General Operation Information - Honeywell T7200D Product Data

T7200D,E, T7300D,E,F AND Q7300 SERIES 2000 PROGRAMMABLE COMMERCIAL THERMOSTATS AND SUBBASES
Intelligent Recovery® Feature
Intelligent Recovery® feature is a Honeywell trademark for
the way the thermostat controls the heating and cooling
equipment during recovery from Unoccupied to Occupied
setting. During recovery, the control point changes gradually
rather than jumping from the energy saving setting to the
comfort setting all at once.
When the Intelligent Recovery® feature is used in heating,
the control point raises gradually, maximizing the use of the
more economical first stage heat to bring the sensed
temperature to the desired comfort setpoint. This minimizes
using the typically more expensive second-stage heat.
The advantages are:
• Comfort setting is achieved at the programmed time and
maintained regardless of weather conditions; occupants
are comfortable.
• Drafts from low temperature discharge air are minimized
during occupied periods.
• Thermostat automatically uses the more economical first
stage of heat as the primary heat source during recovery,
avoiding the use of the expensive second stage heating.
• Comfort and energy savings can be achieved in both
heating and cooling.
• The thermostat reduces heat cycling, extending
equipment life.
Recovery from Unoccupied
The heating heat pump recovery ramp is 3°F per hour, which
differs from the 5°F per hour for conventional systems. The
3°F helps the system use the economical heat pump more
and the expensive auxiliary heat less. The cooling ramp is
5°F, the same as for conventional systems.
Conventional System
The T7200 and T7300D,F Thermostats with Q7300A,G
Subbases are designed for conventional heat/cool applications.
Heat Pump Operation
The T7200E and T7300E,F Thermostats with Q7300C,D
Subbases are used for heat pump applications. Additional
information is required when configured for heat pump
applications.
O and B Terminals for Heating or Cooling Changeover
The Q7300C controls heat pump changeover. The Q7300D is
only used in a heat pump application when the heat pump
controls the reversing valve changeover. See Table 13 for the
operation of the O and B terminals on the Q7300C.
O and B Terminals on a Conventional Subbase
Conventional subbase O and B terminals can be used to
drive dampers and valves. The O terminal is energized on a
call for cooling and the B terminal is energized on a call for
heating.
63-4355—1
Table 13. Operation of Q7300 O and B terminals.
System Selection
Heat
Cool
a
Auto (Heat)
b
Auto (Cool)
Emergency Heat
Off
a
When the system is calling for heat or is de-energized, but
the last function was heat.
b
When the system is calling for cool or is de-energized, but
the last function was cool.
c
When the last function was heating, the operation is the
same as Auto (Heat). If the last function was cooling, the
operation is the same as Auto (Cool).
Fan Operation
When the fan is set to On, the fan is energized continuously
in the Occupied period. The Auto setting energizes the fan
with the heating or cooling system. If the subbase is Q7300D,
the fan cycles with Y1 and W1 during Unoccupied period.
Emergency Heat
When the system is set for Em Heat (on select T7300
Thermostats), the auxiliary heat is stage one and the
compressor stages are locked off. The fan cycles with the
auxiliary heat.

GENERAL OPERATION INFORMATION

Cycle Rates
The thermostat control algorithm maintains the temperature
by cycling stages of heating or cooling to meet setpoint.
Subbase Auxiliary Relay
The Q7300 Auxiliary Relay output acts as a time-of-day
switch to be used with an economizer minimum position
control. The normally open (A1) auxiliary relay contacts are
closed during the Occupied period and open during the
Unoccupied period. The normally closed (A3) auxiliary relay
contacts are open during the Occupied period and closed
during the Unoccupied period. The contacts are in the normal
state during recovery.
22
O Terminal B Terminal
Open Closed
Closed Open
Open Closed
Closed Open
Open Closed
c c