaker that should be open shows
closed, or if the breaker in question
actually is open but the fault is still
present, attempt to clear the fault by
pressing “RESET.”
If the event does not reset, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Observe the calculated load percentage
on A phase displayed on the Module
Output Meter. If the A phase (or Ph B or
Ph C) steady state load percentage
exceeds 110%, perform the following:
If Maintenance Bypass is available,
follow Standard Operating Procedures to
transfer the load to Maintenance Bypass.
If Maintenance Bypass is not available
but the system has an Internal Bypass
Breaker (Q3 on the One-Line Display),
close Q3. Note that depending on the
severity of the overload, the possibility
exists that Q3 could trip if the overload
exceeds the breaker rating.
Investigate the overload condition.
If the Module Output Meter does not
indicate an overload condition, perform
the previous steps and contact your
factory-authorized service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Bypass Breaker
(Q3) Close Fail
Bypass Breaker
(Q3) Open Fail
Bypass Line Fail
Bypass Not Avail
Bypass OF/UF
Controller Error
The bypass isolator has failed to
respond to a close signal.
The bypass isolator has failed to
respond to an open signal.
The bypass source is not present.
This summary event indicates a
problem with the detected bypass
voltage. If bypass is not available,
transfers to bypass are disabled.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The bypass frequency has exceeded the
bypass frequency limit of ± 5 Hz of
nominal. If this alarm is
active, transfers to bypass are disabled.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
This is a summary event that indicates
a DSP communication error.
The Controller Error event is a fault
condition that indicates a loss of
communications in the controls.
Press “SILENCE” to silence the audible
alarm.
Observe the One-Line Display. The
bypass power line feeding the static
switch is green when bypass power is
within normal operating range. If the line
feeding the static switch is orange, gray,
or black, bypass voltage is out of
tolerance. Also check the bypass voltage
readings on the Bypass Meter.
When the bypass returns to normal, this
alarm clears automatically. If all
indications checked above are normal and
the alarm is still present, contact your
factory-authorized service provider.
If there is a problem indicated with the
bypass voltage, investigate and resolve
the issue.
Examples of conditions that could cause
this alarm:
Unstable generator voltage; or, Bypass
isolator opened.
Press “SILENCE” to silence the audible
alarm.
Check the frequency on the Bypass
Meter. If the frequency is outside the
synchronization range, investigate and
resolve the issue.
This alarm is commonly the result of an
uncalibrated generator, or power
anomalies on the utility feed.
Check bypass power for nominal limits.
If bypass frequency appears normal,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to attempt to reset the
fault.
Contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Controls
Comm Fail
Controls Reset
Required
DC Link
Gnd Fault +
DC Link
Gnd Fault -
EMO Shutdown
The Controls Communication Failure
event indicates a loss of communications
between the Controls and Human
Machine Interface (HMI).
The Controls Communication Failure
event is displayed when the HMI
detects a loss of communication with
Controls on the Controller Area
Network (CAN).
An infrequent occurrence that resets
immediately is probably not serious.
This alarm means one or more critical
settings have been changed by user
during UPS operation.
The change(s) will not take effect until
after a UPS Controls reset. This
operation should only be performed by
an authorized service personnel.
This alarm is cleared after UPS
Controls reset.
The positive (or negative) DC Bus has a
ground fault.
The UPS controls monitor the DC Bus
positive (or negative) half for a voltage
imbalance caused by current flow to
ground. This fault means excessive
ground current is detected.
In normal operation, with the batteries
connected, the most likely cause of a
current path to ground is a leaking
battery.
If your system includes an optional
Battery Ground Fault Monitor, check if
the Battery Ground Fault message is
present also.
An Emergency Module Off (EMO)
command has been detected.
A Remote EMO would display the
“REMO Shutdown” alarm.
In response to an EMO, the UPS
transfers to Bypass and shuts off.
If the alarm does not clear, or if the alarm
condition returns, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear the fault.
Perform a visual inspection of the
batteries. Look for signs of leaking
battery acid or excessively corroded
battery terminals.
If there are no visible signs of defective
batteries, open one Battery Breaker.
Press “RESET” and see if the condition
clears. If the condition clears, you have
isolated the problem to that battery
string.
If the condition will not clear, repeat the
test with each connected battery string.
Once the location is identified, or if the
battery string tests are inconclusive,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Resolve the issue that precipitated the
EMO.
For safety, the UPS latches an EPO
event. To clear the latch, press the EMO
Reset pushbutton on the External
Interface Board (EIB).
Verify the EMO is cleared by pressing
“RESET” and observing that the EPO
alarm in the Active Event Window is
gone.
Restart the UPS by pressing “Startup,”
“Manual Start,” and follow the prompts.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
EPO Shutdown
Equip Ovtemp
The UPS shuts down in response to an
active Emergency Power Off (EPO)
command. The EPO signal means the
front panel EPO button was pressed.
This summary event indicates the UPS
is nearing an over temperature
condition. Depending on which sensor is
reporting the high temperature, the
UPS may do one of three things once the
limit is reached: shut down, transfer to
bypass, or transfer to battery operation.
