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17
EQUIPMENT OPERATION DURING A SYSTEM COOL-
ING MODE
Outside-Air Temperature Greater Than 65 F — The TEMP
system thermostat utilizes the relay pack to energize the first
stage of cooling after system cooling mode is selected. When
the reference zone cooling demand is 2.0° F or greater, the sec-
ond stage of cooling is energized or optimized staging is fol-
lowed. The second stage of cooling is released when demand
drops below 1.0° F. The first stage of cooling is deenergized
when the system cooling mode is released.
Outside-Air Temperature Greater Than or Equal to 55 and
Less Than or Equal to 65 F — The TEMP system thermostat
utilizes the relay pack to energize the outside air economizer
after system cooling mode is selected. When the reference zone
cooling demand is 2.0° F or greater, the first stage of cooling is
energized or optimized staging is followed. The second stage
of cooling is energized when the reference zone cooling de-
mand is 2.5° F or greater and the first stage of cooling is ener-
gized. The second stage of cooling is released when demand
drops below 1.0° F. The economizer relay and the first stage
of cooling are deenergized when the system cooling mode is
released.
Outside-Air Temperature Below 55 F — The TEMP system
thermostat utilizes the relay pack to energize the outside air
economizer after system cooling mode is selected. When the
reference zone cooling demand is 2.0° F or greater, the first
stage of cooling is energized or optimized staging is followed.
The first stage of cooling cannot be energized until 5 minutes
after the economizer relay has been energized. The second
stage of cooling is energized when the reference zone cooling
demand is 2.5° F or greater and the first stage of cooling is en-
ergized. The second stage of cooling is released when demand
drops below 1.0° F. The economizer relay and the first stage of
cooling is deenergized when the system cooling mode is
released.
EQUIPMENT OPERATION DURING A SYSTEM HEAT-
ING MODE — The TEMP system thermostat utilizes the
relay pack to energize the first stage of heating after system
heating mode is selected. When the reference zone heating
demand is 2.0° F or greater, the second stage of heating is ener-
gized or optimized staging is followed. The second stage of
heating is released when demand drops below 1.0° F. The first
stage of heating is deenergized when the system heating mode
is released.
Optimize Staging —
The Optimize Staging function es-
tablishes a pattern for the changing temperature conditions of
the reference zone. If the zone temperature conditions are im-
proving, the TEMP system thermostat will not energize the
second stage of heating or cooling.
When the Optimize Staging option is configured to ON, the
TEMP system thermostat energizes the second stage heating or
cooling only if the zone temperature trend has not improved for
a 6-minute time limit. The 6-minute limit is reset if conditions
begin to improve.
When the Optimize Staging option is configured to OFF,
the TEMP system thermostat energizes the second stage heat-
ing or cooling normally.
To configure the Optimize Staging option, set category 4,
option 10. Use the left set point buttons to toggle the option ON
and OFF. The default is ON.
By preventing unnecessary use of the second stage heating
or cooling, the Optimize Staging option allows the heating/
cooling equipment to operate more economically without sac-
rificing individual zone comfort.
When zone temperature conditions exceed the desired occu-
pied level, if first stage heating or cooling is able to improve the
occupied level, second stage heating or cooling is not required.
The TEMP system thermostat uses Optimized Staging to
follow zone conditions and determine when use of first stage is
improving zone conditions. If zone conditions are not improv-
ing, or are becoming worse, the TEMP system thermostat will
energize the second stage of heating or cooling.
System Status Display —
The TEMP system thermo-
stat indicates the system mode and equipment operation by dis-
playing system annunciators. FAN is displayed when the
TEMP system thermostat energizes the fan relay. COOL is dis-
played when the TEMP system thermostat energizes a cooling
relay. HEAT is displayed when the TEMP system thermostat
energizes a heating relay. When a second stage of heating or
cooling is energized, a decimal point is displayed between the
set points.
System Time Guards —
The TEMP system thermostat
has different system time limits (time guards) which prevent an
individual system heating or cooling mode from being selected
after the system mode has been released or after the TEMP sys-
tem thermostat receives power.
HIGH/LOW TEMPERATURE LIMIT TIME GUARD —
This feature functions to keep the HVAC equipment operating
to reduce equipment cycling. By monitoring the supply-air
temperatures, the TEMP system thermostat can adjust opera-
tion to prevent tripping of the heating/cooling temperature
limits.
When the supply-air temperature exceeds the first or second
stage Heating or Cooling Temperature Limit the corresponding
stage of heating or cooling is disabled.
If the TEMP system thermostat is in a system mode, it will
reenergize the appropriate stages of heating or cooling when
10 minutes have passed and the supply-air temperature is no
longer exceeding the first or second stage Heating or Cooling
Temperature Limit.
During equipment operation, when a limit is exceeded, the
following relays are deenergized:
• Second Stage Limit. The second stage relay (H2 or C2) is
deenergized.
• First Stage Limit. The first stage relay (H1 or C1) is deener-
gized.
When the LAT (leaving-air temperature) Monitoring option
is set to ON, the TEMP system thermostat maintains system
heating and cooling supply-air temperature limits and enables
the LAT algorithm.
When the LAT Monitoring option is set to OFF, the TEMP
system thermostat will not maintain heating and cooling supply-
air temperature limits and the LAT algorithm is disabled.
To configure the LAT Monitoring option, set category 4,
option 4. Use the left set point buttons to toggle the option ON
and OFF. The default is ON.
First Stage Cooling Temperature Limit — If the duct
entering-air temperature drops below the First Stage Cooling
Temperature Limit and the LAT Monitoring function is ON,
the TEMP system thermostat will deenergize first stage
cooling.
To configure the First Stage Cooling Temperature Limit op-
tion, set category 4, option 5. Use the left set point buttons to
raise or lower the set point until the desired temperature is
shown. The range of acceptable values is 40 to 45 F, in one de-
gree increments. The default is 45 F.
NOTE: The first stage limit cannot be set higher than the sec-
ond stage limit.
Second Stage Cooling Temperature Limit — If the duct
entering-air temperature drops below the Second Stage Cool-
ing Temperature Limit and the LAT Monitoring function is
ON, the TEMP system thermostat will deenergize second stage
cooling.