OASIS-UM-01
User Manual
Inverter/Charger – Oasis 4000 Rev 1.0
Oasis 4000 Series
SEPTEMBER 2011 ISSUE 01 OASIS-UM-01
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Oasis 4000 Series User Manual Contents 1. Introduction ...... 6 1.1 Warnings and Cautions ...... 6 1.2 Contacting MLT Drives ...... 7 1.2.1 Product Support ...... 7 1.2.2 Contact Details ...... 7 1.2.3 Telephone ...... 7 1.3 System Configuration ...... 8 1.4 Specifications ...... 9 1.4.1 AC Output specifications ...... 9 1.4.2 AC Input specifications ...... 9 1.4.3 DC specifications ...... 9 1.4.4 General technical specifications ...... 10 1.4.5 Climatic conditions ...... 11 1.5 System Description...... 12 2. Setup and Operation ...... 15 2.1 Installing the Oasis 4000 ...... 15 2.1.1 Selecting a suitable location ...... 15 2.1.2 Mounting...... 15 2.1.3 Making the electrical connections ...... 17 2.1.4 Setting up the Oasis 4000 ...... 19 2.1.5 Powering up the Oasis 4000 ...... 19 2.1.6 Powering down the Oasis 4000 ...... 19 2.2 Operation of the Oasis 4000 ...... 22 2.2.1 The user interface ...... 22 2.2.2 Operational Modes ...... 23
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2.2.3 Status indicators ...... 23 2.3 Connecting an external AC source ...... 25 2.3.1 Preparation ...... 25 2.3.2 Installing a Generator ...... 25 3. About Batteries ...... 26 3.1 General ...... 26 3.2 Battery Bank Location ...... 26 3.3 Maintenance ...... 27 3.4 Replacing a Battery ...... 27 3.5 Battery charger settings...... 27 3.5.1 Selecting the battery charging current ...... 28 3.5.2 Selecting the battery charging voltage ...... 28 4. About Solar Panels ...... 29 4.1 Introduction ...... 29 4.2 Using a Solar System with the Oasis 4000 ...... 29 5. Trouble Shooting ...... 30 5.1 Faults ...... 30 5.2 Typical Problems ...... 30 6. Glossary...... 32
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List of Illustrations Figure 1: De-rating the Oasis 4000 output power at high altitude ...... 11 Figure 2: Typical Oasis 4000 System ...... 12 Figure 3: Identifying parts of the Oasis 4000 ...... 14 Figure 4: Positioning the mounting holes ...... 16 Figure 5: M8 Rawl bolt ...... 16 Figure 6: Detail of mounting bolt ...... 16 Figure 7: Detail of hanging bar ...... 16 Figure 8: Removing the user interface connectors ...... 16 Figure 9: AC Input/output Connections on the Oasis 4000 ...... 19 Figure 10: DC cables ...... 20 Figure 11: Oasis 4000 DC connections ...... 21 Figure 12: Oasis 4000 Front panel ...... 22 Figure 13: Selecting the charging current and voltage...... 28
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1. Introduction
1.1 Warnings and Cautions
A safety instruction (message) includes a hazard alert symbol and a signal word, WARNING or CAUTION. Each signal word has the following meaning:
HIGH VOLTAGE: This symbol indicates the presence of a high voltage. It calls your attention to items or operations that could be dangerous to yourself or others operating this equipment. Read the message and follow the instructions carefully.
WARNING: Indicates a potentially hazardous situation which, if not avoided, can result in serious injury or death.
CAUTION: Indicates a potentially hazardous situation which, if not avoided, can result in minor to moderate injury, or serious damage to the product. The situation described in the CAUTION may, if not avoided, lead to serious results. WARNINGS
DANGER OF ELECTRIC SHOCK. There are no user serviceable parts inside the Oasis 4000. DO NOT attempt to make repairs or alterations to the unit. WARNING: This equipment should be installed, adjusted, and serviced by qualified electrical maintenance personnel familiar with the construction and operation of the equipment and the hazards involved. Failure to observe this precaution could result in personal injury.
