Liebert NXC User manual

Liebert NXC 10/15/20kVA
UNINTERRUPTIBLE POWER SUPPLY
USER MANUAL
10H52188UM51 - rev. 1

2 User Manual 10H52188UM51 - Rev. 1 - 09/2011
Liebert NXC
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by printing, copying or similar methods, even of parts,
are reserved.
Offenders will be liable for damages.
All rights, including rights created by patent grant or
registration of utility model or design, are reserved.
Delivery subject to availability. Right of technical
modification reserved.
Liebert NXC may differ from the one displayed on the
front cover.

User Manual 10H52188UM51 - Rev. 1 - 09/2011 3
Liebert NXC Contents
Contents
CHAPTER 1 PRODUCT INTRODUCTION.........................................................................................................................5
1.1 Features........................................................................................................................................................................ 5
1.2 Model Configurations ................................................................................................................................................... 5
1.3 Appearance And Components ...................................................................................................................................... 6
1.3.1 Appearance ................................................................................................................................................................................ 6
1.3.2 Components .............................................................................................................................................................................. 6
1.4 Operating Principle....................................................................................................................................................... 7
1.5 UPS State And Operation Mode .................................................................................................................................... 8
1.5.2 Normal Mode ............................................................................................................................................................................. 9
1.5.3 Bypass Mode .............................................................................................................................................................................. 9
1.5.4 Battery Mode.............................................................................................................................................................................. 9
1.5.5 ECO Mode (For Single UPS System Only).................................................................................................................................... 9
1.5.6 FRC (Frequency Converter) Mode .............................................................................................................................................. 9
1.5.7 Fault State .................................................................................................................................................................................. 9
1.5.8 Maintenance Bypass Mode....................................................................................................................................................... 10
1.6 Specifications ............................................................................................................................................................. 10
CHAPTER 2 SINGLE UPS INSTALLATION AND COMMISSIONING.............................................................................12
2.1 Unpacking Inspection ................................................................................................................................................. 12
2.2 Installation Preparation............................................................................................................................................... 12
2.2.2 Location ................................................................................................................................................................................... 13
2.2.3 Environmental Requirement .................................................................................................................................................... 13
2.2.4 Installation Tools ...................................................................................................................................................................... 14
2.3 External Protective Device .......................................................................................................................................... 14
2.3.1 Rectifier And Bypass Input........................................................................................................................................................ 14
2.3.2 Battery Input (for external Battery) .......................................................................................................................................... 15
2.4 Connecting Power Cables ........................................................................................................................................... 15
2.4.1 Connecting I/O Cables.............................................................................................................................................................. 17
2.4.2 Connecting and Installing External Battery............................................................................................................................... 22
2.5 Single UPS Commissioning ......................................................................................................................................... 23
2.5.1 Check Before Power-On ........................................................................................................................................................... 23
2.5.2 Single UPS Parameters Setting ................................................................................................................................................. 23
2.5.3 Normal Mode Start-Up ............................................................................................................................................................. 26
2.5.4 Battery Mode Start-Up ............................................................................................................................................................. 26
CHAPTER 3 PARALLEL UPS INSTALLATION AND COMMISSIONING.......................................................................27
3.1 Features...................................................................................................................................................................... 27
3.2 Requirements ............................................................................................................................................................. 27
3.3 Connecting Power Cables ........................................................................................................................................... 27
3.3.1 Connecitng I/O Cables.............................................................................................................................................................. 28
3.3.2 Connecting Parallel Cables ....................................................................................................................................................... 28
3.3.3 Connecting external Battery Cables ......................................................................................................................................... 30
3.4 Commissioning Parallel System .................................................................................................................................. 32
3.4.1 Check Before Power-On ........................................................................................................................................................... 32
3.4.2 Parallel System Parameters Setting.......................................................................................................................................... 32
3.4.3 Power-On Commissioning For Parallel System ......................................................................................................................... 33
3.5 Installation And Commissioning For Double Bus System with common neutral .......................................................... 34
3.5.1 Introduction ............................................................................................................................................................................. 34
3.5.2 Installing External Protective Device ........................................................................................................................................ 35
3.5.3 Connecting Power Cables ........................................................................................................................................................ 35
3.5.4 Connecting LBS Cables ............................................................................................................................................................. 35
3.5.5 Setting Parameters Of Double Bus System............................................................................................................................... 37
CHAPTER 4 OPERATION AND DISPLAY PANEL..........................................................................................................38
4.1 Introduction ............................................................................................................................................................... 38
4.1.1 LED Indicators .......................................................................................................................................................................... 38
4.1.2 Audible Alarm (Buzzer)............................................................................................................................................................. 38
4.1.3 Control Buttons........................................................................................................................................................................ 39
4.1.4 LCD And Menu Buttons ............................................................................................................................................................ 39
4.2 LCD Screen Types ....................................................................................................................................................... 39
4.2.1 Start Screen.............................................................................................................................................................................. 39
4.2.2 Primary Screen ......................................................................................................................................................................... 40
4.2.3 Default Screen.......................................................................................................................................................................... 40
4.3 Detailed Description Of Menu Items ........................................................................................................................... 41
4.4 Prompt Window ......................................................................................................................................................... 43
4.5 UPS Alarm Message List .............................................................................................................................................. 43
CHAPTER 5 UPS OPERATION INSTRUCTIONS............................................................................................................46
5.1 UPS Start-Up............................................................................................................................................................... 46
5.2 Transfer Procedures Between Operation Modes ......................................................................................................... 46

