Tony and Kim in front of their new 2,280 watt
off-grid solar home.
Installed by Lean Clean Energy, Marquette, MI.
Congratulations! You are now part of a growing community of people living in an alternative energy home, saving money and protecting our environment. We know it was a big step to take but we are sure you will be happy you took it.
Your energy system comes with a number of manuals that describe the operation of components in detail, but the manuals also include all the available options, even ones you don’t use, so there is lots of reading to get through to figure out exactly how your system works.
This document will summarize your exact system operation and provide a solid basis for understanding the details in your owner’s manuals. It will use common language and will include useful statements that can be used to describe your system operation to novices who will be curious about your alternative energy.
We suggest reading this manual first, then going through the product manuals for more details, particularly for using various menus.
If you have any questions, call Lean Clean Energy. We are happy to help.
How much power can you use at one time?
What if you use more than 40 amps?
The generator is running but the sun is shining!
You now live in a battery powered home. You are “off-grid” meaning that there are no electrical utility “grid” wires coming to your home. Your home is powered by approximately 3,500 pounds of lead-acid deep-discharge batteries designed specifically for solar applications. When fully charged, they store enough energy to power your home for several days, depending on usage.
The 48 volt DC power from the batteries (voltage can vary from 46-63 volts depending on charge level) is “inverted” to 120VAC, 60 Hz, pure sine wave (normal household) power by a device called an inverter (VFX, see components for a detailed description), located above the batteries. This inverter power is comparable but superior to utility power in several ways:
- Inverter power is VERY consistent. The inverter regulates your voltage and frequency very precisely so power from the inverter should never surge to high values or glitch to low values. You no longer need to be concerned about “brown outs” (periods of low voltage on the utility’s grid) because the inverter typically does an excellent job of regulating your power.
- Lightning is also less of a concern for you since your home is not connected to miles and miles of exposed utility wires that could be struck by lightening. To be affected by lighting, a strike would have to occur on or very near your property. Your energy hardware is properly grounded and lightning protected to minimize the chances and impact of lightning effects.
- Power outages are essentially a thing of the past. After a storm, when homes on the grid are without power, you still have electricity because you are not dependent on utility wires.
- Your consistent, high quality, stable power allows devices and appliances to last longer. Your system provides the security and convenience of clean, reliable, high quality energy.
- You will never experience a price increase for your solar energy. Never.
- Your solar energy does not cause the environmental problems associated with conventional power production. It does not require coal mining and transport, foreign oil, or nuclear operations. It does not contribute to mercury contamination of the air or Lake Superior, does not contribute to acid rain and does not produce greenhouse gasses. Your batteries, after many years of service, are recyclable. The rest of your system should last a lifetime. You are now treading lightly on earth without sacrificing the advantages of electricity. Be proud of this, more people should do it.
Your batteries are charged by two independent sources, a fixed array of 2,280 watts of solar panels and a 10KW propane generator. The goal is to charge the batteries as much as possible from the solar panels and charge from the generator only as a last resort.
Battery charging is all done automatically. The generator is managed (started, stopped and regulated) by the inverter. Solar charging is managed by a separate device called a charge controller. Your energy system should be essentially hands-off, except for occasional minor maintenance.
The inverter (VFX) powers your house using energy stored in your batteries.
Morning sun hits the solar panels. They start producing power. The solar charge controller (MX60) “wakes up” to send the solar energy directly to your batteries. Power for your house is still provided by the inverter from the batteries.
Solar battery charging will continue throughout the day as long as the sun shines, more hours per day in summer, fewer in winter. You will charge your batteries with full power on sunny days. Cloudy days generate less power.
The energy produced by the solar panels is directly related to the intensity of sunlight, and to a small degree, air temperature. Solar panels output slightly more energy in cooler temperatures.
All solar energy is used to charge the batteries. The solar charge controller regulates the solar energy charging your batteries according to the battery manufacturer’s specifications and will not let the solar panels overcharge the batteries. Power for your house is still coming from the batteries.
As the sun sets, solar energy fades. The charge controller monitors solar performance. When the sun sets, solar energy ends. The charge controller goes back to sleep (minimum power consumption) so that it is not a burden on the batteries.
Usually (if there were not abnormal heavy loads on the energy system) this solar cycle will provide slightly more than enough energy to recharge the batteries to make up for the energy that was used that day. There should, once again, be enough stored battery energy to power your home for the next few days.
You may have solar surpluses in summer and will probably need occasional recharging from the propane generator in winter.
This is your schematic:
This is basically how your hardware is wired. Exceptions are that you have 16 batteries in a 48 volt battery bank and 12 solar panels in a 54 volt solar array.
The inverter has additional wires: two 120VAC wires coming from the propane generator (not shown), two wires feeding 120VAC to the house (not shown) and two 12 VDC wires going to the generator start relay (not shown).
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Four solar panel breakers are outside, mounted to the solar panel rack. (left) The breakers are special DC solar energy breakers, numbered 1-4 corresponding with the strings of solar panels. The silver can shape device below the solar breaker box is a lightning arrestor which helps protect your solar array from lightning damage. The bare copper wires are connected to a ground rod buried nearby. |
The charged battery bank has enough capacity to power the house normally for a number of cloudy days with no recharge. A few cloudy days should be no problem. Your solar panels will still produce some power through clouds, but considerably less than on a sunny day. Cloudy days will partially recharge the batteries. A couple subsequent sunny days should allow the batteries to fully recharge.
