Power Inverter & Inverter Charger Guides

Ideally an inverter should be installed within 10 feet of the battery bank. If you increase this distance, you will need to use larger DC cables to compensate for a drop in voltage and DC ripple.

All Xantrex Inverter/Chargers are not ignition protected and therefore should not be installed in a gasoline engine compartment. They are approved for installation in a diesel engine compartment.

What type of environmental conditions must I consider when installing an inverter/charger?

All Xantrex Inverter/Chargers must be installed in a dry, well-ventilated compartment. While most units are designed to withstand corrosion from the salty air, they are not splash proof. The units also require a fresh air supply to operate properly.

Choosing the right size of inverter depends on the power requirements of the appliances you expect to operate at any given time. You should consider both the continuous and surge power rating of your appliance. The continuous rating must be high enough to handle all the loads that may run at the same time. The inverter must also be capable of handling the starting surge of all loads that may start at the same time. Loads typically take many times their continuous rating to start.

The length of time you can operate an inverter depends on the amp-hour capacity of your battery bank.

Both sine-wave and modified sine-wave inverter output will operate a computer. However, some monitors and laser printers can only be powered by sine wave output.

Yes, it is possible to operate a small air conditioner in the 5000-9000 BTU range using a higher-powered inverter and battery bank with the right capacity for power. Select an inverter and battery combination that takes into account the startup surge required by the air conditioner.

When shorepower is available, you may leave your inverter ON or OFF. There are advantages and disadvantages to both methods. If the inverter is left ON, you have immediate backup AC power if you lose shorepower. You may not be aware shorepower is lost until your batteries are fully discharged. If you choose to leave your inverter OFF you have the advantage of knowing when you have lost shorepower. This, however, is at the expense of losing automatic backup power capabilities.

All Xantrex Inverter/Chargers incorporate an automatic transfer switch. This switch senses when outside AC Power is present and transfers the load from the inverter to the source of incoming power (shore or generator). The unit also automatically switches from invert mode to charge mode.

The length of time you can operate an inverter depends on the amp-hour capacity of your battery bank.

Both sine-wave and modified sine-wave inverter output will operate a computer, including a laptop. However, some monitors and laser printers can only be powered by sine wave output.

When I check the 115 volt output of a Xantrex inverter with a three light polarity tester, all three lights come on. There is no fault description for the tester covering this. My ground fault outlets do not trip. Is there a problem?

No. What you are seeing is normal if you are testing the output of a Modified Sine Wave (MSW) inverter. The device you�re using is for use with household utility power; the internal wiring of the inverter causes this symptom.

No. A fuse (or circuit breaker, depending on the location and nature of the application) is an integral part of the safe installation of many Xantrex Technology Inc. products. If your installation does not meet the recommendations and specifications in the user guide, it is possible that an unsafe condition may be created, which could result in a fire. Your insurance company may not be obliged to cover damages in this case.

Follow the installation guidelines in the manual for optimal performance and safety of your Xantrex Technology Inc. power conversion product.

The remote on/off switch for Prowatt and Portawattz products is part number 808-9000. It includes 20 feet (6 meters) of cable and works with the following products:

Portawattz inverters (1000, 1750, 3000).

All Prowatt inverters over 800 watts, whether 12 or 24VDC and whether domestic or international.

The remote switch can be purchased through Xantrex E-store www.xantrex.com/estore (under Accessories) if your local Xantrex dealer doesn�t carry it.

The Prowatt and Portawattz models mentioned above can be controlled remotely by an external dry-contact switch. You can find more information on the electrical requirements of the switch at our support FAQ under Prowatt products entitled Prowatt 1000/1750/3000 Remote Control.

NOTE: This switch does not work with XPower Plus inverters. For the XPower 1200 Plus and XPower 1750 Plus inverters, the correct remote switch part number is 808-9500. It is also available through Xantrex E-store. Do not use the electrical information at the above-noted FAQ for XPower Plus inverters.

I've installed the modified sine wave inverter and it's working okay. However, the output voltage doesn't seem right. There is 124 vac between the hot and neutral pins but the safety ground is not at 0 volts with respect to the neutral pin. Instead, the safety ground appears to float about halfway between the neutral and hot pin voltage. Please explain what's going on!

This FAQ applies to Xpower, PROwatt, Portawattz, Jazz and Xantrex inverters, including the inverters integral to Powerpacks.

Your inverter is designed to have loads plugged directly into it and not be permanently connected to an AC distribution system. The fact that the inverter is not a permanent installation means the US NEC (United States National Electrical Code) doesn't apply, and the NEC is the main place where the requirement resides for single-phase 120Vac or 240Vac systems to have neutral bonded to earth. The US standard for inverters of this sort, UL458, does not have a requirement for a bonded neutral on the output of inverters.

Regarding the voltage that the you are measuring, the ground does not float halfway, rather the neutral is not at 0 volts. The grounding is correct, in that loads plugged in will have their chassis held at the same ground potential as the chassis of the inverter, but the neutral has approximately 60V on it instead of the usual 0V. The impact of that is minimal, since wiring and equipment connected to the neutral side of the circuit are required by safety standards to be treated as if they were at 120Vac. This is because there are many receptacles that are wired backwards or 2-prong plugs that are not polarized. As a result the 60V neutral is not accessible to the user, and any shock hazard presented is mitigated by lack of access.

The main safety agencies, CSA, UL, and ETL, have all approved inverters with this half-voltage on the neutral scheme, and the manuals contain warnings not to AC hardwire any of these inverters.

Ideally an inverter should be installed within 10 feet of the battery bank. If you increase this distance, you will need to use larger DC cables to compensate for a drop in voltage and DC ripple

All Xantrex Inverter/Chargers are not ignition protected and therefore should not be installed in a gasoline engine compartment. They are approved for installation in a diesel engine compartment.

