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An alarm will sound when the voltage from the battery drops to
10.7 volts (21.5V for PROwatt 250/24V). This indicates that
the battery requires charging. The user should stop operations
at this time since the PROwatt 250 will shut down automatically
shortly afterwards.
If the low battery alarm sounds when the battery is fully
charged, follow the steps for remedying lack of power output in
section 5.2 (Troubleshooting Guide) of the manual. The alarm
will sound when the inverter is overloaded, in thermal shut-
down, or if there is an excessive voltage drop between the bat-
tery and inverter.
5. Troubleshooting
5.1 Common problems
Buzz in audio systems
Some inexpensive stereo systems and
“boom boxes” will emit a buzzing sound from their loudspeak-
ers when operated from the PROwatt 250. This is because the
power supply in the device does not adequately filter the modi-
fied sine wave produced by the PROwatt 250. The only solu-
tion is to use a sound system that incorporates a higher quality
power supply.
Television interference
The PROwatt 250 is shielded and fil-
tered to minimize interference with TV signals. In some cases,
particularly with weak TV signals, some interference may still
be visible. Try the following corrective measures: