ATO LK Series User manual

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Low Frequency Inverter
User Manual
For LK/LW series Power Star inverters only, models:
LK2000, LK2000-24, LK3000, LK3000-24, LK3000-48, LK6000-24, LK6000-48
220-240V 50-60Hz
Pure Sine Wave

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1.Safety precautions
WARNING! HIGH VOLTAGE! Do not install this product unless qualified to
do so. Read the full user manual before working on this product.
•Electricity can be very dangerous! Never touch bare wires, connectors or
terminals.
•Do not open the inverter case, nor should you try to repair it if broken.
•Avoid any contact with water. Never operate the inverter in an environment
where, or in conditions when, contact with water is likely or humidity is high.
•Avoid any contact with oil or grease.
•Keep the inverter, cables and other components of your system away from
children.
•Never connect the inverter output to any other AC power source.
•Do not cover the inverter. Always place it in a well-ventilated environment
and allow space around the inverter for airflow.
•If you operate the inverter in a vehicle, boat or any other mobile application,
secure the inverter to prevent it from any movement while the vehicle is in
motion. Make sure all the connections are tight.
•Do not place the inverter under direct sunlight or in a high temperature
environment.
•Keep the inverter away from any flammable substances.
•Do not use the inverter in an enclosure containing any type of lead-acid
batteries which might vent explosive gases.
•Always switch on the inverter first, before plugging in any appliances.
The product should be handled and installed by professionals or appropriately qualified
persons. Suitable precautions and safety measures should be taken in all cases.
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1. Product overview
Dear Customer,
Thank you for buying this low-frequency inverter. It has important advantages over high frequency
inverters, such as peak power handling capacity and reliability. This low-frequency inverter can operate
at the peak power level substantially higher than the nominal power, for a period of several seconds –
which is great for starting appliances with high initial power draw (e.g. electric motors). The inverter also
operates using a powerful transformer (as opposed to electronic switching components in high frequency
inverters) - this results in a stronger, sturdier inverter which is less prone to damage.
In addition to the standard function of inverting the power (i.e. converting the battery DC electricity
into mains AC 230V 50Hz electricity), this inverter has other useful features and components:
- It has a mains AC input which can take power from the national grid or a generator. The inverter
is also equipped with a powerful built-in mains charger for charging the batteries (suitable for lead-
acid battery types only), with programmable operating charging current;
- When the mains AC input power is connected the inverter will activate the power transfer switch
to work in a “bypass” mode, where the AC input mains power will be directly connected to the AC
output, therefore “bypassing” the battery-to-output inverter circuit. The active mains input will also
switch on the in-built battery charger unless the charger is set to OFF.
- The inverter can work as an uninterrupted power supply (UPS) unit. By default, when the mains
AC power input is connected and active, it will be connected to the mains AC output through the
bypass transfer switch, powering the appliances directly. If suddenly there is a power cut or mains
AC input is not available for any other reason, the inverter will automatically connect the batteries
and start running the mains AC output from the batteries –without any interruption to the
appliances.
- There is also a choice of operating modes: AC priority or battery (or DC) priority:
oIn the AC priority mode, while the inverter is connected to the mains AC input, it charges
your batteries from mains all the time. Your appliances are also powered by mains.
oIn the battery (or DC) priority mode, even if the mains AC input is connected to the
inverter, it remains deactivated and your appliances are powered by the batteries until the
batteries get too low.
You will find more details about these modes in the Settings section of this manual.
This inverter is powerful enough to run heavy duty appliances with large starting current or power
spikes. When running smaller appliances, for energy saving purposes, the inverter On/Off switch has two
On positions:
- “Power saver off”: this is the full power mode, in which the inverter supplies full power to the
mains output.
- “Power saver auto”: this is the standby or energy saving mode. When the inverter doesn’t have
any load drawing power from its output, in goes into a standby “sleep” mode and switches off the
mains AC output. During this time the inverter uses a reduced amount of power from the battery. If
an appliance is plugged into the inverter AC output, the inverter exits the standby “sleep” mode
immediately and starts supplying the full power again to the mains AC output. The load has to be in
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excess of 25W to wake up the inverter, i.e. plugging something small such as a mobile phone
charger will not make a difference and the inverter will remain in the standby “sleep” mode.
2. Installation and wiring
Before you install the inverter, ensure that it has the correct DC voltage for your system, i.e. the
inverter DC input voltage matches the voltage of your battery bank. For example, if your inverter is 12V
(or 24V / 48V), only use it with a 12V battery bank (24V / 48V bank respectively). Incorrect battery
voltage might damage the inverter.
