Perfect power systems EXT Series User manual

Perfect Power System
 Phone: [phone]
 FAX no: (800)-246-2346
 Technical Assistance: [e-mail]
Document No.: 725-MAN, Rev.B
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Due to continuous product improvement, this document is subject to change without prior notice
Emergency Lighting Inverter
EXT Series(Outdoor)
Single-Phase, 2.1KW ~ 17KW
Installation and Operation Manual

725-MAN Rev B Page 2 of 89
Notice o Rights
This document contains proprietary and con idential in ormation o the manu acturer. No part o this
manual may be reproduced, copied, translated or transmitted, in any orm or by any means, without
the prior written permission o the company.
Notice o Liability
In ormation provided in this manual is intended to be accurate and reliable. However, Per ect Power
Systems. assumes no responsibility or its use, nor or any in ringement o rights o third parties which
may result rom its use. THIS DOCUMENT IS PROVIDED “AS IS” AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MANUAFACTURER
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENT, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
Trademarks
All trademarks and registered trademarks are the property o their respective owners.
Harsh Environment Series Installation and Operation Manual
Document No.: 725-MAN, Rev.B
August 5, 2019

725-MAN Rev B Page 3 of 89
Table of Contents
Table of Contents............................................................................................................. 3
Introduction .................................................................................................................... 5
Scope and Audience................................................................................................................... 5
Sa ety and Warnings .................................................................................................................. 5
Warranty Registration and Warranty Certi icate Request ........................................................ 5
Service ........................................................................................................................................ 5
Chapter 1. Safety .................................................................................................... 6
Chapter 2. Overview ............................................................................................. 1
2.1 Product Description ........................................................................................................... 10
2.2 Product Features ................................................................................................................ 11
Chapter 3. Hardware Overview ............................................................................. 13
3.2 Key Components ................................................................................................................ 14
3.3 Functional Description (Typical) ........................................................................................ 17
3.4 Theory o Operation .......................................................................................................... 19
Chapter 4. Installation ........................................................................................... 21
4.1 Delivery Space Requirements ............................................................................................ 21
4.2 Site Considerations ............................................................................................................ 24
4.3 Delivery and Handling ........................................................................................................ 28
4.4 Storing the System ............................................................................................................. 37
Chapter 5. Operation ............................................................................................. 39
5.1 Starting the Unit or the First Time .................................................................................... 39
Chapter 6. Maintenance ........................................................................................ 42
6.1 Sa ety Precautions ............................................................................................................. 42
6.2 Preventative Maintenance ................................................................................................ 43
6.3 FRU Replacement............................................................................................................... 46
6.4 Calling or Service .............................................................................................................. 53
Chapter 7. Troubleshooting ................................................................................... 54
7.1 Reset Instructions .............................................................................................................. 55
7.2 Troubleshooting Guide and System Alarms ...................................................................... 55
7.3 Using the LCD Display Panel .............................................................................................. 57

Table of Contents
725-MAN Rev B Page 4 of 89
Chapter 8. Specifications ....................................................................................... 6
APPENDIX A - Battery Connections .............................................................................. 65
APPENDIX B - Options ................................................................................................. 73
B.2 Internal Manual Bypass Switch (Make Be ore Break) ....................................................... 74
B.3 Form “C” N/O Contacts or Alarms .................................................................................... 74
B.4 Dry Contact, N/O or N/C Contact with Isolated Common ................................................. 74
B.5 Battery Breaker alarm ....................................................................................................... 75
B.6 External Wrap-around Manual Bypass Switch (same Input and Output Voltage) ............ 75
B.7 Audio Alarms with Silence Switch ..................................................................................... 78
B.8 Remote Status Panel .......................................................................................................... 78
B.9 Transient Voltage Surge Suppressor (TVSS) ...................................................................... 79
B.10 O line Inverter Operation ............................................................................................... 79
B.11 Normally ON/OFF Output Aux. Circuit Breakers ............................................................. 79
B.12 Main Input CB Standard/Higher KAIC .............................................................................. 79
B.13 Main Output CB Standard/Higher KAIC ........................................................................... 79
B.14 Power Flow Mimic ........................................................................................................... 79
B.15 Global Monitoring Systems (GMS) .................................................................................. 80
B.15.1 Local Monitoring via PC with RS-232 ..................................................................... 83
B.15.2 Local Monitoring via PC with RS-485 ..................................................................... 83
B.15.3 RJ45 Ethernet connection ...................................................................................... 83
B.16 Simple Network Management Protocol .......................................................................... 84
B.17 Battery Thermal Runaway Control .................................................................................. 85
B.18 Heater Strip with Adjustable Thermostat ........................................................................ 86
B.19 Battery String Monitoring (Wireless) ............................................................................... 86
B.20 Battery (Individual) Monitoring (Wireless) ...................................................................... 86
Index .............................................................................................................................. 88

