User Guide

TStatSpec
TM
18
CONFIGURE T7350 THERMOSTAT
Intro and Links Configuring T7350
The T7350 is a full-featured commercial programmable
thermostat. The primary opportunity for a commercial
thermostat is in buildings of less than 55,000 square feet.
Examples of these buildings include restaurants, shopping
malls, office buildings and banks. Commercial thermostats are
used on single zone rooftop units, split systems, heat pumps
or hot/chilled systems.
The electronic thermostat consists of two pieces - the cover
assembly and a subbase. The subbase includes the
equipment control connections. The subbase is mounted on
the wall and the thermostat cover assembly is mounted on the
subbase. Different subbases will be used for different
applications including up to Three Heat/Three Cool or Two
Heat/Four Cool, modulating outputs, and dehumidification
high limit control. Each subbase is compatible with the
common cover assembly.
System Level Block Diagram
Fig. 24 illustrates a thermostat system level context diagram.
The next generation thermostat is capable of interfacing with
remote HVAC equipment controls, external sensors and
switches, and a remote wall module. External sensors and
switches include discharge air temperature, outdoor air
temperature, and humidity and occupancy sensor. The remote
wall module includes capability for temperature sensor,
override switch with LED, and warmer/cooler knob.
Fig. 24. System Context Diagram
The thermostat has serial communications to allow
communications with an installer configuration tool and a
future communicating subbase. The thermostat is configured
using Installer Setup through the thermostat keys for basic
setup functions. More advanced features are available
through an installer configuration tool. The installer
configuration tool is compatible with a Palm™ OS handheld
computer. See Fig. 25.
Fig. 25. System Communication Overview
The communicating subbase contains relays, humidity sensor
and power supply.
A Palm Personal Digital Assistant may be connected to the
thermostat via an RJ45 connector and used to configure or
program the thermostat.
Features
• 8-day programming
• Two Occupied and two Unoccupied periods per day
• Individual heat, cool and standby setpoints available for
Occupied and Unoccupied periods.
• Proportional plus Integral (P + I) control eliminates
temperature fluctuations
• Intelligent Recovery control automatically optimizes
equipment start times based on building load
• Intelligent Fan™ feature energizes fan continuously in the
Occupied periods. Fan can also be configured for
conventional heat(OFF with Heat) or electric heat(ON with
Heat) fan operation.
• Convenient overrides allow temporary set point changes.
• Keypad lockout available.
Non-Communicating Subbase
Non-Communicating Subbases have one of the following
configurations:
Three Heat /Three Cool:
This Subbase allows for conventional or heat pump operation.
A total of eight relays are available with thermostat cover
assembly and subbase. The auxiliary relay may be configured
for an economizer, TOD, or dehumidification. This sub base
may be configured for 2 Heat / 4 Cool by using the third stage
of heat for an additional stage of cooling.
4 additional relays: Stage 2 heating, Stage 3 heating (or Stage
4 cooling relay), Stage 2 cooling, and Stage 3 cooling.
• Remote Room Sensor, T7770 or TR 21 or TR22 or TR23
or TR24 / T7771 Wall Module.