This is a potentially serious event.
Press “SILENCE” to silence the audible
alarm.
Resolve the issue that precipitated the
EPO. For safety, the UPS latches an EPO
event. There are two ways to clear the
latch:
1. Press the EPO Reset pushbutton on
the External Interface Board (EIB).
2. From HMI front panel display, press
OK button when ” Press OK to Reset EPO
Latched signal” message is displayed in a
dialog box.
Verify the EPO is cleared by observing
the EPO alarm in the Active Event
Window is gone.
Restart the UPS by pressing “Startup,”
“Manual Start,” and follow the prompts.
Investigate possible causes for a rising
temperature condition, such as loss of air
conditioning, airflow obstructions, etc. If
the ambient temperature is high due to
loss of air conditioning and cannot be
addressed immediately, perform the
following:
1. Press “Transfer,” “Bypass” to transfer
the UPS to bypass.
2. Press “SILENCE” to silence the audible
alarm.
3. Wait at least 15 minutes, then attempt
to reset the alarm by pressing “RESET.”
4. If the alarm clears and proper cooling
has been restored to the UPS, press
“Transfer,” “UPS” to transfer back to
UPS.
If this alarm is present and no external
factors are affecting proper cooling of the
UPS, contact your factory-authorized
service provider.
Liebert NXL alarm and status messages (continued)
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Event Message Event Definition Recommended Action
Equip Ovtemp
Limit
This summary event occurs when one or
more internal temperatures have
exceeded the maximum temperature
setpoint. This is the second of two over
temperature alarms. The first,
“Equipment Overtemperature
Warning,” sets when the detected
temperature is near the limit.
The controls react to this condition in
various ways, depending on which
sensor is reporting the over temperature
condition.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display for system
status:
1. UPS Off
a. If external Maintenance Bypass is
available, close the Maintenance Bypass
Breaker (MBB) to restore power to the
load. Do not attempt to restart the UPS
without first contacting your factoryauthorized service provider.
b. If external Maintenance Bypass is not
available, but the Q3 option is visible on
the One-Line Display, verify the bypass
line is green and close Q3 to restore
power to the load. Contact your factoryauthorized service provider.
2. UPS On Bypass
a. Verify the bypass line is green. If it is
not, contact your factory-authorized
service provider immediately and prepare
to shut down the load.
b. If external Maintenance Bypass is
available, close the Maintenance Bypass
Breaker (MBB) to place the load on
Maintenance Bypass. Do not attempt to
re-transfer to UPS without first
contacting your factoryauthorized service provider.
c. If external Maintenance Bypass is not
available, but the Q3 option is visible on
the One-Line Display, close Q3. Do not
attempt to re-transfer to UPS without
first contacting your factory-authorized
service provider.
3. UPS On Battery
a. Verify the bypass line is green. If it is
not, contact your factory-authorized
service
provider immediately and prepare to shut
down the load.
b. If the bypass line is green, press
"Transfer", "Bypass", to transfer the load
to bypass.
c. If there is a Q3 present on the OneLine Display, close Q3. If Q3 is not
present and external Maintenance
Bypass is available, close the MBB to
place the load on Maintenance Bypass. If
both Q3 and Maintenance Bypass are
present, first close Q3, then close the
external MBB. If Q3 or external
Maintenance Bypass is not available,
shut down the UPS by pressing
"Shutdown", "UPS" and contact your
factory-authorized service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Excess Auto
Rexfers
Excess
Paralleling
Fuse Fail
The UPS has re-transferred too many
times and is now locked on bypass.
The UPS attempts to perform an
automatic transfer back to Inverter, if
the reason for the transfer to bypass is
determined by the controls to be
automatically recoverable; for example,
a temporary overload.
The number of times the UPS attempts
to recover from an automatic transfer to
bypass is limited.
When the number of transfers exceeds
the number allowable (default is 5
transfers per hour), the UPS remains on
bypass, and display this message.
An example of a condition that could
cause this alarm is cycling load to the
UPS where the peak load exceeds the
overload settings. The UPS transfers on
the overload, re-transfers to Inverter,
then the overload returns. Once this
occurs 5 times within one hour, the user
must manually transfer the UPS back
online.
When the controls detect a high
amplitude, short duration overload
condition on the output, the static
switch is turned on momentarily in
parallel with the Inverter to attempt to
clear the condition.
If the fault clears, the controls turn off
the static switch and the load remains
on Inverter. This fault condition
indicates the UPS pulse paralleled too
many times and is now locked on bypass
(auto re-transfers to Inverter are
inhibited).
This is a summary event that indicates
a fuse has opened. There are several
fuses that can cause this fault.
The Fuse Failure event is caused by one
or more fuses reporting a failed status.
The UPS may or may not transfer to
bypass as a result of the failed fuse.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear any active faults
or alarms.
Provided there are no alarms or faults
still present that could prevent a transfer,
press “Transfer,” “UPS,” to transfer back
to Inverter.
If the transfer is successful, press
“RESET” to clear the alarm. Otherwise,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Check the Module Output Meter and
verify the output currents are normal, the
kVA/kW percentages are less than 100%,
and the Rexfer Timeout is 00:00.