CAUTIONS
CAUTION: Always wear personal protective equipment (protective clothing, gloves, and safety boots) while performing an installation or maintenance, to avoid the danger of injuries. CAUTION: Proper grounds, disconnecting devices, e.g. bypass boxes and other safety devices and their location are the responsibility of the user and are not provided by MLT Drives CAUTION: Do not cover the device or store it in a small space - always keep it well ventilated and well away from flammable gases or powders. Components in the device could potentially cause a small electric spark that could ignite flammable gas or powders. Flammable gases are created by batteries and can become a hazard in poorly ventilated spaces. CAUTION: For indoor use only and MUST be installed in a dry area free from conductive liquids or conductive debris. If part of the inverter becomes submerged in water look for a safe way to isolate it at the distribution board and if possible at the batteries.
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1.2 Contacting MLT Drives
1.2.1 Product Support
When contacting Product Support via telephone, email or fax please provide the following information for the fastest possible service:
Type of Inverter Serial number Battery type Battery bank capacity Battery bank voltage A description of the error The above details (apart from the “Description of the error” should be available from your System Configuration sheet (see page 8). Note that the serial number is available on the serial plate that is attached to the bottom of the machine.
1.2.2 Contact Details
Telephone: +27 87 943 2299 Email: [email protected] Address: 97 Garfield Road Kenilworth 7000 Cape Town South Africa
1.2.3 Telephone
You can reach technical support by telephone directly Monday to Friday between 08h00 and 16h30 (GMT +2 hours). Queries outside of these hours should be directed to [email protected] and will be answered at the earliest opportunity. When contacting technical support, please ensure that you have the information listed above available.
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1.3 System Configuration
The system configuration table below should be completed by the installer after installing your Oasis 4000 system. We recommend that you check that it is completed as it contains most of the information needed when contacting MLT Drives for assistance.
Item Parameter Description
1. System Type Oasis ______
2. Serial Number
3. Battery Type
4. Battery Bank Capacity Ah
5. Battery Bank Fuse Fitted Yes No Rating = A
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1.4 Specifications
1.4.1 AC Output specifications AC Output Unit Oasis 4036 / Oasis 4048 Voltage V 230 Volts ±2 %, Single Phase, 2 Wire Output. Frequency Hz 50 Continuous output power kVA 4 Rated output current A 17 Maximum output current A 26 (for 30s), 34 (for 2s) THD V (at rated power) % < 5 Surge protection Yes, Between Phases and to Ground Short circuit protection Yes Internal Protection System . Continuous Overload (using electronic detection) Protection . Short Circuit Protection . Heat-sink over temperature . Over/Under Battery Voltage . Reverse-power protection Control Type Voltage Source, Microprocessor Regulated Waveform Pure sine-wave, low THD
1.4.2 AC Input specifications AC Input Unit Oasis 4036 / Oasis 4048 Rated voltage V 150 – 280 , Single Phase, 2 Wire Input
Rated frequency Hz 45 - 65 Rated input current A 17
1.4.3 DC specifications Battery Input Unit Oasis 4036 Oasis 4048 Battery Voltage (Nominal) V 36 48 Short Circuit Protection Yes , Fused Yes , Fused Charging Voltage V 42.3 / 44.1 (User 56.4 / 58.8 (User selectable) selectable) Charging current A 25 / 50 (User 20 / 40 (User selectable) selectable)
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1.4.4 General technical specifications System Unit Oasis 4036 Oasis 4048 Efficiency % Up to 94 Up to 94 No load power W <30 (0.6 A <30 (0.5 A consumption (Manual Typical) Typical) mode) No load power W 5 5 consumption (Auto mode)
General technical Unit Oasis 4036 / Oasis 4048 specifications EMI Designed to minimise both conducted and radiated EMI emissions Installation Suitable for indoor installation only Mounting method Wall mounted Cooling method Convection Cooled (Heat-sink) Forced air ventilation(Internal components) Air intake at bottom Air discharge through the enclosure sides Enclosure IP30 – Not Weatherproof Colour Cadac Blue
Connectors Oasis 4036 / Oasis 4048 Load Output Terminal Blocks for 10 mm2 wire with bootlace ferrule Input DC (Battery) Cable terminal for 35mm2x10 lugs per pole (positive and negative)
