Forza Atlas 2-3KVA User manual

2 Year
Warranty
Atlas 2-3KVA Model
Power Inverter/UPS System
Service Manual

· Overview and UPS features
· Replacing the battery
· Steps to Open the Case
· Principles of Operation
· Alignments
· Trouble Shooting
· Electrical Specifications
General Information
Important Safety Instructions
Getting started
Conventions
The following conventions are used in this manual to provide
important information for a quick and safe operation of the
UPS.
For qualified personnel only:
AVOID performing any internal service or adjustment to
this product unless there is qualified personnel who can
perform first aid or CPR.
AVOID touching any exposed connections or
components while the UPS is working since there is
dangerous voltage at several points in this product.
Turn off the UPS and disconnect the input power cable
before removing the external protective cover.
AC voltage may be present when AC power is being
supplied.
1.
2.
3.
4.
5.
Denotes a procedure or operation, which, if not
perform correctly, may result in personal injury. Be
sure not to continue operation until indicated
conditions are fully understood and met.
Denotes a procedure or operation, which, if not
perform correctly, may cause damage to the UPS.
Be sure not to continue operation until indicated
conditions are fully understood and met.
This symbol means that there are
some tips or actions recommended by our design
engineers during service operations as a way to
help you finish your job.
Warning:
Caution:
Information and Tips:
STOP
STOP

Steps to open the case
Step 1
High voltage may be present at DC capacitors. Before
opening the external cover, wait for at least five minutes
after turning off the UPS.
Verify the input source (voltage and frequency) before
performing service work.
DO NOT short circuit the batteries.
If the battery connectors (P6, P8) are disconnected,
plug in the input power cord and verify that that there is
input power available before re-connecting the battery
connectors.
After servicing the UPS and before restarting it, perform
a polarity test on the batteries, and make sure the screws
and connectors are tight.
After opening the cover, always make sure that all wires,
connectors, and screws are tight. Then, check if any
components inside are discolored.
Remove related screws as shown in STEP 1.
Slide external cover in the direction shown in STEP 2.
You will see the internal panel.
To open the external case, follow the illustrations below:
6.
7.
1.
2.
3.
4.
1.
2.
3.

Step 2
Step 3

I. INTRODUCTION
All the UPS series are strictly tested and carefully
designed. We always do our best to make our products
more reliable and safer. However, due to the lifetime of
electrical components and some unpredictable reasons,
malfunctioning may occur. If this happens, consult with
qualified and trained personnel. This service manual will
help technicians repair and adjust any trouble that you may
find in your UPS. If the UPS still does not work properly,
contact us and we will gladly solve any problems that you
may have encountered.
Due to the unique features of this UPS series
(Uninterruptible Power System), this unit is very easy to
maintain and service.
The PBC has all the major power components.
All PCBs are interconnected.
Major parts are connected with flexible insulated wires
and plugs.
·
·
·
This service manual consists of 4 major parts:
For a correct and safe operation, make sure to read this
manual carefully before servicing the UPS.
Introduction.
Principle of operation: This section describes the
functions and principles of each part.
Alignments: This section describes the locations and
methods needed to adjust this UPS.
Troubleshooting: This section describes the possible
failure conditions and procedures to repair it.
1.
2.
3.
4.

II. PRINCIPLE OF OPERATION
This 3KVA (2KVA) high input power factor UPS system
contains two major PCB assemblies. They are:
Picture 1 shows how the major circuits are connected and
how the entire system works.
Picture 1 shows how the major circuits are connected and
how the entire system works.
Picture 1: Circuit connection for 2-3KVA.
Includes (1) a charger, (2) a DC power supply, (3) a power
factor correction, (4) a DC-DC converter, (5) an inverter
and (6) output circuits.
Includes protection parts, signaling circuits, regulation
and inverter control circuits.
1. PSDR
2. CNTL

The location of the assemblies in the machine are shown in
picture 2.
The location of the assemblies in the machine are shown in
picture 2.

Picture 2 : Sub-assembly location
Picture 3: Block Diagram for UPS
The block diagram in picture 3 shows the UPS at normal
operation from left to right. When a protection circuit is
triggered or a fault condition occurs, the output supply is
transferred immediately from the inverter to the AC mains
by a bypass relay. This operation will be explained in
another section.
This ON-LINE UPS system resorts to high frequency
PWM techniques to achieve high efficient performance.
When the Full mode is on, the UPS can deliver a clean,
regulated sine-wave output at any load. Each sub-system
is described as follows:
N.F.
CHARGER DC/DC
N.F.
DC/AC
PFC
AC/DC
RY
BATTERY
I/P
O/P
RY

Picture 4: Charger Circuit Diagram
1.POWER STAGE (PSDR)
As shown in picture 1, the power stage consists of a
charger, a power factor correction unit, a DC power supply,
a DC-DC converter, an inverter and output circuits.
The purpose of the charger is to provide power to keep
the batteries full, (Refer to picture 4). The voltage flyback
switching power supply delivers a constant DC voltage
(83.8 VDC) to the batteries. Apart from providing constant
voltage, the power supply also limits the current going into
the batteries thus, protecting and extending their life.
1-1 Charger Sub-System:
Picture 5: Schematic for DC power supply

Picture 6: Schematics for inverter
Picture 7: I/P PFC configuration
1-4 Output Sub-System:
1-5 Input Power Factor Correction Sub-System:
1-6 DC-DC Converter Sub-System:
The bypass relay receives a signal from the control circuit
to switch the output of the UPS from bypass to inverter,
and vice versa. The output noise filter circuit blocks the
EMI noise to the loads.
The purpose of the power factor correction (PFC.) system
is to ensure that the level of the input current is less than 1,
as shown in picture 7.
The primary role of a UPS is to deliver accurate AC power
to the loads connected to it whether the AC line exists or
not. The batteries in the UPS release the stored energy to
start supplying the inverter once the loss in the AC line is
detected.
When the input AC power cord is plugged in, the AC relay
is activated and the AC power goes through noise filter to
the charger and to the line detector. Both DC buses have
voltages at about 1.4 times of input RMS voltage. When the
"on" switch is pressed, the P.F.C. circuit is enabled and the
DC buses are regulated at ±360 Vdc.