725-MAN Rev B Page 5 of 89
Introduction
This manual tells you how to install, start and operate your unit and lets you know how to get more
in ormation or special situations, and provide contact in ormation
Scope and Audience
This guide is intended to be used as a re erence or users responsible or installing, operating, and
maintaining this equipment.
Safety and Warnings
This guide uses the ollowing symbols to draw your attention to certain in ormation.
Symbol Meaning Description
Note Notes emphasize or supplement important points o the main text.
Tip Tips provide help ul in ormation, guidelines, or suggestions or per orming
tasks more e ectively.
Caution Cautions indicate that ailure to take a speci ied action could result in damage
to the hardware.
DANGER The Danger symbol warns users o possible injury or death i instructions are
not ollowed.
Electrostatic
Sensitive
This symbol warns users that the equipment is sensitive to electrostatic
discharge (ESD) and could be damaged i users do not take appropriate
precautions such as using a grounded wrist strap when touching or handling
the equipment.
Warranty Registration and Warranty Certificate Request
Visit our web site at: www.800pwrsrvc.com under download tab
Service
I you require assistance, ill out a Service Report Form at www.800pwrsrvc.com, email us at
[e-mail], or call our 24-hour toll ree hot line (800-797-7782). Please have the
unit’s SERIAL NO. rom the Start-Up label located on the top le t corner o the ront door or speed
assistance.

725-MAN Rev B Page 6 of 89
Chapter 1. Safety
This chapter contains sa ety precautions to observe when operating or servicing electrical
equipment. The symbols shown are used extensively throughout this manual. Always heed these
precautions because they are essential to the sa e operation and servicing o this product.

Safety
725-MAN Rev B Page 7 of 89
DANGER: This Equipment is intended to be permanently connected. Only actory-trained
or authorized personnel should
attempt to install or repair the unit or its batteries system.
Improper installation has proven to be the single most signi icant cause o start-up
problems. High AC and DC electrical voltages are present throughout the unit(s) and
incorrect installation or servicing could result in electrocution, ire, explosion, or
equipment ailure.
DANGER: Read this manual in its entirety be ore per orming the installation, start-up,
operation, or maintenance o the UPS unit or battery systems. Failure to do so could
result in electrocution, ire, explosion, or equipment ailure.
DANGER: All power connections must be completed by a licensed electrician who is
experienced in wiring this type o equipment. Wiring must be installed in accordance with
all applicable national and local electrical codes. Improper wiring may cause damage to
the equipment, injury or death o personnel. Veri y that all high and low voltage input
power circuits are de-energized and locked out be ore installing cables or making any
electrical connections.
DANGER: Exercise extreme care when handling unit and battery cabinets to avoid
equipment damage or injury to personnel. Cabinets weigh several hundred pounds.
DANGER: Test li t and balance the cabinets be ore moving. Maintain minimum tilt rom
vertical at all times. The bottom structure will support the unit only i the orkli t orks are
completely underneath the unit.
DANGER: Observe all battery sa ety precautions during installation or service o the unit
or batteries. Even with the battery circuit breaker in the o position, the danger o
electrocution may still be present. The battery power to the unit must be locked and
tagged “o ” be ore per orming any service or work on the unit. The battery
manu acturer’s sa ety in ormation and material sa ety data sheet are located in a pocket
attached to the inside o le t door o each unit. Failure to ollow those instructions and
the instruction listed above and elsewhere in this manual could result in an explosion,
ire, equipment ailure, or electrocution.