Operator Panel Oasis 4036 / Oasis 4048 User Input 3 position rocker switch to select one of the following modes: . System Off . Manual mode . Auto mode Display Type 3 LED’s. See 2.2.3 Status indicators on page 23
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1.4.5 Climatic conditions Climatic conditions Unit Oasis 4036 / Oasis 4048 Ambient temperature °C -5 ... 45 (continuous operation) Ambient temperature for °C -25 ... 70 transport Maximum ambient for °C 45 continuous rated power Relative humidity % 0 ... 90 (Non-condensing) Maximum altitude above m 1000 (See power de-rating graph sea level for rated power at on page 11 for altitudes higher rated temperature than 1000m)
Figure 1: De-rating the Oasis 4000 output power at high altitude
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1.5 System Description
MLT Oasis 4000 series systems are mechanically and electrically robust and tough, with a wide operating temperature range suitable for operation in harsh environments. The Oasis 4000 has a 150% overload capacity and is the perfect fit for low maintenance, off grid, remote installations. A typical Oasis 4000 system application is shown below in Figure 2 involving the integration of generator backup power, solar energy and batteries
Fuse Solar Array Solar Regulator
Generator
Fuse
Fuse
Battery Bank Load
Figure 2: Typical Oasis 4000 System
The Oasis 4000 system integrates a battery charger with a standalone inverter, so that power is supplied to the local load from the batteries and renewable energy until a generator or utility become available, the load is then connected to the generator or utility and the Oasis 4000 switches to charging mode. In charging mode, the Oasis 4000 will attempt to charge the batteries with the maximum allowed current. If however the load on the Oasis 4000 is large, it will reduce the charging current to prevent the generator from being overloaded. If the generator is still too small to supply the charging current and/or the load, and drops out within the first 5 minutes of charging, the Oasis 4000 will reduce the maximum charging current and try to connect again. This will continue until the generator remains connected. If this has happened due to a large load and the charging current has been greatly reduced, pressing the ‘Reset’ button on the front panel will restore the charging current to its original value. See 3.5 Battery charger settings on page 27 for details on selecting the maximum charging current and voltage.
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If a short circuit or continuous overload condition is present on the output of the Oasis 4000 it will switch off to protect itself, and indicate the error using the buzzer and the front panel LEDs. Once the Oasis 4000 has turned off due to an overload or short circuit error, it will wait 10 seconds and then re-start. If the fault condition is still present after three attempts, it will remain off and the ‘Reset’ button will need to be pressed before it will restart. Make sure to remove the cause of the overload or short circuit before pressing the ‘Reset’ button. For a complete description of all the possible faults and operational modes that can be displayed on the LEDs, refer to 2.2.3 Status indicators on page 23.
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Figure 3: Identifying parts of the Oasis 4000
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2. Setup and Operation
2.1 Installing the Oasis 4000
For optimal performance, please refer to the following instructions regarding the installation and setup of your newly purchased Oasis 4000.
2.1.1 Selecting a suitable location
When selecting a location to mount your Oasis 4000, take note of the following: 1) The Oasis 4000 should be mounted in a well-ventilated area out of direct sunlight. 2) The Oasis 4000 is designed to be wall-mounted, and must therefore be installed upright to allow sufficient cooling. Operating the Oasis 4000 while it is lying flat will cause it to heat excessively. 3) The battery leads should be as short as possible, so the Oasis 4000 will need to be near to the batteries.
4) While charging the batteries, the Oasis 4000 will emit an audible hum. This should be taken into account when selecting a suitable location. Note: At high altitudes the cooling of electrical equipment is degraded by the reduced ability of the thinner air to remove heat from the heatsink. In accordance with the standards, the Oasis 4000 is rated for altitudes up to 1000m above sea level. If it is going to be installed in an area where the altitude is greater than 1000m above sea level, refer to the power de-rating graph (Figure 1) to establish the maximum continuous load.