4 User Manual 10H52188UM51 - Rev. 1 - 09/2011
Contents Liebert NXC
5.2.1 Transfer From Normal Mode To Battery Mode ......................................................................................................................... 46
5.2.2 Transfer From Inverter Mode To Bypass Mode ......................................................................................................................... 46
5.2.3 Transfer From Bypass Mode To Inverter Mode ......................................................................................................................... 46
5.2.4 Transfer From Inverter Mode To Maintenance Bypass Mode.................................................................................................... 46
5.2.5 Transfer From Maintenance Bypass Mode To Inverter Mode.................................................................................................... 47
5.3 UPS Complete Shutdown............................................................................................................................................ 48
5.4 EPO............................................................................................................................................................................. 48
5.5 Auto Restart ............................................................................................................................................................... 48
5.6 UPS Reset ................................................................................................................................................................... 48
5.7 Language Selection .................................................................................................................................................... 49
5.8 Changing Current Date And Time............................................................................................................................... 49
5.9 Control Password ....................................................................................................................................................... 49
CHAPTER 6 COMMUNICATION......................................................................................................................................50
6.1 Installing Intellislot cards ............................................................................................................................................ 50
6.1.1 Intellislot cards Port ................................................................................................................................................................. 50
6.2 Connection Cables For Dry Contact Port ..................................................................................................................... 50
6.3 Connecting USB Communication Cables .................................................................................................................... 52
CHAPTER 7 MAINTENANCE ..........................................................................................................................................53
7.1 Fan Maintenance ........................................................................................................................................................ 53
7.2 Battery Maintenance .................................................................................................................................................. 53
7.3 Cleaning UPS .............................................................................................................................................................. 54
7.4 Checking UPS State .................................................................................................................................................... 54
7.5 Checking UPS Functions ............................................................................................................................................. 54
CHAPTER 8 OPTIONS.....................................................................................................................................................55
8.1 Option list................................................................................................................................................................... 55
8.2 Communication Cables .............................................................................................................................................. 55
8.3 Battery Cabinet........................................................................................................................................................... 55
8.4 Liebert NXC Input Transformer Version ...................................................................................................................... 56
8.5 Liebert NXC Output Transformer Version ................................................................................................................... 56

User Manual 10H52188UM51 - Rev. 1 - 09/2011 5
Liebert NXC Product Introduction
Chapter 1 Product Introduction
Liebert NXC UPS (UPS for short) is an intelligent online UPS system with sine wave output developed by Emerson Network
Power. The UPS offers reliable and high quality AC power to the precision instrument.
The UPS is applicable to supplying AC power to small scale computer centre, network, communication system, automatic
control system and precision instrument.
This chapter introduces the features, model configurations, appearance and components, operating principle, UPS state and
operation mode, and specifications of the UPS.
1.1 Features
The UPS features include:
Compatible with two modes: 3-phase mains output and single-phase mains output. The system wiring must be checked
and the panel setting must be conducted manually
Capable of parallel connection to achieve up to 3 + 1 parallel redundant power
High-frequency double conversion topology structure, with high input power factor, wide input voltage range, and
output immune to grid interference, thus adaptable to areas with unstable mains supply
High power density
Full digital control technology based on digital signal processor (DSP) to achieve high system reliability with
self-protection and fault diagnosis functions
Intelligent battery management to extend the battery life
Operation and display panel with both LCD and LED indication to help you learn about the system operation state and
operating parameters
Capable of ECO power supply mode, which helps you save energy to the maximum extent
Flexible network management with Emerson monitoring software
Fan fault self-test and automatic recognition functions
SNMP card optional, providing network communication function
Capable of connecting multiple battery strings, extending the power supply time of battery mode
1.2 Model Configurations
Three rated power types are available for Liebert NXC UPS: 10kVA, 15kVA and 20kVA.
The model configurations are shown in Table 1-1.
Table 1-1 Model configurations
Type Description
LI6010… (10kVA)
For single UPS system, for 1 + 1 parallel system and above 1 + 1 parallel system,
the external battery cabinet with big capacity is recommended
LI6015… (15kVA)
LI6020… (20kVA)