Safety
725-MAN Rev B Page 8 of 89
DANGER: All power to the unit must be locked and tagged "o " be ore per orming any
service or work on the unit. ailure to do so could result in electrocution.
DANGER: In case o ire involving electrical equipment, only carbon dioxide ire
extinguishers, or those approved or use on electrical equipment, should be used. Use o
water on ires involving live high voltage electrical circuits could present an electrocution
hazard.
DANGER: Extreme caution is required when per orming maintenance. Lethal voltages
exist within the equipment during operation. Observe all warnings and cautions in this
manual. Failure to comply may result in serious injury or death. Obtain quali ied service
or this equipment as instructed.
DANGER: Be constantly aware that the unit system contains high DC as well as AC
voltages. With input power o and the battery disconnected, high voltage at the ilter
capacitors and power circuits should discharge within 30 seconds. However, power circuit
ailures can occur, so you should always assume that high voltage might still exist a ter
shutdown. Veri y that power is o using AC and DC voltmeters be ore making contact.
DANGER: Some components within the cabinets are not connected t
o chassis ground. Any
contact between loating circuits and the chassis is a lethal shock hazard.
DANGER: Internal battery strapping must be veri ied by the customer prior to moving this
unit. This unit contains non-spillable batteries. Keep the unit upright. Do not stack. Do not
tip. Always ollow the battery manu acturer’s sa ety in ormation, located in a pocket
attached to the inside o the le t door o your unit, to prevent an accident that could result in
injury or death.

Safety
725-MAN Rev B Page 9 of 89
DANGER: Lead-acid batteries contain hazardous materials. Batteries must be handled,
transported, and recycled or discarded in accordance with ederal, state, and local
regulations. Because lead is a toxic substance, lead-acid batteries should be recycled rather
than discarded.
Do not dispose o batteries in a ire, the batteries may explode.
Do not open or mutilate the batteries. Released electrolytes are harm ul to the skin and eyes
and may be toxic.
A battery can have a high short circuit current and present a risk o electrical shock. The
ollowing precautions should be observed when working on batteries:
1. Remove watches, rings, or other metal objects.
2. Use tools with insulated handles.
3. Wear rubber gloves and boots.
4. Do not lay tools or metal parts on top of batteries.
5. Disconnect charging source prior to connecting or disconnecting battery
terminals.
6. Determine whether battery is inadvertently grounded. if so, remove the
source of the ground. Contact with any part of a grounded battery can
result in electrical shock. The likelihood of such shock will be reduced if
such grounds are removed during installation and maintenance.
7. Lead-acid batteries can present a risk of fire because they generate
hydrogen gas. The following procedures should be followed:
8. Do not smoke when near batteries.
9. Do not cause flame or spark in battery area.
10.
Discharge static electricity from your body before touching batteries by first
touching a grounded surface.