The system will automatically start the propane generator only if the batteries have discharged to the point where immediate recharging is necessary or, when there is an unusually heavy power demand for an extended period of time.
The inverter can continuously output 3,600 watts of power (almost 5 horsepower, enough to power 4 typical microwave ovens at one time). It is the equivalent of having conventional 30 amp service feeding your house from the utility. That is normally more than enough power to supply most if not all your household needs. You will learn quickly that 100 amp service or even 200 amp service provided for new on-grid house construction is almost NEVER actually needed unless it is an all electric home where electricity is used for heating, cooking, and hot water heating. If a house does actually use that much power at one time (200 amps is over 32 horsepower!) you can be almost certain that most of it is being wasted and that alternatives should be considered.
If for some reason you need more than 30 amps from the inverter (let’s say you are operating your 5HP air compressor, pumping water, operating the microwave and the vacuum cleaner all while the refrigerator is running) the inverter can temporarily provide some additional power (33 amps for up to 30 minutes, 41 amps for up to 5 seconds and 50 amps on a surge) from the batteries but will start the generator if the extraordinary load (>25 amps) persists more than 10 minutes. Your propane generator can provide up to a maximum of 40 amps (4,800 watts or 6.5 HP).
In other words, the inverter will automatically start the generator and switch the load to the generator if the load exceeds a specified maximum power value for a specified time. This prevents the high load from quickly discharging the batteries. The inverter will automatically shut the generator off when the load returns to more normal levels. That means that you do not have to be concerned about how much power you use at one time except that extraordinary loads will cost you the price of propane and wear and tear on the propane generator. Your absolute maximum power capacity from the generator is 40 amps.
Normally, the generator will not be necessary to power your house. The inverter will produce adequate power from your batteries but will start, use and stop the generator if necessary during exceptional circumstances. This will all happen automatically.
Yes. The inverter automatically reduces the battery charging circuits when the load on the generator is high. That means that you CAN use the full 40 amps without overloading the generator. Battery charging will automatically wait until the generator load decreases.
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The power from the inverter (and generator) goes through a 50 amp MAIN circuit breaker located in the shed. 3,600 inverter watts equal 30 amps of current. If you exceed 50 amps out of the inverter, even briefly, this circuit breaker will trip and all power to the house will be shut off. This protects the inverter from overload damage. This breaker will trip BEFORE the “main” breaker inside the house trips. Note: The 12 VDC generator start relay is located in this panel box. |
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There is another breaker panel in the shed. This breaker feeds all the 120 VAC circuits in the shed. It comes after the main breaker so if the main breaker in the shed trips, this breaker will lose power. It is wired directly to the ground fault outlet in the shed. The ground fault protected circuit feeds the lights and outlets in the shed, lights and outlets in the tool shed, the yard light and water pump. All these circuits are ground fault protected and all are fed through this breaker. This breaker is NOT affected by any circuit breakers in the house. You could pull the in-house “main” and this panel would still be active. Tripping the shed “main” (above) disconnects ALL 120 VAC circuits from both the house and the shed from either the inverter or the generator. |
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The propane generator has its own 40 amp circuit breaker located on the generator itself. When you are on generator power, you are limited to 40 amps out of the generator. If you exceed 40 generator amps, even briefly, the breaker will trip and power from the generator will be shut off (but the generator will keep running until the inverter senses a fault). If this trips, the inverter will instantly switch back to battery power and register a “Loss of AC” fault. |
Although there are three breakers ganged together on the generator, only two of them are useful. The center breaker is not functional. This breaker disconnects the generator power from the generator output. Tripping this breaker will stop generator power from going to the VFX inverter and to the house.
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You have a Kohler model 10RY generator, manufactured in 1997. It is rated for 10KW of power @ 240VAC (5KW from each of two 120 VAC feeds). The original 1997 hour meter was broken so actual generator hours is unknown. A new hour meter was installed on Sept. 1st, 2007. Run hours are only visible when the generator is running. The new meter read zero hours. Since the VFX inverter only uses 120VAC from the generator, only half of the generator output is used. The other half is idle. The 240 volt output option is not being used. |
Of the 5KW available to the VFX just over 2KW can be used to charge batteries (this is the VFX inverter’s limit for battery charging). The remaining 3KW is available to power the house while the batteries are charging.
Most of the time, the generator is only moderately loaded, even when charging batteries. This makes life somewhat easy for the generator. The quantity of propane consumed is almost proportional to the load. The generator usually has at least a 2Kw load (battery charging plus house) so it is using propane efficiently and is never running at idle and wasting gas.
Solar is your primary battery charger, year round. During sunny times, the generator may not run for weeks or months. Solar will keep the batteries well charged. The propane generator is used to charge batteries only as a last resort but, as a last resort, it will ensure that you always have adequate power. The generator is started and stopped automatically by the VFX inverter, based on battery voltage set points. The generator may also be used manually every few months to “equalize” the batteries to keep them in optimum condition.
