Frequently asked questions about our products

    In this page we have compiled some of the most frequently asked questions to our technical support department. They are classified in function of the product referred to.

 

Modified sinewave inverters
 
 

What is the maximum power that a  SM-700 can withstand?

     The 700 Watts inverter can supply more than 1500 Watts for a few seconds. The average power that the inverter can supply for half an hour is 1000W, after this time the inverter switches off automatically, and once cool it may be powered up again. In continuous operation this device can supply 700 W at an ambient temperature of 25ºC of ambient temperature, with forced ventilation this power can increase to 900 W.

I have measured the inverter output with my multimeter. I found only 180 Volts, sometimes I found 65 volts. Is it badly calibrated?

        The multimeters commonly used in electricity and many of those used in electronics are designed to measure the root mean square (RMS) value of the sinusoidal signals. They use the relationship between the RMS voltage and the mean (that is the value that they really measure) of the sinusoidal waves. The modified sinusoidal wave is not purely sinusoidal, for this reason this relationship is not valid and the indication of the measurement device is not correct (usually they show a lower value).

        To obtain the value of the RMS voltage we must use true RMS digital multimeters or analogic mobile iron multimeters.

        When the inverter has no load connected it switches to low energy consumption operational mode. During this operational mode the output voltage decreases to 90 Volts (RMS), for this reason if we use a normal multimeter to measure it will only read about 65 Volts.
 
  
       Mathematical note: 

    In a pure sinewave the mean voltage is: 

             Vm = Vp*(2/PI) = Vp*0.64 

         and the RMS voltage is: 

             Vef = Vp*(SQRT(2)/2) = Vp*0.707             (SQRT is the square root) 

         where Vp is the peak voltage. We can see that Vef = 1.11*Vm. 

    In a modified sinewave the mean voltage (with a duty cycle d) is: 

              Vm = Vp*d 

          and the RMS voltage is: 

               Vef = Vp*SQRT(d)                                     (SQRT is the square root) 

    If we calculate the duty cycle for Vef (modified sinewave) = Vef (pure sinewave) for the same Vp: 

               Vp*SQRT(d) = Vp*0.707       ---->       d = 0.707*0.707 = 0.5 

    We can see that Vm = Vp*0.5. So, if Vef = 230 then Vp = 325 and Vm = 162.5. As the multimeters are calibrated to show 1.11 times the measured value, the display will show 162.5*1.11 = 180.375 Volts. 
 

 
What kind of protection do these inverters have?

        These inverters are protected against short circuit, overheating, overvoltages and low voltages. They are not protected against polarity inversion nor against 230 Volts input at the output. The nominal powers are indicated for reactive loads with a power factor greater than 0.8, lower values with higher powers can destroy the equipment.

The inverter operates correctly except on very cold days.

        The first equipment manufactured was designed to operate at an ambient temperature between 0 and 50 degrees centigrade (indoor domestic use), this range has been increased to -15 to 50 degrees. All new equipment (and that which has been modified in factory, since 1992) can operate in the new temperature range.

 What happens if I connect an auxiliary generator to the inverter output?

        If the inverter is not operating, it is possible that nothing will happen, but the most probable situation is that the inverter could be damaged (and the warranty will be lost). The reversible inverters have a specific input for the generator and they have an internal protocol to make the necessary commutations. The non-reversible inverters should not operate with auxiliary generators, but a specific device can be installed to avoid the simultaneous connection of both devices to the load. It is frequent to find installations with two magnetothermic switches labeled "Never switch on both at the same time". Sometimes the inverter or the generator is connected to the home electrical installation using a male plug, this operation has caused damage to the equipment when the disconnection of one while the other is connected is forgotten

Sometimes I have no light. When I go to the inverter, the short circuit LED indicator is lit.

        Although it could be a short circuit or equipment which presents a high consumption at intervals (a water pump, for example) the most usual case is that the battery is discharged. The inverter lights the low charge indicator, after 10 seconds the short circuit LED lights and the inverter stops, at this moment the battery voltage increases (due to no load operation) and the low battery charge indicator switches off, thus the information about the original cause of the malfunction is lost. This problem may also arise if the original cables supplied with the inverter have been modified, increasing their length or decreasing their size.

The clock does not display the time correctly

       The harmonic content of the modified sinusoidal wave causes some clocks (that takes their reference from the grid) to be in advance or in delay. The output frequency of the inverter has a tolerance of 2%. The solution is to use clocks powered with batteries or with a quartz reference.

Some devices operate correctly with the inverter and others don't.

        The harmonic content of the modified sinusoidal wave causes some circuits (specially those that use Triac) to operate incorrectly. It can also happen with very low consumption devices such as electric shavers or videos if no more loads are connected. In this case the problem is caused by the threshold of the load detection circuit, and can be solved, for example,  by switching on a lamp.

Boiler motors do not operate

        Boiler motors do not operate with these inverters and they can be damaged. Sinusoidal inverters must be used with this devices.

The HI-FI produces some noise

        The filters for domestic devices are designed and calculated for sinusoidal waves. Modified sinusoidal waves produce harmonics that are not filtered and produce this noise in HI-FI amplifiers. Try introducing an external filter in the power supply or changing the inverter for a sinusoidal one.

