Inverter Applications - Xantrex 807-1055 Owner's Manual

Freedom HFS IC Owners Guide.book Page 37 Friday, September 11, 2015 2:54 PM

Inverter Applications

The Freedom HFS performs differently depending on the AC loads
connected to it. If you are having problems with any of your loads,
read this section.
Resistive Loads
These are the loads that the inverter finds the simplest and most
efficient to drive. Voltage and current are in phase (that is, in step
with one another). Resistive loads usually generate heat in order to
accomplish their tasks. Toasters, coffee pots, and incandescent
lights are typical resistive loads. It is usually impractical to run
larger resistive loads—such as electric stoves and water heaters—
from an inverter due to their high current requirements. Even
though the inverter can most likely accommodate the load, the size
of battery bank required would be impractical if the load is to be run
for long periods.
975-0727-01-01
Motor Loads
Induction motors (that is, motors without brushes) require two to six
times their running current on start up. The most demanding are
those that start under load, for example, compressors and pumps. Of
the capacitor start motors (typical in drill presses, band saws, etc.),
the largest you can expect to run is 1/2 to 1 hp (the transfer relays
are rated at 2 hp). Universal motors are generally easier to start.
Since motor characteristics vary, only testing will determine
whether a specific load can be started and how long it can be run.
If a motor fails to start within a few seconds or loses power after
running for a time, it should be turned off. When the inverter
attempts to start a load that is greater than it can handle, it will turn
itself off after a few seconds.
Long Transfer Times
The Freedom HFS may take a long time
(~ 0.1–0.2 seconds) to transfer to inverter mode when shore power
is cut off while powering a motor load. Motor loads typically
"freewheel" when power is removed (for example, a grinder) and
causes a longer transfer time. The longer transition from shore
power to inverter power may cause connected computers or other
sensitive equipment to operate incorrectly. To avoid this effect, do
not connect motor loads together with sensitive equipment to the
inverter for power.
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