Trane RRU150F N Series Installation, Operation And Maintenance Manual page 10

General Information
Low Pressure Control
ReliaTel Control
When the LPC is opened for one continuous second, the
compressor for that circuit is turned off immediately. The
compressor will not be allowed to restart for a minimum
of three minutes.
If four consecutive open conditions occur during the first
three minutes of operation, the compressor will be locked
out, and a manual reset will be required to restart the
compressor.
Dual Refrigerant Circuits
The two independent refrigerant circuits incorporate a
split face coil with thermal expansion valves (TXVs),
service pressure ports and refrigerant line filter driers as
standard. An area will be provided for replacement suction
line driers. Refrigerant circuit one (1
with a factory installed and preset refrigerant capacity
control (RCC) to prevent evaporator coil temperatures
below approximately 38°F (109 lb suction).
High Pressure Control ReliaTel Control
The high pressure controls are wired in series between the
compressor outputs on the RTRM and the compressor
contactor coils. If the high pressure control switch opens,
the RTRM senses a lack of current while calling for cooling
and locks the compressor out.
On dual circuit units, if the high pressure control opens,
the compressor on the affected circuit is locked out. A
manual reset for the affected circuit is required.
Space RH Sensor (Optional) (4190-7019)
Field installed, wall mounted humidity sensor is used to
control activation of the hot gas reheat dehumidification
option. Humidity set points can be selected for relative
humidity levels between 40 percent and 60 percent.
Space Temperature Sensor (Optional)
(4190-1094)
Field installed, wall mounted temperature sensor with
adjustable cooling setpoint thumb wheel is used to control
space cooling and heating setpoints.
High Temperature Sensor (BAYFRST001A)
This sensor connects to the RTRM Emergency Stop Input
on the LTB and provides high limit "shutdown" of the unit.
The sensor is used to detect high temperatures due to fire
in the air conditioning or ventilation ducts. The sensor is
designed to mount directly to the sheet metal duct. Each
kit contains two sensors. The return air duct sensor is set
to open at 135°F. The supply air duct sensor is set to open
at 240°F. The control can be reset after the temperature has
been lowered approximately 25°F below the cutout
setpoint.
10
st
Stage) is equipped
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. Refer to "Sequence of Operation," p. 18
detailed unit control and operational modes.
Control Input (Occupied/Unoccupied)
Terminals are provided on the terminal strip labeled
RRUTS 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 coil pre-piped and
circuited with a low pressure switch. Refer to
Operation," p. 18 for detailed unit control and operational
modes.
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 accessible through a hinged access panel. The
unit is factory equipped with provisions to accept an
optional field installed 100 percent return air damper
controlled by a direct coupled actuator that is electrically
interlocked with the outdoor air damper to allow
100 percent return air recirculation in the Unoccupied
cooling mode. The standard damper tray is blocked off to
allow 100 percent outdoor airflow.
Modulating Indirect Gas-Fired Unit Heater
The unit will have fully modulating, high turndown,
indirect gas-fired, Category IV unit heater. The heating
section will include a high turndown power burner and a
stainless steel heat exchanger. The power burner shall
have a modulating range from 30 MBh low fire to full firing
rate. The heat exchanger will be constructed of type 304
stainless steel and be a drum and tube design capable of
draining internal condensate to an external s/s flue and
drain tube assembly.
Units will be suitable for use with natural 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 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.
for
"Sequence of
RRU-SVX02F-EN