2.1.2 Mounting
The Oasis 4000 is designed to be wall-mounted. Once a suitable location has been chosen, use the following information as a guide to make the mounting process easier: 1) Using a 14mm masonry drill bit, drill 4 holes 55mm deep using Figure 4 on page 16 as a guide. 2) Insert the M8 rawl bolts (Figure 5) into the holes, and tighten with a 13mm spanner. 3) The spacers supplied on the shaft of the bolt should ensure that there is a 2 – 4mm gap between the washer and the wall (Figure 6).
4) Holding the Oasis 4000 vertically, lift it onto the bolts, so that the hanging bars fit between the washers and the wall (Figure 7). Caution: The Oasis 4000 is quite heavy; dropping it could result in personal injury and damage to the machine. It is therefore recommended that this step be performed by 2 people.
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300mm
m m 0 4 3
Figure 5: M8 Rawl bolt Figure 4: Positioning the mounting holes
Figure 6: Detail of mounting bolt Figure 7: Detail of hanging bar
Figure 8: Removing the user interface connectors
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2.1.3 Making the electrical connections
Once your Oasis 4000 has been mounted on the wall, you can begin making the electrical connections. Follow these steps to make the task as simple as possible. Caution: Failure to follow these instructions carefully could increase the risk of personal injury, death or damage to property or equipment. If in doubt about anything, contact MLT Drives for assistance. 1) Remove the 14 screws that secure the front cover, taking care not to let the cover fall when removing the final screws.
2) Carefully pull the cover towards you until you have access to the user interface connectors (Figure 3). 3) Disconnect the cables from the user interface connectors by pushing the tab gently away from the connector and pulling the plug out. (See Figure 8) 4) Once both connectors have been removed, the front panel can be put aside. 5) The ‘Load’ connections inside the Oasis 4000 will need to be connected into your distribution board to provide power to your house. These connections should be made with 6mm² cables, which can be brought in from the bottom of the machine through the cable-gland provided. Take care to connect the Live wire to the ‘L’ terminal and the Neutral wire to the ‘N’ terminal. 6) If you are installing a generator, make sure it is switched off and any ‘Automatic starting’ circuitry is disabled before continuing. Referring to Figure 9, bring 6mm² cables through the cable gland provided into the ‘Generator’ terminals of the Oasis 4000, taking care to connect the Live wire to the ‘L’ terminal and the Neutral wire to the ‘N’ terminal. While every attempt has been made to insure the safety and reliability of the Oasis 4000, there is a chance that connecting the generator incorrectly could cause damage to the unit. 7) If the Oasis 4000 is being used without a generator, the ‘Generator Neutral’ terminal inside the unit must be connected to the Earth so that external earth-leakage protection devices can operate correctly. In installations with a generator, the generator chassis must be grounded to the same earth as the Oasis 4000. 8) The ‘Earth’ terminal inside the Oasis 4000 must be grounded to reduce the risk of electrical shock and to ensure that external earth-leakage protection device can operate correctly.
9) The Oasis 4000 comes from the factory with battery leads pre-installed. It is not recommended that these be removed or lengthened. If, however, replacing the DC cables is unavoidable, make sure to use cables of the same size and rating (35mm²) to avoid any problems.
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10) Caution: Once all the internal electrical connections have been made check that they are secure, as a loose connection could get hot enough to cause a fire. Note: External protection devices such as fuses, circuit breakers and earth-leakage protection are the responsibility of the owner, and not of MLT Drives. MLT Drives cannot be held responsible for personal injury, death or damage to property or equipment caused by the improper use or installation of this equipment. It is therefore recommended that all the electrical connections must be made by a qualified electrician or an MLT Drives approved installer.
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Figure 9: AC Input/output Connections on the Oasis 4000
2.1.4 Setting up the Oasis 4000
After making the electrical connections and before powering up your Oasis 4000 for the first time, it is recommended that you follow the instructions in ‘3.5 Battery charger settings’ on page 27. Once the settings are correct, the front panel must be replaced, taking care to reconnect the cables to the user interface connectors.
Secure the front panel by replacing the screws.
2.1.5 Powering up the Oasis 4000
1) Make sure all source (Generator or utility) and load AC wires and the DC cables are connected correctly and securely inside the Oasis 4000, and that the front cover is secured. 2) Make sure the rocker switch on the front panel of the Oasis 4000 is in the ‘Off’ position.