Verify the Inverter box on the One-Line
Display is green.
Investigate any other active alarms or
faults before attempting to clear this
fault.
Press “RESET” to clear the fault.
If the Event Window is clear, press
“Transfer,” “UPS” to transfer the load
back to Inverter.
If the “UPS” button is grayed out, or
pressing the “UPS” button does not
transfer the unit back to Inverter, or if
the UPS immediately transfers back to
bypass, contact your factory-authorized
service provider.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display and other
indicators to determine the state of the
unit and take appropriate action.
Contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Event Message Event Definition Recommended Action
Inlet Ovtemp
Excess Auto
Rexfers
Excess
Paralleling
The air flowing into the UPS is too
warm.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The UPS has re-transferred too many
times and is now locked on bypass.
The UPS attempts to perform an
automatic transfer back to Inverter, if
the reason for the transfer to bypass is
determined by the controls to be
automatically recoverable; for example,
a temporary overload.
The number of times the UPS attempts
to recover from an automatic transfer to
bypass is limited.
When the number of transfers exceeds
the number allowable (default is 5
transfers per hour), the UPS remains on
bypass, and display this message.
An example of a condition that could
cause this alarm is cycling load to the
UPS where the peak load exceeds the
overload settings. The UPS transfers on
the overload, re-transfers to Inverter,
then the overload returns. Once this
occurs 5 times within one hour, the user
must manually transfer the UPS back
online.
When the controls detect a high
amplitude, short duration overload
condition on the output, the static
switch is turned on momentarily in
parallel with the Inverter to attempt to
clear the condition.
If the fault clears, the controls turn off
the static switch and the load remains
on Inverter. This fault condition
indicates the UPS pulse paralleled too
many times and is now locked on bypass
(auto re-transfers to Inverter are
inhibited).
Press “SILENCE” to silence the audible
alarm.
Check the Inlet Air Temperature on the
One-Line Display and verify the reading
is accurate, i.e. is the room temperature
warmer than normal?
If the room temperature is warmer than
normal, investigate and resolve the issue.
If the room temperature is normal, and
the Inlet Air Temp reading on the OneLine Display is higher than normal,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear any active faults
or alarms.
Provided there are no alarms or faults
still present that could prevent a transfer,
press “Transfer,” “UPS,” to transfer back
to Inverter.
If the transfer is successful, press
“RESET” to clear the alarm. Otherwise,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Check the Module Output Meter and
verify the output currents are normal, the
kVA/kW percentages are less than 100%,
and the Rexfer Timeout is 00:00.
Verify the Inverter box on the One-Line
Display is green.
Investigate any other active alarms or
faults before attempting to clear this
fault.
Press “RESET” to clear the fault.
If the Event Window is clear, press
“Transfer,” “UPS” to transfer the load
back to Inverter.
If the “UPS” button is grayed out, or
pressing the “UPS” button does not
transfer the unit back to Inverter, or if
the UPS immediately transfers back to
bypass, contact your factory-authorized
service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Fuse Fail
Inlet Ovtemp
Inp Phase
Rotation
Input Contact XY
If this event is active, an external signal is wired into Channel Y of Input Contact Isolator #X.
If the display shows Case 1 above (blank message), it means the contact channel is set to default but the
default message was erased.
If the display shows Case 2, the user-programmed event is active and the displayed text is customer
defined.
If the display shows Case 3, the contact is active but was not pre-programmed (default condition).
If the display shows Case 4, the controls force the Rectifier into Reduced Input Current Limit operation
(this limits the amount of current available to charge the battery - typically during generator operation).
This alarm message is self-clearing. When the condition is no longer present, the message and any control
activity tied to the alarm will revert to normal.
This is a summary event that indicates
a fuse has opened. There are several
fuses that can cause this fault.
The Fuse Failure event is caused by one
or more fuses reporting a failed status.
The UPS may or may not transfer to
bypass as a result of the failed fuse.
The air flowing into the UPS is too
warm.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The correct input phase rotation should
be clockwise, or A-B-C. This alarm
indicates the sensed input phase
rotation is counter-clockwise.
If this alarm occurs on an operational
unit, it typically indicates upstream
work was performed (input side) and the
input wiring was connected incorrectly.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The displayed text for this alarm is
dependent on settings.
In response to this alarm, the user may
see 1 of 4 possible messages:
1. No message but the help icon
(lowercase “i“) is present;
2. A custom message programmed by
the user;
3. “Input Contact XY” if the contact is
unconfigured;
4. “Reduced Rect ILimit” if the contact is
programmed as Pre-assigned.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display and other
indicators to determine the state of the
unit and take appropriate action.
Contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Check the Inlet Air Temperature on the
One-Line Display and verify the reading
is accurate, i.e. is the room temperature
warmer than normal?
If the room temperature is warmer than
normal, investigate and resolve the issue.
If the room temperature is normal, and
the Inlet Air Temp reading on the OneLine Display is higher than normal,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Verify correct phase rotation at the input.
If the phase rotation is correct, contact
your factory-authorized service provider.