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Product Introduction Liebert NXC
1.3 Appearance And Components
1.3.1 Appearance
The UPS device appearance is shown in Figure 1-1.
Front view Rear view
Figure 1-1 UPS appearance
1.3.2 Components
UPS module front panel
As shown in Figure 1-2, the UPS module front panel provides ventilation holes, operation and display panel, LED indicators, DIP
switch and battery cold start button.
Figure 1-2 UPS module front panel
Ventilation hole Operation and display panel
LED indicator
DIP switch and battery
cold start button (with
protective cover)

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Liebert NXC Product Introduction
UPS module rear panel
As shown in Figure 1-3, the UPS module rear panel provides parallel ports, Load Bus Synchronization ports, terminal block,
Intellislot cards port, dry contact ports, USB port and ventilation holes. The SIC-SNMP card in the Intellislot cards port is optional,
it is sold separately.
Figure 1-3 UPS module rear panel
Figure 1-4 show the location of user I/O connectors
Figure 1-5
Note
Non-authorized personnel are prohibited from opening the UPS chassis cover.
1.4 Operating Principle
The operating principle of the UPS is shown in Figure 1-6.
Figure 1-6 UPS operating principle
1. The UPS is composed of mains input (mains and bypass), I/O filter, rectifier/PFC, charger, inverter, bypass, battery, DSP
controller, System Control Power and UPS output.
2. When the mains is normal, the rectifier will start, and the charger will charge the battery string. Before turning on the UPS,
the output voltage is the bypass voltage, and the mains supplies power to the load through the bypass. After turning on the UPS,
the inverter output is connected to the load, and the mains supplies DC power to the inverter through the rectifier/PFC circuit.
The inverter then converts DC power into pure sine wave AC power, and supplies AC power to the load through the electronic
transfer switch.
3. When the mains is abnormal, the rectifier/PFC circuit boosts the battery voltage and supplies it to the inverter. The inverter
then converts it into pure sine wave AC power, and supplies AC power to the load through the electronic transfer switch.
4. After the mains returns to normal state, the UPS will automatically transfer from battery mode to Normal mode, the mains
supplies DC power to the inverter through the rectifier/PFC circuit, and then the electronic transfer switch supplies DC power to
the load.
Input filter
Bypass
Inverter Output filter
Rectifier/PFC
Auxiliary
p
ower
Charger
DSP
controller
Battery
Bypass input
Mains input Output
Parallel port LBS port
Intelligent card
port (with
protective cover)
Dry contact port USB port Ventilation hole

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Product Introduction Liebert NXC
1.5 UPS State And Operation Mode
The UPS state and operation mode include: Normal mode, Bypass mode, Battery mode, FRC (Frequency Converter) mode, ECO
mode, Fault state and Maintenance Bypass mode. The operation schematic diagrams of Normal mode, Bypass mode, Battery
mode, Maintenance Bypass mode ECO mode and FRC mode are shown in Figure 1-7.
Figure 1-7 Operation schematic diagram
For the LED indicators introduced in this section, refer to 4.1.1.
Bypass input
Mains input
Normal mode
Output
Bypass input
Mains input
Bypass mode
Output
Bypass input
Mains input
Battery mode
Output
Bypass input
Mains input
Maintenance
Bypass mode
Output
Bypass input
Mains input Output
ECO mode
Mains input Output
FRC mode