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You can start the generator manually, using buttons on the “Mate” (the display unit in your house), or by the run switch located on the generator, but this is normally unnecessary. Generator operation is normally automatic, controlled by the inverter software. Keep the run switch on auto. The Common Fault Lamp will light to warn of high engine temperature, low coolant level, low oil pressure, overcrank or overspeed. |
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If you do start the generator manually, the VFX inverter will automatically transfer the generator power to the house and start charging the batteries. If you started the generator manually it will continue to run until you shut it off manually.
Whenever the generator is running, it always charges batteries and powers the house at the same time. This is important to remember. When the generator is running, the house is not powered by the batteries. The batteries are busy charging as fast as possible to minimize generator run time. Your generator has more than enough capacity to do both things at the same time.
There is no need to change your electrical use when the generator is running. The only difference you might notice is that plug-in electric clocks might run slightly slower (lose 1 minute for each hour the generator runs) because generator power is not as precisely regulated as inverter power. When the generator is loaded (as it is when batteries are charging) its voltage and frequency will decrease slightly. This is normal and acceptable and is mostly noticeable in electric plug-in clocks that use the electrical frequency to measure time. The clocks slow down a little.
Starting the generator, switching from battery power to generator power, back to battery power, and shutting the generator down is normally all done automatically by the VFX inverter. The transfer is essentially transparent.
After several days of minimal sunshine or heavy electrical loads, the inverter may start a generator charge cycle before sunrise. Charging batteries to full with the generator alone takes up to 17 hours. However, during the day, the solar panels will assist in charging the batteries with whatever solar energy is available, even while the generator is running. Together, they will considerably reduce the time needed to fully charge the batteries. When the sun is shining, the generator should run for considerably less than 17 hours to fully charge batteries.
If the generator fails (does not start or does not output power) there will be an error indication on the “Mate” (the display unit in your house). Generator failures require your immediate attention because the generator was your last resort for battery charging, remember?
But, even if the generator fails, there is still some power reserve in the batteries, providing a day or more to correct any generator issues. In other words, the generator is programmed to recharge the batteries, not because the batteries are completely discharged, but because the batteries are at the recommended minimum (50%) discharge value. When generator charging is initiated, there is still a significant amount of battery power available, but the batteries need to be charged as soon as possible.
Waiting to charge past the charge set point discharges the batteries more deeply than recommended. This doesn’t immediately destroy the batteries, but it does them no good, it reduces their overall life slightly, and should be avoided.
Batteries should be recharged as specified. A failed generator should be repaired or another charging source should be brought in ASAP. Minimize household electrical loads until the batteries can be recharged.
If the sun shines after the generator fails, the batteries will recharge with solar energy and you will have more time to repair the generator.
If you wait to repair the generator too long, the batteries reach an absolute minimum voltage set point (lower than the recharge set point). The inverter will automatically shut off, disconnecting your household AC to protect the batteries from over discharge damage. You will need to recharge the batteries to get household power back again. Power will return automatically when adequate power (generator or battery) is available.
You have enough battery capacity to use electricity in your home as you need it, year round, 24 hours per day. Solar panels will normally keep the batteries adequately charged and the propane generator will supplement solar charging only when necessary. The energy system will automatically regulate itself.
When properly tilted for the seasons, your solar array is optimized to produce plentiful power in summer, needing only occasional help from the propane generator. In winter, the propane generator will be needed more frequently to make up for the winter reduction in solar energy. But even in winter, you will need the generator much less than if you had no solar panels, and far less than if you had no batteries.
Your alternative energy system provides reliable, environmentally clean, high quality power, saves you money on propane, minimizes generator run hours, and minimizes generator maintenance and repairs.
Because of the earth’s tilt, relative to the sun, the length of day (and amount of available solar energy) varies with the season of the year. Various weather monitoring organizations calculate solar “peak hours” (average number of hours per day that solar panels will produce the equivalent of peak power) for specific geographic locations. “Peak hours” considers the length of day, dawn and dusk hours (reduced energy), angle of the sun to the collector surface, and the number of cloudy days per season in its calculations (based on 30 years of data) to derive average daily peak solar hours.
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Actual performance of tilted (+/-
15 degrees from latitude) flat plate |
In Marquette, MI, at 46.5 degrees latitude, flat plate collectors optimally tilted to 20 degrees from horizontal for summer typically get 6 peak hours of solar energy on Summer Solstice (June 21). On Winter Solstice (December 21), panels tilted to the optimal 65 degrees from horizontal typically get only 2 peak hours of solar energy. Winter brings an unavoidable 66% reduction in available solar energy. Summer offers three times more energy than winter! Tilting the solar panels seasonally ensures that they can collect the maximum amount of solar energy for their surface area. Changing tilt is typically done only twice a year, a week before the solar equinoxes (March 21 and Sept. 21) or as soon thereafter as weather permits. Notice the worst month is December but February is 75% better. |
Note that the graph above is for +15/-15 degrees tilt from latitude. The optimum tilt for Marquette is now considered to be 20 degrees from horizontal in summer and 65 degrees in winter. This will improve the solar panel output slightly.
Solar panels operate on light energy, not temperature, but they are affected by temperature. In winter, cold air contains less solar energy-absorbing moisture so there is a slight increase in solar panel output. Sunlight can reflect off snow on the ground in front of the panels and add a little to the direct solar energy. Solar panels also output more power when they are cooler. A clear cold winter day with snow on the ground maximizes solar panel output, but short winter days still ultimately limit total winter power.
