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General Information
Unit Nameplate
One Mylar unit nameplate is located on the outside of
enclosure. It includes the unit model number, serial
number, electrical characteristics, refrigerant charge, unit
wiring diagram numbers, as well as other pertinent unit
data. A small metal nameplate with the Model Number,
Serial Number, and Unit Weight is located just above the
Mylar nameplate, and a third nameplate is located on the
inside of the control panel door.
Compressor Nameplate
The Nameplate for the Scroll Compressor is located on the
compressor lower housing. Max amps is listed on the
nameplate and is the absolute highest amp load on the
compressor at any operating condition (does not include
locked rotor amps or inrush). This value should never be
exceeded.
Gas Heat Nameplate
The nameplate for the Gas Heater is located on the inside
of the gas heat enclosure. Allowable operating values of
Min and Max input rate, manifold pressure, and air rise for
the heater is listed on the nameplate.
Unit Description
Table 1. Available tonnages
Air Cooled Tonnages
Each one-piece rooftop air conditioner ships fully
assembled from the factory. An optional roof curb,
specifically designed for the S_HN units is available from
Trane. The roof curb kit must be field assembled and
installed according to the latest edition of the roof curb
installation manual.
Trane Commercial Rooftop Units are controlled by a
Symbio™ 800 control system that consists of a network of
modules and are referred to as Low Level Intelligent
Devices (LLID). The acronym (LLID) is used extensively
throughout this document when referring to the control
system network. These modules through Proportional/
Integral control algorithms perform specific unit functions
which provide the best possible comfort level for the
customer.
They are mounted in the control panel and are factory
wired to their respective internal components. They receive
10
90
105
120
130
150
and interpret information from other unit modules, sensors,
remote panels, and customer binary contacts to satisfy the
applicable request for economizing, mechanical cooling,
heating, and ventilation. Refer to the following discussion
for an explanation of each module function.
Note: The Symbio™ 800 coin cell tray should never be
taken out unless the Symbio 800 is powered on or
the Symbio 800 needs to be powered on shortly
after replacing the battery. Failure to do this may
shorten the battery life.
Ventilation Override Module
IKF12
The Ventilation Override module initiates specified
functions such as; space pressurization, exhaust, purge,
purge with duct pressure control, and unit off when any one
of the five (5) binary inputs to the module are activated. The
compressors and condenser fans are disabled during the
ventilation operation. If more than one ventilation sequence
is activated, the one with the highest priority is initiated.
High Pressure Limit Controls
High Pressure controls are located on the discharge lines
near the scroll compressors. They are designed to open
when the discharge pressure approaches 650 ± 10 psig.
The controls reset automatically when the discharge
pressure decreases to approximately 550 ± 10 psig.
However, the compressors on that circuit are locked out
and a manual reset diagnostic is initiated after the fourth
occurrence of a high pressure condition.
Morning Warm-Up—Zone Heat
When a system changes from an unoccupied to an
occupied mode, or switches from STOPPED to AUTO, or
power is applied to a unit with the MWU option, the heater
in the unit or external heat will be brought on if the space
temperature is below the MWU setpoint. The heat will
remain on until the temperature reaches the MWU setpoint.
If the unit is VAV, then the VAV box/unocc relay will
continue to stay in the unoccupied position and the VFD
output will stay at 100% during the MWU mode. When the
MWU setpoint is reached and the heat mode is terminated,
then the VAV box/unocc relay will switch to the occupied
mode and the VFD output will be controlled by the duct
static pressure. During Full Capacity MWU the economizer
damper is held closed for as long as it takes to reach
setpoint. During Cycling Capacity MWU the economizer
damper is allowed to go to minimum position after one hour
of operation if setpoint has not been reached.
Compressor Motor Winding Thermostats
A thermostat is embedded in the motor windings of each
Scroll compressor. Each thermostat is designed to open if
the motor windings exceed approximately 221°F. The
thermostat will reset automatically when the winding
RT-SVX073A-EN
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