FAQs
About Xantrex / TBS / Studer / Cristec - What is Independent Power - Maximising Charge Sources - What's Real & What's Dreaming
The Economical approach to system sizing - What is an inverter? - Output Waveforms - Battery Systems
Inverter Q & A - Appliance and Load Questions - Common Installation Problems - Voltage Problems - Inverter Summary
About Xantrex
Xantrex is the world leader in advanced power electronics, building products since 1983. With the acquisition of leading brands Statpower, Heart Interface and TRACE, Xantrex can offer a wide range of AC and DC systems and solutions that provide AC power anywhere. With models ranging from 150 watts up to 4500 watts, Xantrex also provides battery chargers, charge controllers and battery monitors. Xantrex products are smaller, smarter and more efficient than traditional power conversion equipment and are widely used in applications such as renewable and distributed power, mobile power and commercial applications.
About TBS Electronics
TBS was founded in 1984 and developed a range of toroidal transformers as used in high end power inverters. Seeing the opportunity that presented with power inverters, they developed their own line of products in 1996. Released under the brand names of either Alessi or Powersine, their sophisticated product offerings are all low end power (under 1000watts), and today are branded simply as the TBS Pure Sine range. TBS pride themselves on bullet-proof design principles, and our history with the product range has proven this design brief to be TRUE.
About Studer
Based in Switzerland, Studer Innotec manufacture a range of high end power inverter / charger combination units. Truly capable for uses across a range of applications such as solar off-grid, mobile, industrial and marine just to name a few markets. Their sturdy and reliable designs ensure that Studer products keep going and going for many years.
About Cristec
Cristec design, develop and market electrical equipment for mobile energy requirements. Their innovative approach and experience in switch mode technology ensure a wide range of available products, both standard and special order requirements. With their production facility located in France, Cristec have been building and supplying products for over 14 years, in conjunction with their parent company Enag. Cristec not only supplies battery chargers, they can offer power converters, redundant power systems and Bureau Veritas approved charging products as well.
What is Independent Power?
Independent power is the ability to go anywhere you want without being tied to mains AC power. It is the ability to generate, store and use your own power, be it low voltage DC, or mains quality AC power. The basic component of an independent power system is the storage battery designed to hold low voltage power for use from various appliances. Advance Power Electronics then convert this energy by applying modern solid-state electronic technology to create compact, efficient, cost-effective and reliable power converters to supply the required type of power used by most electronic and electrical equipment. This is achieved through the use of power semiconductor chip technologies, compact and highly efficient high frequency power switching circuits and software-based control technology.
In an independent power system, many different components work in a hybrid type set up with the common goal of Giving you the power to be Free.
Maximising Charge Sources.
In an independent power system, revitalising the storage power in the battery is one of the most important requirements for sustained power. The need to maximise as many recharge sources is the key to having the maximum available power to use. One of the most common comments we receive from users across the market is the statement "we run from a solar system", but do not elaborate any further on what makes up their total "System". Using the term "Solar System" is really a generic term for describing a self sustainable application, but it is amazing how many people do not truly understand onboard independent power. When looking for independent power, users must realise that they rely on power more than they can imagine, from fridges and lighting direct from the onboard battery, to running microwaves and televisions from the AC power inverter just as a basic example.
The independent power system relies on maximising as many battery recharging sources as possible. In brief these charging sources can be from:
Solar panels
Feeding via a regulator into your batteries. This system is generally sized to power your main DC load (refrigeration), as well as provide some charge over and above this demand. It is important to remember that solar panels are ONLY a charging source for your batteries.
Smart Battery charger
The real heart of the independent power system is a smart battery charger, and is often overlooked by most people with the least amount of investment made in this area. Very rarely will a solar system fully charge your batteries, while a smart charge will do so nearly every time (if 240vac mains power is provided for sufficient periods and the battery charger is sized to your system properly).
Alternator Charge
Often overlooked, but is another major charge source while travelling. For advanced use of this charge, a smart regulator can be applied which turns your alternator into a three stage smart battery charger.
Wind Turbines
Often only used in Marine or Land based applications, but with power generated from the Wind.
Portable AC Generator
Often the most efficient means of recharging batteries. Running an AC generator provides the fastest, most accurate charging rate if used through a smart battery charger as previously described.
The main point we want to push to everyone is this, if you rely on your batteries to power your independent power system, be sure to look beyond just "putting on a few solar panels", and look at other methods of charging. It is a good thing to remember the following:
You can never have too many charging sources!
What's Real & What's Dreaming.
When using inverters many people have different conceptions on what can be run realistically. Here is a general overview of What's Real & What's Dreaming.
