Outback Power Systems GFX International Series Operators Manual - Manual (Page 18)

Operation
16 900-0112-01-00 Rev B
Generators
A generator should be sized to provide enough power for both loads and battery charging.
¾ The generator needs a single circuit which is sized to provide current to all inverters on a given phase or leg.
¾ It is usually recommended that the generator be sized at twice the wattage of the inverter system. 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.
¾ Using the MATE system display, it is recommended to set the AC source to gen when connecting a generator.
If the setting is left on grid, the inverter’s internal settings will still be set for utility-grade power. Unless the
generator delivers extremely high-quality power, it might not be accepted. (Alternately, the inverter might
accept the generator and attempt to sell power back to it.) Changing to gen will remove the requirements
for high-grade power and will prevent selling.
The generator is required to have a stable output before its power is accepted by the inverter. Some
generators with less stable or uneven outputs may not be accepted.
When using capacitor-excited generators or self-excited induction generators, there can be side
effects while using the Input Support feature (see page 17). These generators do not always deliver
full output when operating in parallel with another source of power, such as the Input Support
feature. The inverter’s battery charger may work erratically or at a low charge rate. It may be
necessary to disable the Input Support feature. Consult the generator manufacturer if necessary.
Transfer
The inverter uses a transfer relay to alternate between the states of inverting and of accepting an AC
source. Until the relay energizes, the AC HOT IN and AC HOT OUT terminals are electrically isolated
from each other; when it closes, they become electrically common. When the relay changes states,
the physical transfer delay is approximately 12 milliseconds.
¾ The AC NEUTRAL IN and AC NEUTRAL OUT terminals are electrically common regardless of the state of
the relay.
¾ The relay contacts are limited to 30 amps per phase or leg. The continuous loads on that output should
never exceed this number. When connected to an AC source, the inverter cannot limit the load current. An
overload condition is possible.
CAUTION: Equipment Damage
Current draw in excess of the inverter’s transfer relay rating can damage the transfer
relay. This damage is not covered by warranty.
The inverter does not filter or clean up the power from the AC source. The voltage and power quality
received by the output loads is the same as that of the source. If the voltage or quality do not meet
the inverter’s input limits (see page 15), it will disconnect and return to the inverting mode.
¾ If the AC source meets the inverter’s requirements but is irregular, any fluctuations will be transferred to the
loads. If the loads are sensitive, it may be necessary to improve the quality of the AC source.
¾ For a smoother transition, it may be useful to raise the inverter’s lower acceptance limit. The default setting
is 208 Vac. A higher setting will cause the inverter to transfer sooner in the event of a quality problem.
In a stacked system, slaves are ordered to transfer at the same time as the master. If a slave does not
sense an AC source, it will suffer a Phase Loss Error (see page 37). The slave will continue inverting.