725-MAN Rev B Page 10 of 89
Chapter 2. Overview
This chapter provides an overview o the Single-Phase Lighting Inverter Standard Series.
2.1 Product Description
The Harsh Environment Single-Phase Lighting Inverter is manu actured to provide critical power or
lighting during a power outage. The Lighting Inverter meets or exceeds the li e sa ety codes o UL924
and UL1778. These codes were established to allow emergency lighting inverters to provide critical
power to the lighting circuits during a power ailure.
I input power to the inverter is lost during a power outage, the system draws clean sine wave
power automatically rom its internal battery supply without any interruption. Power is provided or
90 minutes, su icient time or sa e and orderly evacuation rom the acility.
An optional output trans ormer allows multiple output voltages as well as input voltages that are
di erent rom output voltages. They are available in 3kva to 17kw with input or output voltages o
120, 208, 240, 277 or 480 VAC, single phase. This in ormation is shown on the nameplate located on
the inside ront door o the unit and should be recorded on page 5 o this manual.
The internal valve regulated lead-acid (VRLA), maintenance- ree batteries provide 90 minutes o
backup power. When input power is restored, the Lighting Inverter resumes normal operation
automatically and begins recharging the batteries immediately.
An internal bypass circuit maintains power to the load in case an internal unit ailure occurs.
Comprehensive monitoring capabilities include a Liquid Crystal Display (LCD) panel and ive dry relay
contacts or remote monitoring.
Table 2-1 lists the cabinet dimension, and Figure 2-1 shows them.
Table 2-1. Harsh Environment Series Cabinet Dimensions
kVA/KW Cabinet Size (Including Battery)
(W x H x D in Inche )
Cabinet Type
3KVA ~ 5KW 39” x 73.5” x 20” See Figure 4-1
6.5kVA ~17 KW 51” x 77.5” x 33.5” See Figure 4-2

Overview
725-MAN Rev B Page 11 of 89
Figure 2-1. Series Single-Phase Lighting Inverter Cabinets Outdoor Series
2.2 Product Features
Item Component Function
1 Input Contactor K1
The input contactor is multi unctional. First, it provides
connections or the input power to the unit. Secondly,
the contactor disconnects the input line when an outage
occurs so that there is no back eeding o power into the
power line. Finally, the contactor allows or automatic
unit operation upon a complete discharge o the
batteries. No operator intervention is required when
power to the unit is restored a ter a complete battery
discharge.
2 Battery Charger
The battery charger maintains the batteries at ull
charge. A ter a battery discharge, the charger will
automatically recharge the batteries upon restoration o
input power. This circuit is on the Power Board.

Overview
725-MAN Rev B Page 12 of 89
Item Component Function
3 Power Board Assembly with IGBTs The Power Board is bolted onto the IGBT (Insulated Gate
Bipolar Transistor) blocks that are mounted on a heat
sink. The complete Heat Sink Assembly with IGBTs and
Power Board is replaceable as a single part. This FRU
(Field Replaceable Assembly) converts all the power, i.e.
input AC power converted to DC bus, battery power
boosted to DC bus, and inally DC bus power converted
to output AC power using PWM technology or a smooth
AC sine wave. In case o a catastrophic ailure, the
complete Heat Sink Assembly is easily replaceable using
only a screwdriver. The Power Board also contains the
housekeeping power supplies and drivers or the IGBTs.
The entire assembly provides the landing place or all
internal input, output, DC cables and metering devices
or control and monitoring o the unit input and output
currents.
4 Control Board The microprocessor with unit speci ic irmware and
control circuitry is located on the Control Board. The
Control Board is mounted on the cabinet door and
communicates with the Power Board (A2) via a ribbon
cable. It monitors the input and output voltages and
generates the command to close or open the input
contactor and to sense and change the status o the
bypass static switch. The Control Board sends data to the
LCD panel located on the door where actual status and
parameters are displayed. It additionally provides
optional AS400, RS232, and RS485 output capabilities
and supports various communication including SNMP
option.
5 Output Static Switch This SCR solid-state switch connects the output o the
inverter (UPS) to the load. It is connected on the primary
side o the optional output isolation trans ormer. This
switch shuts o in case o a problem or ailure within the
unit and trans ers the load directly to the utility input via
the bypass static switch. It maintains its status opposite
to that o bypass switch.
6 LCD Display Panel The LCD (Liquid Crystal Display) panel provides all the
input, output, battery metering and alarm data, and UPS
status or customer use on a constantly scrolling set o 2
de ault screens with continuous update.
7 Optional Output Isolation Trans ormer The output isolation trans ormer provides isolation
between the inverter and protected output. The power
to the primary o this trans ormer is received rom the
unit and is trans ormed to required output voltage
levels. It will also add another screen to the main menu.
8 Optional Maintenance Bypass Switch The MBS (Maintenance Bypass Switch) removes the
critical load rom the backup power and provides utility
input directly to the load in case o a unit mal unction or
during system maintenance.
9 Battery Bank The battery bank consists o sealed, maintenance- ree
batteries. The batteries provide emergency power during
power outages. The battery bank includes a breaker or
over current protection and DC disconnect.

