The Xantrex SW Series II line of sine wave inverters has been
the workhorse in the inverter industry for many years. Xantrex
listened to its customers and has completely re-designed their
line of sine wave inverters to incorporate numerous new features
and operational improvements. Their new SW Plus units are
available in 24 and 48V versions with continuous power outputs
of 2.5, 4.0 and 5.5 kVA.
Some of the biggest improvements over the old SW Series II
- Non-volatile memory so you don't lose all of your settings
if you disconnect it from your battery bank (intentionally
- Much higher surge rating (up to 4x the continuous power
rating for 5 seconds)
- Continuous power output is maintained up to 104°F (i.e.
no temperature derating of power output)
- More accessible AC wiring compartment connections.
- Battery temperature compensation connection port is now on
the DC side making it easier to route the temperature sensor
down to the battery bank.
- More user friendly 3 level menu operating system (user,
basic & advanced)
- Flash memory for future software upgrades (no more
- A lower dollar-per-watt cost than the SW Series II.
- Higher efficiency than "Brand-O" in the more
commonly used lower power range.
Two SW Plus inverters can be connected or "stacked" in
series for 120/240 VAC output or in parallel for straight 120
VAC output. It also has the same dual AC input (i.e. generator
and utility grid) and dual transfer switch capability of the SW
Series II. The SW Plus improves on the utility power management
capabilities of the SW Series II by using the utility as the
backup to a renewable energy source and turning the utility
charger completely off when not needed. This reduces the power
consumed from the utility and lowers the noise produced by the
inverter's transformers. It is also easier to program to take
advantage of your utility's time of day billing (i.e. invert
power from the batteries when utility rates are high and charge
from the utility when rates are low). The SW Plus inverters can
be monitored/controlled remotely via one of their inverter
control modules (ICM/25 or ICM/50) and they feature the same
2-year warranty that the SW Series II had.
On the negative side, the SW Plus inverters have the same old
34-52 step approximation to an AC sine wave output (i.e. not
"true" sine wave") so you may encounter problems
running some sensitive AC loads. They are also physically
different in size than the old SW Series II so they won't fit on
an existing power panel as a straight replacement. New power
panels featuring the SW Plus inverters should be available by
the summer of '04. The SW Plus does not have the built-in
automatic generator start and auxiliary relays of the old SW
Series II, but they are available as optional add-on modules (GSM
& ALM). Currently the SW Plus inverters cannot sell any
excess power back to the utility company, but they should be
able to do so by the fall of '04 and you will have to use their
separate grid-tie interface.
Overall, we think the improvements that Xantrex has incorporated
into their SW Plus line of inverters make them a great choice
for a remote or grid connected power system. Please look at the
unit prices and options listed below as well as the attached
spec sheet. If you have any questions, please don't hesitate to
give us a call or send us an