FAQs – Answers for Questions

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Inverter Questions

  1. What is an inverter?
  2. What forms of payment do you accept?
  3. What is the difference between grid–tie and off–grid inverters?
  4. What is the difference between true (pure) sine wave and modified sine wave inverters?
  5. What equipment generally runs well on a modified sine–wave inverter?
  6. My ICOM M–504 marine VHF transmitted crystal clear output, but now that I have installed a modified sine wave inverter on my boat, I am told there is background noise when I transmit with the inverter on. What can I do?
  7. What range of AC supply voltage does my inverter–charger require to charge my battery bank?
  8. What range of DC supply voltage does my inverter require to provide AC power at its rated voltage?
  9. How do inverters work?
  10. What is an AC transfer switch?
  11. Can I leave my inverter on all the time, unattended?
  12. Should I leave my inverter on when connected to shore power?
  13. Do you offer discounts from the MSRPs shown in your price list? (See prices)
  14. What are the product warranty details?
  15. Is technical support available?
  16. Can you explain Magnum Energy® inverter model numbers?
  17. Where can I find the owner's manual for my inverter?

Solar Panel Questions

  1. What is a solar panel?
  2. Do these solar panels have built–in inverters?

General Topics

  1. What are your payment terms?
What is an inverter?

Wikipedia notes that an inverter is an electrical device that converts electricity from DC to AC required by many types of electrical equipment. One possible inverter DC power source is batteries. Other possible DC power sources are solar panels or turbines driven by micro–hydro or wind energy. Environment particulars of an installation recommend the best DC power source(s). Once that local source of DC power is established, inverters can provide AC electricity in lieu of (or in addition to) a grid source or generator.

In the case of grid–tie inverters, power supplied locally can replace or defray demand from the grid. Dependent upon local power demand, local conditions, and the sizing of solar panels or wind generators in a particular installation, locally generated power may exceed local demand. At such times power can be sold back to the grid if the utility company offers net metering. When this occurs, a home's electric power meter will rotate opposite its normal direction. In the case of off–grid inverter applications, systems can be cost–effectively engineered to supply AC power to homes anywhere, in remote jungle or island villages, research stations, or to Bedouin nomads beyond the loom of city lights. Sail and power vessels comprise another key inverter market segment. back to top

What forms of payment do you accept?

We are wholesale distributors. We sell to established distributors, retail merchants, system integrators, and repair businesses across the Asia–Pacific region, the Greater Middle East and North Africa. We accept letter of credit. We also accept all major credit cards, wire transfer, and cash, of course. Renewable energy product end–users, please see our where to buy page. Prospective distributors, retailers, and service centers, please contact us. back to top

What is the difference between grid–tie and off–grid inverters?

Grid–tie inverters have additional internal components which enable them to match the phase of their sine wave electricity to that supplied by the grid. Off–grid inverters operate independently of any grid to supply local demand, thus do not require those same phase-matching components. These off–grid inverters generally transfer locally produced power in excess of local demand to a local storage battery bank since there is no grid connection.

In contrast, most grid–tie inverters are engineered to produce no power when the grid goes down. Thus, grid–tie inverters are not a source of backup power. When the grid comes back online, locally produced grid–tie electricity can augment power supplied from the grid, replace power from the grid, or transfer local generated power, in excess of demand, to the grid. back to top

What is the difference between true (pure) sine wave and modified sine wave inverters?

Magnum Energy's modified sine wave inverter output is stepped square wave. It is compatible with most AC electric motors although they may not run at peak efficiency as when powered by true sine wave power. Some electronic devices, for instance, some electronic battery chargers (e.g. Makita), laser printers, flourescent lighting, are incompatible with modified sine wave output. Modified sine wave inverters are less expensive to make and buy than sine wave inverters. Modified sine wave inverters may introduce electronic noise into other circuits, which can require an additional DC to DC converter to eliminate such harmonics, or AC ripple, from critical circuits which experience this noise.