725-MAN Rev B Page 13 of 89
Chapter 3. Hardware Overview
This chapter provides an overview o the system hardware. It includes a description o the system’s
theory o operation.

Hardware Overview
725-MAN Rev B Page 14 of 89
3.2 Key Components
Figure 3-1 shows the key system components and Table 3-1 describes them.
Figure 3-1 Key Components or all other units (typical)

Hardware Overview
725-MAN Rev B Page 15 of 89
Table 3-1. Key Components description
Callout Component Name De cription
1 Heatsink FRU Assembly
Power board (A1) The power board is bolted onto the Insulated Gate
Bipolar Transistor (IGBT) blocks mounted on a heat sink.
The complete heat sink assembly with IGBTs and power
board is a single Field Replaceable Unit (FRU) that
converts all the power:
Input AC power converted to DC bus
Battery power boosted to DC bus
DC bus power converted to output AC power using PWM
technology or a smooth AC sine wave
I a catastrophic ailure occurs, the heat sink assembly
can be replaced using only a screwdriver. The power
board also has the housekeeping power supplies and
drivers or the IGBTs. The entire assembly provides the
landing place or all internal input, output, DC cables,
and metering devices or controlling and monitoring the
unit input and output currents.
Bypass static switch
(PB2)
Bypass static switch is closed only upon inverter ault or
output overload condition.
Inverter static switch
(PB1)
The SCR solid-state switch connects the output o the
inverter (UPS) to the load. It is connected on the primary
side o the optional output isolation trans ormer. I
problem or ailure occurs in the unit, this switch shuts o
and trans ers the load directly to the utility input via the
bypass static switch. It maintains its status opposite to
that o the bypass switch.
2 Input 2-Pole terminal block (TB1) Customer Input power connection. See 4.3.6 (page 32)
3 Ground Lug (input and output) 2-barrel lug or Input and Output Ground. See 4.3.6
(page 32)
4 Output 2-Pole / 3-pole terminal block (TB1) Customer output connection. See 4.3.6 (page 32)
5 Control board (A2) The microprocessor with unit speci ic irmware and
control circuitry is located on the Control Board. The
Control Board is mounted on the cabinet door and
communicates with the Power Board (A2) via a ribbon
cable. It monitors the input and output voltages and
generates the command to close or open the input
contactor and to sense and change the status o the
bypass static switch. The Control Board sends data to the
LCD panel located on the door where actual status and
parameters are displayed. It additionally provides
optional AS400, RS232, and RS485 output capabilities
and supports various communication including SNMP
option.
6 LCD display panel Provides continuously updated input, output, battery
metering and alarm data, and UPS status or customer
use on a constantly scrolling set o 2 de ault screens.
7 Terminal block or removing heat sink assembly
(TB4)
5-position terminal block (TB4). This terminal block
provides quick and easy removal o power assembly.
8 Fan trans ormer, Control power trans ormer (T2)
Behind panel.
Provides 120 VAC to the ans, with taps to match unit
output voltages.

