24-volt electromechanical control circuit shall include control transformer and contactor pressure lugs for power wiring. Units shall have single point power entry as standard.
Accessories/Options
Electric Heaters — Factory or field- installed electric heat modules shall be available for installation within basic unit. Electric heater elements shall be constructed of heavy-duty nickel chromium elements internally delta connected for 240 volt, wye connected for 480 and 600 volt. Staging shall be achieved through the unitary control processor (UCP). Each heater package shall have automatically reset high limit control operating through heating element contactors. All heaters shall be individually fused from the factory, where required, and shall meet all NEC and CEC requirements when properly installed. Power assemblies shall provide single-point connection. Electric heat modules shall be UL listed or CSA certified.
Roof Curb — The roof curb shall be designed to mate with the unit’s downflow supply and return 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. Curb design shall comply with NRCA requirements. Curb shall be shipped knocked down for field assembly and shall include wood nailer strips.
Economizer — This accessory shall be either field or factory-installed and shall be available with or without barometric relief.The assembly includes fully modulating 0-100 percent motor and dampers, minimum position setting, preset linkage, wiring harness with plug, spring return actuator and fixed dry bulb control.The barometric relief shall provide a pressure operated damper that shall be gravity closing and shall prohibit entrance of outside air during the equipment “off” cycle. Optional solid state or differential enthalpy control shall be available for either factory or field installation.The factory-installed economizer arrives in the shipping position and shall be moved to the
operating position by the installing contractor.
Powered Exhaust —The field installed powered exhaust, available for 6-10 ton units, shall provide exhaust of return air, when using an economizer, to maintain better bulding pressurization.
Remote Potentiometer — The minimum position setting of the economizer shall be adjusted with this accessory.
Manual Outside Air Damper — Factory or field-installed rain hood and screen shall provide up to 50 percent outside air.
Motorized Outside Air Dampers — Factory or field-installed manually set outdoor air dampers shall provide up to 50 percent outside air. Once set, outdoor air dampers shall open to set position when indoor fan starts.The damper shall close to the full closed position when indoor fan shuts down.
Discharge Air Sensing —This factory or field-installed option provides true discharge air sensing in heating models. This sensor is a status indicator readable throughTracer® orTracker®. This option is available for microprocessor controlled units.
Oversized Motors — Factory or field- installed direct drive oversized motors shall be available for high static applications.
Through the Base Electrical Access — An electrical service entrance shall be factory provided allowing electrical access for both control and main power connections inside the curb and through the base of the unit. Option will allow for field installation of liquid-tight conduit and an external field-installed disconnect switch.
Through the Base Electrical with Disconnect Switch — Factory-installed 3- pole, molded case, disconnect switch with provisions for through the base electrical connections are available.The disconnect switch will be installed in the unit in a water tight enclosure with access through a swinging door. Factory wiring will be provided from the switch to the unit high voltage terminal block. The switch will be UL/CSA agency recognized. Note:The disconnect switch will be sized per NEC and UL guidelines but will not be used in place of unit overcurrent protection.
Through the Base Electrical with Circuit Breaker —This option is a factory- installed, thermal magnetic, molded case, HACR Circuit Breaker with provisions for through the base electrical connections.The circuit breaker will be installed in a water tight enclosure in the unit with access through a swinging door. Factory wiring will be provided from the switch to the unit high voltage terminal block.The circuit breaker will provide overcurrent protection, be sized per NEC and UL guidelines, and be agency recognized by UL/CSA.
Powered or Unpowered Convenience Outlet —Thisfactory-installed option is a GFCI, 120v/15amp, 2 plug, convenience outlet, either powered or unpowered. When the convenience outlet is powered, a service receptacle disconnect will be available.The convenience outlet is powered from the line side of the disconnect or circuit breaker, and therefore will not be affected by the position of the disconnect or circuit breaker.This option can only be ordered when theThrough the Base Electrical with either the Disconnect Switch or Circuit Breaker option is ordered.
Clogged Filter/Fan Failure Switch — A dedicated differential pressure switch is available, factory-installed, to achieve active fan failure indication and/or clogged filter indication.These indications will be registered with either a zone sensor with status indication lights or an Integrated Comfort™ System.This option is available for microprocessor controlled units.
Reference or Comparative Enthalpy — Factory-installed Reference or Comparative Enthalpy option shall be available when a factory-installed Economizer is ordered.This option is available for microprocessor controlled units.
High Pressure Cutout —This factory- installed option is offered for units that do not have High Pressure cutout as standard. All 3-phase units with scroll compressors include High Pressure Cutout as standard.
Hinged Access Doors — Sheet metal hinges are available factory-installed on the Filter/Evaporator, Supply Fan/Heat, and the Compressor/Control Access Doors.