Position the inverter in a cool, dry, well ventilated space as close to the main battery bank as
possible, to make sure that the DC battery cables are as short as possible. Remember that long cables
might cause a voltage drop in the inverter incoming power supply which will affect the systems
performance. The unit can be mounted in any position –on a horizontal or vertical surface.
The overall wiring diagram for the inverter is provided below. Wiring diagram for
LK/LW Series Power Star inverters
Ensure that the inverter is switched off during the installation. It is recommended that you always
connect the inverter to the battery bank first, as the battery power ultimately starts the inverter. If the
inverter is connected to the AC input only, with the batteries disconnected or too low, the inverter will not
switch on.
It is very important to choose the right cables depending on the length which you require between
the inverter and the battery bank. This is both for efficiency and safety reasons. The following table
provides guidance on the recommended cable cross section (area in mm2of the metal core of the cable):
Product code
Cable length 0-1.5m
Cable length 1.5-4.0m
LK2000-24 (2000W 24V), LK3000-48 (3000W 48V),
25mm2
35mm2
LK3000-24 (3000W 24V), LK6000-48 (6000W 48V)
35mm2
50mm2
LK2000 (2000W 12V)
50mm2
70mm2
LK3000 (3000W 12V), LK6000-24 (6000W 24V)
70mm2
90mm2
Fuse
AC
output
AC input
Earth
Main domestic battery bank
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The above table relates to the multi strand copper cable (for marine applications tinned copper is
recommended). If the cable you intend using is different (such as single strand or aluminium) or you
require distances longer than 4m, please contact your inverter supplier or distributor for advice.
Please note that if there is a problem obtaining, for example, a 90mm2cable, you can purchase 2 x
50mm2cables or even 3 x 35 mm2cables. To use one cable is always preferred but it does not matter
whether one cable or multiple is used, as long as the square areas add up to the same or higher than the
required. The performance of any system can be increased by having thicker and shorter cables, so it is
advised to keep the length as short as possible. If you can’t source the cable for the inverter locally, your
inverter supplier or distributor should normally be able to offer you this cable.
When connecting the inverter to the battery using the correct heavy duty cable, follow the
guidelines below:
•Connect the cable though a suitable fuse with an isolator switch, or a circuit breaker. The
minimum current rating of such fuse / switch / circuit breaker depends on the input voltage of your
inverter and the nominal rated power. For example, if your inverter is 3000W 24V, then at nominal
power 3000W it would draw around 3000W / 24V = 125A from the battery. So the fuse / switch or a
circuit breaker should be rated at 125A. This assumes that the inverter is not intended for loads
which will have a peak power in excess of 3000W (in such case the amp rating of the fuse / switch
or a circuit breaker should be higher).
•The fuse (or a circuit breaker) should be fitted as close to the battery terminal as possible,
ideally within 15cm from it. This way it will protect the full length of cable from the battery to the
inverter from a potential short circuit. In most cases it is installed on the positive cable.
•After fitting the fuse / switch / circuit breaker, it is advised to connect the cable ends to the
inverter terminals first. Keep the switch or a circuit breaker in Off position. Only after that should
you connect the other end of the cable to the terminals of your battery bank: red positive (+)
terminal of the inverter to the positive (+) of your battery bank, and black negative (-) of the inverter
to the negative (-) of your battery bank.
•Cables joining batteries in your bank should be similar or thicker than the inverter cables.
WARNING! Do not reverse the polarity of the battery cables. If the battery bank is
connected to the inverter with the wrong polarity, the inverter will be damaged.
The next step is wiring the AC output and AC input of the inverter. Keep the inverter switched off
during this procedure. The overall connection scheme is provided below.
Wiring AC input and output terminals of
LK/LW Series Power Star inverters
Output
Input
AC
Power out
AC
Power in
<
<
<
<
<
<
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Remove the cover on the AC side of the inverter to access the AC terminals. The inverter has 3
terminals for the AC output (Live, Neutral and Earth) and 3 terminals for the mains AC input (Live,
Neutral and Earth). If your inverter includes an AC output socket, internally this socket is connected to
the AC output terminals.
Note: the order of output and input AC terminals of your inverter might be different
compared to the order shown on the diagram above. Always follow the signs
printed on the inverter casing to identify the correct terminals.