Check the wires landed on Input Contact
Isolator #X.
If the signal is not active, or no wires are
present, contact your factory-authorized
service provider.
Liebert NXL alarm and status messages (continued)
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Event Message Event Definition Recommended Action
Input Contact
Interface #1 (or
#2)
Communication
Failure
Input Current
Imbal
Input Current
Limit
Input Disconnect
(Q1) Open
Input Disconnect
(Q11) Open
Input Filter Cycle
Input Contact Interface #1 (or #2) has
failed to communicate in a timely
fashion.
The detected input currents are not
balanced.
This latching alarm indicates a
potential problem in the input filter.
The controls automatically open the
filter contactor in response to this
condition.
The filter contactor must be manually
closed once it opens in response to this
alarm.
An active Input Current Limit alarm
means the detected input current (RMS)
exceeds the limit setpoint (default is
125%). This may be normal depending
on various operating conditions, such as
input voltage level, output load level,
and whether the batteries have recently
discharged.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The rectifier disconnect device indicates
that it is in the open position.
The externally mounted input isolator
indicates that it is in the open position.
The Input Filter Disconnect is locked
open.
The Input Filter Disconnect Cycle
counter has exceeded the setpoint. The
Input Filter Disconnect opens
automatically as determined by the
disconnect settings, or because of an
unusual condition.
An example of a setting would be to
automatically open the filter disconnect
under light load conditions to improve
the input power factor. An example of
an unusual condition would be
unbalanced currents on the input,
possibly because of a suspect component
in the filter itself.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to attempt to clear the
alarm condition.
If the alarm clears, press “Startup,”
“Device Control,” “Close Trap” to
manually close the filter contactor.
If the contactor remains closed, check the
Input Meter and verify the input currents
are balanced.
If the contactor re-opens and the “Input
Current Imbalance” returns, silence the
alarm, leave the filter contactor open, and
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Observe the meters on the One-Line
Display for input voltage level, battery
charge/discharge current, and output load
percentage kW. Investigate any abnormal
readings.
If the reason for the alarm cannot be
determined, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm.
Attempt to manually close the disconnect
by pressing “Startup,” “Device Control,”
“Close Trap.”
If the condition which caused the filter
disconnect to lock open is still present, it
re-opens.
If the disconnect cannot be manually
closed or the alarm cannot be cleared,
contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Input Not Avail
Internal Comm
Error
Inv Overload Ph
A
Inv Overload Ph
B
Inv Overload Ph
C
Inv Ovld
Exceeded
This summary alarm means there is a
problem with input power. It is not
acceptable to the Rectifier.
If the unit is running normally when
this event occurs, the UPS goes to
battery.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
This is a summary event caused by an
interruption in communication between
the controls and a device on the
Controller Area Network (CAN).
The Internal Communication Error
event indicates a loss of communications
between the controls and an external
device.
The Internal Communication Error is
displayed when the controls detect a
loss of communication to a device on the
Controller Area Network (CAN).
An infrequent occurrence that resets
immediately is probably not serious.
An overload condition is active on A (or
B, or C) phase.
A phase load condition exceeds 105%.
A countdown timer is displayed on the
One-Line Display in response to this
alarm, and indicates the time remaining
until a transfer to bypass occurs. The
length of time remaining until transfer
is directly proportional to the severity of
the overload.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
This message is displayed in response to
an overload on one or more output
phases.
When an overload occurs, the controls
display a countdown timer that displays
the time remaining until a transfer to
bypass occurs. The length of the timer is
inversely proportional to the amplitude
of the overload. When the timer reaches
zero, the UPS transfers to bypass and
populates the Active Event Window
with this alarm.
This fault is non-latching. When the
underlying condition is no longer
present, this fault and any control
activity tied directly to this fault reverts
to normal.
Press “SILENCE” to silence the audible
alarm.
Examine the One-Line Display. The
Rectifier input line feeding the Input
Breaker should be green. If not,
investigate source power to the UPS.
If input power is good, and this alarm is
active, contact your factory-authorized
service provider.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear the alarm.
If the alarm cannot be reset, or if the
alarm condition returns, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Check the Module Output Meter and note
the A phase (or B, or C) load percentage.
If possible, reduce A phase (or B, or C)
loading.
If the steady state load remains above
105%, allow the UPS to transfer to
bypass and contact your factoryauthorized service provider.
If the displayed load percentage is less
than 100% and the alarm is still active,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Observe the load percentages for each
phase on the Module Output Meter. If the
load is less than 100%, attempt to
transfer back to Inverter by pressing
“Transfer,” “UPS.”
If the transfer is successful, investigate
the reason for the overload and take
appropriate action.
If the transfer is unsuccessful, contact
your factory-authorized service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Inverter Fault
ISS SCR Shorted
LBS Inhibited
LBS Operating
This summary event indicates a
potentially serious problem in the
Inverter.
The controls react to an Inverter fault in
different ways depending on the root
event that caused the fault. If bypass is
available, the controls transfer to static
bypass.
A restart may or may not be possible
The controls have detected voltage on
the Inverter (Line side) side of the
Inverter Static Switch.