What type of environmental conditions must I consider when installing an inverter/charger?

Xantrex recommend using only high-quality deep cycle batteries in Wet, Gel or AGM (Absorbed Glass Matt) technologies to be used with Xantrex products. Deep-cycle batteries are designed specifically for a deep discharge and a rapid recharge. Wet cell batteries include 6-volt (golf cart) batteries and require some maintenance. Gel cell batteries and AGM batteries are sealed and typically require very little maintenance. Do not use starting batteries for inverter applications.

Battery Overview

A battery is a device that stores energy while it is being charged and releases energy while it is being discharged. There are a lot of different battery technologies, but lead acid batteries, which consist of plates of lead dioxide and spongy lead, immersed in a sulphuric acid solution contained in a durable housing, are most appropriate for use with inverters and mobile power solutions.

Lead acid battery technology has come a long way since 1859, the year it was invented. You no longer have to check the state of charge with a hygrometer, or top the batteries up with distilled water. Batteries are now safer, more reliable and in some cases, virtually maintenance free. Lead acid batteries are recommended for use with inverters because:

Deep Cycle Verses Starter Batteries

Lead acid batteries are suitable for applications requiring a big, sudden discharge of current (what you need to start the engine on a boat, or in a car or RV) or a slow, steady discharge of current (to run your scooter, or watch a TV). These two classes of application generally require different battery technology, but they share some chararacteristics. Lead acid batteries of similar amp hour capacity will require about the same length of time to recharge, and all lead acid batteries are damaged by heat, and by storage in a discharged state.

The technology for starter batteries is simple. Many thin plates of lead in the electrolyte give lots of surface area, thus lots of potential current. This is the kick you need to get your car to start on a frosty morning.

Thick plates make batteries better suited to deep cycling � the type of battery that works best with an inverter. Thick plates aren�t the best for short high current use. If you have a quality deep cycle battery, you can discharge and recharge it more than 1500 times. A starting battery can be discharged perhaps 30 times before it will no longer accept a charge.

Because of the differences in the way the lead plates inside the battery are placed, the battery charging requirements are slightly different for the two styles of battery. Batteries that are not charged in accordance with manufacturer�s instructions can over gas (referred to as �boiling�) if overcharged, or sulfate if undercharged. Improper charging reduces the battery capacity and life cycle; that�s why it�s important to use the right charging technology to protect your investment in your batteries.

Unless they are properly charged, you won�t get the rated capacity back out of the batteries. There�s no free lunch: You can�t take energy out that you haven�t put in. Further, you�ll shorten the life cycle of any battery if it�s not properly charged. This is because the sulfur crystals which are deposited on the active material of the plate during discharge (while you are running your inverter or DC load) will not be forced back into solution during the charge cycle. Over time, these crystals become harder and thicker, reducing the access of the electrolyte to the plate and ultimately reducing the battery�s capacity.

How big a battery is needed?

Check the FAQ http://www.xantrex.com/support/howlong.asp for the Xantrex Technology Inc. battery calculating tool. You will need to know the wattage of the product or products you wish to run in order to use this tool.

Batteries last longest if you only discharge to 50% of capacity and then recharge as soon as possible after the discharge. If you want to run a 1 amp light for 50 hours between charging, you would need a battery which will deliver about 100 amp-hours. Although you can discharge a battery much further than this, you will begin to decrease the battery�s cycle life. A good deep cycle battery might deliver 1,500 (or more) discharges to the 50% level. By increasing the discharge to 95% you can reduce cycles to a hundred or so. So don�t undersize your battery bank, or you will be buying batteries much more often than necessary.

Gel Cell, Absorbed Glass Mat (AGM) or Liquid Cell (Flooded Lead Acid) Batteries?

Which type of battery you buy depends on your application, your charging system, your budget, your willingness to trade convenience for cost, and weight considerations. Some advice applies to all types of batteries. The following advice is not meant to supersede specific product instructions or cautions supplied by the battery manufacturer.

There are a few factors that need to be considered before you determine the quantity of batteries needed. First, consider the type of battery you intend to use with your application. Next, determine the size of the battery and the number of amp hours you require between charge cycles. Most people have a 400-450 amp-hour battery bank, but this depends on use of your system.

Why do my batteries go dead when i use the inverter/charger in inverter mode?

A Xantrex inverter takes available battery power and converts it to AC power to operate household appliances. In many cases there are additional "hidden loads" that will draw power from the inverter even when they are turned off. Some examples are: TV tubes being kept warm and microwave & VCR clocks. In addition to AC loads, there may also be DC loads that draw power from the same battery bank as the inverter. These loads can include CO detectors, accent lighting, bay lights, and water pumps. Phantom loads may consume over 70 amp hours per day and most banks will be depleted in about three days with the inverter running with no loads on connected.

Multistage charging ensures batteries receive optimum charging, but with minimal wear and tear, regulating the voltage and current delivered to the batteries in three automatic stages:

Bulk: Replaces 70-80% of the battery�s state of charge at the fastest possible rate.
Absorption: Replenishes the remaining 20-30% of charge, bringing the battery to a full charge at a slow, safe rate.
Float: Voltage is reduced and held constant in order to prevent damage and keep batteries at a full charge.

Xantrex Technology has recently launched a new educational series entitled �Tech Doctor� for marine, commercial and recreational vehicle applications. Designed for dual usage, the series is produced for editorial reproduction and industry education. Written by Xantrex Sales Engineer Don Wilson, who conducts technical training seminars throughout the country, the series covers topics of general interest in an easy-to-understand, Q & A format. Xantrex also encourage its partners to use articles in this series as a tool to educate their customers.