3) Connect the Negative battery cable to the Negative (-) terminal of the battery. 4) Put the pre-charge cable onto the Positive (+) terminal on the battery and hold it there for about ten seconds, this will pre-charge the DC capacitors inside the Oasis 4000 so that there is no spark when the Positive cable is connected. 5) Leaving the Pre-charge cable on the Positive (+) terminal of the battery, connect the Positive cable onto the Positive (+) terminal on the battery as well. See Figure 11. 6) Make sure the battery connections are secure.
7) Put the rocker switch into the desired position, i.e. Either ‘Auto’ or ‘Manual’ to start the Oasis 4000.
2.1.6 Powering down the Oasis 4000
If it is necessary to turn off or disconnect your Oasis 4000 for some reason, follow these simple steps: 1) Put the rocker switch into the ‘Off’ position.
2) If a source such as a generator or utility is connected, make sure it is turned off.
3) If required, the Oasis 4000 can now be disconnected from the batteries. 4) Once disconnected from the batteries, connect the Pre-charge cable to the Negative cable, this will discharge the DC capacitors inside the Oasis 4000. 5) If required, the front cover of the Oasis 4000 can now be removed.
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WARNING: There is the possibility of dangerously high voltages inside the Oasis 4000 if the connected Generator or Utility is not turned off.
Figure 10: DC cables
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Figure 11: Oasis 4000 DC connections
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2.2 Operation of the Oasis 4000
The Oasis 4000 has been designed to be very simple to operate. The entire user interface consists of only three LEDs, a rocker switch and a reset button. This section explains the function of each of these items.
2.2.1 The user interface
Figure 12: Oasis 4000 Front panel
LEDs The LEDs are used to indicate the status of the Oasis 4000, refer to ‘Status indicators’ on Page 23 for a complete description of the functions of the LEDs. Rocker switch Put this switch into the ‘Auto’ position to enable automatic load sensing, where the Oasis 4000 will go into a low power standby mode when there is no load connected.
Putting this switch into the ‘Off’ position will turn off the output of the Oasis 4000. Note: All power to the load will be lost. Put this switch into the ‘Manual’ position to force the Oasis 4000 to run regardless of the presence of a load.
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Reset button Press the reset button to re-start the Oasis 4000 if it has turned off due to a fault. Note: Make sure to remove the cause of the fault before resetting the Oasis 4000.
2.2.2 Operational Modes Off: In ‘Off’ mode, the Oasis 4000 will stop supplying power to the load and charging the battery. Auto: In ‘Auto’ mode the Oasis 4000 will run in a low power standby mode if no load is connected. This helps to reduce the current drawn from the batteries while the Oasis 4000 is not in use. If a load greater than 20W is switched on, the Oasis 4000 will detect it and start up automatically. If a source is connected, the Oasis 4000 will use the source to power the load and charge the batteries. Manual: In this mode the Oasis 4000 will run continuously, even if there is no load connected. If a source is connected, the Oasis 4000 will use the source to power the load and charge the batteries. Battery charging: If a source (Generator or Utility) is connected while the Oasis 4000 is in either ‘Auto’ or ‘Manual’ mode, the Oasis 4000 will connect the load directly to the source and begin charging the batteries. When the battery charging is complete, the Oasis 4000 will stop charging but leave the load powered by the source until the source is stopped, at which point the Oasis 4000 will resume supplying power to the load from the batteries.
2.2.3 Status indicators
The LED’s on the front panel along with the audible alarm indicate the status of the Oasis 4000. The following table describes all of the possible combinations.
Indicators Inverter status Required Action (If any)
All LEDs flashing in The Oasis 4000 is connected to Putting the Oasis 4000 into alternating Red, Yellow, the batteries and has power, but ‘Auto’ or ‘Manual’ mode will Green pattern is in the ‘Off’ mode. cause it to start.
Green LED lit The Oasis 4000 is operating normally, supplying power to the load.
Green LED flashing The Oasis 4000 is in a low power slowly. (On for about 1 standby mode. If a load is turned second every 3 seconds) on, the Oasis 4000 will start automatically.