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Liebert NXC Product Introduction
1.5.2 Normal Mode
When the mains input is normal, the load is provided with voltage-stabilized and frequency- stabilized power by the inverter,
and meanwhile the battery is charged.
In Normal mode, the inverter indicators are on (green).
1.5.3 Bypass Mode
If the overload overtime, inverter or rectifier failure appears during the UPS operation in Normal mode, the UPS will transfer to
Bypass mode, that is, the load is powered by the bypass source, which comes directly from the mains input; if the rectifier is
normal, the internal charger will charge the battery. In Bypass mode, the inverter indicators are off.
Note
In the event of mains failure or mains voltage out of range in Bypass mode, the UPS will shut down and stop the output.
1.5.4 Battery Mode
Upon mains failure, rectifier overload or mains voltage out of range, the rectifier and internal charger will become inoperative,
and the battery will supply power to the load through the inverter. The inverter indicators are on together with buzzer alarming,
which notifies you that the UPS is in Battery mode.
Note
1. The battery has been fully charged before delivery. However, transportation and storage will inevitably cause some capacity loss.
Therefore, it is required to charge the battery for eight hours before putting the UPS into operation, so as to ensure the adequate
backup time for battery.
2. The battery cold start can also be used to start the UPS from the Battery (charged) mode upon mains failure. Therefore, the battery
power can be used independently for improving the system availability to some extent.
1.5.5 ECO Mode (For Single UPS System Only)
In ECO mode, the load is powered by bypass when the bypass voltage is normal, and the load is powered by inverter when the
bypass voltage is abnormal. ECO mode is an energy-saving operation mode. For power equipment insensitive to power grid
quality, you can use the ECO mode for power supply through bypass to reduce the power loss.
Note
1. In ECO mode, if the bypass failure or abnormal bypass voltage appears when the output is not overloaded, the UPS will transfer to
Normal mode. However, if the bypass failure or abnormal bypass voltage appears when the output is overloaded, the UPS will not
transfer to Normal mode, but shut down the bypass.
2. In ECO mode, the efficiency of the UPS is up to 98%.
1.5.6 FRC (Frequency Converter) Mode
This mode can be used for mains and load with different frequencies (60/50Hz or 50/60Hz).
1.5.7 Fault State
In Normal mode, the UPS will transfer to Bypass mode if the inverter failure or UPS overtemperature appears. In Battery mode
(with no bypass mains), the UPS will shut down and stop the output if the inverter failure or UPS overtemperature appears. In
Fault state, the fault indicators will turn on, the buzzer will keep beeping, and the corresponding fault information will be
displayed on LCD.

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Product Introduction Liebert NXC
1.5.8 Maintenance Bypass Mode
If the maintenance and repair for UPS is needed, you can switch the load to the Maintenance Bypass through maintenance
bypass MCB, and the power to the load is uninterrupted. The maintenance bypass Miniature Circuit Breaker is located on the
rear panel of the UPS device, and the capacity meets the requirements of total load capacities.
Note
When the UPS has malfunctions and can not working normally, please get in touch with the nearest Emerson branch office or local
service centre. It is prohibited to repaire by yourself, otherwise the personnel injury and damage to the equipment will occur.
1.6 Specifications
The specifications are listed in Table 1-2.
Table 1-2 Specifications
Item Specifications
LI6010… (10kVA) LI6015... (15kVA) LI6020… (20kVA)
Input
Rated voltage 380Vac/400Vac/415Vac; default 400Vac
Voltage range
304Vac ~ 478Vac, at full load
228Vac ~ 304Vac, linear derating
228Vac, at half load
Rated frequency 50Hz/60Hz; default 50Hz
Frequency range 40Hz ~ 70Hz
Power factor ≥0.99, at full load; ≥0.98, at half load
Output
Rated power 9kW 13.5kW 18kW
Voltage 3-in 3-out: 230Vac ± 1%, 3-phase balance load
3-in 1-out: 230Vac ± 1%
Frequency synchronization range Rated frequency ±8%Hz
Frequency track rate 0.6Hz/s (single UPS), 0.2Hz/s (parallel system)
Rated power factor 0.9
Crest factor 3:1
Voltage harmonic distortion < 2% (linear load), < 5% (non-linear load)
Dynamic response recovery time 60ms
Overload capacity At 25°C: 105% ~ 125%, 5min
125% ~ 150%, 1min
Bypass voltage Upper limit: +10%, +15% or +20%; default: +15%
Lower limit: -10%, -20%, -30% or -40%; default: -20%
Mains efficiency > 93%, up to 94%
Battery
Type Sealed, lead-acid, maintenance-free battery
Block(12V) No. Per positive and negative string: 30, 32, 34, 36, 38, 40; default: 32
Rated voltage 360Vdc ~ 480Vdc
Charge power
4.5kW, 0°C ~ 30°C
4.05kW, 30°C ~ 35°C
3.6kW, 35°C ~ 40°C
Adjust automatically according to the ambient temperature
Transfer
time
Mains←→Battery 0ms
Inverter←→Bypass
Synchronous transfer: ≤1ms
Asynchronous transfer (default): ≤20ms
Or 40ms, 60ms, 80ms and 100ms are available
Noise ≤58dB
Panel display mode LED and LCD
Safety IEC/EN 62040-1:2008