Since photovoltaic solar panels are designed to produce electricity, not heat, and since panels are more efficient when cool, they are designed to avoid heat buildup. The panels will not melt more than 1-2 inches of snow cover on a sunny day. Snow blocks sunlight from reaching the energy converting material of the panels. The array cannot make electricity when covered by snow because most of the light is reflected by the snow, not absorbed by the panels.
Small amounts of ice or snow will melt when the sun shines, even in very cold weather, but large amounts of snow on the panels will not melt and must be removed manually with a plastic roof rake or push broom. This is very easy to do since the surface of the panels are glass and the panels are tilted almost vertical in winter. It usually takes only a minute or two and does not have to be done very often, even in Marquette winters. Small amounts of snow will melt off when the sun shines. Ice will melt when the sun shines. Almost always, panels will be snow free and operate normally.
This battery description is by far the longest but, in the end, very little has to be done to the batteries. The description is long because batteries are the most critical but least understood of all the components. This section should be read thoroughly at least once. It gives a thorough working knowledge of battery operation.
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Description: You own 16 Surrette 6-CS-17PS deep-discharge solar storage batteries rated at 6 volts and 546 amp hours each. A “battery” is any collection of individual “cells”. Each of your “batteries” is actually three independent 2 volt cells (one red cap per cell) internally wired in series in a single package, called “a battery”. Each battery weighs 221 lbs. 16 x 221 = 3,536 lbs of batteries! |
Warranty: Failure within 36 months from the date placed in service yields FREE REPLACEMENT, not including freight charges from the factory to the applicable destination. After the first 36 months of service, defective batteries will be adjusted for a period of up to 120 months prorated from the date first in service at prices in effect at time of adjustment. The average life expectancy is 15 years.
Deep discharge solar storage batteries are designed to be more deeply discharged than regular automobile batteries. They provide lower surge currents but higher continuous current. They also are rated for many more charge cycles than car batteries, extending their life far beyond car battery life.
“Amp hour” (Ah) ratings indicates how many amps you can get from a battery at a specified rate. Low amp hour batteries store less energy, high stores more energy. 546 Ahs is considered high.
Your 6 volt 546 Ah batteries are arranged in two strings of eight. There are eight batteries connected in series on the top shelf, eight more in series on the bottom shelf. Eight 6 volt batteries connected in series makes 48 volts @ 546 amp hours (in series, voltage adds, Ah stays the same). Paralleling the top shelf with the bottom shelf keeps the voltage the same but adds the amp hours. Your final configuration is 1,092 Ah of batteries @ 48 volts.
48 volts is called the “nominal” or “working” voltage. The actual voltage will vary anywhere from 47– 64 volts depending on level of charge and amps going in or out. This is normal. Voltage is only a rough estimate of charge. See “maintenance” below for more details.
Useful capacity: So, 1,092 Ah @ 48 volts should provide about 50,000 watts (A x Volts = Watts) of power for an hour? Well, yes and no. First, you can’t output that much through the inverter, a breaker will trip, and second, 50,000 watts (50Kw) for an hour would completely discharge a fully charged battery. Complete discharge shortens the battery life considerably. We don’t do that.
The manufacturer requires a full recharge when the batteries are 50% discharged. So in reality, no more than 50% of your battery capacity is useful, but this value allows the batteries to last a very long time. Discharging more deeply shortens the battery life. Charging more frequently extends the battery life. Fortunately, solar tends to charge at least a little almost every day, keeping the batteries well into the top half of charge, extending their life and ensuring that you always have plenty of reserve power.
Charging: To remain at maximum power and long life, the batteries should be recharged according to the manufacturer’s specifications. Overcharging or undercharging damages the batteries and shortens their useful life. The manufacturer’s charge values have been set in the VFX and Mate (for generator charging) and in the MX60 (for solar charging). All devices are configured to automatically charge the batteries properly. See the VFX, Mate and MX60 specification tables below for actual values.
Maintenance: Batteries are pretty simple to maintain. Keep them charged, warm (not hot) and watered. They will perform. Battery voltage is a rough indication of the battery charge but, voltage varies widely (+/- a few volts) depending on whether the batteries are charging, discharging, or idle. The chargers compensate for this variation by reacting to averaged values over time instead of instantaneous values.
Water levels should be kept just below the sight tubes so gasses can escape freely. Specific gravity values should be checked periodically (see next paragraph) and equalization charges should be performed as needed (see “Equalization” below)
The most precise indication of charge is the specific gravity of the acid in the battery. This is simply measured manually with a low cost battery hydrometer. The batteries are fully charged when the acid in each cell (each battery cap, three per battery) has a specific gravity of 1.255 – 1.275. A reading of only 1.180 – 1.200 is a 50% discharged cell. All cells should be nearly equal, whatever value you measure. An anomaly could mean the cell is damaged or needs equalization.
If batteries don’t seem to be holding their charge as normal, a cell might be damaged, but this is not common. It is more likely that they are either cold (see “Temperature” below) or need equalizing (a controlled battery overcharge that forces it to become more accepting of a charge). Equalization is performed according to manufacturer’s specifications. See “Equalization” below.