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Green LED flashing The Oasis 4000 is busy charging quickly. the batteries. Once the charge cycle is complete, the Green LED will stop flashing.
Yellow LED flashing and The Oasis 4000 has overheated. Allow the Oasis 4000 to audible alarm beeping. cool down, and it will re- start automatically.
Yellow LED lit and The battery voltage is too low, Charge the battery. audible alarm beeping. and the Oasis 4000 has turned off to protect the battery.
Yellow LED pulsing The Oasis 4000 is currently briefly every 2 seconds. connected to an external AC source, which is being used to power the load.
Red LED flashing and The battery voltage is very high. Find and remove the cause audible alarm beeping. The Oasis 4000 has shut down to of the high battery voltage protect itself. (Usually an external wind or solar charger).
Red LED lit and audible There was a continuous overload Remove the excess load or alarm beeping. or short circuit condition on the the cause of the short and output of the Oasis 4000. press the ‘Reset’ button.
All LEDs flashing The generator voltage is out of Find the cause of the simultaneously. range. incorrect generator voltage, and correct it.
Red and Yellow LEDs The external AC source is Turn off the AC source flashing, and audible connected to the Load terminals (generator or grid) and the alarm beeping. of the Oasis 4000. Oasis 4000, and correct the wiring fault.
Three short beeps every The battery voltage is low and the To avoid a loss of power, 2 seconds. Oasis 4000 will turn off shortly. charge the batteries and/or remove excess loads.
Red and green LEDs lit The Oasis 4000 is overloaded, To avoid a loss of power, and audible alarm and will switch off shortly. turn off excess loads. sounding continuously.
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2.3 Connecting an external AC source
Follow these steps when connecting an external AC source such as a generator or utility to ensure your safety.
2.3.1 Preparation
Before starting the installation ensure that you read the owner’s handbook for the generator that you are installing and that you are fully aware of requirements such as minimum cable size and generator siting information. MLT Drives recommends using 6mm² wire to connect your generator to your Oasis 4000.
2.3.2 Installing a Generator
1) Power down the Oasis 4000 by completing the instructions in ‘Powering down the Oasis 4000’ on page 19, taking care to disconnect the user interface connectors when removing the front panel. 2) If a generator or utility is connected, double check that it is OFF and any ‘Automatic starting’ circuitry that could cause the generator to start is disabled.
3) Referring to Figure 9, bring 6mm² cables from the generator or utility through the cable gland provided into the ‘Generator’ terminals of the Oasis 4000, taking care to connect the Live wire to the ‘L’ terminal and the Neutral wire to the ‘N’ terminal. While every attempt has been made to insure the safety and reliability of the Oasis 4000, there is a chance that connecting the generator incorrectly could cause damage to the unit. 4) Make sure to ground the generators chassis to the same Earth connection as the Oasis 4000.
5) Once all the internal electrical connections have been made, check that they are secure as a loose connection could get hot enough to cause a fire. 6) The front cover must now be replaced taking care to re-connect the cables to the user interface connectors. 7) Replace the 14 screws that secure the front panel. 8) Follow the instructions in ‘Powering up the Oasis 4000’ on page 19 to re-start your machine.
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3. About Batteries
3.1 General
A number of lead acid batteries are used together to form the battery bank for the Oasis 4000. Basically there are two types of lead acid battery that can be used as follows:
“Standard, Gel, Sealed or Low Maintenance” battery which is another name for a normal car battery. This type of battery is designed to provide a large current for a very short period of time. They are not designed to be regularly discharged by more than 25% of their capacity. This battery is suitable for backup applications. “Deep cycle” lead acid batteries are designed to be repeatedly discharged to at least 50% of their capacity, which makes them suitable for homes using solar power or off-grid power use. Thus if in your application you are repeatedly charging and discharging your batteries you should be using deep cycle batteries. If, however, you are using your system as a UPS, low maintenance batteries may be sufficient. Standard batteries can be flooded batteries which require regular maintenance or sealed which are maintenance free. Deep cycle batteries are available only in the flooded variety. If standard batteries are suitable, maintenance free type should be selected as they do not require topping up of their electrolyte during their life. Your Oasis 4000 will have either a 36 or 48 volt battery bank while the number of batteries will depend on the capacity required. Batteries will be connected in series to give the required 36 or 48 volts. Further strings of batteries may be connected in parallel with the first group to increase the capacity of the battery bank.
