Vertiv Liebert APM 300 User manual

APM 300 Integrated UPS Single Module And Parallel System
User Manual
Version V1.5
Revision date March 10, 2017
BOM 31012521
Emerson Network Power provides customers with technical support. Users may contact the nearest
Emerson local sales office or service center.
Copyright © 2011 by Emerson Network Power Co., Ltd.
All rights reserved. The contents in this document are subject to change without notice.
Emerson Network Power Co., Ltd.
Address: Block B2, Nanshan I Park, No.1001 Xueyuan Road, Nanshan District, Shenzhen, 518055, P.R.China
Homepage: www.emersonnetworkpower.com
E-mail: [e-mail]

Special Declaration
Personnel Safety
1. This product must be installed and commissioned by professional engineers of the manufacturer or its
authorized agent. Failure to observe this could result in product malfunction or personnel safety risk.
2. Take the time to read this product manual and the safety precaution thoroughly before installing and
commissioning this product. Failure to observe this could result in product malfunction or personnel
safety risk.
3. This product cannot be used as power supply of life support equipment.
4. Never dispose of the internal or external battery of this product in a fire, as it may explode and
jeopardize personnel safety when exposed to flame.
Product Safety
1. If this product will be stored or remain de-energized for a long period, it must be placed in a dry and
clean environment within specified temperature range.
2. This product should be used in an appropriate operating environment. For details, refer to the section
on the environmental requirement in this manual.
3. It is prohibited to use this product in places:
Where the temperature and relative humidity are outside the specifications
Subject to vibrations or shocks
Where conductive dusts, corrosive gases, salts, or flammable gases are present
Near heat sources or strong electromagnetic interferences
Disclaimer
Emerson disclaims any and all responsibility or liability for the defection or malfunction caused by:
Application range or operating environment outside the specifications
Unauthorized modification, improper installation or operation
Force majeure
Other actions not in compliance with the instructions in this manual

Safety Precaution
Always observe the following safety symbols!
Used to alert the user to the risk of death or severe injury should the unit be used improperly.
Used to alert the user to the risk of injury or equipment damage should the unit be used improperly.
Used to advise the user to carefully read and observe this unit though it may not cause damage.
This manual contains important instructions that should be followed during installation and operation of
this Emerson APM 300 integrated UPS system (UPS for short).
Read this manual thoroughly before installing, servicing and using the UPS.
The UPS must be commissioned and serviced by trained engineers approved and qualified by the
manufacturer or its agent. Failure to do so could result in personnel safety risk, equipment malfunction
and invalidation of warranty.
The UPS has been designed for commercial and industrial use only, and is not for use in any life support
application.
Warning
This is a Class C3 UPS product for commercial and industrial application in the second environment. Installation
restrictions or additional measures may be needed to prevent distrubances.
Conformity and standards
The UPS complies with CE 2006/95/EC&93/68/EEC (low voltage safety) and 2004/108/EC, with Australia and New
Zealand EMC Framework (C-Tick), and with the following product standards for UPS:
IEC62040-1 general and safety requirements for UPS
IEC62040-2 EMC, class C3
IEC62040-3 performance requirements and test methods
Continued compliance requires installation in accordance with these instructions and the use of manufacturer
approved accessories only.
Multiple power sources
This UPS system receives power from more than one source . Disconnection of all AC sources and the DC source is
required before servicing.
This UPS has several
circuits that are energized with high DC as well as AC voltages. Check for voltage with both AC
and DC voltmeters before working within the UPS.

