DropBear_UserManual
RE_PROD_0012 Version2
Page 11 of 22
Date Issue 28/07/2020
Generator/Grid
Because the DropBear is an off or on grid system, it is possible to connect it to the grid, a
generator or both. These options must be specified upon purchase as the electrical design varies
with each option. However, retrofitting is also available.
If purchasing separately, inverter-generators are recommended for use with DropBear due to their
better power quality. If voltage, frequency or current waveforms of the generator are not of a high
enough quality, then it will be rejected by the inverter.
NOTE:
Selectronic has the recommendation of a 9.5 kVA generator for the SPMC481 (5kW) and a
14kVA for the SPMC482 (7.5kW).
The following specifications must also be met for a guaranteed compatibility with the inverter.
-
Generator waveform THD: < 10%.
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Generator Vrms range: 180 ~ 264Vac
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Generator voltage crest factor (Vpeak/Vrms): < 1.6
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Generator peak voltage: <380V
-
Frequency range: 45Hz ~ 55Hz
-
Frequency slew rate: <0.3Hz/sec
Generator Auto-Start
RedEarth’s DropBear is fitted with terminals that allow the connection of an auto-start generator.
The SP Pro is configured to start the generator when the batteries reach a State of Charge (SOC)
of 30% and stop when they reach a SOC of 40%. In the event that the generator does not turn on,
the batteries will discharge down to 20% and then the inverter will stop outputting power under
“LOW SOC fault”.
Low SOC Shutdown:
The SP Pro has a safety feature that determines a low battery cut-off. When this
level (low voltage) is reached, the inverter will turn off under “low battery fault”
and will need to be turned back on manually. See “How to Operate -> Restart”
section on how to bring the system back to operation
Internal Components