If these solutions don’t help, the batteries might need de-sulfating (a more intense form of equalization). De-sulfating usually rejuvenates batteries. The bottom line is to maintain batteries properly so that they are always in optimum condition and don’t need corrective treatment. Occasional equalization is expected, but damage is not expected. When maintained properly, batteries should give many years of trouble free service.
Temperature - Summer Vs Winter: Anyone who drives a car in winter knows that batteries are affected by temperature. As temperature drops, so does the capacity of the battery. Your solar batteries are no different. Their output will vary with battery (not air) temperature.
Batteries are specified (Ah @ volts) at room temperature (77 degrees Fahrenheit). Their actual value varies with temperature - fewer Ah when cold, more when warm - but there is a trade off. As they get warmer, their short term Ah output increases but their long term life decreases. As they get colder, their short term Ah output decreases but their long term life increases. Room temperature (77 degrees Fahrenheit) is optimal for a battery.
Your batteries are enclosed in an insulated box. When ever the batteries charge or discharge, they generate heat. In winter, the insulated box will help keep the batteries warmer. In summer, the insulated box will help keep the batteries cool when daytime temperatures are high or when the shed is heated by the propane generator. The objective is to minimize extreme temperature swings, optimize battery output and extend battery life as much as possible.
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The shed temperatures should be kept reasonable so that the VFX and MX60 do not overheat in high ambient temperatures or when the propane generator is running. There is a thermostatically controlled fan (right) installed in the shed that will blow cool air into the shed if the inside air temperature exceeds 90 degrees. There is a temperature sensor (white) on the front of the fourth battery on the top shelf. This sensor is the “out” sensor that feeds the white Min/Max thermometer located on top of the battery box. This white thermometer will indicate at a glance what the minimum and maximum temperatures have been. The “in” value is the temperature inside the shed. The “out” value is the temperature of the batteries inside the battery box. The minimum and maximum values can be viewed by the touch of a button and can be reset when desired. |
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The batteries have a recommended upper temperature limit of 115 degrees Fahrenheit. Hotter batteries will shorten their life. There is no lower limit for the batteries (charged batteries won’t freeze until they reach -40 degrees Fahrenheit) but their output drops steadily as they get colder. Discharged batteries (more water, less acid) freeze sooner. Warm, but not hot, is best.
Battery temperature also affects the recharging set points. Colder temperatures require slightly higher voltage while warmer temperatures require slightly lower voltage. There is a green temperature sensor on your batteries (on the same battery as the white sensor). It is used by both the VFX and the MX60 to automatically adjust the charge set points to compensate for actual battery temperature. This ensures that the batteries are charged properly, regardless of battery temperature.
Equalization: Batteries need to be periodically “equalized” to keep them in top condition. Equalization is a normal maintenance routine specified by the battery manufacturer and needs to be done only occasionally, every few months. It uses power, produces hydrogen gas and uses up some battery water. Equalization consists of deliberately overcharging the batteries to 64 volts for 3 hours (manufacturer’s specifications) to force stubborn sulfides crystallized on the battery’s lead plates back into liquid sulfuric acid. This keeps the battery lead plates uncluttered for making electricity.
In order to make sure the batteries stay healthy, they should not be discharged over 50% and should be regularly charged back to near full capacity (“Absorption” charge). For flooded lead-acid batteries, full capacity is really only achieved by equalizing the batteries. An ‘Equalize’ charge should be performed every one to six months depending on how deep and how often your batteries get discharged. Deep discharges and infrequent recharges require monthly equalization.
Solar recharges almost daily in summer and less in winter. Equalize in March for summer and in September and December in winter.
The VFX will not automatically perform an ‘Equalize’ charge. The user must use the MATE to manually start an Equalization charge. The MX60 solar charge controller can automatically initiate an equalization charge if programmed to do so but may require generator power to complete the equalization cycle. We suggest equalizing manually.
WARNING: Keep battery box covers on at all times while charging! During equalization (and absorption charging), the batteries electrolyze a little battery water into explosive hydrogen and oxygen gasses. These gasses beneficially stir up the electrolyte in the batteries (it looks like the acid is boiling) and need to be vented out of the battery box and out of the shed. If not properly vented, the gas could accumulate near the ceiling of the shed. Simply turning on a light could cause an explosion. Fortunately, there are several ways that the gasses are vented.
Venting is automatically accomplished by the MX60 which energizes a small brushless fan (no sparks) on the bottom of the right battery box cover. This fan automatically turns on as the battery nears the gassy higher voltages and pressurizes the battery box. It safely forces the hydrogen gas (lighter than air) out of the battery box vent pipe on the shed’s back wall. The fan will continue to vent until battery voltage drops. The batteries do not produce gas until they are nearing full charge.
The large shed exhaust fan also allows air to exchange freely between the shed and the outside.
The batteries also get warm as they are overcharged during equalization. 115 degrees is the maximum acceptable battery temperature. Higher temperatures damage the batteries. The brushless fan, on when batteries are nearing full charge, adds cooler air to the battery box.
Water may need to be added to the batteries to make up for that lost during the equalization cycle. Water levels should always be checked after the batteries have been equalized. Refill batteries with distilled water, not mineralized tap water.
Your inverter is made by OutBack Power Systems. It is a model VFX 3648 (vented FX, 3,600 watts @ 48 volts) and has a 2 year warranty. The VFX typically requires no maintenance.