Warning: high leakage current
Earth connection is essential before connecting the input supply (including the AC mains and battery). The UPS
must be earthed in accordance with local electrical codes.
Earth leakage current exceeds 3.5mA and is less than 3000mA.
Transient and steady state earth leakage currents, which may occur when the equipment is started, should be
taken into account when selecting instantaneous RCCB or RCD devices.
RCCBs must be selected insensitive to DC unidirectional pulses (Class A) and transient current pulses.
Also note that the earth leakage currents of the load will be carried by this RCCB or RCD.
Warning: backfeeding protection
This UPS is fitted with a contact closure signal for use with an external automatic disconnect device (supplied by
others) to protect against backfeeding dangerous voltage into the input terminal through the bypass static switch
circuit. A label must be added at the external power disconnect device to warn service personnel that the circuit is
connected to the UPS. The text of the label has the following meaning: Risk of voltage backfeed! Isolate the UPS,
then check for hazardous voltage between all terminals including the protective earth before working on this
circuit.
User-serviceable parts
All equipment maintenance and servicing procedures involving internal access requires the use of a tool and
should be carried out only by trained professionals. There are no user-serviceable parts behind covers requiring a
tool/special key for removal.
Battery voltage exceeds 400Vdc
All physical battery maintenance and servicing requires the use of a tool or a key and should be carried out only by
trained personnel.
Take special care when working with the batteries. When connected together, the battery terminal voltage will
exceed 400Vdc and is potentially lethal.
Battery manufacturers supply details of the necessary precautions to be observed when working on, or in the
vicinity of, a large bank of battery cells. These precautions should be followed implicitly at all times. Attention
should be paid to the recommendations concerning local environmental conditions and the provision of protective
clothing, first aid and fire-fighting facilities.
Warning
The area around the cover of the monitoring board is a static sensitive area, take anti-static measures when
accessing this area.
Warning
When selecting the UPS system pre-stage distribution protection equipment, ensure that it complies with the
local electric regulations.
The specified upstream breakers are required to obtain the conditional short-circuit current rating, Icc at 10kA
symmetrical rms. The specified upstream breakers should comply with an IEC 60947 series standard.

The Manual Covers The Following Equipment
Product
Model
APM 300
Liebert APM 300

Revision Information
V1.0 (August 17, 2011)
Initial release.
V1.1 (April 3, 2014)
Adopt new manual format with options added; add Hazardous Substances Or Elements Announcement in
Appendix 2.
V1.2 (October 10, 2014)
Change the address of Emerson Network Power Co., Ltd.; add Frequency converter mode, Dual bus (LBS)
system mode, and ECO mode in Section 1.5; change Figure 6-5; change the description in Section 7.1.
V1.3 (March 26, 2015)
Modify Figure 2-3 and Figure 5-1.
V1.4 (December 8, 2015)
Add a Warning in Safety Precatuions.
V1.5 (March 10, 2017)
Update Appendix 2.

Contents
Chapter 1 Overview ................................................................................................................................................... 1
1.1 Features......................................................................................................................................................... 1
1.2 Composition .................................................................................................................................................. 1
1.3 Design Concept.............................................................................................................................................. 2
1.3.1 System Design ..................................................................................................................................... 2
1.3.2 Bypass................................................................................................................................................. 2
1.3.3 System Control Principle ....................................................................................................................... 3
1.3.4 UPS Power Supply Switch Configuration ................................................................................................. 4
1.3.5 Battery Circuit Breaker (BCB) ................................................................................................................. 5
1.4 Parallel System............................................................................................................................................... 5
1.4.1 Parallel System Features........................................................................................................................ 5
1.4.2 Parallel System Requirements................................................................................................................ 6
1.5 Operation Mode............................................................................................................................................. 6
1.6 Battery Management (Set By Commissioning Engineer)................................................................................... 9
1.6.1 Normal Function .................................................................................................................................. 9
1.6.2 Advanced Function............................................................................................................................... 9
1.6.3 Battery Temperature Compensation .....................................................................................................10
1.7 Battery Protection (Set By Commissioning Engineer) ......................................................................................10
Chapter 2 Mechanical Installation.............................................................................................................................11
2.1 Notes............................................................................................................................................................11
2.2 Preliminary Check .........................................................................................................................................11
2.3 Environmental Requirements ........................................................................................................................11
2.3.1 UPS Location.......................................................................................................................................11
2.3.2 Battery Location..................................................................................................................................12
2.3.3 Storage ..............................................................................................................................................12
2.4 Positioning ...................................................................................................................................................13
2.4.1 Moving The Cabinet.............................................................................................................................13
2.4.2 Clearances ..........................................................................................................................................13
2.4.3 Cable Entry .........................................................................................................................................13
2.4.4 Final Positioning And Fixing..................................................................................................................13
2.5 Mechanical Installation..................................................................................................................................13
2.5.1 Installation drawing .............................................................................................................................13
2.5.2 Mechanical Connection Between Cabinets.............................................................................................14
2.5.3 Installing Power Module.......................................................................................................................15
Chapter 3 Electrical Installation ................................................................................................................................17
3.1 Power Cables ................................................................................................................................................17
3.1.1 System Configuration ..........................................................................................................................17
3.1.2 Maximum Steady State AC And DC Currents ..........................................................................................17
3.1.3 Distance From Floor To UPS Connection Point........................................................................................18
3.1.4 Notes .................................................................................................................................................18

