Outback FX-R Series Installation Manual

Planning
14 900-0166-01-01 Rev A
Generator

FXR inverters can accept power from a single-phase generator that delivers clean AC power in the range
of voltage and frequency specified for that model.
~ Inverters stacked for split-phase output (120/240 Vac) can work with both output lines of a
split-phase generator.
~ Inverters stacked for three-phase output can work with three-phase (120V/208Y) generators.

The inverter/charger can provide a start signal to control an automatic start generator. If automatic
generator starting is required, the generator must be an electric-start model with automatic choke. It
should have two-wire start capability. For other configurations, additional equipment may be required.

In any configuration, the inverter may need to be specifically programmed using the system display.
Perform all programming according to the specifications of the generator and the required operation of
the inverter. Parameters to be programmed may include generator size, automatic starting requirements,
and potential fluctuations in generator AC voltage.

A generator that is to be installed in a building usually should
not
have a bond between the neutral and
ground connections. The generator should only be bonded if there is a specific need. Installations in
North America are expected to bond the neutral and ground at the main electrical panel. See page 18 for
more information on neutral-ground bonding.
Generator Sizing
A generator should be sized to provide enough power for all expected use.

A conservative estimate assumes that both the loads and charging will be maximized at the same time.
However, this can result in an oversized generator with inefficient operation.

A smaller generator may be used for average loads with the inverter’s
Support
mode providing support
from the batteries during peak loads. The loads can be manually disconnected while charging.

In general, the generator should be sufficiently powerful to handle all necessary load surges.
Other considerations:

Available generator power may be limited by ratings for circuit breakers and/or generator connectors.

Many generators may not be able to maintain AC voltage or frequency for long periods of time if they are
loaded more than 80% of rated capacity. This statement may not apply to inverter-based generators,
which typically have more stable voltage and frequency regulation.

If a split-phase 120/240 Vac generator is powering a single-phase 120 Vac inverter system with no other
compensation, it may suffer from balancing issues. The OutBack FW-X240 or PSX-240 balancing
transformers may compensate for this condition.
Three-Phase Source
As noted above, FXR inverters stacked for three-phase power can accept three-phase (120V/208Y)
sources. In addition, two inverters can accept two phases of a 120V/208Y three-phase source to
power a split-phase load panel if necessary. There are several concerns when operating this way.

The inverters must be stacked in three-phase configuration. One must be designated
Master
and the
other as
B Phase Master
. See page 39 for more information.

The inverters will continue to deliver 120V/208Y output. They can power 120 Vac loads, but cannot
power 120/240 Vac loads.