3.2 Battery Bank Location
When selecting a suitable location for your battery bank, take the following into consideration:
Batteries MUST be installed in a well-ventilated environment away from direct sunlight Ensure that the battery leads are as short as possible for maximum efficiency and avoid extending the battery cables that ship with your Oasis 4000. A Battery Fuse MUST ALWAYS be installed and be as close as possible to the batteries! ALWAYS observe the electrical wire colour coding convention i.e. connect the red wire to POSITIVE, and the black wire to NEGATIVE
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3.3 Maintenance
Battery maintenance required will be detailed in the documentation supplied with the battery and for flooded batteries generally includes checking of the electrolyte levels on a regular basis and topping up with distilled water when necessary Providing it is maintained and sited correctly, a good quality battery should last at least 3 year’s continuous use before needing replacement.
3.4 Replacing a Battery
Always replace a battery with a battery of the same type and capacity. Never replace a flooded battery with a maintenance free battery or vice-versa. If you are not sure about the type and capacity of the batteries installed refer to the System Configuration guide on page 8. To replace a battery: 1) Follow the instructions for Powering down the Oasis 4000 on page 19 2) Taking care not to short circuit the battery terminals, disconnect and remove the faulty battery.
NOTE: To prevent short circuits it is recommended that you always use an insulated spanner when connecting or disconnecting individual batteries or battery banks.
3) Place the new battery in position and connect and tighten positive and negative connections (red positive, black negative). 4) Repeat steps 2 and 3 for any other batteries that need replacing.
5) Replace Battery Fuse and, if applicable, Solar Array Fuse. 6) Follow the instructions for Powering up the Oasis 4000 on page 19.
3.5 Battery charger settings
It is important to select the correct charging current and voltage for your batteries during the installation of your Oasis 4000, also if you increase or decrease your battery capacity or replace the battery bank with a different type of battery it may be necessary to change the battery charger settings. Before removing the front cover or making any adjustments, follow the instructions on page 19 for powering down and discharging your Oasis 4000.
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3.5.1 Selecting the battery charging current
The battery charging current can be set by the charging current select jumper (see Figure 5) on the control card inside the Oasis 4000. The jumper selects between 20A and 40A for the Oasis4048 or 25A and 50A for the Oasis 4036. Note that the actual charging current will depend on the battery voltage and the load. Figure 13 shows all the possible jumper configurations. The Oasis 4000 always ships with the jumpers removed as in Figure 13A. The battery charging current should not be set to more than 15% of the nominal Ah capacity of your batteries.
3.5.2 Selecting the battery charging voltage
The battery charging voltage can be set by the charging voltage select jumper (see Figure 13) on the control card inside the Oasis 4000. The jumper selects between 56.4 and 58.8V on an Oasis 4048 or 42.3 and 44.1V on an Oasis 4036. Figure 13 shows all the possible jumper configurations. The Oasis 4000 always ships with the jumpers removed as in Figure 13A. Generally “Standard, Gel, Sealed or Low Maintenance” batteries should be charged at the lower voltage setting, and flooded Deep cycle batteries should be charged at the higher voltage setting.
Figure 13: Selecting the charging current and voltage. PAGE 28 SEPTEMBER 2011 ISSUE 01 OASIS-UM-01
4. About Solar Panels
4.1 Introduction
The term solar panel refers to a panel comprising a number of Photovoltaic (PV) cells which convert sunlight into electricity.. Solar panels are a source of renewable energy which is becoming increasingly accessible.
As with most renewable systems solar panels are unable to provide energy at all times as there may be insufficient sunlight available. To fill the gaps, electricity can be supplied from storage batteries or generators in stand-alone systems or from the electricity grid in grid connected systems.
4.2 Using a Solar System with the Oasis 4000
If you are considering adding a solar system to your installation, contact MLT or the person who installed your system for advice on the type of solar regulator you should use and for details on its installation.
