Product Data. Features/Benefits. 50PQ Single-Package Rooftop Heat Pump Units 50 Hz. Nominal 52.8 kw (15 Tons)

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1 Product Data 50PQ Single-Package Rooftop Heat Pump Units 50 Hz Nominal 52.8 kw (15 Tons) Single-Package Rooftop Heat Pump Unit with the Following Innovative Standard Features: Cycle-LOC compressor anticycle protection Chronotemp defrost controls high- and low-pressure cutout switches and freeze protection thermostat suction line accumulators on each independent circuit two-in. return-air filters refrigerant filter driers galvanized steel cabinet with prepainted protection on all externally-exposed surfaces single power entry to unit Features/Benefits Compact, vertical discharge units easily convert to horizontal discharge, combining installation flexibility with efficient performance and easy maintenance. Easy maintenance and conversion All units are factory shipped in the vertical discharge configuration for fit-up to standard roof curbs, but can be easily converted to horizontal discharge with the use of one of the horizontal supply/return curbs or adapter. Compact and self contained, the unit is readily transported, rigged, and installed. Prepunched lifting holes and factory-supplied lifting hardware make the rigging job easier still. The terminal board located in the base unit control box allows easy connection to room thermostat, outdoor thermostat(s), economizer, and electric heat. Self-supporting panels allow quick removal for easy servicing. Copyright 1995 Carrier Corporation Form 50PQ-C1PD

2 The convenient slide-in filter track holds 51 mm (2-in.) filters, permitting easy maintenance. Efficient operation, dependable performance Built with energy efficiency in mind, the 50PQ cooling coils use copper tubing and mechanically bonded aluminum plate fins. All coils are completely degreased at the factory to eliminate coil blowoff problems. The 50PQ016 unit features two rugged semi-hermetic compressors with positive lubrication, vibration isolators, crankcase heater, and reliable, internal motor protection. Two independent refrigerant and electrical circuits, each with its own compressor, reversing valve, expansion device, coil circuit, and Cycle-LOC device protection, improve part-load efficiency and reduce operating costs while providing standby reliability. Special check valves and capillary tube refrigerant metering provide improved heat transfer for the best performance possible during both heating and cooling modes. The patented Chronotemp defrost system uses time and temperature to keep the outdoor coil frost-free for economical, dependable cooling operation at temperatures down to 4.4 C (40 F) as shipped from the factory. Accessory Motormaster head pressure control permits unit operation in cooling at outdoor ambient temperatures down to 29 C ( 20 F). Refrigerant circuit protection assures dependability. Loss-of-charge/ low-pressure cutout protection allows operation at lower ambient conditions while protecting against low-charge operation. Freeze protection thermostat protects against indoor coil frost buildup. High-pressure switch protects against above normal operating pressure. Replaceable filter driers trap moisture and dirt. Capillary tube refrigerant metering precisely controls refrigerant flow, preventing slugging and floodback, while maintaining optimum unit performance. Units equipped with economizer have a thermostatically controlled, fully modulating damper which admits up to 100% outdoor air and provides low-cost cooling. Dry bulb thermostat governs economizer cooling changeover to provide lowest cost operation in mild weather. Belt-driven indoor-air fans provide quiet and efficient operation. The beltdriven indoor-fan motor allows available static pressure to be adjusted to meet job requirements. In addition, indoor fans are capable of moving ample air quantities and achieving high external static pressures suitable for the most demanding applications. Direct-drive outdoor-air fans are factory lubricated and positioned for quiet, efficient vertical discharge. Carrier-specified semi-hermetic compressors are equipped with crankcase heaters and internal linebreak for protection against overcurrent and over-temperature conditions, as well as Cycle-LOC compressor Table of contents protection. If any safety device trips, Cycle-LOC compressor protection prevents short cycling by shutting off the compressor until the Cycle-LOC protection mechanism is reset. Compressor restart is accomplished at the space thermostat. The crankcase heater prevents refrigerant dilution of oil during off cycles, ensuring proper lubrication at all times and prolonging compressor life. The weather-resistant cabinet is designed for durability under all climatic conditions. The unit cabinet is made of Carrier Weather Armor galvanized steel, which is bonderized and prepainted for long life and attractive appearance, and provides protection on all externally exposed surfaces. Page Features/Benefits...1,2 Model Number Nomenclature...2 Physical Data...3 Standard Capacity Ratings...4 Options and Accessories...4,5 Base Unit Dimensions...6 Accessory Dimensions...7,8 Selection Procedure...9,10 Performance Data Electrical Data...16 Typical Piping and Wiring...16 Typical Wiring Schematic...17 Controls...18 Application Data...19,20 Guide Specifications Model number nomenclature 2

