SBS AT10.1 SERIES, Operating And Service Instructions

Page: 44 / 104

OPERATING THE AT10.1
38
2.3.8. Using the Low Level Detector (LLD)
The AT10.1 is equipped with a summary (common) alarm relay safety
override circuit. This feature forces the alarm relay contact to transfer,
sending an alarm, even if there is a catastrophic failure of the AT10.1
control circuitry. A low battery voltage triggers the safety circuit.
Main Control PC Board (A1) hardware, not software, maintains the low
level detect circuit. Therefore, to remotely monitor this alarm, user
connections must be made at terminal block (TB3). The summary alarm
contacts (TB4) on the Auxiliary Alarm Relay PC Board will not signal a
low level detect alarm.
If you have a dc power supply, you can adjust the battery voltage that
triggers the alarm. On the back of the Main Control PC Board (A1), find
the potentiometer
RA1 , as shown in the figure below.
Disconnect all ac and dc power sources from the AT10.1. Connect your
dc power supply to the AT10.1 dc output terminals (TB1+/-), positive to
positive and negative to negative. Adjust the power supply to the voltage
at which you want to activate the alarm.
NOTICE
You need at least 50% of the nominal output voltage to power
the AT10.1 Main Control PC Board (A1).
Adjust
RA1
with a small jeweler's screwdriver clockwise until the alarm
just activates. A red LED indicator ( DS10 ) next to RA1 indicates when
the alarm is active.