HVAC Guide Specifications
Parallel Flow Terminal Fan Powered Units
Size Range:
90 to 2060 cfm
Carrier Model Number (45R Units):
45RA (Analog Electronic Control)
45RC (CCN VAV Electronic Control)
45RD (BACnet VAV)
45RN (No Control or DDC by Others)
45RP (Pneumatic Control)
45RV (CCN VVT)
45RB (BACnet VVT)
Part 1 — General
1.01 SYSTEM DESCRIPTION:
Fan powered terminal unit shall be completely factoryassembled and wired, with blower, blowermotor, mixing plenum and primary air damper containedin a single unit housing. Primary airflowcontroller shall compensate for central system pressurefluctuations. When room temperature requiresmaximum heating, the (direct digital electronic) (analogelectronic) (pneumatic) pressure independentvelocity controller shall maintain the minimum primaryairflow setting by modulating the damper. Theinduction fan shall run and the staged electric heatingcoil (hot water coil), if supplied, shall be energized(activated). As room temperature begins torise, the heating coil shall be deenergized (deactivated).As room temperature calls for maximumcooling, the velocity controller shall maintain themaximum primary airflow setting.
1.02 QUALITY ASSURANCE:
A. Terminals shall be certified by use of the AHRIStandard 880 Certification Program and carry theAHRI seal.
B. The terminal unit shall be ETL listed as a completeassembly. All electrical components shall be ULlisted and installed in accordance with the NEC. Allelectrical components shall be mounted in sheetmetal control enclosures. Electrical connections shallbe single point.
1.03 DELIVERY AND STORAGE
Units shall be stored and handled as per manufacturer’srecommendations.
Part 2 — Products
2.01 EQUIPMENT
A. General:
Factory assembled, externally powered, horizontalfan powered terminal unit with blower, blowermotor, mixing plenum and primary air damper containedin a single unit housing with a low heightphysical dimension of 105/8 inches.
B. Unit Cabinet:
1. Constructed of 20 gage zinc-coated steel. Allprimary air inlet collars shall accommodatestandard flex duct sizes. Unit discharge shall beround or rectangular, suitable for flanged ductconnection.
2. Unit casing shall be lined with dual density,1/2-in. thick, 11/2 lb density fiberglass insulationthat meets UL 181 and NFPA 90A.
3. (Optional) Foil Encapsulated Insulation:
Unit casing shall be lined with foil reinforced,wrapped edges, 1/2-in. thick, 11/2 lb densityfiberglass insulation that meets UL 181 andNFPA 90.
4. (Optional) Cellular Insulation:
Unit casing shall be lined with 3/8-in. thick,smooth surface, closed-cell elastomeric thermalinsulation for fiber free application.
C. Damper Assembly:
The primary air damper assembly shall be constructedof heavy gage steel with solid shaft rotatingin Delrin bearings. Damper blades shall incorporatea flexible gasket for tight airflow shutoff and operateover a full 90 degrees.
D. Fan(s):
Fan shall be of the forward curve, centrifugal type.The fan motor shall be single speed, single-voltage(120, 208/240, 277), 60 cycle, single phase,energy efficient design, permanently lubricated,using permanent split capacitor for starting and bespecifically designed for use with an SCR (fan speedcontroller). Motor must have thermal overload protection.The fan motor shaft shall be connecteddirectly to the fan and the entire fan assembly shallbe isolated from the unit casing to prevent transmissionof vibration.
E. Electrical Requirements:
Units shall have a single connection for power, andoperate on 120,208/240 or 277 vac (standard) singlephase, 60 Hz power as shown on the equipmentschedule. Units with three-phase electric heat shallbe factory wired for single point performance(including 208/240 v 3-wire or 480 v 4-wire).When specified and coordinated, units shall be wiredand shipped with proportionally connected phasing.
F. Controls:
1. Units shall have pressure-independent pneumatic,electronic, or communicating controls,as specified, capable of maintaining requiredairflow set points ± 5% of the unit's capacityat any inlet pressure up to 6 in. wg. The controllersshall be capable of resetting betweenfactory or field-set maximum and minimum(>350 fpm inlet duct velocity) set points to satisfythe room thermostat demand. The unitshall be equipped with a center point cross-mounted flow sensor. The sensor will providea differential pressure signal amplified to equalat least 2 times the velocity pressure with anaccuracy of at least ± 10% throughout therange of 350 to 2600 fpm inlet duct velocity,depending on the controller employed.
2. Sensor Type:
a. The unit shall be equipped with an amplifiedlinear averaging flow probe locatedhorizontally across the inlet. The sensorwill provide a differential pressure signalamplified to equal 3 times the velocity pressurewith an accuracy of at least ± 10%throughout the range of 350 to 2600 fpm inlet duct velocity, depending on the controller employed.
b. The unit shall be equipped with a four quadrant linear cross sensor. This is a multi-point center averaging, inlet flow sensor, available for use with pneumatic, analog electric and digital electric control type units.
G. Special Features:
1. Electric Heating Coil:
The terminal unit manufacturer shall supply electric coils and shall be UL listed. Construct coil casing with minimum of 20-gage zinc coated steel. Elements shall be 80/20 nickel chrome and supported by ceramic insulators. The integral control panel shall be housed in a NEMA 1 enclosure, with hinged access door for access to all controls and safety devices. Electric coils shall contain a primary automatic reset thermal cutout and differential pressure airflow switch for proof of airflow. Electric coils shall include fused or non-fused door interlocking disconnect switch, manual reset cutout, mercury contactors, fuse block, dust-tight enclosure construction, all mounted and/ or wired within the control enclosure.
2. Hot Water Coil:
Hot water coil casing shall be constructed with minimum 20 gage galvanized steel. Coils shall be factory installed on the terminal unit. Fins shall be rippled and corrugated heavy gage aluminum, mechanically bonded to tubes. Tubes shall be copper with minimum wall thickness of 0.016 in. and with male solder header connections. Coils shall be leak testedto 400 psig. Number of coil rows and circuitsshall be selected to provide performance asrequired by the plans. Coil performance datashall be based on tests run in accordance with AHRI Standard 410.