3 Physical data SI OPERATING WEIGHT (Kg) Base Unit 795 Unit with Economizer 864 Roof Curb 91 COMPRESSOR Quantity...Type DA8180 Oil (L) 2.6 (each) REFRIGERANT (Capillary Control) R-22 Charge (Kg) System System OUTDOOR COIL Copper Tubes, Aluminum Fins Rows 3 Fins/m 550 Total Face Area (m 2 ) 2.06 OUTDOOR AIR FAN Propeller Type, Direct Drive Nominal Airflow (L/s) 4760 Quantity...Diameter (mm) Motor (kw) 0.75 INDOOR COIL Copper Tubes, Aluminum Fins Rows 3 Total Face Area (m 2 ) 1.7 INDOOR AIR FAN Centrifugal, Adjustable, Belt Driven Quantity...Size (mm) x 254 Nominal Airflow (L/s) 2450 Speed Range (r/s) Maximum Allowable Speed (r/s) Fan Pulley Pitch Diameter (mm) 132 Speed Change per Full Turn of Movable Pulley Flange (r/s) 0.87 Movable Pulley Max Full Turns from Closed Position 5.4 Factory Speed Setting (r/s) 19.0 INDOOR AIR FILTER, Type Fiberglass Quantity...Size (mm) x 508 x x 508 x 50 NOTE: System 1 consists of upper portion of outdoor coil and lower portion of indoor coil, and System 2 consists of upper portion of the indoor coil and lower portion of outdoor coil. Physical data English OPERATING WEIGHT (lb) Base Unit 1750 Unit with Economizer 1900 Roof Curb 200 COMPRESSOR Quantity...Type DA8180 Oil (oz) 88 (each) REFRIGERANT (Capillary Control) R-22 Charge (lb) System System OUTDOOR COIL Copper Tubes, Aluminum Fins Rows 3 Fins/in. 14 Total Face Area (sq ft) 22.2 OUTDOOR AIR FAN Propeller Type, Direct Drive Nominal Airflow (Cfm) 10,100 Quantity...Diameter (in.) Motor (Hp) 1.0 INDOOR COIL Copper Tubes, Aluminum Fins Rows 3 Total Face Area (sq ft) 18.3 INDOOR AIR FAN Centrifugal, Adjustable, Belt Driven Quantity...Size (in.) x 10 Nominal Airflow (Cfm) 5200 Speed Range (rpm) Maximum Allowable Speed (rpm) 1450 Fan Pulley Pitch Diameter (in.) 5.2 Speed Change per Full Turn of Movable Pulley Flange (rpm) 52 Movable Pulley Max Full Turns from Closed Position 5.4 Factory Speed Setting (rpm) 1140 INDOOR AIR FILTER, Type Fiberglass Quantity...Size (in.) x 20 x x 20 x 2 NOTE: System 1 consists of upper portion of outdoor coil and lower portion of indoor coil, and System 2 consists of upper portion of the indoor coil and lower portion of outdoor coil. 3

4 Standard capacity ratings SI and English STANDARD COOLING HIGH-TEMPERATURE HEATING LOW-TEMPERATURE HEATING AIRFLOW Capacity Power Capacity Power Capacity Power Input Input COP Input COP L/s Cfm kw 1000 Btuh (kw) kw 1000 Btuh (kw) kw 1000 Btuh (kw) , , , COP Coefficient of Performance NOTE: Standard ratings are net values, reflecting the effects of circulating fan motor power and heat. Cooling Standard: 26.7 C (80 F) db, 19.4 C (67 F) wb indoor entering air temperature and 35 C (95 F) db air entering outdoor unit. High-Temperature Heating Standard: 21.2 C (70 F) indoor entering air temperature and 8.3 C (47 F) db, 6.1 C (43 F) wb air entering outdoor unit. Low-Temperature Heating Standard: 21.1 C (70 F) indoor entering air temperature and 8.3 C (17 F) db, 9.4 C (15 F) wb air entering outdoor unit. Options and accessories ITEM OPTION* ACCESSORY Integrated Economizer X X Electric Heater X X Emergency Heat Package and Relays X Roof Curbs (Vertical and Horizontal) X Horizontal Adapter X Remote Control Panel X Thermostat and Subbase X Time Guard Control Device X Power Exhaust X Two-Position Damper X Barometric Relief Damper X Motormaster Head Pressure Control X Glycol Coil X *Factory Installed. Field Installed. HEAD PRESSURE CONTROL The 50PQ016 standard units are designed to operate at outdoor temperatures down to 1.7 C (35 F). With accessory Motormaster control (condenser-fan speed modulation), units can operate at outdoor temperatures down to 29 C ( 20 F). The head pressure control, which mounts in the outdoor-air section, modulates the outdoor-fan motor to maintain correct condensing temperature. Refer to price pages for more details, or contact your local Carrier representative. THERMOSTAT GLYCOL COIL Zone thermostat (24 v) provides one- or 2-stage cooling for control of unit. Matching subbases are available with or without tamperproof switches and automatic changeover. Glycol coil is intended for add-on type applications or new work where a boiler system is available. Glycol coil and electric heat cannot be installed together. NOTE: Dimensions in ( ) are in millimeters. 4