User Manual 10H52188UM51 - Rev. 1 - 09/2011 11
Liebert NXC Product Introduction
Item Specifications
LI6010… (10kVA) LI6015... (15kVA) LI6020… (20kVA)
EMC
Conduction emission IEC/EN 62040-2
Immunity I
≤16A, IEC/EN 61000-3-3; 16A < I ≤75A, IEC/EN 61000-3-11
Harmonic current I ≤16A, IEC/EN 61000-3-2; 16A < I ≤75A, IEC/EN 61000-3-12
Surge protection IEC/EN 61000-4-5, endurance level 4 (4kV) (live line to earth),
level 3 (2kV) (during live lines)
Protection level IP20
Ambient
condition
Operating temperature 0°C ~ 40°C
Storage temperature -40°C ~ +70°C (battery excluded); -20°C ~ +55°C (battery
included)
Relative humidity 5%RH ~ 95%RH, non-condensing
Altitude < 2000m; derating according to GB/T3859.2 when higher than
2000m
Size W × H × D 500mm × 1240mm × 860mm
Weight
Net weight
215kg with Battery 32 Blocks
315kg with Battery 64 Blocks
415kg with Battery 96 Blocks
520kg with Battery 128 Blocks
115kg without Battery
Gross weight
245kg with Battery 32 Blocks
345kg with Battery 64 Blocks
445kg with Battery 96 Blocks
550kg with Battery 128 Blocks
145kg without Battery

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Single UPS Installation and Commissioning Liebert NXC
Chapter 2 Single UPS Installation And Commissioning
This chapter introduces the installation, cable connection and commissioning of the single UPS.
Each site has its peculiarity, so this chapter provides the guidance with general installation procedures and methods for the
installation engineer, who should conduct the installation according to the actual conditions.
Warning: professional installation
The UPS should be installed by a qualified engineer according to the information contained in this chapter. If any problem is found,
please get in touch with Emerson local service centre immediately.
The UPS shall not be powered on without approval of the commissioning engineer.
For other equipments which are not introduced in this manual, the detailed information about mechanical installation and electrical
installation are delivered with the equipment.
Note: 3-phase 5-line for power input
The UPS can be connected to 3-phase 5-line (L1, L2, L3, N, PE) TN, TT and IT AC power distribution system (IEC/EN 60364-3).
2.1 Unpacking Inspection
After the UPS arrival, you should unpack it and check the following items:
1. Visually inspect the UPS appearance for transportation damage. If any problem is found, please notify the carrier
immediately.
2. Check the accessories and models against the delivery list. If any problem is found, please notify the dealer immediately.
2.2 Installation Preparation
Prior to transportation, make sure of the height of the door enough and not other
obstacles standing in the passage. Refer to the following for dismantling of machine
cabinet.
Remove cover plate, side plates and fillings first.
Place dismantled cover plate on pallet sloped position, and then fix cover plate and
pallet with ironclads, so a slope form, push UPS along the slope.
Routine maintenance operations may involve removal of front and rear panels. Space
must be provided to permit the unit to be rolled back and forward.
Always install the Stabilizing Brackets to enhance the stabilizing of the UPS. If the UPS
needs to be moved after Stabilizing Brackets have been attached, the Brackets must be
removed.
To remove the Stabilizing Brackets, unscrew all the nuts and bolts holding it in place and slide it out from under the UPS.
When the UPS has reached its new position, push the Brackets into its down position again, and tighten the screws.
Brake Pad: with 19mm wrench in clockwise direction to screw the Brake Pads down to the ground, in this way to prevent the
UPS moving.

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Liebert NXC Single UPS Installation and Commissioning
2.2.2 Location
To extend the UPS life, the place chosen must offer:
The UPS must be installed vertically, on a level and even surface
Convenient wiring
Adequate operator access area
Adequate ventilation to meet the heat dissipation requirement
No corrosive gas, such as sulphur dioxide and so on
No excessive moisture or heat source
No excessive dust
Compliance with fire-fighting requirements
Operating temperature compliant with the specifications, see Table 1-2 for details
2.2.3 Environmental Requirement
UPS room
The UPS is designed for indoor installation, which should be installed in a clean and well-ventilated environment, so as to keep
the ambient temperature within the specifications.
The internal fans provide the forced air cooling for the UPS. Cooling air enters the UPS through the ventilation holes on the front
panel, and exhausts the hot air through the back ventilation holes. Therefore, do not obstruct the ventilation holes. Maintain at
least 200mm clearances between the front, rear, side panels of the UPS and the wall or adjacent equipment (see Figure 2-1), so
as not to obstruct the UPS ventilation and heat dissipation. Otherwise, the UPS internal temperature will rise, which will shorten
the UPS life.
If necessary, an indoor exhaust fan should be installed to keep the indoor temperature from rising. An air filter should be used
where the UPS is to operate in a dusty environment.
Figure 2-1 Installation clearances
Note
The UPS should be installed only on the concrete surface or other non-flammable surfaces.
Note: for exchanging the UPS
Power Module or the Battery
Tray a front clearance o
f
950mm is necessary.
50mm
50mm
General view