3.1.5 Power Cable Connecting Terminals .......................................................................................................18
3.1.6 Protection Ground...............................................................................................................................18
3.1.7 External Protective Device....................................................................................................................18
3.1.8 Connecting Power Cables.....................................................................................................................19
3.1.9 Connecting External Power Cables ........................................................................................................20
3.2 Control Cables And Communication Cables ....................................................................................................22
3.2.1 Overview ............................................................................................................................................22
3.2.2 Input Dry Contact Port.........................................................................................................................23
3.2.3 BCB Port .............................................................................................................................................23
3.2.4 Maintenance Bypass Switch And Output Switch State Port ......................................................................24
3.2.5 Output Dry Contact Port ......................................................................................................................24
3.2.6 Remote EPO Input Port ........................................................................................................................25
3.2.7 RS485 Port, RS232 Port And Intellislot Port ............................................................................................25
Chapter 4 Operator Control And Display Panel .........................................................................................................26
4.1 Introduction..................................................................................................................................................26
4.1.1 LED Indicators .....................................................................................................................................26
4.1.2 Audible Alarm (Buzzer) ........................................................................................................................27
4.1.3 Control Keys .......................................................................................................................................27
4.1.4 LCD And Menu Keys.............................................................................................................................28
4.2 LCD Screen Types ..........................................................................................................................................28
4.2.1 Start Screen ........................................................................................................................................28
4.2.2 Primary Screen....................................................................................................................................28
4.2.3 Default Screen ....................................................................................................................................29
4.3 Detailed Description Of Menu Items...............................................................................................................30
4.4 Prompt Window............................................................................................................................................32
4.5 Alarm List......................................................................................................................................................32
Chapter 5 Operating Instructions..............................................................................................................................37
5.1 Brief Introduction..........................................................................................................................................37
5.1.1 Precautions.........................................................................................................................................37
5.1.2 Power Switches ...................................................................................................................................37
5.2 UPS Start-Up Procedures ...............................................................................................................................38
5.2.1 Start-Up Procedures ............................................................................................................................38
5.2.2 Start-Up Procedures Into Battery Mode (Battery Cold Start).....................................................................39
5.3 Procedures For Transfer Between Operation Modes........................................................................................40
5.3.1 Transfer From Normal Mode To Battery Mode........................................................................................40
5.3.2 Transfer From Normal Mode To Bypass Mode.........................................................................................40
5.3.3 Transfer From Bypass Mode To Normal Mode.........................................................................................40
5.3.4 Transfer From Normal Mode To Maintenance Mode................................................................................40
5.4 Battery Test Mode Procedures .......................................................................................................................41
5.5 System Test Procedure ..................................................................................................................................42
5.6 UPS Shutdown Procedures.............................................................................................................................42
5.6.1 Procedures For Completely Powering Down UPS ....................................................................................42
5.6.2 Procedures For Completely Powering Down UPS While Maintaining Power To Load...................................43

5.7 EPO Procedures.............................................................................................................................................43
5.8 UPS Reset Procedures After EPO.....................................................................................................................43
5.9 Automatic Restart .........................................................................................................................................44
5.10 Selecting Language .....................................................................................................................................44
5.11 Changing The Current Date And Time...........................................................................................................44
5.12 Command Password....................................................................................................................................44
Chapter 6 Battery......................................................................................................................................................45
6.1 Introduction..................................................................................................................................................45
6.2 Safety ...........................................................................................................................................................45
6.3 Power Cable..................................................................................................................................................46
6.3.1 Overview ............................................................................................................................................46
6.3.2 Battery Installation ..............................................................................................................................47
6.3.3 Battery Connection..............................................................................................................................47
6.4 Reference Current And Connection Of External BCB ........................................................................................48
6.5 Battery Maintenance .....................................................................................................................................50
6.6 Disposal Of The Used Battery .........................................................................................................................50
Chapter 7 Parallel System And Dual Bus System .......................................................................................................52
7.1 Overview ......................................................................................................................................................52
7.2 System Installation Procedures ......................................................................................................................52
7.2.1 Preliminary Checks ..............................................................................................................................52
7.2.2 Cabinet Installation..............................................................................................................................52
7.2.3 External Protective Device....................................................................................................................53
7.2.4 Power Cable........................................................................................................................................53
7.2.5 Parallel Control Cable...........................................................................................................................53
7.2.6 Remote EPO........................................................................................................................................54
7.3 Operation Procedures For Parallel System ......................................................................................................55
7.3.1 Startup Procedures In Normal Mode......................................................................................................55
7.3.2 Maintenance Bypass Procedures ...........................................................................................................56
7.3.3 Isolation Procedures (Of One UPS In A Parallel System)............................................................................56
7.3.4 Insertion Procedures (Of One UPS In A Parallel System)...........................................................................56
7.3.5 Procedures For Completely Powering Down UPS ....................................................................................57
7.3.6 Procedures For Complete UPS Shutdown While Maintaining Power To Load .............................................57
7.4 Dual Bus System............................................................................................................................................57
7.4.1 Cabinet Installation..............................................................................................................................57
7.4.2 External Protective Device....................................................................................................................58
7.4.3 Power Cable........................................................................................................................................58
7.4.4 Control Cable......................................................................................................................................58
Chapter 8 Options .....................................................................................................................................................60
8.1 Option List ....................................................................................................................................................60
8.2 Option ..........................................................................................................................................................60
8.2.1 Bypass Load Sharing Inductor ...............................................................................................................60
8.2.2 Battery Temperature Sensor.................................................................................................................62
8.2.3 Air Filter..............................................................................................................................................63