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The VFX (located in the shed above the batteries) is the brain and work horse of your energy system. It monitors battery voltages, controls the propane generator, charges the batteries as necessary and converts battery power to 120 VAC pure sine wave power at 60 Hz at up to 3,600 watts continuously. When it starts the generator, the VFX synchronizes the household power to the generator, switches the house power to the generator and switches it back again to battery power when it wants to shut the generator off. |
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The VFX ground is in this box. |
On the bottom of the gray end of the inverter, there are two circuit breakers. The large breaker (left) is the 175 amp battery power breaker. This breaker disconnects the batteries from the inverter. Since the VFX is powered by the batteries, tripping this breaker will shut the inverter off by cutting off its power supply. This breaker does not disconnect the solar charge controller from the batteries. The smaller breaker (right) opens the circuit from the MX60 solar charge controller. Opening this breaker disconnects the solar charger from the batteries but does not affect the VFX. This breaker shuts the MX60 off. |
The VFX has two heavy sets of wires on the right side.
- The heavy red and black wires are the battery feeds to the inverter. Red is positive and goes to the big breaker, then to the inverter. Black is negative to the inverter. These wires power the inverter and provide battery energy that is converted to AC power for the house.
- The flat black cable in the back is the power from the MX60 solar charger. The positive lead connects to the small breaker and then to the battery cables inside the inverter box. The solar charge controller power does not go into the inverter itself, it goes into the batteries. It merely connects to the battery cables inside the gray VFX box.
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The metallic cable has two 120VAC “in” wires from the generator and two “out” wires to the house from the VFX. The VFX has three smaller wires plugged into it on the left side.
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The VFX has indicator lamps that give a quick status report of VFX conditions.
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There is another LED located just below the Aux terminals. It will be lit green when the Aux output is active. When Aux is active it runs the propane generator. |
“Battery” - Nominal Battery Voltage LEDs
“Status” LEDs
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VFX Battery Charging Sequence
The following diagram shows the algorithm that the VFX uses to charge the batteries. When generator voltage is connected to the VFX’s AC input terminals, the VFX will connect in about 30 seconds (default setting to let the generator warm up a little) and pass the AC voltage from the generator through the VFX’s AC transfer switch to the house or shed loads connected to the VFX’s AC output terminals. When an AC voltage source connects to the VFX, a battery charging sequence begins.
The VFX does not start the generator if there are heavy amp loads. The VFX only starts the generator when the battery voltage drops to the specified value. In the Mate, the AGS system does start the generator when there are heavy amp loads. See “AGS” in the Mate manual for load start details.
The following bullets describe the steps in the VFX battery charging sequence.
- The first stage of the charging sequence is the “Bulk” stage. The VFX uses as much AC current as possible (up to 20 amps) from the generator to raise the battery voltage to the “Absorb” voltage setting. The time period of the “Bulk” stage will vary with the battery bank’s age, capacity and voltage. It typically takes 10+ hours.
- Once the “Absorb” voltage has been reached, the VFX will use the necessary AC current to sustain this voltage for the “Absorb Time” (for your batteries, 3 hours). The AC current will decrease as the “Absorb” charge continues.
- After the “Absorb Time Period”, the VFX goes into “Silent”
mode. The generator is automatically turned off and the VFX
continues to monitor the battery voltage.
If the generator has been automatically started on a low voltage condition using AGS (see MATE manual), the VFX will automatically turn off the generator after the “Absorb Time Period”. This is the end of the automatic charge cycle. - If a generator has been manually started, the VFX will charge as above then will let the battery voltage drop to the “Refloat” voltage. Then it will start a ‘Float’ charge.
- The ‘Float’ stage will raise the battery voltage to the “Float Setpoint” for the “Float Time Limit”.
- After the “Float Time Limit” (default of 1 hour), the VFX goes back into ‘Silent’ mode and waits until the battery voltage drops to the ‘Refloat’ voltage again. It then repeats the ‘Float’ charge for the “Float Time Period”. The VFX will continue this cycle of ‘Silent’, ‘Refloat’ and ‘Float’ until the manually started generator is manually shut off.
VFX Battery Charging Values
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Absorption / Bulk voltage -58.8 Absorb time – 3 hrs |
Float voltage -53.2 Float time – 2 hrs |
Equalize voltage – 63.2 Equalize time -2 hrs |
For the solar charge cycle, see the MX60 description.
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You own twelve Evergreen solar panels, each rated for190 watts @ 18 volts. They have a 5 year workmanship and 25 year power warranty (meaning after 25 years you will still get at least 80% of rated power). Added together they are designed to generate 2,280 watts of power when perpendicular to full sun. They are arranged in 4 series strings of three panels so that the nominal (working) voltages add to 54 volts (18 volts X 3 panels per string= 54 volts per string). The power adds to 570 watts per string (190 watts per panel X 3 panels = 570 watts per string). |
Wiring all 4 strings in parallel adds the power of all four strings but keeps the string voltage the same, so the result (4 strings X 570 watts per string) is 2,280 watts of power at 54 volts.
54 Volts? But the batteries are only 48 volts! Yes, we know. Here is where two secrets come into play. The key is to realize the relationship between volts and amps. Power = Volts x Amps. If you operate a device at higher voltage, it requires fewer amps for the same power. Lower voltage requires more amps for the same power. Simple math.