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Single UPS Installation and Commissioning Liebert NXC
UPS room (when Battery is integrated)
A small amount of hydrogen and oxygen will be generated at the end of battery charging, therefore, you must ensure that the
fresh air ventilation of battery installation environment meets the EN50272-2001 requirements.
The battery ambient temperature should be the constant temperature, for the ambient temperature is the main factor to affect
the battery capacity and life. The battery standard operating temperature is 20°C, operation above this temperature will
shorten the battery life, and operation below this temperature will reduce the battery capacity. If the battery average
temperature in operation rises from 20°C to 30°C, the battery life will be reduced by 50%; if the battery temperature in
operation exceeds 40°C, the battery life will be decreased exponentially. In general, the enabled ambient temperature of the
battery is 15°C ~ 25°C. The battery should be kept away from heat and ventilation holes.
When the UPS uses an external battery, you must install a battery protective device (such as fuse or circuit breaker) in areas near
the battery, and use the shortest wiring distance for the protective device and battery connection.
Storage
The UPS must be stored indoors, so as to be protected against the excessive moisture or overtemperature environment, when
the UPS does not need to be installed immediately. The battery requires dry and low temperature, well-ventilated environment
for storage, and the most suitable storage temperature is 20°C ~ 25°C.
Warning: battery hazards
During the battery storage, the battery must be periodically charged according to the battery instructions. You can connect the UPS to
the mains temporarily when charging the battery, so as to charge the battery for battery activation.
2.2.4 Installation Tools
Prepare installation tools according to Table 2-1. The tools must be insulated and ESD-proof processed prior to use.
Table 2-1 Installation tools list
Installation tool Specification Application
Cross screwdriver EJ5100mm Remove the screws of the terminal block cover, or open the chassis
Slotted screwdriver EJ375mm Connect I/O cables
Wire-pressure plier YT-12 Press wires for I/O terminal block
Diagonal plier MTC3C Make I/O cables
2.3 External Protective Device
The circuit breaker or other protective devices must be installed at the external AC input port of the UPS. This section provides
the general guidance for qualified installation engineer. The qualified installation engineer should learn about the local wiring
regulations for the equipment to be installed.
2.3.1 Rectifier And Bypass Input
Overcurrent
The appropriate overcurrent protective device should be installed on the mains input power distribution, and the current
capacity of power cable and the system overload requirements should be taken into account in installation (see Table 2-1). It is
recommended to use the thermo magnetic circuit breaker which satisfies with IEC/EN 60947-2 tripping curve C (normal) when
the current value reaches 125% of the current value listed in Table 2-2.
Split-bypass
When the system adopts split-bypass, separate protective devices should be installed at the mains input power distribution
respectively for the mains and bypass.
Main/Bypass backfeed protection
When using the main/bypass backfeed protection function, you need to install a protective device with auxiliary contact
function at the user’s gross mains input air breaker (including the main input and bypass input), and this auxiliary contact signal
should be connected to the system dry contact port.

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Liebert NXC Single UPS Installation and Commissioning
Note
1. The same neutral line must be used for the rectifier and bypass power.
2. For IT power grid system, the quadrupole protective device must be installed at the UPS external I/O power distribution.
Earth leakage current
The residual current detector (RCD) for the UPS upstream input power distribution should be:
Sensitive to the DC unidirectional pulse (level A) in power distribution network
Insensitive to the transient current pulse
General sensitivity type, settable: 0.3A ~ 1A
The residual current circuit breaker (RCCB) must be sensitive to the DC unidirectional pulse (level A) in power distribution
network, but insensitive to the transient current pulse, as shown in Figure 2-2 respectively.
Figure 2-2 RCCB symbols
When using the earth RCD in split-bypass system or parallel system, the RCD should be located at the upstream input power
distribution terminal to avoid generating the false alarm.
The earth leakage current introduced by the RFI filter in the UPS ranges from 3.5mA to 1000mA. It is recommended to confirm
the sensitivity of each differential device of the upstream input power distribution and downstream power distribution (to
load).
2.3.2 Battery Input (for external Battery)
The overcurrent protective device has been placed into the battery cabinet, when you choose the battery cabinet option
provided by Emerson. Otherwise, the external battery cabinet should provide DC compatible fused circuit breaker, so as to
provide the overcurrent protection for the UPS and its batteries.
2.4 Connecting Power Cables
I/O cables and battery cables are required for connection. When connecting the cables, you should follow the local wiring
regulations, take the environment situation into account, and refer to Table 3B of IEC/EN 60950-1. The max. current in different
operating modes is listed in Table 2-2, the recommended min. cable CSA is listed in Table 2-3. Select the appropriate cables
according to Table 2-2 and Table 2-3.