This indicates that an SCR is shorted.
With the Output SCRs turned off, there
should be no voltage present inside the
UPS.
This is a non-recoverable fault, and
inhibits normal start up of the UPS.
With LBS operation enabled, conditions
required to allow LBS operation are not
met.
Voltage or Frequency differences sensed
by the LBS control are preventing the
ability of LBS to function correctly.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
Load Bus Synchronization (LBS) is
enabled and is active.
This status message informs the user
that one system in an LBS system has
lost its synchronization source (usually
its own Bypass) and is now
synchronized to the other system by the
LBS controls.
This status message is self-clearing.
When the condition is no longer present,
the alarm and any control activity tied
to the alarm reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Check the One-Line Display to determine
the state of the UPS. If both the Rectifier
and Inverter are
shut off, press “RESET” to attempt to
clear any latched alarms or faults.
Attempt a restart by pressing “Startup,”
“Manual Start,” and follow the prompts to
place the UPS back in service.
If the startup fails, contact your factoryauthorized service provider.
If the Rectifier and Inverter appear to be
running, press “RESET” to attempt to
clear any latched alarms or faults, then
attempt a transfer by pressing “Transfer,”
“UPS.” If the transfer is successful,
contact your factory-authorized service
provider.
If the transfer is unsuccessful, contact
your factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Turn off Control Power to clear the event.
Wait 5 minutes before re-applying
Control Power.
If the fault fails to clear, contact your
factory-authorized service representative.
Press “SILENCE” to silence the audible
alarm.
Check both Systems and verify normal
operation:
a. Both Systems running online on
inverter; b. Neither System in
Maintenance Bypass; c. No Bypass,
Input, or Synchronization errors present
on either system. If the cause of the
alarm cannot be determined by checking
both Systems, contact your factoryauthorized service provider.
Under normal circumstances, none. If
this message is active, and there is no
clear reason why the LBS circuit should
be active, contact your factory-authorized
service provider.
Liebert NXL alarm and status messages (continued)
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Event Message Event Definition Recommended Action
Leading Pwr
Factor
Load on Bypass
Load on Maint
Byp
Low Batt
Capacity
Low Batt
Shutdown
Low Battery
Warning
With a load of 80% or greater, the
controls have calculated the output
Power Factor to be less than .95 leading.
Leading Power Factors result in wasted
energy. If the Power Factor is less than
.95 leading, the UPS output is de-rated
to compensate for output losses.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The load is being supplied by bypass. None.
The load is on Maintenance Bypass. None.
One or more battery circuit breakers are
open. This alarm applies if the system
includes more than one battery circuit
breaker, and at least one is closed, but
one or more are open.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
The Battery has reached End of
Discharge (EOD).
There is no longer enough energy left in
the battery to run the Inverter with the
current load.
If bypass is available, the UPS attempts
to transfer the load to bypass at EOD.
The battery is nearly depleted, and the
unit shuts down very soon.
The Low Battery Warning setpoint is
adjustable under User Settings. This
alarm means the calculated time
remaining on battery is now less than
the Low Battery Warning setpoint.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Check the Output Meter readings and
verify the Output Power Factor. If the
displayed power factor is less than .95
leading, and the load is greater than 80%,
reduce the load or investigate.
Contact your factory-authorized service
representative.
Press “SILENCE” to silence the audible
alarm.
To clear this alarm, verify all battery
breakers are closed. Investigate any open
breakers.
Press “SILENCE” to silence the audible
alarm.
Once power is restored, attempt a normal
restart of the UPS.
If the restart fails, contact your factoryauthorized service provider.
Check to see if bypass is available by
observing the One-Line Display.
Acceptable bypass voltage is indicated by
a green power line feeding the Static
Bypass Switch (BPSS) box. If bypass is
available, press “Transfer,” “Bypass” to
transfer to bypass. If the bypass is
qualified, the UPS transfers to the bypass
source.
If bypass is not available, prepare to shut
down critical loads, or remove nonessential loads in order to extend battery
run time so that critical loads may be
shut down in an orderly manner.
Liebert NXL alarm and status messages (continued)
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Event Message Event Definition Recommended Action
Low Power
Factor
Main Control
Fault
The output power factor is low.
The output power factor is less than
70% leading or lagging. A simplified
explanation of power factor is the ratio
of energy being supplied to energy being
used by the load. For a given load, the
current output of the UPS goes up as
power factor decreases.
This results in the UPS output being
derated.
For example, study the following:
Load = 100 kw @ 400V
amps = kw X 1000 / volts X power factor
X 1.73
(square root of 3)
100kw X 1000 = 100000
400volts X .9PF X 1.73 = 622
100000/622 = 160 amps
Now, replace the .9 power factor (typical
computer load power factor) with .7
power factor:
100kw X 1000 = 100000
400volts X .7PF X 1.73 = 484
100000/484 = 207 amps
The load remains the same, but the
current required to supply it is roughly
30% higher. The extra current is wasted
energy that can result in nuisance trips
of breakers, overheating of cables, and
other unwanted conditions. The UPS
cannot control the output power factor.