All wires waste a little bit of energy as heat. As more amps run through a wire, more energy is wasted as heat. Fewer amps lose less energy so, operating the panels at a higher voltage reduces the amps (but not the power), reduces the energy loss (because of fewer amps), and allows us to use smaller wires (saves you money) more efficiently (less wasted energy). In other words, 54 volts can transmit the same power more cheaply and efficiently than 48 volts.
But the batteries are still only 48 volts?
Yes, but the solar panels are not connected directly to the batteries. There is an intermediary, the MX60 MPPT charge controller, which performs an adjustment to the solar panel operating voltage that maximizes the solar energy. The second secret is that solar panels are constant current devices, not constant voltage devices. That means that their operating voltage and resultant power is dependent on the battery voltage.
Consider this, if a solar panels outputs 10 amps in full sun and the batteries are at 50 volts, power = 50 volts X 10 amps = 500 watts of power from the solar panel. If battery voltage drops to 25 volts and the solar panel still outputs 10 amps in full sun (because it is a constant current device) 25 volts X 10 amps = 250 watts. You only get ½ the power from the same solar panel!
Also, solar panels generate more power when cold than when hot.
In other words, the power from the solar panel is dependent on its operating voltage and temperature. If the solar panels were connected directly to the batteries, low battery voltage would reduce the solar panel power when the batteries need recharging most. Solar panel output would be highest when the batteries were fully charged! That is inefficient. See the MX60 “MPPT” description to learn how this is corrected.
The MX60 (Maximum Power Point Tracking MPPT, 60 amp capacity) is capable of handling up to 3,200 watts of solar panels and is 98% efficient. It performs several important functions:
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It controls how much solar energy goes to the batteries. Batteries can be destroyed by overcharging. It routinely manages solar output to recharge batteries to specific set points and can initiate a battery equalization cycle. It boosts the solar energy by operating the solar panels at their maximum power point (MPPT) instead of the battery voltage. You typically get a 20 to 45% power gain in winter and 10-15% in summer. Actual gain varies widely depending on weather, temperature, battery state of charge, and other factors. It controls the battery box pressurization fan, based on battery voltage. It logs 64 days of performance data for the solar panels It communicates data to the hub |
The MX60 is the gatekeeper between the solar panels and the batteries. It regulates solar charging cycles, charging batteries according to the manufacturer’s specifications. It requires no maintenance and once configured, it operates daily, whenever the sun shines. At night (no solar energy), it sleeps.
Maximum Power Point Tracking (MPPT)
The MX60 charge controller is also capable of electronically operating the solar panels at whatever voltage produces the maximum power, independent of battery voltage. Every seven minutes the MX60 “sweeps” the solar panels electronically to find the solar panel maximum power point (MPP). It operates the solar panels at whatever voltage generates the maximum solar energy then transforms all power to the battery, regardless of the battery voltage. Don’t be surprised to see your 54 volt solar panels operating at 90 – 100 volts! That is just the MX60 doing its MPPT thing.
The MX60 MPPT feature typically boosts panel output by an annual average of +30%. That is significant since a modest 30% boost of 2,280 watts is the equivalent of 684 additional watts of solar panels. At $4.75 per watt, the MX60 produces as much additional power as buying more solar panels worth $3,249! (plus mounting hardware and wiring). The MPPT is a VERY valuable feature.
These are the conditions when MPPT is most useful:
- Cold weather - solar panels work better at cold temperatures, but without an MPPT you are losing most of that. Cold weather is most likely in winter - the time when sun hours are low and you need the power to recharge batteries the most.
- Low battery charge - the lower the state of charge in your battery, the more current a MPPT puts into them - another time when the extra power is needed the most.
- You can have both cold weather and low battery charge at the same time. MPPT is most helpful under these conditions.
The MX60 Solar Battery Charge Cycle
The MX60 charge controller is a sophisticated multi-stage battery charger that uses several regulation stages to allow fast recharging of the battery system while ensuring a long battery life.
The MX60 charge cycle is similar to the manual generator charge cycle except that the generator is not involved. The MX60 starts with a bulk charge then - depending on the amount of solar energy available, absorption, then float. This cycle continues until the solar day ends.
When it wakes, it starts a bulk battery charge cycle using as much solar energy as is available. If there is enough power in a day to reach the absorption set point, it initiates an absorption cycle then, if the absorption time specification is reached, it floats the batteries for the rest of the day, keeping the batteries topped off. Set points are adjusted properly according to battery temperature which the MX60 reads from the VFX through the Hub. This is all done automatically.
MX60 Battery Charging Values
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Absorption / Bulk voltage -58.8 Absorb time – 3 hrs |
Float voltage -53.2 Float time – 2 hrs |
Equalize voltage – 63.2 Equalize time -2 hrs |
The MX60 cannot start the generator. Only the VFX can start the generator.
BULK This stage provides the maximum power to the battery -- voltage increases while charging. A Bulk charge is automatically initiated when the battery voltage is below the Absorb and Float voltage set points. The Bulk charge will continue until the Absorb voltage set point is achieved.
ABSORBING This stage limits the amount of power going to the battery -- the voltage is held constant. The Absorb charge will continue for the duration of the Bulk cycle or until the 2 hour (default) Absorb time limit is reached. Example, if a Bulk charge takes 1 hour to reach the Absorb voltage set point then the Absorb charge will continue for 1 hour as well. However, if a Bulk charge takes 3 hours to reach the Absorb voltage set point then the Absorb charge will continue for 2 hours only. A Bulk charge will be re-initiated if the battery voltage is not sustained at the Absorb voltage.