When wiring the AC output of the inverter from the socket or AC output terminals:
•Make sure that all other AC power sources are fully isolated from the circuits to which you
intend to connect the inverter AC output. If you connect the inverter AC output to a circuit which
already has live AC power in it, the inverter will be damaged immediately.
•Use a suitable Residual Current Device (RCD) on the inverter AC output for safety and
protection.
•The inverter has a built-in AC output circuit breaker rated at 30A. If you intend to use the
inverter with smaller AC loads, it is recommended that you install a smaller fuse (3A, 10A, 13A) on
the AC output of the inverter (or use appropriately fused plugs / sockets).
We recommend multi core tri rated AC cable when the inverter is used on a boat or on a vehicle as
this is much safer when vibration is likely. A single solid household AC cable is suitable if the product is
being used as a power source for a house or installation free from vibration.
The inverter also has a 30A circuit breaker installed on the AC input side. If you are planning to use
the inverter with reduced through-power (including “bypass” and battery charging), install a smaller fuse
on the AC input of the inverter, e.g. 3A, 10A or 13A.
When connecting the inverter earth, please note
that the earth wires for AC input and AC output are
connected inside and both are connected to the
inverter case. Use a suitable earthing cable to connect
the inverter casing to the boat’s earth or a bonding
system, vehicle chassis or an earthing rod (for
stationary installations).
To complete this part of the installation and test the unit: after the inverter has been connected to
the battery bank turn the isolator switch between the inverter and the battery on. Then turn the On/Off
switch of the inverter to “Power Saver Off” position. The LEDs will cycle through the test routine and the
unit should go into the inverter mode and 230V AC should be produced on the output AC terminals.
When the AC battery charging or mains input power is required connect the AC input to the
inverter and it will enter the “bypass” mode to start supplying the input AC power to the output AC power
directly. The changeover to mains AC input takes about 10 milliseconds and is hardly noticeable. If the
battery charger is On (default setting) it will start charging the battery bank according to the pre-
programmed battery charging stages (see Appendix 1 for more details).
Installing the remote On/Off control (can be purchased separately)
If you have purchased a remote On/Off switch with 5m cable for your inverter, it can be plugged
into the “Remote control”socket located on the battery terminals side of the inverter.
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Keep the inverter turned off when you plug the remote switch for the first time. In the future,
always make sure to keep the main switch of the inverter in Off (middle) position if you intend to use a
remote switch connected via the “Remote control”socket.
If you haven’t bought a separate remote On/Off switch, the built-in black On/Off control panel on
top of the inverter can be used as a remote switch. For that disconnect the inverter from the battery and
AC, then turn the inverter On for 5 sec. to discharge internal capacitors. Remove 4 screws holding the
panel, take it out and disconnect the cable from the socket inside. Use a suitable length/grade 6-pin
RJ11 extension cable to move the black On/Off panel to the new location. Cover the hole in the inverter
case thoroughly with tape.
Connecting a generator
This inverter can accept power from a generator connected to the mains AC input of the inverter.
Note: for best performance, it is recommended that the generator nominal power
rating is twice as high as the nominal power of the inverter. Lower power rating of
the generator might cause a problem when the inverter works with high loads.
To proceed with the installation of the generator, keep the inverter off and start the generator.
When it is ready and running at normal speed, connect the generator’s output to the inverter’s AC input
terminals. There must be no load connected to the inverter (nothing connected to the AC output of the
inverter) at this point. Then, turn on the inverter. At this point the load can be connected.
3. Operation modes
The inverter main switch panel has a 3-position rocker switch and 3 LED lights:
(1)
Switch: power saver auto position
(2)
Battery charge LED indicator
(3)
Inverter work LED indicator
(4)
Alarm and fault LED indicator
(5)
Switch: power saver off position
(6)
Switch: unit off (middle) position
Built-in black On/Off control panel
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According to the switch position, the inverter will have one of the following modes:
•Unit off (middle position): The inverter is off, there is no AC output. The battery charger is off.
•Power saver off: the inverter is producing full power. The exact operating mode depends on
whether AC input power is connected to the inverter or not. If the AC input is connected, the
inverter will be operating in the bypass mode and the battery charger will be working.
•Power saver auto: the inverter is in the sleep mode and will only provide power if a load is
connected to the AC output. If there is no load connected, the inverter will continue ‘sleeping’ to
save energy. Please note that the load must exceed 25W to turn on the inverter output –small
loads such as mobile phone chargers, LED lights etc will not be enough to exit the sleep mode.
