Inverter FAQ

Q. What is an inverter?
An inverter is a power device which takes DC power (battery or solar, for example) and converts it into AC power for running your home and office electronic equipment and appliances.
Q. How is an inverter different from a UPS?
UPS means Uninterruptible Power Supply. A typical UPS includes an inverter, static switch, rectifier (charger) and battery all working together to give you uninterrupted power supply. Usually lower capacity UPS systems come with all components (including batteries) in one box. UPS is usually designed for short Backup service, say 30mins because they come with low-rated rectifiers. An "INVERTER solution" comprises of an Inverter equipment, auto switching mechanism, charger and battery bank. This solution can rightly be referred to as a UPS. Inverters are usually designed with higher capacity chargers to be able to handle large battery banks which enable them to deliver longer power Backup to your equipment.
Q. How do I know if I need a sine wave, or if I can live with a modified sineWave?
The following gadgets work well with a modified sine wave: computers, motor-driven appliances, toasters, coffee makers, most stereos, ink jet printers, refrigerators, VCRs, many microwave ovens, etc. Appliances that are known to have problems with the modified sine wave are some digital clocks, some battery chargers, light dimmers, some chargers for hand tools. Pure Sine Wave is the best waveform because it works for all appliances.
Q.What constitutes an Inverter
An Inverter functions by converting the Alternating current (AC) input to Direct current (DC) in the converter charger circuit and reconverting to AC in the inverter circuit. Batteries are connected either in series or in parallel (depending on the DC voltage configuration of the Inverter) to the input of the Inverter and automatically come on when the AC supply fails. An inverter has the following key elements: Mains Power sensing circuit: When the AC Power comes below 110VAC or above 280VAC or if there is a total mains failure, the system automatically switches to the back-up source of power. Battery charger: A module that charges the battery when AC comes and prepares battery to give back energy in case of mains power failure. Inverter (DC-to AC converter): A system that would convert the energy stored in the battery/batteries to give back-up power to appliances i.e. 230VAC 50Hz.
Q.What constitutes a Good Inverter?
Fast Mains Power sensing circuits: In case of power failure, a good inverter would switch to battery for Backup so fast that the time of switching is not to be perceptible. As a result some appliances that required a higher start current, like the refrigerator can be driven using Inverter. Battery charger System: Battery is the life of the Inverter. An Inverter lives on battery so it is the responsibility of the Inverter to protect the battery and use it optimally and enhance its life. Inverter battery lifetime is maximized if the battery is always powered from a constant current charger. A good power Inverter gives constant charging current to batteries irrespective of the A. C Voltage i.e. whether the AC Voltage is 150 or 270V, the battery gets nearly the same charging current. This protects the battery plates from damage and power Inverter has an advanced trickle charging mechanism built in the system to prevent batteries from overcharging and to increase the battery life.
Q.What are the essential protections & features for a good Inverter?
Overload protection with Auto-resetting: As you apply load (freezer, bulb, fan, computers etc.) more than inverter capacity (during Inverter ON condition), it will warn you with Beep Sound & LED Indication, in this situation the system will shut down Output for a few seconds and then start to check the load on Inverter, and do this process again & again until you reduce the load & when the loads become within the capacity of the Inverter, the Inverter will stop beep sound and off the OVERLOAD indication and will supply the power to your appliances automatically. Low battery /deep discharge protection: The battery must be protected from discharging completely. Lead Acid batteries / SMF / Tubular batteries should not be discharged below a certain threshold level. The battery deep discharge protection is required because a deeply discharge battery is difficult to recharge.
Q.Battery over charge Protections?
Overcharging occurs when battery continues to get charged with high value of current after getting fully charged. Such charging corrodes the battery plates and reduce the battery life. Hence battery- overcharging protections is necessary because if battery is getting over charged frequently, then it will reduce the life of battery.
Q.Short circuit protection?
A good Inverter must also protect itself from damage. Since an Inverter is a consumer product and is connected on house wiring , chance of risk must be minimized. It must have a built-in short circuit protection, so that if any equipment connected across it were to be short circuited, the Inverter itself should not get damaged due to drawing high current.
Q.Reverse battery protection?
It means when the batteries to Inverter connected in reverse (i.e. +ve of battery to -ve of Inverter and -ve of batteries to +ve of Inverter),The system should not damage.
Q.Frequency stability?
Many appliances are by design dependent on the frequency of the Input power (normal Input Supply Frequency (50Hz +/- 5%). The output wave from the Inverter should be stable (50Hz) for proper functioning of these equipment's.
Q.CCCV Battery charger?
Inverter battery life time is maximized if the battery is always powered from a constant current constant voltage (CCCV) charger.
Q.What are 'Deep Cycle', 'Tubular', 'Gel' and 'AGM' batteries?
Deep cycle is the term used to refer to batteries designed with thicker positive plates, which are capable of retaining electricity for a longer period of time. Some deep cycle VRLA batteries are manufactured with 3.5mm plates or higher and the 12v200Ah weighs about 65kg. Wetcell Tubular batteries have up to 8mm plates and the 12v200Ah weighs about 75kg. Tubular batteries are designed with plates formed in tubular shape unlike others with flat plates. There are the two types of valve-regulated lead-acid (VRLA) battery. For efficient recombination of charge gas, VRLA technology requires that the acid electrolyte be immobilized. The electrolyte may be gelled, or it may be absorbed into a glass mat separator(Absorbed Glass Mat, or AGM).
Q. Will it power air conditioners?
A. Yes, inverters can power anything that regular electricity can power as long as the right inverter is selected and you have enough battery capacity to last you as long as you want your setup to last. However, it is not cheap to run air conditioners and other heavy appliances like microwave, heaters, boilers from battery power unless money is not an issue.
Q. How many days will my setup last?
A. How long your setup lasts depends on the battery capacity, the appliances you run either individually or concurrently. We try as much as possible to design systems for at least 24 hours when regular power supply fails. Your setup can last for even one week if you want to.
Q. Is the inverter maintenance free?
A. Yes, our inverters are durable and very reliable. They must be installed in environment where they are protected from water, dust and enclosures with adequate ventilation or cooling.
Q. What happens after the power in the battery is exhausted?
A. Your connected devices (the load) will lose electricity supply immediately. You'll need to recharge the batteries with either grid power (PHCN), generator or solar panel/wind turbine depending on your preferrred power source.
Q. Power supply is terrible in my area, how can I recharge the batteries?
A. Batteries are recharged using regular ac power supply, generators (as long as the generators have a higher rating than the inverter) so that enough current will be available to charge the batteries while powering regular appliances. These are your options unless you want to generate your own electricity using solar panels or wind turbines.
Q. How long does it take to charge my batteries?
A. It depends on the battery capacity and the source of charging. Our inbuilt battery chargers come with enough amps to limit recharge time to 6 - 10 hours. Again, it also depends on the state of discharge.
Q. Where do I buy reliable Inverters and get excellent service and support?
A. Please contact SystemTrust (ICT) Limited or any of our authorized resellers and service providers.