The UPS has transferred to Bypass due
to a loss of communications with the
Main Controller.
All Transfers, Startup, Shutdown, and
Metering screens are locked out.
The Controls attempt to reestablish
communications but will not return the
load to inverter automatically.
Press “SILENCE” to silence the audible
alarm.
Evaluate the load on the UPS. For more
information, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm.
Contact your factory-authorized service
provider.
If communications are reestablished, the
One-Line Display will be restored;
however, Liebert does not recommend
attempting to return the load to inverter
until a service visit has been made and
action taken to determine why the fault
occurred.
Action will involve resetting the UPS
controls by removing and then reapplying
control power.
Therefore, it will be necessary to utilize
maintenance bypass, either by closing the
Q3 internal bypass breaker, or by closing
the optional external Maintenance
Bypass Breaker (MBB). Liebert does not
recommend the user, or operator, attempt
this without first speaking with an
authorized service associate from Liebert.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Maintenance
Bypass
Breaker(MBB)
Open
Man Rexfer
Inhibit
Manual Xfer
Inhibit
Max Load Alarm
Ph A
Max Load Alarm
Ph B
Max Load Alarm
Ph C
The external maintenance bypass
breaker indicates that it is in the open
position.
This summary event means the
conditions required to perform a manual
transfer to Inverter (online) are not met
(Inverter must be in sync with bypass).
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
This summary event means the
conditions required to perform a manual
transfer to bypass are not met (Inverter
must be in sync with bypass).
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal
The user adjustable maximum load
alarm threshold was exceeded. This is a
“notification only” type alarm, meaning
the UPS takes no action other than
sounding an audible alarm based on this
setpoint. The setting allows the user to
monitor the load status of the UPS.
For example, if the current load on
Phase A (or B, or C) is 50%, the user can
set this setpoint to 80% and an alarm is
received if the added load exceeds 80%.
The alarm may also be configured with
a delay, to prevent nuisance alarms due
to cycling loads.
The alarm is self-clearing. Once the load
level decreases to less than 95% of the
level setting, the alarm clears.
The condition clears from the Active
Event Window when manual re-transfers
are enabled.
A possible reason for this condition is an
unstable generator. If the generator
frequency is not stable, or not at 50 Hz,
the Inverter may have difficulty
maintaining or acquiring synchronization
with the bypass source.
To check the synchronization of the
Inverter to bypass, click “Transfer” and
observe the synchroscope. A non-sync
condition is indicated by a varying phase
angle error, rather than a stable “0”
degree indication.
If the unit is not on generator, and the
bypass voltage otherwise appears normal,
contact your factory-authorized service
provider.
The condition clears from the Active
Event Window when manual transfers
are enabled.
A possible reason for this condition is an
unstable generator. If the generator
frequency is not stable, or not at 50 Hz,
the Inverter may have difficulty
maintaining synchronization with the
bypass source.
To check the synchronization of the
Inverter to bypass, click “Transfer” and
observe the synchroscope. A non-sync
condition is indicated by a varying phase
angle error, rather than a stable “0”
degree indication.
If the unit is not on generator, and the
bypass voltage otherwise appears normal,
contact your factory-authorized service
provider.
Press “SILENCE” to silence the audible
alarm.
Check the kW load % displayed for A (or
B, or C) phase.
To check the setpoint for the alarm, press
“Config,” “User Settings,” “Adjustable
Setpoints,” “Max Load Alarm.”
Compare the setpoint to the displayed
load percentage. If the load percentage
displayed is correct and the value exceeds
the setpoint, raise the setpoint to clear
the alarm, or reduce the load below the
setpoint.
Contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Multiple Fan Fail
On Gen Active
Outlet Ovtemp
Limit
This summary event is active when
more than one fan has failed.
The UPS input source is generator.
An external signal is being used to
inform the UPS when the power source
is generator rather than utility, and the
signal is active.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
The difference between the inlet air
temperature and the outlet air
temperature is too great.
This alarm means excessive heat is
being generated internally resulting in a
higher than normal exhaust air
temperature.
If the Bypass is within limits, the UPS
reacts to this alarm by transferring to
Bypass and shutting off the Inverter.
This alarm is self-clearing. When the
condition is no longer present, the alarm
and any control activity tied to the
alarm reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear the alarm.
If the alarm will not clear, contact your
factory-authorized service provider.
Under normal conditions, no user action
is required.
If the UPS is not actually on generator
and this message is active, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Check the Inlet Air Temperature on the
One-Line Display and verify the reading
is accurate, i.e. is the room temperature
warmer than normal?
If the room temperature is warmer than
normal, investigate and resolve the issue.
If the room temperature is normal, and
the Inlet Air Temp reading on the OneLine Display is higher than normal,
contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Output Fault
Rectifier Fault
This summary event occurs when the
detected system output exceeds
acceptable limits in either voltage or
frequency.
If the UPS was on Inverter at the time
of the event, the UPS transfers to
bypass provided the bypass voltage is
available.
If the UPS was on bypass at the time of
the event, the UPS shuts down rather
than allowing unacceptable voltage to
reach the load.