True sine wave (also called pure sine wave) inverters produce nearly perfect sine wave output, with less than 3% harmonic distortion, which will power all AC electric motors and electronic devices. Output is utility grade and possibly even better. Producing sine wave output requires more components than producing modified sine wave output, therefore sine wave inverters are more costly to produce, more expenive to buy. Comparing a modified sine wave inverter to a sine wave inverter rated at equivalent continuous output, the modified sine wave inverter tends to have a higher surge rating. At startup, some electric motors can draw three to seven times their continuous running current. Make sure your inverter will accomodate this surge by checking its specifications against your device's startup requirements. back to top

What equipment generally runs well on a modified sine–wave inverter?

Devices that create a simple resistive load (turning electricity into heat), such as toasters, toaster–ovens, and coffee makers, generally work well on modified sine–wave inverters. Many devices that create inductive loads (driving motors), for instance, devices with electrically driven moving parts, such as blenders, coffee grinders, fans, food processors and refrigerators (compressor has moving parts), usually work well on modified sine–wave inverters. Some electronic devices, like handheld tool rechargers or flourescent lights, may require sine–wave poweer, but most personal computers work on modified sine–wave power. back to top

My ICOM M–504 marine VHF transmitted crystal clear output, but now that I have installed a modified sine wave inverter on my boat, I am told there is background noise when I transmit with the inverter on. What can I do?

This noise is due to transient harmonics created by the modified sine wave inverter. A true sine wave inverter should not create this background noise. You can turn off the inverter when using the VHF, you can install a true sine wave inverter, or you can install a DC to DC converter which will filter out this noise from energy supplied to critical systems such as your VHF. back to top

What range of AC supply voltage does my inverter–charger require to charge my battery bank?

A 230 Volt Magnum Energy® inverter–charger will charge batteries when supplied with a range of 50 Hz voltage from 160 VAC to 290 VAC. A 120 Volt Magnum Energy® inverter–charger will charge your batteries when supplied with a range of 60 Hz voltage from 80 VAC to 140 VAC. This wide variation in supply voltage values makes for a robust system. It permits operation with a wide variety (and quality) of generators. Minimum and maximum fault voltage values can be altered with the Magnum Energy ME–RC or the ME–ARC remote controls. To learn more about these and other inverter accessories, click to the inverter documents section. back to top

What range of DC supply voltage does my inverter require to provide AC power at its rated voltage?

For 12 Volt inverters, the acceptable range of input battery voltage is 9 to 17 VDC. For 24 Volt inverters, the acceptable range is 18 to 34 VDC. For 48 Volt inverters, the acceptable range is 36 to 67 VDC. These values are found in your product manual or product data sheet.

For example, consider the 4.1 kW (4.1 kVA), 230 VAC, 24 VDC inverter model MS4124E. Its data sheet, document number 64-0495 Rev C (see data sheet page 2, top, "Input Battery Voltage Range") shows that this inverter, rated for 24 VDC battery applications, will accept from 18 to 34 VDC. It will produce true sine wave output of 230 VAC (+/- 5%) at 50 Hz (+/- 0.4 Hz). To locate inverter data sheets, click to the inverter documents section. back to top

How do inverters work?

The only moving parts in modern inverters are cooling fans. In basic terms, inverters feed DC electricity into opposite sides of a transformer using pairs of switching transistors. These switching transistors create the alternating current. Switching the transistors fifty times per second produces 50 Hz alternating current output. The transformer changes the voltage of the supplied electricity to the inverter's rated output. Capacitors and inductors filter the output waveform to reduce the transmission of harmonic components.

If supplied with AC electricity, inverter–chargers can rectify and transform that current into DC electricity of appropriate voltage to charge storage batteries. A voltage regulator in the charging system allows four–stage charging with battery temperature feedback. The four charging phases are bulk, absorb, float, and full charge. The full charge mode is designed to prevent battery over charging. You can read more about charging and temperature sensing specifics in your inverter manual. back to top

What is an AC transfer switch?