Hardware Overview
725-MAN Rev B Page 16 of 89
Callout Component Name De cription
9 Control trans ormer use (F1) Behind panel Control trans ormer over current protection
10 Fan use (F2), behind panel Fan overcurrent protection.
11 Fan(s) Provides system cooling.
12 Output isolation trans ormer T1, as required Provides isolation between the inverter and protected
output. Power to the primary o this trans ormer is
received rom the unit and is trans ormed to the
appropriate output voltage levels. It also adds a screen
to the main menu.
13 Inverter test switch (S2) Push-button switch or testing the Lighting Inverter and
its batteries or proper operation. When the unit is
operating, pressing and holding in switch SW-2 trans ers
the system to battery operation. The system continues
to run on batteries until the switch is released. When the
switch is released, the system returns to normal
operation so long as input power is present.
14 (Optional) Main Input breaker (CB3) Provides input overcurrent protection (optional).
15 Battery breaker (CB1) Provides overcurrent protection or battery bank.
16 (Optional) Main output breaker (CB2) Provides output overcurrent protection (optional).
17 (Optional) Output Auxiliary Breakers Normally ON/OFF Output Auxiliary Breakers (Optional)
18 (Optional) Gnd/Neu terminals Gnd/Neu terminals or optional auxiliary output
breakers.
19 (Optional) bypass switch Optional: Removes the critical load rom the backup
power and provides utility input directly to the load in
case the unit mal unctions or during system
maintenance (optional). See section 3.3.5.
20 (Optional) TVSS (Transient Voltage Surge
Suppressor)
This option is a no- use, ail-sa e surge suppressor
eaturing a ail-sa e sel -protected design, visual
indicator.
21 (Optional) Inter aces terminal blocks or customer
connection (General location)
Option customer connections i.e.. when 120Vac is
required, orm “C” contact terminals, each terminal is
marked accordingly or proper connection re er to each
option or connection details in each cabinet size.
22 Maintenance ree lead acid battery(s) Batteries are sealed, maintenance- ree, sel -regulated
lead acid construction, to provide emergency power
during power outages. Other battery options are
available upon request.
23 (Optional) Heater Strip Thermostat Controller Adjustable thermostat Control (Optional)
24 Manual holder Manual is located inside the unit in the holder
25 Front door Air Filter Air ilters are installed to prevent dust and moisture
entering the units

Hardware Overview
725-MAN Rev B Page 17 of 89
3.3 Functional Description (Typical)
Figure 3-2 shows the major blocks within the system and the sections ollowing the igure describe
them.
Figure 3-2. Major System Blocks
3.3.1 Inverter
The inverter accepts the available DC power rom the recti ier or the battery banks and converts it to
AC power or the critical load.
3.3.2 Battery Charger
The battery charger converts AC power into regulated DC power to recharge and maintain the
charge on the battery bank. The charger is ully automatic, with a current-limiting eature that
prevents battery damage in case o a charger mal unction.
The charger is sized so that the batteries are maintained at ull charge, even when the input voltage
is at the low line limit or inde inite periods o time.

Hardware Overview
725-MAN Rev B Page 18 of 89
3.3.3 Output Transformer
The output trans ormer is used or multiple output voltage units only. It per orms the ollowing
unctions:
 It provides excellent common mode and normal mode noise isolation o the load rom the input
or inverter power.
 It provides voltage trans ormation and tight regulation o the output voltage, while the system
operates rom its internal inverter.
 It can be used to provide a di erent voltage rom the input source voltage.
3.3.4 Battery
The battery bank consists o 8, 10, 12, 16, or 20 12-Volt batteries. These batteries provide the
reserve energy to sustain the load when suitable AC input power is not present. The batteries are
sealed, maintenance- ree, valve-regulated lead acid (VRLA) construction.
3.3.5 Maintenance Bypass Switch
3.3.6 Internal Maintenance Bypass Switch, MBS Switch – Optional
Internal Manual Maintenance Bypass Switch is a (3) position “UPS”, “SBS” and “BYPASS” rotary
switch, when set to “BYPASS” provides power directly rom UPS main input eed to the load which
ensures continuous power to critical load without interruption.
Caution: Do not leave the switch in the SBS position; otherwise, a loss o power to the
critical load will occur when the inverter is de-energized.
3.3.7 Efficiency Optimizer Function: (OFF Line Inverter Mode)
When input power is available, the batteries are charged and AC output rom the inverter supports
the critical load via the inverter static switch. This is normal mode, during which the inverter static
switch is closed, and the bypass static switch is opened. The bypass static switch is closed only
during inverter aults or manual operation, in which case the critical load is supported by output
power rom the bypass static switch.
This is normal operation or true-double convention UPS. However, higher e iciency UPS operation
can be achieved to reduce electricity costs by operating the unit as an “o -line inverter.” This
scenario reverses the normal operating mode. Normally, the bypass static switch is closed as long as
the input voltage and input requency are within ±10% o the normal input voltage range and ±3 Hz
o the normal input requency range, and the inverter static switch is opened. In o -line inverter
mode, the inverter static switch is closed only i input power ails or when and out-o -voltage and
requency condition exists.
By eliminating the requirement or an output voltage regulation o ±10% (voltage window range) or
± 15% (selectable) voltage window range:

