Xantrex Technology FREEDOM HF 1800 - Manual (Page 54)

40 Freedom HF Owner’s Guide
Inverter Applications
The Freedom HF 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 (i.e. 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.
Motor Loads
Induction motors (motors without brushes) require two to six times their
running current on start up. The most demanding are those that start under
load (e.g. 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
Xantrex has observed a specific situation where the Freedom HF may take a
long time (~ 0.1–0.2 seconds) to transfer to inverter mode when shore
power fails. This can occur when the Freedom HF is used to power motor
loads where the motor is able to “freewheel” when power is removed (for
example, a grinder). This long transfer may cause connected computers or
other sensitive equipment to operate incorrectly. To avoid this effect,
Xantrex recommends not to connect motor loads together with sensitive
equipment to the inverter for power.
Freedom HF InvChg Owners Guide.book Page 40 Thursday, November 24, 2011 11:20 AM