16 User Manual 10H52188UM51 - Rev. 1 - 09/2011
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Table 2-2 Max. steady state AC and DC current
UPS rated
power (kVA)
Rated current (A)
Mains input current1, 2 upon battery
charging with max. ability Gross output current2at full load Battery discharging current
upon min. battery voltage
380V 400V 415V 380V 400V 415V
10 (3-in 3-out) 22 22 22 15 15 14 34
10 (3-in 1-out) 22 22 22 45 44 42 34
15 (3-in 3-out) 31 31 31 23 22 21 50
15 (3-in 1-out) 31 31 31 69 65 63 50
20 (3-in 3-out) 36 36 36 30 29 28 67
20 (3-in 1-out) 36 36 36 90 87 84 67
Note:
When selecting the battery cables, according to the current value shown in table, the max. allowable voltage drop is 4Vdc. Do not ring
the cables, so as to avoid increasing the electromagnetic interference (EMI).
1: The mains current input of the rectifier and bypass.
2: Non-linear load (switch mode power) affects the neutral cable design of output and bypass. The neutral cable current may exceed
the rated phase current, in general, 1.732 times as large as the rated current (not applicable, when 3-in 1-out mode)
Table 2-3 Single UPS cable CSA (unit: mm2, ambient temperature: 25°C ）
Model Input Output Bypass Neutral cable PE Battery
10kVA (3-in 3-out) 4 4 4 4 4 6
10kVA (3-in 1-out) 4 10 10 10 10 6
15kVA (3-in 3-out) 6 6 6 6 6 10
15kVA (3-in 1-out) 6 16 16 16 16 10
20kVA (3-in 3-out) 10 10 10 16 10 16
20KVA (3-in 1-out) 10 25 25 25 16 16
The recommended UPS I/O MCB capability is listed in Table 2-4, select the MCBs according to your requirements.
Note
The UPS is high leakage current equipment, it is not recommended to configure the MCB with leakage current protection function.
Table 2-4 UPS MCB selection
Model Input interface
Recommended capability of input
external MCB Battery MCB Output
interface
Main Bypass
10kVA (3-in 3-out) Terminal block 35A 35A DC 35A Terminal block
10kVA (3-in 1-out) Terminal block 35A 63A (1P) DC 35A Terminal block
15kVA (3-in 3-out) Teminal block 50A 50A DC 63A Terminal block
15kVA (3-in 1-out) Teminal block 50A 80A (1P) DC 63A Terminal block
20kVA (3-in 3-out) Teminal bock 63A 63A DC 80A Terminal block
20kVA (3-in 1-out) Teminal block 63A 125A (1P) DC 80A Terminal block
Note:
The 3-in 1-out MCB (125A) is used to connect the bypass input upon split-bypass configuration. The main MCB (63A) can be used
only upon common source configuration

User Manual 10H52188UM51 - Rev. 1 - 09/2011 17
Liebert NXC Single UPS Installation and Commissioning
2.4.1 Connecting I/O Cables
The power cables of the UPS should be connected through the I/O terminal block located on the UPS rear panel. Figure 2-3
gives the terminal layout of the I/O terminal block.
Figure 2-3 Terminals layout of the I/O terminal block
Power distribution mode
According to the user’s requirements, the I/O cable connections can be configured into four types:
3-in 3-out, common source configuration (factory default),
3-in 3-out, split-bypass configuration,
3-in 1-out, common source configuration,
3-in 1-out, split-bypass configuration.
Self-distribution
The four I/O cable connection procedures of the self-distribution are as follows:
3-in 3-out, common source configuration (factory default)
1. Connect the live lines (input phase L1, input phase L2 and input phase L3), N line and PE line respectively to the I/O terminal
block (U1, V1, W1 and N1 and PE terminals) of the UPS.
Short connect U1 and U2, V1 and V2, W1 and W2 of the UPS I/O terminal block using the copper shorting bar 3 respectively
(factory default).
2. Connect the live lines (output phase L1, output phase L2 and output phase L3), N line and PE line respectively to the I/O
terminal block (U3, V3, W3 and N3 and PE terminals) of the UPS, as shown in Figure 2-4.
OUTPUT GND MAINS INPUT BYPASS INPUT EXT. BATTERY
BAT+ BAT-
BAT