This summary event indicates a
potentially serious condition in the
Rectifier circuit. The controls respond to
this by turning off the Rectifier, opening
the input filter contactor, and placing
the UPS on battery operation. This fault
is non-latching. When the underlying
condition is no longer present, this fault
and any control activity tied directly to
this fault reverts to normal.
Press “SILENCE” to silence the audible
alarm.
Check the Active Event Window and
investigate other events to further
analyze.
Press “RESET” to attempt to reset any
latched events.
Check the One-Line Display to determine
the system status (on UPS, Bypass, or
Off).
Check the input and bypass (dual input
only) and observe the One-Line colour.
Green indicates good power present,
orange means power is present but
outside nominal range, and gray means
power is not present.
If the load is off and the input voltage is
ok, attempt to restart the UPS by
pressing “Startup,” “Manual Start,” and
follow the prompts.
If the Input Meter indicates input or
bypass is not available, investigate and
resolve the power problem.
If the load is on bypass and all alarms are
reset, press “Transfer,” “UPS,” to attempt
to transfer back to Inverter.
If the issue cannot be resolved, contact
your factory-authorized service provider.
Observe the One-Line Display and the
Active Event Window for current UPS
condition - On Battery?
Observe the colour of the Bypass Line on
the One-Line Display. If green, bypass is
available. This is significant, because if
the batteries fail, the UPS transfers
safely to the bypass line. If the UPS is on
battery, and the bypass line on the OneLine Display is not green, contact your
factory-authorized service provider
immediately and prepare to shut down as
the UPS turns off once the batteries are
depleted. Press “SILENCE” to silence the
audible alarm.
Press “RESET” to attempt to clear the
fault condition. If the Rectifier Fault
clears, press “Startup,” “Manual Start,”
“Rectifier” to attempt to restart the
Rectifier. If this is successful, observe
normal operation of the Rectifier,
indicated on the One-Line Display by a
green outline around the Rectifier box,
and normal DC Bus voltage on the DC
Bus Meter. If the Rectifier starts
normally, attempt to close the input filter
contactor by pressing “Startup,” “Device
Control", "Close Trap".
If the UPS is not on battery, but
transferred to bypass, contact your
factory-authorized service provider. If the
Rectifier Fault was cleared by pressing
"RESET", but the fault returns as soon as
a Rectifier restart is attempted, contact
your factory-authorized service provider.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Redundant Fan
Fail
Regen Active
Regen Failure
This alarm indicates a fan has failed Press “SILENCE” to silence the audible
alarm.
Contact your factory-authorized service
provider.
Regeneration Mode is a service mode
that is normally controlled by the
service technician.
Regeneration Mode Status or Alarm
messages are generally intended for the
service person.
This status message informs the user
the UPS is in Regeneration Mode. This
status message is self-clearing. When
the condition is no longer present, the
alarm and any control activity tied to
the alarm reverts to normal.
Regeneration Mode was initiated and
terminated because of an abnormal
condition.
Once Regeneration Mode is active, any
condition, for example an Inverter
Overload, other than the user manually
stopping Regeneration Mode, causes
this message to appear.
Regeneration Mode is a service mode
that is normally controlled by the
service technician.
Regeneration Mode Status or Alarm
messages are generally intended for the
service person.
This status message informs the user
the UPS is in Regeneration Mode.
This status message is self-clearing.
When the condition is no longer present,
the alarm and any control activity tied
to the alarm reverts to normal.
Liebert NXL alarm and status messages (continued)
Under normal circumstances, none. If
this message is active, and there is no
clear reason why the UPS is in
Regeneration Mode, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to attempt to clear the
alarm.
If Regeneration Mode was not manually
initiated by service, or if this alarm will
not reset, contact your factory-authorized
service provider.
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
Regen
Terminated
Remote Off BPSS
Remote Off Inv
Remote Off Rect
Regeneration Mode is a service mode
that is normally controlled by the
service technician. Regeneration Mode
Status or Alarm messages are generally
intended for the service person.
This status message informs the user
that Regen Mode is no longer active.
This status message is self-clearing.
When the condition is no longer present,
the alarm and any control activity tied
to the alarm reverts to normal.
The Static Bypass Switch (BPSS) was
turned off by an external signal.
This indicates an external signal forcing
the BPSS to remain off is active.
This type of signal is wired into an
Input Contact Isolator and the specific
channel is assigned as Remote Off
BPSS.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
The Inverter was turned off by an
external signal.
This indicates an external signal forcing
the Inverter to remain off is active.
This type of signal is wired into an
Input Contact Isolator and the specific
channel is assigned as Remote Off
Inverter.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
The Rectifier was turned off by an
external signal.
This indicates an external signal forcing
the Rectifier to remain off is active.
This type of signal is wired into an
Input Contact Isolator and the specific
channel is assigned as Remote Off
Rectifier.
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
Under normal circumstances, none. If
this message is active, and there is no
clear reason why the UPS was in
Regeneration Mode, or if the command to
terminate Regeneration Mode was not
issued, contact your factory-authorized
service provider.
Check the state of the Remote Off BPSS
signal.
