Trane Horizon OABE/F, Installation, Operation And Maintenance Manual

Page: 14 / 92

General Information
14 OAU-SVX004D-EN
Space Temperature / RH Sensor (Optional)
Field installed, wall mounted temperature sensor
(BAYSENS036A) and humidity to control space cooling,
heating and dew point.
High Temperature Sensor
The Discharge Air Temperature Sensor (DTC) supplies a
continuous signal to the MCM. Factory setting for
Discharge Air Temperature (DTC) Discharge Air
Temperature Setpoint (MDTS) is 90°F (adj 70–100°F), the
unit will be shut down, and require a manual restart if
Discharge Air Temperature exceeds MDTS for 10 minutes
(adj 10–25 minutes). If DAT exceeds Discharge Air High
Temperature Cutoff (DHCS) of 125°F for 10 minutes, the
unit will shut down and require manual restart.
Outdoor Air Temperature and Relative
Humidity Sensor
This factory installed combination outdoor air sensor
located in the outdoor air hood is designed to sense both
outdoor air temperature and relative humidity for use by
the microprocessor controller to make required
ventilation, cooling, dehumidification and heating
decisions. Control Input (Occupied / Unoccupied)
Terminals are provided on the terminal strip labeled
OAUTS for a field installed dry contact or switch closure to
put the unit in the Occupied or Unoccupied modes.
Hot Gas Reheat
This option shall consist of a hot-gas reheat coil located on
the leaving air side of the evaporator.
100 Percent Outdoor Air Hood with
Damper and Filters
Factory-installed and -integrated 100 percent outdoor air
hood with damper controlled by a direct coupled actuator
and 2 in. (50.80 mm) permanent and washable aluminum
mesh filters (mist eliminators) removable through a
hinged access panel. The unit is factory equipped with
provisions to accept an optional field installed100 percent
return air damper controlled by a direct coupled actuator
that is electrically interlocked with the outdoor air damper.
Modulating Indirect Gas-Fired Burner
The unit will have fully modulating, high turndown,
indirect gas-fired heat. The heating section will include
high turn-down burners and a stainless steel tubular heat
exchanger. The heat exchanger will be constructed of
type 439 stainless steel and be a tubular design capable of
draining internal condensate. External flue to be
constructed of type 430 stainless steel.
Units will be suitable for use with natural gas or Liquid
Propane (LP) gas.
Through the Base Electrical with
Disconnect Switch
Factory installed 3-pole, molded case disconnect switch
with provisions for through the base electrical connections
will be included. The disconnect switch, with integral
overcurrent circuit breaker, will be installed in the unit in a
water tight enclosure with access through a hinged door.
Factory wiring will be provided from the switch to the unit
high voltage terminal block. The switch will be UL/CSA
agency recognized.
Through the Base Gas Piping
The unit will include provisions for installing through the
base gas piping. The factory installed option will have all
piping necessary including an external shutoff piping yoke
with pre-assembled, manual gas shut-off valve, elbows,
and union. The manual shut-off valve will include an 1/8 in.
(3.17 mm) NPT pressure tap. This assembly will require
minor field labor to install.
Hinged Access Doors
Hinged access doors with hold open brackets will be
factory-installed.
Modulating Electric Heat
The unit may have fully modulating, SCR electric heat. The
primary heating section will include open coil heating
elements, automatic and manual cut-outs, low voltage
controls, air proving switch, maximum 48 amps per circuit
and fusing for heaters over 48 amps. For ductwork
installation, refer to
“Ductwork,” p. 38 .