Basic household AC appliances such as Televisions, Microwaves, computers etc. are all suitable to run from the correctly sized and the correct type of inverter.
Here are a few ideas that are not workable, or highly uneconomical:
Air conditioners are highly uneconomical to work off an inverter. Most large inverters these days can power AC's with no problem, but the battery bank will nearly always let the system down. If you must run an air conditioner, look for an inverter that load shares with a generator, as the generator will be the primary power source, with the Inverter assisting in start up loads. Battery chargers will be more important here, so ensure the right sized charger is used.
YOU CANNOT run a battery charger off a Power Inverter connected to the same battery bank. This generates a loop sequence that only discharges your batteries quicker that the charger can recover them. This is due to the losses and inefficiencies within the inverter and battery charger.
Large heating elements such as frypans, toasters and fast boil kettles are very uneconomical to run from a power inverter. They require a large inverter system, quick battery charging capabilities and sufficient storage within the battery system. Generally to do this you would require around 400amps storage @ 12 volts, along with an inverter over 2000watts. The charging would have to come from a large battery charger running from an AC generator (forget solar in this case). The easiest solution is to just run your generator to begin with.
The Economical approach to system sizing.
Our recommendations when it comes to system sizing is this:
Sit down and list everything that you would ever want to run from your power inverter. Once this is done, look for any appliance with a power rating above 2000watts and strike these off your list (or be sure to include an AC generator in your system).
Then look for any appliance between say 1000 to 2000watts, and work out how essential each of these items are.
It is easy to record the power output of each of your appliances on our appliance usage chart on page 28. Now for the important part; how long will you realistically want to run each appliance over a normal day (if you overstate your true requirements here, your system can become oversized, and cost far more than necessary). For help in sizing your system, have a look at our usage tables at the back of this catalogue.
What is an inverter?
Modern inverters have caused a quiet revolution in the way we live with independent power systems, by providing silent 240 volt AC electricity anytime, anywhere. An inverter transforms the DC electricity stored in your batteries into standard household 240 volt power. With an inverter you don't have to rely on hard to find DC powered appliances, or a noisy generator to enjoy the comforts of home anywhere.
Our range of power inverters are efficient and reliable devices that come in a variety of sizes and power ranges to meet just about any power need. We offer portable models designed for light AC loads such as televisions, right up to high power hardwired units that provide electricity away from utility power. Inverters are available as just a stand alone DC to AC power inverter, or in a combination unit which features the power inverter, smart battery chargers and automatic AC transfer switch to recharge your batteries after using the inverter.
Output Waveforms.
The biggest choice in power inverters is their output waveform. In today's inverter systems which simulate mains power electronically, there are two types of AC power inverters available; modified sine wave or pure sine wave.
The differences between these types of inverters are subtle, but significant in the way that they operate certain types of loads.
Modified Sine wave Inverters
These units are adequate to power most household appliances and power tools. Generally being less expensive, these units can tend to present certain compromises and incompatibility with some of your loads. Some examples of incompatibility are:
- Microwave ovens
- Laser Printers
- Laptop , mobile phone, portable power tools and camcorder battery packs
- C-Pap respirator machines
- Test and measure equipment
- Televisions and computer screens
Pure Sine Wave Inverters
These inverters are the most sophisticated inverters on the market today. They are designed to precisely replicate and even improve on the quality of electricity supplied by utility companies. There is generally no compatibility issues with any appliance run from a pure sine wave power inverter.
Battery Systems.
To ensure the maximum life from your batteries, always look to follow the following rule for discharging batteries:
Do not discharge starting batteries below around 90% state of charge. Starting batteries are not designed to sustain DC loads for any length of time (Look how quickly car batteries go flat if a light is left on).
Do not discharge deep cycle batteries below 50% state of charge. By following this rule recharge times will be far quicker, and the longevity of the battery banks will be greatly improved.
For this reason above, deep cycle batteries are the only real choice for inverter operation. Remember that in your DC system, the power inverter will most probably be your greatest low voltage, DC load, however this load is usually for short times only (e.g. using your inverter to run a microwave).
In a normal sedan, it is not recommended to use an inverter above the 300watt size due to the battery installed in the vehicle. To help make your inverter work for longer periods of time, simply run the engine more frequently to keep the batteries charged.
For loads greater than 500watts, a properly sized and designated battery bank would be required to run everything in your system (such as lights, fridges, inverter, DC Television just to list a few). Be sure to ensure that you have the suitable recharging abilities to keep the system working effectively (see the Maximising Charge Sources for further information).
