Sterlco M2B+ Controller - Manual (Page 24)

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button is released, at which time the 30-second time-out will restart. After 30-seconds, the
system will recycle to the “Power Available/System OFF” state.
Starting the Unit (Remote)
REMOTE START option is similar to the water process sequence. Closure of pins 5 and 6 of
header J6 initiates the start sequence. The display flashes MODE IS OFF, PRESS START
TO RUN. THE VENT/FILL timer counts down from 10 minutes. After the VENT/FILL
timer has elapsed, the controller will automatically go to the second vent operation for 10
minutes. Upon completing the second vent operation the controller will automatically go to
the run mode.
The controller may also be started or stopped locally by depressing the controller start button
or stop buttons.
4-4 Tuning
Autotuning
The factory default for the controller is automatic half/full heat for water units,
and full heat for oil units. If an autotune cycle is completed, do not switch to
low heat without performing a new autotune cycle. Failure to autotune will
result in poor control of the process. Subsequent changes from one heat setting
to another require autotune to be run.
The Tune button is used to toggle the autotune process. If no autotune operation is in
progress, pressing the Tune button starts the autotune operation. The “AutoTune” message is
displayed on the LCD. If an autotune operation is already in progress, pressing this button
again will immediately stop the autotune operation. The display will return to the “Running”
message.
During the autotune process, the control point is the ‘To Process’ probe or the ‘Remote
Selected’ probe. The tuning constants (i.e. rate, reset and gain) can be altered in setup mode.
The unit’s cycle time is selectable in one-second increments. The heat and cool cycles have a
minimum pulse of one second.