If this signal is not active, or if no signal
wires are present, contact your factoryauthorized service provider.
Check the state of the Remote Off
Inverter signal.
If this signal is not active, or if no signal
wires are present, contact your factoryauthorized service provider.
Check the state of the Remote Off
Rectifier signal.
If this signal is not active, or if no signal
wires are present, contact your factoryauthorized service provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
Event Message Event Definition Recommended Action
REPO Shutdown
Restart in
Process
Restart Inhibited
Service Code
Active
Temp Sense Fail
Xfer to Byp
Failed
The UPS shuts down in response to an
active Remote Emergency Power Off
(REPO) command.
Automatic Restart is in progress. This
message clears when the Automatic
Restart sequence is complete.
Automatic Restart of the UPS is not
allowed because of an external signal.
Automatic Restart Inhibit is active
when signaled from an external source.
The signal is wired into Input Contact
Interface (ICI 1).
This event is for informational purposes,
and informs the user that Service Code
is currently running.
This status message is self-clearing.
When the condition is no longer present,
the alarm and any control activity tied
to the alarm reverts to normal.
An equipment temperature sensor is
reporting an invalid temperature. The
controls ignore temperatures from a
failed sensor.
An event (such as an Inverter fault)
caused an attempted automatic transfer
to bypass and the transfer failed.
The controls detect the Static Bypass
Switch (BPSS) failed to assume the load
and the Inverter was off.
Press “SILENCE” to silence the audible
alarm.
Resolve the issue that precipitated the
REPO.
For safety, the UPS latches an REPO
event. There are two ways to clear the
latch:
1. Press the Reset pushbutton on the
External Interface Board (EIB).
2. From HMI front panel display, press
OK button when ” Press OK to Reset EPO
Latched signal” message is displayed in a
dialog box.
Verify the REPO is cleared by observing
the REPO alarm in the Active Event
Window is gone.
Restart the UPS by pressing “Startup,”
“Manual Start,” and follow the prompts.
To complete the Automatic Restart, follow
the prompts on the display.
Investigate and resolve the external
signal forcing the UPS to remain off.
If you do not have an ICI, or if there are
no external off signals input to the UPS,
contact your factory-authorized service
provider.
Under normal circumstances, none.
If this message is active, and Service
Code is not loaded, contact your factoryauthorized service provider.
Press “SILENCE” to silence the audible
alarm.
Press “RESET” to clear the alarm.
If the alarm cannot be reset, or if the
alarm condition returns, contact your
factory-authorized service provider.
Press “SILENCE” to silence the audible
alarm.
Check the Event Log by pressing “Status
Reports,” “Event Log” to investigate why
the UPS tried to transfer to bypass and
why the BPSS failed.
If Q3 is available (as displayed on the
One-Line Display), close Q3 to restore
power to the load.
Press “RESET” to attempt to clear any
latched alarms or faults.
If conditions appear normal, attempt to
restart the UPS by pressing “Startup,”
“Manual Start” and follow the prompts.
Contact your factory-authorized service
provider.
Liebert NXL alarm and status messages (continued)
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Liebert NXL UPS Operation and Maintenance Manual 250-300-400-800kVA
NOTES:
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Ensuring The High Availability
0f Mission-Critical Data And Applications.
Emerson Network Power, the global leader in enabling business-critical
continuity, ensures network resiliency and adaptability through
a family of technologies—including Liebert power and cooling
technologies—that protect and support business-critical systems.
Liebert solutions employ an adaptive architecture that responds
to changes in criticality, density and capacity. Enterprises benefit
from greater IT system availability, operational flexibility and
reduced capital equipment and operating costs.
While every precaution has been taken to ensure the accuracy
and completeness of this literature, Liebert Corporation assumes no
responsibility and disclaims all liability for damages resulting from use of
this information or for any errors or omissions.
© 2009 Liebert Corporation
All rights reserved throughout the world. Specifications subject to change
without notice.
® Liebert is a registered trademark of Liebert Corporation.
All names referred to are trademarks
or registered trademarks of their respective owners.
Technical Support / Service
Web Site
www.liebert.com
Monitoring
800-222-5877
monitoring@emersonnetworkpower.com
Outside the US: 614-841-6755
Single-Phase UPS
800-222-5877
upstech@emersonnetworkpower.com
Outside the US: 614-841-6755
Three-Phase UPS
800-543-2378
powertech@emersonnetworkpower.com
Environmental Systems
800-543-2778
Outside the United States
614-888-0246
Locations
United States
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P.O. Box 29186
Columbus, OH 43229
Europe
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Zona Industriale Tognana
35028 Piove Di Sacco (PD) Italy
+39 049 9719 111
Fax: +39 049 5841 257
Asia
7/F, Dah Sing Financial Centre
108 Gloucester Road, Wanchai
Hong Kong
852 2572220
Fax: 852 28029250
Manual reference: SLI-25514_REV 00_04-09
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The global leader in enabling Business-Critical Continuity.
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Business-Critical Continuity, Emerson Network Power and the Emerson Network Power logo are trademarks and service marks of Emerson Electric Co.
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