Sequence Of Operations - Honeywell T7351 Information

T7351 PROGRAMMABLE COMMERCIAL THERMOSTAT
E. Testing Guarantee
Service:

SEQUENCE OF OPERATIONS

The heating and cooling setpoints shall be individually adjustable for both the occupied, unoccupied and standby periods. The
thermostat shall have a minimum deadband of 2° F (1° C) (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:
A. Heating:
B. Cooling:
C. Economizer Interface: The auxiliary relay contacts of the subbase shall be connected to the economizer's minimum
D. Dehumidification:
E. Heating Setback and
Cooling Setup:
63-4372
Prior to installation, the contractor shall provide copies of submittals.
The contractor is responsible for assuring that conduit and wire quantity, size, and type are suitable
for the equipment supplied.
Upon completion, the contractor shall conduct a total system test for the owner and engineer.
All components, parts, and assemblies supplied by the manufacturer shall be guaranteed against
defects in materials and workmanship for 12 months.
Warranty service shall be performed by the contractor.
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 gain),
the duration of that temperature deviation (integral gain), and the rate of change of the deviation
(derivative gain).
The thermostat shall energize heating equipment when space temperature falls below heating
setpoint.
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 gain),
the duration of that temperature deviation (integral gain), and the rate of change of the deviation
(derivative gain).
The thermostat shall energize cooling equipment when space temperature exceeds cooling
setpoint.
(Optional Remote Equipment) A solid state enthalpy changeover control shall determine the
capability of the outdoor air to provide free cooling (optional). The system shall operate as follows:
a. Free cooling available from Outdoor Air: On a call for cooling, the system shall enable the
economizer to provide free cooling. If this does not meet the space demand, the system shall
call for mechanical cooling to satisfy the programmed setpoint.
b. Free Cooling Not Available From Outdoor Air: On a call for cooling, the system shall hold the
economizer to minimum position and cooling shall be energized to satisfy the programmed
setpoint.
position potentiometer or power circuit.
a. Occupied Period: The auxiliary relay contact will close, allowing the economizer to operate
normally and be available for free cooling if outdoor conditions permit.
b. Unoccupied Periods: The auxiliary relay contact will open, defeating the economizer
minimum position.
The thermostat shall provide five methods for dehumidification:
a. Minimum On - Increasing the compressor minimum on time.
b. Reset - lower the cooling setpoint.
c. Reheat - cooling and simultaneous reheat.
d. Auxiliary output - to external dehumidifier.
e. Hot gas bypass - auxiliary output operates depending on humidity level and number of active
cooling stages.
Initiation of heating setback or cooling setup for each of 7 or 365 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 shown in Table 1.
2