In our experience, the most suitable batteries for larger systems (average of 50amps+ per day) are the Six-Volt, Golf buggy variety of battery. Two of these in series up to 12 volts provides the best reserve capacity that you could expect for your independent power system.
Inverter Q & A:
These Questions and Answers are designed to help better understand the working of power inverters, and the usage of common appliances from them.
How long will my batteries last? Each time I run my inverter a high pitched alarm is sounding?
This is the most often asked question regarding power inverters, and is the most difficult to answer. The length of time that your batteries will last is proportionate to the size of the battery, the load of your inverter, what other loads are running from the battery and what charging sources are connected. Without knowing all of these factors no one can give a precise answer.
What we can however do is look at the power requirements of the appliances you need to run, how long do you intend to run them and what other DC appliances are going to use the batteries. For a complete break down on this, look at page 24 & 25 for simple workings to determine your battery and charging requirements.
The high pitched alarm being experience can come from two problems: Insufficient battery cables creating voltage drop, or, a depleting battery capacity. If the alarm keeps going off, even when your batteries are fully charged, have someone look at your battery cable set up for undersized cables, or loose connections powering the inverter.
Inverters will draw power from your batteries when not in use, and the unit is turned on. This can vary from around .02 amps right up to 2amps depending on the unit and design of their standby systems (low cost inverters generally draw more than quality units). If you leave your inverter turned on with no load attached, the draw from your batteries will be 1 amp per hour; 24amps per day; or 168 amps over a week. The simplest solution to this is to just turn the inverter off when not required as the battery drain then becomes zero. Many of our inverters feature standard or optional remote on/off controls.
Sizing your inverter is a difficult task, and is not made any easier by different brands and manufacturers rating the power of their units at different temperature ratings. The power output of an inverter is dramatically decreased as its internal temperature rises (this is sometimes called its 5, 10 & 30 minute rating; but in reality if the inverter cannot remove the heat quick enough, then the power will rapidly drop off). Many of our models are rated at a staggering 40 C, such as Prosine, with a classic comparison between a Prosine 1000 and a low cost 1500watt modified as follows. The following table provides a comparison between the Prosine 1000i rated at 40 C and a common 1500watt inverter rated at 25 C.
If your inverter gets too warm, it will simply shut down until the unit cools down. As mentioned above, the hotter your inverter gets, the less AC power it will deliver (hence the new designs such as Prosine that allow for rapid removal of warm air from the inside workings).
When measuring the AC voltage from my inverter, the multimeter is only showing 183 volts AC.
Appliance and Load Questions:
Common Installation Problems
To attempt to rectify this issue, many installers are recommending a Mains Earth Neutral Connection (MEN), which bonds the Neutral to the Earth, thereby nominating the Neutral conductor. We recommend that this modification only be done by qualified installers, and that ATL are informed of all AC output changes.
Voltage Problems.
In nearly all voltage supply issues the problem relates to battery cable supply.
In an independent power system, you generally would find an inverter and battery charger system working to the common goal of providing power. What ties each of these together are the battery cables to supply the power to run to or from the batteries and unfortunately, the most common installation error is to undersize battery cables to load and recharge sources. Always read product recommendations, or check with your supplier to know and understand exactly what size battery cable is required for your products.As a guide, we have included below a conversion table from the commonly used American Wire Gauges (AWG or B&S), to the Australian measurements of mm2. Note: Sometimes gauges are expressed as follows (e.g. 4/0 is the same as 0000)
Voltage Conversion Tale AWG 0000 000 00 0 2 4 6 8 10 12 Mm2 107.3 85.0 67.4 53.5 33.6 21.2 13.3 8.4 5.3 3.3
Inverter Summary.
One thing that you will find in the market place are substantial price differences from one inverter to another, not only between Modified and Pure sine wave but also between different brands. Due to the market for such items becoming more competitive, there is a growing demand for a large number of products entering the market that are made for the lowest possible price, with no regard to over all reliability or actual performance.
At the cheaper end of the scale a consumer would expect to pay around $500 - $1200 for a cheap 1000 watt inverter.
A consumer after a good quality unit could expect to pay $1800 plus for a 1000 watt inverter.
When shopping around for a power inverter ask yourself if you want a cheap inverter that, over the long run may end up costing you more and possibly damage your valuable equipment; or a good quality unit that may cost a little more but will give you many years of faithful fault free service? Keep in mind that in a situation where you rely on batteries for your power, an unreliable inverter could cost you a lot more money than you expected.Obviously the answer is realistic power usage requirements and diligent research into the attributes of the actual inverter system before handing over your hard earned case - or you may regret it later!