The AC transfer switch built into Magnum Energy® inverter–chargers automatically passes externally generated electricity through to devices connected to your inverter, any time externally generated power is available. When externally generated power is not available, the inverter switches from pass–through mode to invert mode within (about 16) milliseconds. back to top

Can I leave my inverter on all the time, unattended?

A complete answer depends on many factors. One factor is the total continuous electric load of devices you will power by inverter. Another factor is the start–up (surge) power requirements of those devices, especially if several devices will be starting on inverter power at the same instant. Some motors can require 3 to 7 times their continuous power requirement to start. Well–designed holding plate refrigeration systems will engage a cooling pump several seconds before the compressor starts, in order to stagger these start–up loads.

A third factor is the (amp–hour) capacity of your battery (bank), at the estimated rate of current drain, compared to total electric demand until recharge is possible. Compare how many amps are required for how many hours by your devices to how many amp–hours of electric storage your battery bank provides. Note that wet–cell deep–cycle batteries will deliver longest service life when they are discharged not more than 50% of their rated capacity. An option which gives you more flexibility is addition of an automatic generator start module. If you are unable to return in time to start your generator, it will perform this task for you. back to top

Should I leave my inverter on when connected to shore power?

The automatic transfer switch in your inverter–charger is like having automatic overdraft protection on your checking account. It will keep your devices operating as long as sufficient battery energy is available. Be aware of your system's limits. Within milliseconds of shore power turning off, your inverter will quietly commence whatever work the shore power was performing.

If you have no other alternative charging source and no automatic generator start module, you might only discover shore power had not been working when one electric device or another fails to work or unexpectedly stops. Your refrigerator might still be cold, but you could find your batteries are deeply discharged. When you establish the specifications for your system, keep in mind whether you will manage your power requirements and actively monitor your system, or whether you require a system that works without intervention. back to top

Do you offer discounts from the MSRPs shown in your price list?

Yes. We offer volume discounts to preferred distributors. Contact us for detailed information. back to top

What are the product warranty details?

The standard Magnum Energy® factory warranty of two years on inverters and inverter–chargers is included with each unit. Accessory equipment comes with a one year warranty. Statement of warranty is included in the owner's manual for the device. Please see the inverter documents section for your product's manual. back to top

Is technical support available?

Magnum Energy® offers direct factory technical support by telephone as covered in each product manual. For preferred distributors, Magnum Energy® offers password protected web access support. back to top

Can you explain Magnum Energy® inverter model numbers?

Magnum Energy® inverter model numbers generally follow a format which incorporates the inverter's main features. Learn about Magnum Energy's model numbers. back to top

Where may I find the owner's manual for my inverter?

Click to owner's manuals for all Magnum Energy® products. You will need JavaScript enabled on your computer. back to top

What is a solar panel?

Solar panels are comprised of numerous solar cells, also called photoelectric cells or photovoltaic cells. These cells are photodiodes, a type of photodetector which converts light energy into electric energy by means of the photovoltaic effect discovered in 1839. For his 1905 description of the photovoltaic effect, Albert Einstein won the 1921 Nobel Prize in Physics. The photovoltaic effect is exhibited by some materials when exposed to light. In general terms, light creates voltage between two electrodes connected to such semiconductors.

Solar cells are grouped into modules, called solar panels, which can generate significant voltage. A number of semiconductor materials actually exhibit some photovoltaic property. This property may be counter–productive in some electronic devices, which is one reason many devices are housed in opaque containers. Solar panels generate DC electric energy which inverters can then convert into AC electricity to power devices. back to top

Do these solar panels have built–in inverters?

Mage® Solar PV modules do not have built–in inverters. They are designed to be connected to a free–standing inverter such as those produced by Magnum Energy, Inc. back to top

What are your payment terms?

We accept ACH, Wire Transfer, or Letter of Credit. No credit cards or checks are accepted. back to top

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