Hardware Overview
725-MAN Rev B Page 19 of 89
 System e iciency increases by 2 to 4% depending on the model.
 Total power loss is reduced.
 The output AC voltage in the mode o operation ollows proportionally to the input line voltage.
The system supports two o -line inverter modes:
 A ast trans erring version, with a quarter cycle (2.5 milliseconds).
 A slow trans erring version, with 25 cycles (400 milliseconds to 1 second).
Fast trans erring time is required when loads are sensitive to voltages such as HID lights and other
voltage disturbances that a ect their operation. We recommend you use the higher e iciency
version i the output voltage regulation is not critical.
3.4 Theory of Operation
The ollowing section describes the system’s theory o operation.
3.4.1 Standby Mode and Normal Mode
A ter power is applied to the system, the system enters standby mode and per orms a sel -test.
During this period, the start subroutine checks or input voltage, and proper operation o the
inverter and bypass SCRs. A ter the sel -test completes success ully, the system enters normal mode.
During normal mode:
1. Input contactor K1 receives a closing signal that connects input power to the DC supply
trans ormer.
2. The DC recti ier supplies the battery charger, control board, and the DC/AC inverter circuit.
3. The battery charger is activated, allowing the batteries to be charged continuously.
4. The on-line DC/AC inverter converts the DC voltage to a PWM wave orm. This wave orm is
iltered and reconstructed to a desired AC output.
3.4.2 Response to Input Power Failure
I the system controller senses a change in input requency greater than ± 3 Hz or an out-o -range
input voltage, it:
 Considers the event as an input ailure and opens the input contactor immediately, isolating the
unit rom the acility.
 Turns o the charger and makes the battery bank a DC supply source to the inverter circuit,
maintaining an uninterrupted AC supply to the protected load.
 Issues a UPS ALARM message on the LCD display panel.
When the acility power returns, stabilizes, and is in phase with the backup power, the system
controller closes the input contactor and the system returns to normal mode. I the battery voltage

Hardware Overview
725-MAN Rev B Page 20 of 89
drops below 16% o its nominal value and the acility power remains o , the system enters into alert
mode.
3.4.3 UPS Alert
The system controller issues an ALERT message on the LCD display panel i any o the ollowing
conditions occurs:
 Internal ailure
 System overheats
 Battery bank undervoltage
During an alert:
 The system stops its backup operation.
 The inverter SCRs are switched OFF.
 Bypass SCRs are switched ON.
 A summary alarm 5V signal is sent to the hardwired inter ace.
The system remains in this mode until power is cycled or the system is repaired.
3.4.4 UPS Alarm
The system controller issues a UPS ALARM message on the LCD display panel i any o the ollowing
conditions occurs:
 Input power ailure
 Output overload
When the system is in alarm mode, inverter IGBs remain on and an alarm signal may be sent to the
signal inter ace. The system resets itsel when the problem no longer exists.
3.4.5 Output Loads
The system is designed to power any luorescent or incandescent HID lighting. However, certain
types o loads exhibit an excessive inrush current when irst turned on or at other times during
operation.
As a result, the capacity o the system might need to be greater than the capacity that is estimated
based on requirements shown on the system’s nameplate. I you have questions about powering
unusual loads rom your system, contact your dealer or the actory.