Specifications

Space Temperature Alarm (Comfort Trend) —
See Table 6 for Space Temperature Alarm Specifications.
Table 6 — Space Temperature Alarm
FUNCTION DESCRIPTION
Controllers Monitor Thermostat/Zone Controller
Sensor Required
None (Space Temperature Sensor
is in Thermostat)
Sensor Wiring None, Sensor Integral to Thermostat
Input
Comfort Trend Demand
Comfort Trend Time Limit
Output
SE01, Comfort Trend Error (Space
Temperature Alarm)
Category/Option
7.4 (Comfort Trend Demand)
7.5 (Comfort Trend Time Limit)
Configuration Values
7.4 — Range0Fto25.5 F
7.5 — Range 0 to 255 minutes
Configuration Increments
7.4 - 0.1° F
7.5 - 1 minute
Associated Functions None
OPERATION — A space temperature (Comfort Trend) alarm
indicates when the system is unable to maintain space tem-
perature comfort conditions. Space temperature alarms are
an indication that the HVAC system operation has difficulty
maintaining zone space temperature. The temperature de-
mand of the space or zone is the difference between the set
point (either heating or cooling) and actual space tempera-
ture of the zone.
When the demand of the zone exceeds the Comfort Trend
Demand value (category 7, option 4), the thermostat begins
to calculate the temperature trend of the zone. The tempera-
ture trend is simply the "real time" ability of the space to
lower or reduce the temperature demand of the space. The
time is measured during the period when the temperature
trend does not show improvement, or indicates conditions
between set point and space temperature are getting worse.
When the length of time measured reaches the Comfort Trend
Time Limit value, a Space Temperature alarm is initiated.
CONFIGURATION TO ACTIVATE ALARM — To acti-
vate a space temperature alarm, configure the Comfort Trend
Demand set point to any value except 0. Configure the Com-
fort Trend Time Limit set point.
CONFIGURATION TO NORMALIZEALARM — The space
temperature alarm will automatically clear when the system
can properly condition the space. To remove any alarms, fol-
low the procedure to clear the alarm from the thermostat and
network using manual reset.
CONFIGURATION EXAMPLE
Occupied Space Cooling Set Point: 72 F
Occupied Space Heating Set Point: 68 F
Comfort Trend Demand: 4.5 F
Comfort Trend Time Limit: 7 minutes
The system is operating normally without alarm during
the Cooling mode. The trend of the space temperature indi-
cates that the system is unable to keep the space within set
points, and space temperature rises to 76.5 F. The trend of
the space temperature is not improving, and temperature con-
ditions are getting worse for at least 7 minutes. At that time,
a space temperature (Comfort Trend) alarm (SE01) is initi-
ated. The alarm will automatically clear when the system
can properly maintain space temperature conditions within
the space.
The alarm is removed using the manual reset. The system
will not return to normal without being reset.
CLEARING THE ALARM FROM THE THERMOSTAT —
Space temperature alarms can be cleared or "erased" from
the system in three ways:
• Cycle power to the thermostat OFF, then ON.
• Reset the Unit Thermostat. Initiate a reset by switching
the Unit Reset option to the ON (Category 7, Option 11).
• Switch the configuration value for Comfort Trend
Demand or the Comfort Trend Time Limit to zero, then
back to an acceptable range (category 7, options 4 or 5).
Discharge Air Temperature Alarm (Heat/Cool
Mode Error) —
See Table 7 for Discharge Air Tempera-
ture Alarm specifications.
Table 7 — Discharge Air Temperature Alarm
FUNCTION DESCRIPTION
Controllers Monitor Thermostat
Sensor Required
Remote Duct Sensor (RDS): Monitor
Only Mode
Duct Temperature Sensor: VVT Mode
Sensor Wiring
RDS: Wires to Terminal 13 and 15
Duct Temp Sensor: None, sensor
integral to damper
Input Unit Discharge Air Temperature
Output
SE07, Heat Mode Alarm; SE08,
Cool Mode Alarm
Category/Option
7.9 (Heat Mode Alarm Set Point)
7.10 (Cool Mode Alarm Set Point)
Configuration
Values
7.9 — Min 0, Max 140
7.10 — Min 0, Max 140
Configuration
Increments
1° F
Associated
Functions
None
OPERATION
Heating Mode — Alarm is issued when unit discharge tem-
perature is not above the heating mode error set point.
Cooling Mode — Alarm is issued when unit discharge tem-
perature is not below the cooling mode error set point.
CONFIGURATION TO ACTIVATE ALARM — To acti-
vate alarm, configure error set points for Heat/Cool mode
(0 to 140 F). An automatic 10-minute warmup/cooldown
period is initiated before any temperature checking begins.
CONFIGURATION TO NORMALIZE ALARM — When
unit discharge temperature rises above the heat mode error
set point, the heat mode alarm is normalized. When unit dis-
charge temperature drops below the cool mode error set point,
the cool mode alarm is normalized.
For example, the Heating/Cooling Mode Error set points
are 90 and 55 F. During a heat mode, after 10-minute heat-
ing period, if discharge temperature does not increase above
90 F, a heat mode error is generated. After discharge tem-
perature increases to above 90 F, the alarm is normalized.
During cooling mode, after a 10-minute cooling period, if
discharge temperature does not drop below 55 F, a cool mode
error is generated. After the discharge temperature decreases
to below 55 F, the alarm is normalized.
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