8.2.4 SIC Card..............................................................................................................................................63
8.2.5 Relay Card...........................................................................................................................................64
8.2.6 UF-RS485 Card ....................................................................................................................................67
8.2.7 Modbus Card ......................................................................................................................................68
8.2.8 LBS Cable............................................................................................................................................68
8.2.9 Parallel Cable ......................................................................................................................................68
Chapter 9 Communication ........................................................................................................................................69
9.1 SNMP Protocol Communication.....................................................................................................................69
9.2 Modbus Protocol Communication..................................................................................................................69
9.3 Dry Contact Communication..........................................................................................................................69
Chapter 10 Service And Maintenance........................................................................................................................70
10.1 Safety .........................................................................................................................................................70
10.2 Service Procedures Of Power Module And Bypass Module .............................................................................70
10.2.1 Notes ...............................................................................................................................................70
10.2.2 Service Procedures Of Power Module...................................................................................................70
10.2.3 Standard default procedure (when load transfer to Bypass is allowed) for service the bypass module.........71
10.3 Replacement Procedures Of Air Filter ...........................................................................................................72
10.4 Maintenance Of UPS And Options.................................................................................................................72
Chapter 11 Specifications..........................................................................................................................................73
11.1 Conformity And Standards...........................................................................................................................73
11.2 Environmental Characteristics .....................................................................................................................73
11.3 Mechanical Characteristics ..........................................................................................................................73
11.4 Electrical Characteristics (Input Rectifier) .....................................................................................................74
11.5 Electrical Characteristics (Intermediate DC Circuit) .......................................................................................74
11.6 Electrical Characteristics (Inverter Output) ...................................................................................................75
11.7 Electrical Characteristics (Bypass Mains Input)..............................................................................................76
11.8 Efficiency, Heat Losses And Air Exchange......................................................................................................76
Appendix 1 Glossary..................................................................................................................................................77
Appendix 2 Hazardous Substances And Content.......................................................................................................78
10.2.4. Alternate Procedure (When Load transfer to Bypass is not allowed): ......................................................71

Chapter 1 Overview 1
APM 300 Integrated UPS Single Module And Parallel System User Manual
Chapter 1 Overview
This chapter briefly introduces the features, composition, design concept, parallel system, operation mode,
battery management and battery protection of the Liebert APM 300 UPS (UPS for short).
1.1 Features
The UPS is connected between a critical load (e.g. a computer) and mains power to provide high quality power
for the loads. The UPS has the following advantages:
Increase power quality
The UPS protects its output against the input power change through the internal voltage and frequency
controller.
Improve noise rejection
Due to the application of AC-DC-AC conversion mode, the noise in the input power is effectively filtered, and
the load gets clean power supply.
Provide mains failure protection
If the input power fails, the UPS will work in battery mode, and the power supply to the loads will not be
interrupted.
1.2 Composition
The UPS consists of a main power cabinet and a switch cabinet. The cabinets use steel framework structure
enclosed by removable panels, with the top panels and side panels fixed by screws. The UPS structure is shown
in Figure 1-1. The UPS component configuration is provided in Table 1-1.
Main power cabinet
Cover
Power module
Switch cabinet
Cover
Bypass module
Adjustable foot
Figure 1-1 UPS structure