The TV screen has a line that moves vertically

        See the previous question.

 

Sinewave inverters
 
 
 

What kind of protections do these inverters have?

        These inverters are protected against short circuit, overload, overtemperature, polarity inversion and abnormal voltage variations. They are not protected against the input of 230 Volts to the output.

What happens if I connect an auxiliary generator to the inverter output?

        If the inverter is not operating, it is posible that nothing will happen, but the most probable situation is that the inverter could be damaged ( and the warranty will be lost). The reversible inverters have a specific input for the generator and they have an internal protocol to make the necessary commutations. The non-reversible inverters should not operate with auxiliary generators, but a specific device can be installed to avoid the simultaneous connection of both devices to the load. It is frequent to find installations with two magnetothermic switches labeled "Never switch on both at the same time". Sometimes the inverter or the generator is connected to the home electrical installation using a male plug, this operation has caused damage to the equipment when the disconnection of one while the other is connected is forgotten.

Some devices operate correctly but others don't

        The inverter has an external threshold power adjuster in order to reduce the stand-by power consumption. Some devices such as electric shavers or videos will have a consumption lower that this threshold: in this case, the solution to the problem is to readjust the threshold power or switch on a lamp previously.

Should I care about power factor?

    The efficiency falls when the power factor decreases, so if you have limited energy (as in solar energy systems) it's highly recommended to have a power factor as near as possible to one.
 
The lights oscillate during battery charging

    A conventional charger generates a lot of voltage ripple. If you can't switch the load to the generator during charging, then we recommend using a high frequency charger or a Soléner charger (available soon).
 
 

Analogical charge controller AVA
 
 

What is the use of the "Direct charge/Regulated charge" switch?

        The charge controller should be used in the position "Regulated  charge" during normal operation. The other position allows the system to perform an equalising charge and also allows the charge controller to continue charging even in a fault situation.

The charge controller produces a rattling noise during the day time

        The most frequent cause is that the battery is damaged, discharged or disconnected. The switch "Direct charge" should be selected. If the voltmeter shows more than 16 Volts (for 12 Volts models) the battery is badly connected or broken. If this is not the case, an electric circuit fault may be the cause, this is usually produced by a short circuit in the installation.

 
 

Digital charge controller DSP
 
 

What is the cable that hangs from the charge controller?

        It is a temperature sensor that allows the charge controller to correct the battery voltage. It is located outside the charge controller so that the internal heat does not affect the sensor.

The batteries start boiling and lose water. Should this be avoided by the charge controller?

        When the charge controller is in a equalizing cycle the battery produces hydrogen and oxygen due to the hydrolysis of the electrolyte (boiling). This also happens during the normal charge procedure. However, if it happens continuously it is possible that the charge controller is not suitable for this type of battery; each battery manufacturer (and each battery model) require different charging procedures. Soluciones Energéticas manufactures charge controllers for the most commoly used batteries in the market, such as those manufactured by Hoppecke (Germany) or Tudor (Spain).

    The most advanced models allows the user to change all the charging set points on site using a menu. With the standard models this is not possible, and the right model, adapted to the individual characteristics of the battery being used, should be acquired.

What is the use of the internal adjuster?

        It is used to correct the display contrast when necessary (with extreme temperatures).

The display shows nothing

        Perform the following steps to solve the problem:

 - Push the reset button
 - Check the supply to the battery input
 - Readjust the display contrast using the internal potentiometer
 - If  nothing appears on the display or the display is very tenuous, the device needs a revision in factory

The display shows black rectangles

        If the rectangles are in both lines, readjust the contrast using the internal potentiometer. If they are in the upper line, press the reset button. If nothing happens, send it for repair.

The charge controller shows "Over current, push RESET". What is happening?

        The models manufactured before 1996 had a function for thermal limitation using software that operates when the operational current remains higher than the nominal current for more than ten seconds. On cold days, the PV modules produce more current than the nominal current, in these cases in installations designed to operate with peak current near to nominal current this protection will become operational. Since January 1996 none of the charge controllers manufactured have this protection.

The display shows "This charge controller is for 24 Volts"

        This happens when the voltage supplied to the charge controller is (or has been) lower than 16 Volts: check the voltage of the system, the state of charge of the batteries and the cable size. Note that these operations should be performed with load operation. Once checked, push the reset button.

The charge controller shows "Mode: fault Code C555". What is happening?

        The microprocessor has detected a fault in the analogical subsystem which does not allow correct operation. Send it for repair.

 The charge controller emits some noise at sunset

        The charge controller has an energy saving system that disconnects the charge relay when the charging current is lower than the self-consumption current. At sunrise or sunset the charge controller checks this current every few seconds, opening or closing the relay and producing this noise.
 

Digital charge controllers DSS and DSD
 
 

What is the cable that hangs from the charge controller?

        It is a temperature sensor that allows the charge controller to correct the battery voltage. It is located outside the charge controller so that the internal heat does not affect the sensor.

The batteries start boiling and lose water. Should this be avoided by the charge controller?

