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SINGLE STAGE HEAT PUMP PROGRAMMABLE COMMERCIAL THERMOSTAT
2.0
SEQUENCE OF OPERATIONS
The heating and cooling setpoints shall be individually adjustable for both the occupied and unoccupied periods. The
thermostat shall have a minimum deadband of 2 F (no mechanical heating or cooling shall operate within this
deadband). Space temperature deviation above the cooling setpoint or below the heating setpoint shall generate a
demand signal to control the system as follows.
2.1
Heating
2.1.1
The thermostat shall control the heating output based on the demand signal communicated from the
thermostat program, taking into account both space temperature deviation (proportional error) and the
duration of that temperature deviation (integral error).
2.1.2
The thermostat shall energize heating equipment when space temperature falls below heating
setpoint.
2.2
Cooling
2.2.1
The thermostat shall control the cooling output based on the demand signal communicated from the
thermostat program, taking into account both space temperature deviation (proportional error) and the
duration of that temperature deviation (integral error).
2.2.2
The thermostat shall energize cooling equipment when space temperature exceeds cooling setpoint.
2.3
Heating Setback and Cooling Setup
Initiation of heating setback or cooling setup for each of 7 days shall be provided by a programmed time
schedule manually entered into the thermostat. When all or a portion of a manually programmed schedule is
unavailable, the thermostat shall control to the default program as follows:
Heating Setpoints
Cooling Setpoints
2.4
Setpoint Recovery from Unoccupied to Occupied
The thermostat shall employ Intelligent Recovery™. This shall select the optimum time to begin building warm
up or cool down based on setpoints and occupied program as follows:
2.4.1
Heating: 5 F per hour.
2.4.2
Cooling: 5 F per hour.
2.5
Fan Operation
2.5.1
Fan operation shall be energized with calls for cooling and calls for heating (optional).
2.6
Heating and Cooling Operation Minimum On and Off Times
The thermostat shall incorporate a program to maintain minimum-stage operation in both the heating and
cooling:
2.6.1
Cooling: 2 minutes on and 4 minutes off.
2.6.2
Heating: 2 minutes on and 4 minutes off.
2.7
Power Interruption
The system shall cycle off and provide timed restaging of heating or cooling equipment upon restoration of
power. The restaging operation shall occur according to minimum stage operation times incorporated in the
thermostat. A power interruption is annunciated by a blank LCD display.
2.7.1
During a power interruption less than 2 hours, the thermostat retains all programmed occupied and
unoccupied start times and temperatures as well as the present time and day.
63-4361
Table of Default Program
Occupied
70 F (21 C)
78 F (26 C)
2
Unoccupied
55 F (13 C)
90 F (32 C)
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