CAUTION: DO NOT connect solar panels directly to the batteries, a solar regulator must be used, otherwise damage to the batteries and or Oasis 4000 could result.
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5. Trouble Shooting
5.1 Faults
If there is a fault with the Oasis 4000, the LEDs and audible alarm will indicate what fault has occurred. Refer to ‘Status indicators’ on Page 23 for a complete list of faults and the action required to correct them. If you have a fault that is not addressed in this manual then you should contact the person who installed your Oasis 4000 or, alternatively, MLT Drives product support. See ‘Contacting MLT Drives’ on Page 7.
5.2 Typical Problems
Why does the Oasis 4000 not connect to a running generator?
Check that any circuit breaker on the generator is in the up position, and the Oasis 4000 is in either ‘Auto’ or ‘Manual’ mode. If the generator voltage is very low or high, all three LED’s on the front of the Oasis 4000 will begin flashing simultaneously. If this happens, check the generator output to ensure that it is operating correctly. If the generator is operating normally, check the wiring between the generator and the Oasis 4000 for a fault. The allowable input voltage range can be found in the specifications on page 9. Why does the generator connect and then immediately drop out?
This could be caused by overloading of the generator. Check that the generators rated capacity is large enough to supply the load that is connected to the Oasis 4000. Turn off some loads if necessary. If the generator is very small and drops out soon after the Oasis 4000 begins charging, the Oasis 4000 will reduce the charging current before re-starting the charging cycle. If this has happened due to a large load on the output of the Oasis 4000, the charging current may be very low; pressing the reset button on the front of the Oasis 4000 will restore the charging current to that set by the jumper. (Refer to 3.5.1 Selecting the battery charging current, on Page 28). Why didn’t I get the usual capacity from my storage batteries?
Were the batteries fully charged to start with? To ensure a consistent performance from the batteries it is important that they are charged correctly. Each battery type (flooded deep cycle, sealed, gel etc.) has different charging requirements. Incorrect adjustment of battery settings is the most common cause of reduced backup time from your batteries. For Flooded Lead Acid Batteries it is important to check the battery electrolyte level periodically. Never leave the battery cells with the electrolyte below the required level. One or more of the batteries in the battery bank could be faulty. Check the batteries in accordance with the manufacturer’s documentation and replace as necessary.
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Flooded lead-acid batteries can be checked with a hydrometer. All batteries should measure the same specific gravity ±10%. Sealed batteries can be tested with a multi-meter. All batteries should measure the same voltage. Why doesn’t my Oasis 4000 ‘wake up’ when I switch on a load?
Is the load large enough? The load sensing feature of the ‘Auto’ mode requires a minimum load of 20W to be connected before the Oasis 4000 will start. A single cell- phone charger, for example, is not large enough. Try switching on a light bulb or TV to increase the load, or putting the Oasis 4000 into ‘Manual’ mode. A typical compact fluorescent or ‘Energy saver’ light bulb uses about 11W.
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6. Glossary
AC Alternating current. The utility, generators, and inverters can supply AC. The AC voltage to homes in South Africa is described as 230V AC 50Hz meaning 230V RMS that is alternating between a positive voltage and a negative voltage 50 times a second. DC Direct current. Batteries, solar panels (PV) and some wind turbines provide DC. The Oasis 4000 can take DC from batteries and output 230V AC to supply homes and businesses. Generator This is a machine that usually runs off diesel or petrol to provide AC power. Generators are usually only run when needed. Generators need to be run periodically to keep their moving parts functional. Generators usually provide most power per litre when they are electrically loaded to 80% of their rating. Grid/Utility This is an AC power source that is usually will be present most of the time. The utility is often provided by some power producing company and is not always reliable due to lack of capacity. PV Photo voltaic cell. Also known as solar panels. PV cells generate DC electricity when sunlight strikes them. SRC or A source (abbreviated as SRC) is the general definition for an AC supply SOURCE such as the Grid or a Generator. Wind This is a modern form of wind mill. Wind turbines generate electricity when Turbine their blades are rotated by the wind. Wind turbines usually generate DC.
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