Product Overview

BAC-1xx63/1xxx63 Series (6 Relays and 3 Analog Outputs) Section 42 Application Guide S
Sequence of Operation (BAC-1xx63/1xxx63)
FlexStat (All Models) Common Features
Space Temperature Setpoints and Modes
The rst step in seing up an uncongured FlexStat is to select the units
of operation, Celsius or Fahrenheit. Once set, temperature values are
adjusted in both rmware and Control Basic for the proper values/units.
The most basic operating parameters controlling the FlexStats operation
are the space temperature setpoints. There are four setpoints during
normal operation of the FlexStat; unoccupied heating setpoint, unoccu-
pied cooling setpoint, occupied heating setpoint and occupied cooling
setpoint.
Likewise, there are four corresponding setpoint limiters: unoccupied
heating max, unoccupied cooling min, occupied heating max, and oc-
cupied cooling min. When the setpoints are adjusted from the FlexStat’s
user interface display, rmware applies the appropriate limit to the
setpoint being edited.
Another limit that applies to setpoints is the minimum setpoint dif-
ferential. This dierential is adjustable via the user interface. It cannot,
however, be set less than the minimum setpoint dierential limit (de-
fault of 1° F/C), which itself is only adjustable from interface software.
The function of the limit works in two ways. If either the occupied or
unoccupied heating setpoint is being edited from the user interface, it
cannot be raised any closer to the corresponding occupied or unoccu-
pied cooling setpoint than the minimum setpoint dierential even if the
heating setpoint being edited is less than its maximum limit. Conversely,
if the occupied or unoccupied cooling setpoint is being edited from the
user interface, the cooling setpoint is allowed to be adjusted down to its
minimum limit. However, the corresponding occupied or unoccupied
heating setpoint is always maintained at this minimum setpoint dier-
ential distance from the cooling setpoint with the heating setpoint being
lowered if necessary.
The FlexStat controls its output operations based on two setpoints, ac-
tive heating setpoint and active cooling setpoint. Under normal, non-
override operation, these setpoints are set, based on the current schedule
state being on, to either the occupied heating and occupied cooling
setpoints. If the present schedule state is o, then the active heating and
active cooling setpoints are set to the unoccupied heating and unoccu-
pied cooling setpoints. Active heating and cooling setpoints can be set to
other values under the circumstances described in the occupancy over-
ride sequence under the Occupancy Mode section and when the unit is
in Standby Mode as described in the Standby Mode section.
Heating Proportional Band and Cooling Proportional Band (both
previously combined and called “Deadband” in rmware R1.4.0.1 and
earlier) are adjustable from the user interface and are used in staging or
modulating the outputs throughout the various application congura-
tions. Specic uses of both proportional bands are described further in
the sequence information in the following pages. (The parameter Mini-
mum Proportional governs the lower limits of both proportional bands
and is adjustable only from interface software.)
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The current heating/cooling mode of the FlexStat is displayed on the
user interface. This mode determines which outputs are energized based
on space temperature and active setpoint values. The heating/cooling
mode is set to heating if the space temperature falls below the active
NOTE: This information reects rmware version R2.0.0.13 or later
(but specications and sequences are subject to change and
may vary according to model and options).