make all heating, cooling and/or ventilating decisions in response to electronic signals from sensors measuring indoor and outdoor temperatures.The control algorithm maintains accurate temperature control, minimizes drift from set point and provides better building comfort. A centralized microprocessor shall provide anti-short cycle timing and time delay between compressors to provide a higher level of machine protection.
Control Options
Inlet Guide Vanes shall be installed on each fan inlet to regulate capacity and limit horsepower at lower system requirements.When in any position other than full open they shall pre-spin intake air in the same direction as fan rotation.The inlet guide vanes shall close when supply fan is off, except in night setback.
The inlet guide vane actuator motor shall be driven by a modulating dc signal from the unit microprocessor. A pressure transducer shall measure duct static pressure and modulate the inlet guide vanes to maintain the required supply air static pressure within a predetermined range.
Variable Frequency Drives (VFDs)
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 the VFD shall reduce its output frequency to maintain operation. Bypass control to provide full nominal air flow in the event of drive failure shall be optional.
Ventilation Override
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
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 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
ServiceValves
Service valves shall be provided factory installed and include suction, liquid, and discharge 3-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. 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.
LonTalk Communication Interface
Available either field or factory-installed for constant volume units. When installed on a constant volume unit, this LonTalk board will allow the unit to communicate as aTrane Comm5 device or directly with generic LonTalk Network Building Automation System Controls.
Stainless Steel Drain Pans
Sloped stainless steel evaporator coil drain pans are durable, long-lasting and highly corrosion resistant.
Black Epoxy Coated Condenser Coil
The coil provides corrosion protection to condenser coils for seacoast application. The protection is a factory applied thermoset vinyl coating, bonded to normal aluminum fin stock.The uniform thickness of the bonded vinyl layer exhibits excellent corrosion protection in salt spray tests performed in accordance with ASTM B117.