FLOAT This stage reduces the charging voltage to prevent overcharging of the batteries. A Float charge follows after the Absorb charge is completed. The MX60 will not re-initiate another Bulk charge if the Float voltage set point is not sustained, however, it will continue to charge the battery until the Float voltage set point is achieved. Note: A Bulk charge can be initiated if the battery voltage falls below the Float voltage set point if the re-Bulk (ReBV) voltage option is set.
MX60 Display and Menus
The display window and touch buttons allow you to view a number of summary screens and to set up charging parameters. The display normally offers a summary screen showing real-time performance of the solar system, including: battery voltage, solar panel voltages, amps from the solar panels, amps to the batteries (after MPPT boost), watts of power being produced, and the mode of operation (bulk, absorption, float, equalize), KWh produced that day and total KWh produced. See page 14 of the MX60 manual. The menus allow you to set up how the MX60 charges batteries. These values are listed above. Details are in the MX60 manual.
MX60 Logs
The MX60 is the only device in your energy system that logs performance data. Up to 64 days of performance data is stored in memory and can be accessed from the display window on the MX60. The logs are not accessible through the Mate. The logs record 64 days of: amp hours, watt hours, time in “float” and also logs total lifetime power production. See the logging section of the MX60 manual for details.
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Flashing green LEDs
show that |
The Hub is merely a networking device. It allows the VFX, MX60 and the Mate to connect to each other. It is powered by the VFX and requires no maintenance. The Hub has no adjustments or display. It is merely a junction for communication. Devices are connected to the Hub through their Mate ports. Its only specification is that the Mate must be plugged into the Mate 1 port (the Mate 2 port is not functional) and the VFX must be plugged into Port 1. Any future Outback devices can be plugged into any remaining port. All devices plugged into the hub can be accessed through the Mate. |
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Read your Mate manual for descriptions of the summary screens (read “Summary Screens”) |
The Mate is how you, the user, typically communicate with your Outback devices. Each device has its own Mate port for direct access but, the Mate can access any device connected to the Hub through its extensive menu system. Programming of the VFX and MX60 can be done through the Mate. Normally, the Mate will toggle (every 20 seconds) between the VFX and the MX60, showing summary screens for each so that you can always be aware of what is going on in your system. |
You can turn the propane generator on or off manually by using the Mate (Try it! – read “The ‘AC IN’ Hot Key” in your Mate manual)
There are three significant buttons that you should become familiar with:
- AC IN takes you directly to generator control menus
- INV takes you directly to the VFX inverter control menus
- Pressing the left two keys on the Mate at the same time from anywhere in the menu system takes you to the MAIN menu
The remaining unmarked buttons are used to navigate menus and to select or change settings. Their purpose varies depending on which menu is displayed at the time. See the Mate manual for details.
The only programming necessary for the Mate itself is to choose how summary screens are displayed and for the AGS (Automatic Generator Start) system that will start and stop your propane generator automatically.
There is already a basic generator start/stop system in the VFX, but the AGS system in the Mate is much more sophisticated. The AGS setting in the Mate does not directly turn the propane generator on and off. Instead, the Mate AGS settings override the basic generator start settings in the VFX and force the VFX to start/stop the generator according to the Mate’s settings. Since AGS settings are stored in the Mate, the Mate must be connected to the hub for the AGS settings to work.
Settings within the Mate are stored in non-volatile memory, meaning that the Mate can be disconnected and reconnected without needing to be reprogrammed. Your Mate has been programmed with the appropriate generator start/stop settings for your system.
Mate AGS Battery Charging Values
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24 hour start voltage – 48.3 |
2 hour start voltage -47.2 |
2 minute start voltage - 44 |
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Absorption / Bulk voltage -58.8 Absorb time – 3 hrs |
Float voltage -53.2 |
Equalize voltage – 63.2 Equalize time -2 hrs |
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Load start – 3KW Load start delay 5 min. |
Load stop – 2KW Load stop delay 10 min |
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With AGS settings, the generator will automatically start of the battery voltage falls below 48.3 volts for more than 24 hours (normal discharge over time), or 47.2 volts for 2 hours (low batteries experiencing a moderate load for an extended time), or 44 volts for 2 minutes (low batteries heavily loaded). Once started automatically, it will charge until the batteries reach 58.8 volts (Absorption voltage) and will be held at that voltage for 3 hours (Absorption time), then the generator will automatically shut off.
The generator will automatically start if the load exceeds 3KW for 5 minutes and will automatically shut off if the load falls below 2 KW for 10 minutes.
Read “AGS Setup” in your Mate manual for more details.
Read the “Menu Map” section of the Mate manual. Many of these setting do not apply to you because you are not grid tied and do not have wind or hydro power, but it is useful to be able to read the menu map to get to where you want to go when you want to go there.
We hope this manual has given you a solid, basic knowledge of your system. With this knowledge, the owner’s manuals for your hardware should not seem so confusing. We are confident that you will enjoy many years of trouble free solar energy and will be available to answer any questions you might have about your system.
Let the sun shine!