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APM 300 Integrated UPS Single Module And Parallel System User Manual
Table 1-1 UPS component configuration
Component
Quantity (pcs)
Remark
Main power cabinet
1
Standard component
Switch cabinet
1
Standard component
Bypass module
1
Standard component
Power module
1 ~10
Mandatory option. Installed at site
1.3 Design Concept
1.3.1 System Design
As shown in Figure 1-2, the AC mains source is converted by the rectifier into DC power. The inverter converts
that DC power from the rectifier or the DC power from the battery into AC power, and provides the AC power
for the load. The battery powers the load through the inverter in the event of a power failure. When the
inverter is faulty or turned off, the mains source can also power the load through the static bypass.
Input
Maintenance bypass switch
Bypass input switch
Rectifier input switch
Bypass input
Mains input
Battery charger
Output switch
Automatic inverter switch
Inverter
Rectifier
Static switch
Maintenance bypass
UPS output
Battery
Output
Input Output
Bypass input
Mains input
Rectifier input switch
Rectifier
Maintenance bypass switch
Bypass input switch
Battery Battery charger
Inverter
Static switch
Automatic inverter switch
Maintenance bypass
Output switch
UPS output
Figure 1-2 System schematic diagram
If UPS maintenance or repair is necessary, the load can be transferred to the maintenance bypass without
power interruption.
1.3.2 Bypass
The circuit block labeled static switch in Figure 1-2 contains an electronically controlled switching circuit that
enables the load to be connected to either the inverter output or to a bypass power source through the static
bypass line. During normal system operation, the load is connected to the inverters; but in the event of a UPS
overload or inverter failure, the load is automatically transferred to the static bypass line.
During normal operating conditions, the inverter output and bypass supply must be fully synchronized so as to
achieve a clean (no-break) load transfer between the inverter output and static bypass line. The
synchronization between the inverter output and static bypass is achieved through the inverter control
electronics, which make the inverter frequency track that of the static bypass supply, provided that the bypass
remains within an acceptable frequency window.

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APM 300 Integrated UPS Single Module And Parallel System User Manual
A manually controlled, maintenance bypass supply is incorporated into the UPS design. It enables the critical
load to be powered from the maintenance bypass supply while the UPS is shut down for routine maintenance
and repair.
Note
When the UPS is operating in bypass mode or on maintenance bypass, the connected equipment is not protected from
power failures or surges and sags.
1.3.3 System Control Principle
Normal operation
Normal mode: It means that the UPS has normal input mains, the rectifier and inverter operate normally, the
load is supplied by the inverter, and the battery is in stable floating charge state.
(Pa rallel System) Note: As each UPS module outputs are connected in parallel, the system checks that the
inverter control circuits are perfectly synchronized with one another and with the bypass in terms of both
frequency and phase, and that they have the same output voltages. Current supplied to the load is
automatically divided among UPSs. A warning message appears while synchronization is in progress.
Mains abnormal
When the mains fails or is abnormal, the rectifier will stop working automatically, and the system will transfer
to battery output (through inverter). The length of the operation time in battery mode depends on the load
and the battery capacity. During this period, if the battery voltage falls to the EOD voltage and the mains still
has not been recovered, the inverter will stop working automatically, and the UPS operator control and display
panel will display corresponding alarm messages.
Mains recovery
When the mains resumes normal within allowable time, the rectifier will start automatically (at this time its
output power will increase gradually) and supply the load and charge the battery again. Therefore, the power
supply to the load will not be interrupted.
Battery disconnection
If the battery system is taken out of service for maintenance, it is disconnected from the rectifier/charger and
inverters by means of a battery switch. The UPS shall continue to function and meet all of the specified
steady-state performance criteria, except for the power outage back-up time capability.
UPS module failure
In case of inverter failure, automatic inverter switch failure, output fuse blowout and bypass STS failure, the
load will automatically transfer to the bypass, and the output power supply will not be interrupted. In this
situation, please contact the local customer service center of Emerson Network Power Co., Ltd for technical
support.
(Pa rallel System) In the event of a fault in a UPS module, it will automatically exit from the parallel system. If
the system is still capable of providing the required load, the remaining modules will continue to supply the
load with no interruption. If the remaining modules are no longer capable of fulfilling power requirements, the
load will automatically transfer to the bypass.
Overload
If the inverter is overloaded or the inverter current remains outside the specifications (refer to Table 11-6)
longer than the specified time, the load will automatically transfer to the bypass without power interruption. If
both the overload and the current are reduced to a level within the specified range, then the load will be
transferred back to the inverter. In case of output short circuit, the load will be transferred to the bypass, and

