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 Xantrex
is a company that specializes in power inverters offering small portable
units as well as full high-power, true sine wave (TSW) systems for residential
and commercial applications. The company also carries a line of high power
mobile products for marine and RV use. The Xantrex PROwatt SW Series
True Sine-Wave AC power inverters fall into this category and are
available in 600, 1000 and 2000 watts versions. These inverters are designed
with high surge capability, capable of providing the necessary current
to start up demanding electrical loads. We received the PROwatt SW 2000
Inverter capable of supplying an amazing 2000 watts of true sinewave
power (120V at 16.6 amps max). True sinewave inverters are more complicated
than the cheaper modified sinewave designs and cost significantly more
to produce. Since many products have issues when running from a modified
sinewave inverters, the pure sinewave designs are more desirable in some
applications.
The PROwatt
SW 2000 is a compact unit measuring only 3.9" x 11.8" x 13.7" (H x W x D), making it ideal
for use in work trucks, recreational vehicles,
marine vessels and other commercial vehicles. The unit weighs
a modest 11 pounds. Power and Fault indicators give the
user feedback in the event the inverter encounters a problem with line
voltage, overloading, or overheating. The low-voltage alarm occurs when the battery drops to 11.0 volts and shuts down at 10.5VDC to prevent over-draining of the battery. Over-voltage detection and sutdown occurs at 15.5VDC. The dual GFCI AC outlets can provide
up to 120VAC at a maximum of 16.6 amp. There is also a power jack on the
front for USB chargeable devices that provide 5V at 500mA.
When the inverter is used with a remote control, the PROwatt SW Series
has the ability to provide automatic vehicle ignition lockout using the RJ45 jack.
This shuts down the inverter's output when the vehicle's ignition is not
switched on to prevent accidental battery drain.
 Back
Panel
The back of the PROwatt SW 2000 has large positive and negative
terminal lugs to supply the high current needed for this power inverter.
Maximum input current is specified at 162 amps with a peak current of 205 amps
(for a maximum of 5 minutes). Xantrex recommends an inline fuse rated at 250 amps. A separate ground lug is also provided for safety.
Two small internal fans keep the unit cool while operating under heavy
loads. Even though this unit is efficient, it can dissipate a significant
amount of heat when fully loaded, so proper ventilation is required for reliable operation.
 Output
Voltage
The AC output power provided by the PROwatt SW 2000 inverter looks
very similar if not better than the power produced by the utility company.
The smooth waveform is virtually free of higher frequency harmonics that
often cause issues with sensitive electronics. The inverter is designed
to provide power for all types of electrical loads including, variable
speed power tools, advanced electrical appliances, microwaves and more.
The PROwatt SW 2000 provides household AC power anywhere. We measured
the output voltage and were pleasantly surprised to see a clean
120VAC. The voltage on the scope measured 340 volts peak-to-peak,
which is 120 volts RMS. An exact measurement using a Fluke 77 IV DMM read 120.9VAC with a frequency of 59.94 hertz.
 Operation
Installation of the inverter is important and users must be aware of the heavy duty cabling needed to supply the high current to the unit. Calculating worst case voltage drop is important to prevent the inverter from shutting down during high current draw. Xantrex recommends using 4/0 gauge wire with a maximum cable length of 6 feet from the battery. This wire has a DC resistance of 50 micro-ohms per foot at room temperature. At 200 amps the IR (current x resistance) drop is about 200*0.00005*6 or 0.06 volts. While this does not appear to be much, power dissipated by the cable itself is about 12 watts under these conditions. In addition, the voltage drop will decrease the operating margin of the inverter as it approaches the shutdown voltage of 10.5 VDC as the battery drains. This is why it is very important to use the heaviest gauge wire possible to minimize power loss due to IR drop.
The inverter is designed to operate at temperatures ranging from 32°F − 104°F (0°C − 40°C). We installed the unit into our Nissan Armada truck for test purposes. Once the inverter is connected to the battery, the user must press and
hold the power button down to turn the inverter on or off. We tested the inverter
with a standard 300-watt halogen lamp, which is a simple load with no
current transients. The input voltage to the inverter displayed 12.5 volts and 0.28 kilowatts (280 watts) as the load. The display toggles between the two readings every few seconds. The output voltage remained at 120 volts regardless of
the load we presented on the inverter. This inverter has a solid design and appears to be load independent.
Conclusion
The PROwatt SW 2000 true sinewave power inverter (under $400 street) is a great design
that provides a large power capability in a compact chassis. The safety
features keep power in check and notifies the user in the event of a
problem. Protection features include
Low Voltage shutdown (10.5 VDC), Low Voltage alarm (11.0 VDC), Over Voltage protection (15.5 VDC),
Overload shutdown,
Over Temperature shutdown, and
GFCI protection. The unit held up well during our tests and we found the PROwatt SW 2000 both easy
to use and reliable (comes with a full 2-year warranty). If you need a true sinewave power inverter for mobile
or marine use, you owe it to yourself to check out the PROwatt SW Series
power inverters from Xantrex.
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Kevin Nakano
Special "Thanks" to Mitul Chandrani for providing us support during this review.
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