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Internal Diagram- Models with Electromechanical Relays
The internal diagram displays the location of the control features for the relay versions of the 685B-Series. The
alert and alarm set points are adjusted via the single turn potentiometers. The alarm relay is set using the first
potentiometer, and the alert relay is set using the third. The alert relay trips when the set percentage of the alarm
value is reached. Time delays for both functions are controlled using the second and fourth potentiometers. Alert
and alarm relays can be reset remotely by using the RESET and COMM pins or by using the internal reset switch
as seen on the upper right hand corner of the diagram.
Using the first dipswitch beneath the terminal connectors, relay operation can be selected to be either latch or
continuous. The second and third dipswitches set the alert and alarm relay configuration to be energized or de-
energized. The diagram above indicates the contacts that are normally open and normally closed when the dip
switch is set to “de-energized. When the dipswitch is changed to “energized”, the normally open and normally
closed contacts would be reversed. The fourth dipswitch is used to activate the
calibration mode
for condition
simulation during the setup process. This is explained in detail on page 12.