If you want to change the active “Power saver auto”mode to “Power saver off”and
vice versa, turn the switch to the middle position “Unit off” first, wait until the
inverter switches off, and then switch it into the other mode.
The detailed description of these operating modes is provided below.
Power saver off, AC input is connected. If
the AC input is connected, the inverter will be
working in the AC mode 01 (in the top left
corner of the inverter LCD display there will be
a sign “>> 01”) as shown on the picture. In the
centre of the screen the input (I/P) sign will
have arrows pointing from it to Bypass and
battery icons. The display will show AC input
voltage at the bottom, as well as AC output.
Power saver off, AC input is disconnected.
If the AC input is disconnected, the inverter
will be working in the Battery (inverter) mode
02 (in the top left corner of the inverter LCD
display there will be a sign “>> 02”) as shown
on the picture. In the centre of the screen
there will be an arrow pointing from the battery
to the inverter and to output (O/P). AC input
voltage will show 000V.
Power saver auto. The inverter will be
working in the Power saver mode 03 (in the
top left corner of the inverter LCD display
there will be a sign “>> 03”) as shown on the
picture. The inverter will be ‘sleeping’ in
standby until a load (>25W) is connected to
the inverter output. The signs “OUTPUT” and
“O/P” will be flashing on the screen.
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Silent
Operation mode/
fault code
Operating mode
Battery information
Input voltage
and frequency
Left –Right
select
Press and hold both to access
settings
Up –
Down
select
Confirm Silent
Output voltage
and frequency
Load
information
Bypass mode
4. LCD display
The inverter shows operational information and provides access to various settings via the LCD
display.
The table below provides information about various signs on the LCD display and their meaning.
Sign
Meaning
When a problem happens, this sign
appears with a fault code next to it (see
Troubleshooting)
Operating mode (see Operating Modes)
Silent mode in inverter mode
Displays the output voltage which can be
set to 220V, 230V or 240V
Displays the output frequency which can
be set to 50Hz, or 60Hz.
Displays and alternates every 3 sec.
between the current battery capacity as a
% and battery voltage.
Displays and alternates every 3 sec.
between AC input frequency and voltage.
Displays and alternates every 3 sec.
between AC output frequency and
voltage.
The inverter is working in the bypass
mode
If the display shows HIGH, the AC input
voltage is too high. If it shows LOW, the
AC input voltage is too low. If L (live) and
N (neutral) is reversed it will flash every 1
second.
The inverter is working in the inverting
mode
There has been a short circuit detected
Displays the load capacity in either VA or
W whichever is higher
Too much power is being drawn through
the inverter. Flashes once a second.
The load is connected
The battery is charging
Low battery warning, flashes once a
second
Shows the battery capacity
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The main functions of the 4 buttons under the LCD display are described below.
5. Settings
To access the settings menu of the inverter please follow the steps below:
1. Switch the inverter On in the Power Saver Off mode.
2. Wait for 3 seconds and then press and buttons together and hold them for a further 3
seconds. The inverter will ‘Beep’ and the first editable parameter will start flashing on the screen.
3. Press to navigate through the different parameters to set.
4. Select a setting and it will begin to flash. Press and follow the instructions below to choose
different options.
5. Once you have finished the changes, press CONFIRM to record the new settings. The
inverter will make a beeping sound to confirm. Restart the inverter by switching it OFF and then
ON for the settings to take effect.
Setting 1: Output AC voltage (208 220 230 240)
This setting is to provide the right AC output voltage for your
electronic appliances. The default voltage range for
appliances in the UK is 230V - 240V AC; other countries
might have different requirements.
After selecting the required AC output voltage, press to
move to the next parameter.
Setting 2: Output AC frequency (AF 50 60)
This setting is for the output frequency. Choose from AF (auto
detection of frequency), 50Hz or 60Hz. The default value for
the UK is 50Hz. If this parameter is set to AF, the inverter can
detect the frequency from the mains AC input.
Button
Function
Silent
Press and hold for 3 seconds to switch between silent and sound mode.
Settings
Press the two select buttons and hold them for 2 seconds to enter the Settings
mode
Left-Right select
Only valid in the Settings mode. Used to select a different parameter. Hold it for
> 1 sec.
Up-Down select
Only valid in the Settings mode. Used to select a value or type of a particular
parameter. Hold it for > 1 sec.
Confirm
Only valid in the Settings mode. Used to confirm new data. Hold it for > 1 sec.
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