Onwa Marine Electronics KAP-833 - Manual (Page 29)

External Alarm Installation 8 6
An external buzzer may be connected to the port ALARM, terminals ALA+ and
ALA-.
The ALA- output will be 10 volts when the alarm is not sounding (with alarm
connected), and approximately 0 volts when active. We recommends a 12-volt
piezo buzzer with maximum current draw not exceeding 250 milliamps be
connected to this output.
If a larger type siren or alarm unit, which draws in excess of 250 milliamps is
used, this must be connected via a relay. The KAP-833 external alarm circuit is
used to energise the relay coil and power to the siren or alarm unit is connected
via the relay contacts.
The external alarm output is activated if the stopwatch timer or commercial alarm
has been sounding for longer than one minute.
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