18 User Manual 10H52188UM51 - Rev. 1 - 09/2011
Single UPS Installation and Commissioning Liebert NXC
Figure 2-4 3-in 3-out, common source configuration cable connection
3-in 3-out, split-bypass configuration
1. Remove all the copper shorting bars 3 from the UPS I/O terminal block.
2. Connect the live lines (mains input phase L1, mains input phase L2 and mains input phase L3), N line and PE line respectively
to the I/O terminal block (U1, V1, W1 and N1 and PE terminals) of the UPS.
3. Connect the live lines (bypass input phase L1, bypass input phase L2 and bypass input phase L3) and N line respectively to the
I/O terminal block (U2, V2, W2 and N2 terminals) of the UPS.
4. Connect the live lines (output phase L1, output phase L2 and output phase L3), N line and PE line respectively to the I/O
terminal block (U3, V3, W3 and N3 terminals and PE terminal) of the UPS.
Copper shorting bars
No. 3 UPS MODULE
INTERNAL BATTERY
RECT INV
CHARGER COMMUNICATION
PORTS
OP. AND DISP.
PANEL
OUTPUT
MAINS INPUT
EXT. BATTERY
STS

User Manual 10H52188UM51 - Rev. 1 - 09/2011 19
Liebert NXC Single UPS Installation and Commissioning
Figure 2-5 3-in 3-out, split-bypass configuration cable connection
3-in 1-out, common source configuration
Warning
The factory default of this UPS is 3-in 3-out, common source configuration. Change the power distribution mode of the UPS to 3-in
1-out according to the steps described in the following section Changing power distribution mode. Continue the following input and
output power cable connection and power-on commissioning after confirming that the change has been successful.
1. Confirm that the power distribution mode of the main UPS has been changed to 3-in 1-out according to the steps described
in the following section Changing power distribution mode.
2. As shown in Figure 2-6, paste the insulating film (accessory) on the copper shorting bar 10, and insert the buckles into the
corresponding holes on the copper shorting bar 10.
Assembling Completed status
Insulating film
Copper shorting
Buckle
bar 10
Figure 2-6 Pasting the insulating film to the copper shorting bar 10
3. As shown in Figure 2-7, short connect U2, V2 and W2 terminals using the copper shorting bar 7, short connect the PE
terminals of the I/O terminal block of the UPS using the copper shorting bar 10 with insulating film, short connect U3, V3 and
W3 terminals using the copper shorting bar 5, short connect U1 and U2 terminals using the copper shorting bar 6, short
connect N1 and N2 terminals, and two N3 terminals using the two copper shorting bar 4.
UPS MODULE
INTERNAL BATTERY
RECT INV
CHARGER COMMUNICATION
PORTS
OP. AND DISP.
PANEL
OUTPUT
MAINS INPUTEXT. BATTERY
STS
BYPASS INPUT
Buckle
Assembling
Insulating film
Completed status
Copper shorting
bar 10

20 User Manual 10H52188UM51 - Rev. 1 - 09/2011
Single UPS Installation and Commissioning Liebert NXC
Figure 2-7 3-in 1-out, common source configuration cable connection
4. Connect the copper shorting bar 8 to one end of the copper shorting bar 7 (see Figure 2-7), and connect the live line (input
phase L1) to the copper shorting bar 8.
5. Connect the live lines (input phase L2 and input phase L3), N line and PE line respectively to the I/O terminal block (V1 and
W1 terminals) of the UPS, one screw hole of the copper shorting bar 4 with N1 and N2 terminals, and one screw hole of the
copper shorting bar 10.
6. Connect the output L line, N line and PE line respectively to the copper shorting bar 5, copper shorting bar 4 with two N3
terminals, and the other screw hole of the copper shorting bar 10.
3-in 1-out, split-bypass configuration
Warning
The factory default of this product is 3-in 3-out, common source configuration. Change the power distribution mode of the main UPS to
3-in 1-out according to the steps described in the following section Changing power distribution mode. Continue the following input
and output power cable connection and power-on commissioning after confirming that the change has been successful.
1. Confirm that the power distribution mode of the main UPS has been changed to 3-in 1-out according to the steps described
in the following section Changing power distribution mode.
2. As shown in Figure 2-6, paste the insulating film (accessory) on the copper shorting bar 10, and insert the buckles into the
corresponding holes on the copper shorting bar 10.
3. As shown in Figure 2-8, short connect the two PE terminals of the I/O terminal block of the UPS using the copper shorting bar
10 with insulating film, short connect U2, V2 and W2 terminals using the copper shorting bar 7, short connect U3, V3 and W3
terminals using the copper shorting bar 5, short connect N1 and N2 terminals, and two N3 terminals using the two copper
shorting bar 4.
Copper shorting bars
No. 6 No. 7 UPS MODULE
INTERNAL BATTERY
RECT INV
CHARGER COMMUNICATION
PORTS
OP. AND DISP.
PANEL
OUTPUT
MAINS INPUT
EXT. BATTERY
STS
Copper shorting bars
No. 5
No. 4
No. 8
No. 10
No. 4