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APM 300 Integrated UPS Single Module And Parallel System User Manual
the inverter will shut down. Five minutes later, the inverter will start up automatically. If the short circuit is
removed at this point, the load will be transferred back to the inverter. The transfer is determined first of all by
the features of the protective device of the system.
In the above two situations, the UPS operator control and display panel will display alarm messages.
(Pa rallel System) The control logic system constantly monitors load requirements and controls the power
supplied by the two UPS modules. In the event that an overload condition is sustained for greater than a preset
time, the load will transfer to the bypass, when the number of active modules is unable to satisfy load
requirements. The load returns to the inverter if the power is reduced to a value that can be sustained by the
number of active modules in the system.
Maintenance bypass
The UPS has a second bypass circuit, i.e. maintenance bypass, which provides a safe working environment for
the engineers to provide regular maintenance or repair to the UPS system and at the same time provide
unregulated mains supply to the loads. The maintenance bypass can be manually selected through the
maintenance bypass switch, and it can be disconnected by turning the switch to OFF.
Warning
The internal maintenance bypass must NOT be used when the UPS system is comprised of more than two UPS modules
in parallel.
1.3.4 UPS Power Supply Switch Configuration
Figure 1-3 describes the block diagram of the UPS module. The UPS has split bypass configuration (that is, the
bypass adopts independent mains input) and common source configuration. In split bypass configuration,
the static bypass and maintenance bypass share the same independent bypass power supply. Where a
separate power source is not available, the input supply connections of the bypass input switch (Q2) and
rectifier input switch (Q1) would be linked together (linked before delivery) to make the bypass input and
rectifier input use mains power of the same route.
During the normal operation of the UPS, except for the maintenance bypass switch Q3, other switches shall be
closed.
Bypass input
Shorting copper bar
of common input
configuration
Mains input Rectifier input
switch Q1
Rectifier Inverter
Automatic
inverter switch
Output
switch Q5 UPS Output
Static switch
Maintenance switch Q3
Battery
charger
BCB
Battery
Bypass input switch Q2
Maintenance bypass switch Q3
Figure 1-3 UPS power supply switch configuration

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APM 300 Integrated UPS Single Module And Parallel System User Manual
1.3.5 Battery Circuit Breaker (BCB)
The external battery shall be connected to the UPS through the BCB. The BCB box is an option, which shall be
installed near the battery. The BCB is closed manually or electrically. The BCB has undervoltage tripping coil.
Upon the battery undervoltage, the UPS control circuit will send a signal to the coil to trip the BCB. It also has a
magnetic trip facility for overload protection.
1.4 Parallel System
As shown in Figure 1-4, two UPS modules can be parallel-connected to form a parallel system to increase the
system capacity or reliability, or both. The load is equally shared between the paralleled UPSs.
Qin UPS 1 Qin UPS 2
Qout UPS 1 Qout UPS 2
UPS 1 output UPS 2 output
L1, L2, L3L1, L2, L3 NN
Supplied by others
Input mains supply
L1, L2, L3, N
Charger
Rectifier
STS
Inverter
Input mains supply
L1, L2, L3, N
Charger
Rectifier
Inverter
STS
UPS 2 output distribution
unit 0~2 pcs
L1, L2, L3, N L1, L2, L3, N
UPS 1 output distribution
unit 0~2 pcs
UPS 1 output distribution UPS 2 output distribution
Figure 1-4 Parallel system
1.4.1 Parallel System Features
1. The hardware and software of parallel system are completely the same as those of single UPS module. The
parallel configuration is achieved through settings in configuration software. The parameter settings of each
UPS module in parallel system should be the same.
2. Parallel control cables are connected in a ring, providing both system reliability and redundancy. Dual bus
control cables are connected between any two UPS modules of each bus. The intelligent parallel logic provides
the user with maximum flexibility. For example, shutting down or starting up UPS modules in a parallel system
can be done in any sequence. Transfers between normal and bypass modes of operation are synchronized and
self-recoverable, for example, following overloads and their clearance.
3. The total load of the parallel system can be queried from each UPS module's LCD.

