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MechanicalSpecificationsVariable Frequency Drives (VFDs) shall
be factory installed and tested to
provide supply fan motor speed
modulation. The VFD shall receive a
2-10 VDC signal from the unit
microprocessor based upon supply
static pressure and shall cause the
drive to accelerate or decelerate as
required to maintain the supply static
pressure setpoint. When subjected to
high ambient return conditions
(>100°F) (>37.3°C) the VFD shall be
limited to a maximum output of 48
hertz until the temperature drops below
100°F (37.3°C). Bypass control to
provide full nominal air flow in the
event of drive failure shall be optional.
Ventilation Override shall allow a
binary input from the fire/life safety
panel to cause the unit to override
standard operation and assume one of
two factory preset ventilation
sequences, exhaust or pressurization.
The two sequences shall be selectable
based open a binary select input.
Outside Air
Manual Outside Air
A manually controllable outside air
damper shall be adjustable for up to
25 percent outside air. Manual damper
is set at desired position at unit
start up.
Economizer shall be factory installed.
The assembly includes: fully
modulating 0-100 percent motor and
dampers, minimum position setting,
preset linkage, wiring harness, and
fixed dry bulb control. Solid-state
enthalpy and differential enthalpy
control shall be as a factory or field
installed option.
Exhaust Air
Barometric Relief
The barometric relief damper shall be
optional with the economizer. Option
shall provide a pressure operated
damper for the purpose of space
pressure equalization and be gravity
closing to prohibit entrance of outside
air during the equipment off cycle.
Power Exhaust Fan
Power exhaust shall be available on all
units and shall be factory installed. It
shall assist the barometric relief
damper in maintaining building
pressurization.
Unit Options
Service Valves
Service valves shall be provided factory
installed and include suction, liquid,
and discharge three-way shutoff
valves.
Through-The-Base Electrical Provision
An electrical service entrance shall be
provided which allows access to route
all high and low voltage electrical
wiring inside the curb, through the
bottom of the outdoor section of the
unit and into the control box area.
Non-Fused Disconnect Switch
A factory installed non-fused
disconnect switch with external handle
shall be provided and shall satisfy NEC
requirements for a service disconnect.
The non-fused disconnect shall be
mounted inside the unit control box.
GFI Convenience Outlet
(Factory Powered)
A 15A, 115V Ground Fault Interrupter
convenience outlet shall be factory
installed. It shall be wired and powered
from a factory mounted transformer or
field powered through a separate 115V
circuit. Unit mounted non-fused
disconnect with external handle shall
be furnished with factory powered
outlet.
GFI Convenience Outlet
(Field Powered)
A 15A, 115V Ground Fault Interrupter
convenience outlet shall be factory
installed and shall be powered by
customer provided 115V circuit.
Hinged Service Access
Filter access panel and supply fan
access panel shall be hinged for ease of
unit service.
Condenser Coil Guards
Factory installed condenser vinyl
coated wire mesh coil guards shall be
available to provide full area protection
against debris and vandalism.
Accessories
Roof Curb
The roof curb shall be designed to
mate with the unit and provide support
and a water tight installation when
installed properly. The roof curb design
shall allow field-fabricated rectangular
supply/return ductwork to be
connected directly to the curb when
used with downflow units. Curb design
shall comply with NRCA requirements.
Curb shall ship knocked down for field
assembly and include wood nailer
strips.
Trane Communication Interface (TCI)
Shall be provided to interface with the
Trane Integrated Comfort system and
shall be available factory installed. The
TCI shall allow control and monitoring
of the rooftop unit via a two-wire
communication link.
The following alarm and diagnostic
information shall be available:
UCP Originated Data
Unit operating mode
Unit failure status
Cooling failure
Heating failure
Emergency service stop indication
Supply fan proving
Timed override activation
High temperature thermostat status
Zone temperature
Supply air temperature
Cooling status (all stages)
Stage activated or not
Stage locked out by UCP
HCP status for that stage
Compressor disable inputs
Heating status
Number of stages activated
High temperature limit status
Economizer status
Enthalpy favorability status
Requested minimum position
Damper position
Dry bulb/enthalpy input status
Outside air temperature
Outside relative humidity
Sensor Failure
Humidity sensor
OAT sensor
SAT sensor
RAT sensor
Zone temperature sensor
Mode input
Cooling/heating setpoints from sensors
Static pressure transducer
Unit mounted potentiometer
SAT from potentiometer
Air reset setpoint from potentiometer
Unit configuration data
Gas or electric heat
Economizer present
High temp input status
Local setpoint
Local mode setting
Inlet guide vane position