        When the charge controller is in a equalizing cycle the battery produces hydrogen and oxygen due to the hydrolysis of the electrolyte (boiling). This also happens during the normal charge procedure. However, if it happens continuously it is possible that the charge controller is not suitable for this type of battery; each battery manufacturer (and each battery model) require different charging procedures. Soluciones Energéticas manufactures charge controllers for the most commoly used batteries in the market, such as those manufactured by Hoppecke (Germany) or Tudor (Spain). These models allow the user to select one out of four batteries with internal jumpers.

The display shows nothing

        Perform the following steps to solve the problem:

 - Push the reset button
 - Check the supply to the battery input
 - If  nothing appears on the display or the display is very tenuous, the device needs a revision in factory

The display shows black rectangles

        If the rectangles are in both lines, readjust the contrast using the internal potentiometer. If they are only in the upper line, press the reset button. If nothing happens, send it for repair.
 

General
 
My inverter (or charge controller) doesn't ouput power. Is it damaged?

        It may be damaged, but it is probably protecting your accumulator from a deep discharge. About three out of four of the devices returned for servicing work correctly, and the problem is a discharged accumulator. These "faults" occur after a few cloudy days, or in new sites where the user wastes the (limited) energy until the system shuts down.

        All our devices have indicators (LED or display) that show the reason for disconnection. If the disconnection is due to an over-discharged accumulator, the only solution is to wait for it to recharge. Returning the device for "servicing" generates high transportation and test costs.

When does a PV module charge more?

        The PV modules use blue, violet and ultraviolet light to produce energy, they do not use infrared (heat). The voltage of each PV cell decreases about 2 mV per each degree of increase in temperature. In conclusion, the PV modules charge more on cold days than on hot days, they even continue charging on cloudy days due to the fact that ultraviolet radiation is not filtered by the clouds. Nevertheless, when the days are cold they are also short, so in winter the PV module charges more but for less time.

The battery is boiling. Is it dangerous?

        The boiling of a battery is due to the hydrolysis of the electrolyte which produces hydrogen and oxygen. It is not dangerous if the battery room is well ventilated, but in any case avoid the production of fire or sparks near the batteries. The boiling is normal during equalizing charges.

What is a DC/DC converter used for?

        Whenever power is transferred from a generator to a load the efficiency is maximum when the output impedance of the generator is equal to the input impedance of the load. In direct pumping systems (without batteries) the DC/DC converter allows the use of a DC motor-pump using a PV module of the same power to supply water from sunrise to sunset. In conventional systems, to obtain this it is necessary to use two PV modules or to supply water only at midday.

        Also the DC/DC converter incorporates well and water tank sensors in order to stop pumping when the well has no water or when the water tank is full.

Why are 12 Volts cables so thick?

        Cables are thick when the current is high. If we have a load of 1000 Watts operating at 12 Volts, we will need more than 83 Amps to make it operate, whereas if operating at 220 Volts, 4.5 Amps would be enough. This difference of 20 times the current is the reason that we will need 20 times more copper (for the same distance) if we do not want the cable to melt. If we also consider the maximum voltage drop allowed by the "National electrical code", the size of the cable must be even higher due to the low voltage.

        For this reason, if you increase the length of the input cables to the inverters, you should perform this using cables of the same size or larger than the original ones. We do not recommend this, as it will affect the efficiency of the device.

What is the relationship between Watts, Watt hours, Amps, Amps hour, Amps hours/day, peak Watts,...?

        First we need to distinguish clearly the difference between power and energy. As a clarification we can compare* with water: if a pipe transports a flow (power) of, for example, 3,000 litres/hour, after 10 hours we will have 30,000 litres (energy). If this system is used for 10 hours a day we will have 30,000 litres/day. Let's now make the comparison with electricity:

        We have a brazier of 300 Watts. If this brazier is connected for 2 hours the energy consumed will be 300 Watts * 2 hours = 600 Watt hours. If it is connected 4 hours a day: 300 Watts * 4 hours / 1 day = 1,200 Watt hours/day. The unit Watt hour (Wh) is equivalent to the litres of water in the previous example.

    Summary of brazier of 300 W operating 4 hours a day:

    -    Power : 300 Watts = 0.3 kW
    -    Energy consumed: 1,200 Watt hours = 1.2 kWh
    -    Energy consumed per day: 1,200 Watt hours/day = 1.2 kWh/day

        The power of a device can be compared with the flow of water, and the energy consumed by this device can be compared with the volume of water consumed. Alternatively, the power can be compared with the speed of a car and the energy with the distance covered.

        The Amp is the unit of electric current. With this unit we can perform the same calculation as before, using current in place of power and load in place of energy. The Amp is widely used in renewable energies due to the fact that the battery capacity is given in Amp hours, not in Watt hours. There is not a direct relationship between Amp hours and Watt hours as the voltage of the battery is not constant.

        The peak Watts (Wp) are the maximum power that a device can supply or consume. The technical specifications of a PV module show the power that will be supplied in the best conditions of tilt angle, temperature, atmospheric clearness, load impedance, etc...

* This comparison is simplified: the electrical equivalent of the flow will be the current, and the water volume will be equivalent to the electrical charge.

 

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