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APM 300 Integrated UPS Single Module And Parallel System User Manual
1.4.2 Parallel System Requirements
A UPS system consisting of two paralleled UPS modules behave as if it were one large UPS with the advantage
of presenting higher reliability. To ensure that all modules are equally used and to comply with relevant wiring
rules, the following requirements apply:
1. All UPS modules must be of the same rating and must be connected to the same source.
2. Any RCD, if installed, must be of an appropriate setting and located upstream of the common neutral
bonding point. Alternatively, the device must monitor the protective earth current of the system. Refer to
Warning: high leakage current before Contents.
3. The outputs of the two UPS modules must be connected to a common output bus.
1.5 Operation Mode
The UPS is an on-line, double-conversion, reverse-transfer UPS that permits operation in these modes:
Normal mode
Battery mode
Automatic restart mode
Bypass mode
Maintenance mode (manual bypass)
ECO mode
Parallel and redundancy mode
Dormancy mode
Common battery mode
Frequency converter mode
Dual bus (LBS) system mode
Normal mode
As shown in Figure 1-5, the UPS rectifiers derive power from the AC mains input source and supply DC power
to the inverters, which continuously supply the AC load. Simultaneously, the charger, which derives power
from the rectifiers, float or boost charges the associated backup battery of the UPS.
Rectifier input switch
Mains input
Battery charger
Output switch
Inverter
Rectifier
UPS output
Battery
Automatic inverter switch
Mains input
Rectifier input switch
Rectifier
Battery Battery charger
Inverter Automatic inverter switch
Output switch
UPS output
Figure 1-5 Schematic diagram of normal mode
Battery mode
As shown in Figure 1-6, the UPS is operating in battery mode when the battery is supplying backup power to
the load through the inverters. Upon mains failure, the UPS automatically transfers to battery mode without
power interruption to the load. Upon restoration of the AC mains, the UPS automatically transfers back to
normal mode without the necessity of user intervention, without power interruption to the load.

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APM 300 Integrated UPS Single Module And Parallel System User Manual
Output switch
Inverter
Rectifier
UPS output
Battery
Automatic inverter switch
Rectifier Inverter Automatic inverter switch
Output switch
UPS output
Battery
Figure 1-6 Schematic diagram of battery mode
Note: Battery start function is available for switching the UPS on into Battery (charged) mode directly during
mains failure. Thus, the battery power can be used independently to increase the UPS utility.
Automatic restart mode
The battery becomes exhausted following an extended AC mains failure. The inverters shut down when the
battery reaches the EOD voltage. The UPS can be programmed to automatic restart after EOD after a set
variable delay time. This mode and any delay time are programmed by the commissioning engineer.
During the delay time before automatic restart, the UPS charges the battery so as to avoid power interruption
to load in case of a following power failure.
In case the UPS is not programmed to automatic restart, you can use the FAULT CLEAR key to manually start
the UPS.
Bypass mode
As shown in Figure 1-7, during normal mode operation, if the inverters fail, are overloaded or turned off, the
static switch will perform a transfer of the load from the inverters to the bypass source, with no interruption in
power to the load. Should the inverters be asynchronous with the bypass, the static switch will perform a
transfer of the load from the inverters to the bypass, with interruption in power to the load. This is to avoid
paralleling of unsynchronized AC sources. This interruption is programmable but typically set to be less than
3/4 of an electrical cycle, for example, less than 15ms (50Hz) or less than 12.5ms (60Hz).
Bypass input switch
Bypass input
Static switch
Output switch
UPS output
Bypass input
Bypass input switch
Static switch
Output switch
UPS output
Figure 1-7 Schematic diagram of bypass mode
Maintenance mode
As shown in Figure 1-8, if UPS maintenance or repaired is needed, you may use the manual maintenance
bypass switch to transfer the load to the maintenance bypass, with no interruption in power to the load.
Maintenance bypass switch
Bypass input
Maintenance bypass
UPS output
Bypass input
Maintenance bypass switch Maintenance bypass
UPS output
Figure 1-8 Schematic diagram of maintenance mode
Warning: risk after load transfer to maintenance bypass
After the UPS is transferred to maintenance bypass, the power modules and bypass module are inoperative and the LCD
has no display, only the green indicator of the
input SPD shows that the UPS has mains input, but the output terminals
corresponding to closed output distribution switches and the neutral bars are energized.