5 ELECTRIC HEATER POWER EXHAUST When used with accessory/optional economizer, power exhaust helps to relieve building overpressurization. Available either as a factory-installed option or for field installation with high-temperature limit switches and overcurrent protection. Nominal heating capacity of this heater is 36 kw. An emergency heat subbase and relay are included to allow the compressor to be switched off manually and electric heat to be switched on manually if the system malfunctions. This feature can also be used for quick morning warm-up or to lock out compressor. 5

6 Base unit dimensions NOTES: 1. Space required for service clearance and airflow: Allow 1.8 m (6-0 ) above the unit; 2.1 m (7-0 ) on filter access panel end; and 1.2 m (4-0 ) on remaining sides of unit. 2. Dimensions in ( ) are in millimeters. 6

7 Accessory dimensions ROOF CURBS AND HORIZONTAL ADAPTER NOTE: To prevent the hazard of stagnant water build-up in the drain pan of the indoor-air section, unit can only be pitched as shown. LEGEND COMP SECT. Compressor Section NOTES: 1. Roof curb accessory is shipped unassembled. 2. Insulated panels, 1 2-in. thick neoprene-coated, 2 lb density. 3. Dimensions in ( ) are in millimeters. 4. Direction of airflow. 5. Roof curb: 18 gage steel. 6. Attach all ductwork to roof curb. ACCESSORY CURB PACKAGE NO. HEIGHT DESCRIPTION A B C 50PQ (305) Standard Curb 14 High 50PQ (610) Standard Curb for Units Requiring High Installation 50PQ (610) Horizontal Supply and Return Curb 5-6 (1676) (64) 1-6 (457) 50DP (584) Pre-Assembled, High-Static, Horizontal Adapter 6-2 (1880) (159) (371) 7

8 Accessory dimensions (cont) HORIZONTAL SUPPLY/RETURN ADAPTER NOTES: 1. The 50DP is a fully factory preassembled horizontal adapter which includes an insulated high static regain transition duct to substantially improve fan static performance. 2. Dimensions in ( ) are in millimeters. ACCESSORY REMOTE CONTROL PACKAGE (Accessory Remote Control Panel and Accessory Thermostat Shown) NOTE: Dimensions in ( ) are in millimeters. 8

9 Selection procedure SI I Determine job requirements. Estimated cooling requirements: Cooling load Total Capacity (TC)...40 kw Sensible Capacity (SHC) kw Outdoor-Air Temperature (OAT) C Temperature of Air Entering Indoor Coil Dry-bulb (Edb)...27 C Wet-bulb (Ewb) C Air Quantity (flow rate) L/s External Static Pressure (ESP) (loss in ducts and diffuser) kpa Estimated heating requirements: Heating load...35 kw at Winter Design Temperature... 8 C Temperature of Air Entering Indoor Coil...21 C Power Supply Options: Economizer, Electric Heat. II Determine unit size. Select unit on cooling capacity required. Enter cooling capacity table at required air quantity (2500 L/s) and indoor coil entering wet-bulb temperature (20 C). Read down table for gross total capacity (TC) and gross sensible capacity (SHC) opposite the condenser entering air temperature (36 C). Read a TC of 46 kw and SHC of 33.4 kw. Unit power requirements is 15.2 kw. (These gross capacities must be adjusted for the effects of indoor fan motor heat and the sensible heat capacity needs to be further adjusted for dry-bulb temperature other than 26.7 C. See sections IV and V.) To correct gross sensible heat capacity for an entering air dry-bulb of 27 C, use the formula (Note 3, Cooling Capacity table). Corrected SHC kw = SHC + [1.23 x 10-3 (1 BF) x (Cdb 26.7) x L/s] SHC = [1.23 x 10-3 x (1 0.06) x ( ) 2500] kw = = 34.3 kw III Heating requirements. To obtain indoor fan motor heat (kw), all accessory pressure drops must be considered, including any requirement for accessory electric heat. Enter integrated heating ratings at 2500 L/s and 21 C Edb. At 8 C (air entering outdoor coil) find 23.5 kw integrated heating capacity at 9.8 kw input. The heating load requirement is 35 kw at 8 C, thus 11.5 kw of supplementary electric heat is needed. The 36 kw heater will easily meet the requirements. IV Determine indoor fan performance. To obtain the ESP of the fan, the ESP of the ductwork must be added to the pressure drops of the accessories. Air requirement of system is 2500 L/s at 0.20 kpa ESP (duct resistance). The electric heater pressure loss is kpa and loss in economizer option is kpa; the total fan ESP is the sum of these, or kpa. From the fan performance table, Pa ESP at 2500 L/s of air requires 2.11 kw at 21.6 r/s (by interpolation). V Adjust capacities for effects of indoor fan motor heat. Net adjusted capacities are obtained by adding fan heat to integrated heating capacity and subtracting fan heat from gross cooling capacities. Total power requirements are increased by the fan kw. kw shaft 2.11 kw input = = = 2.64 kw motor efficiency 0.80 Adjusted Integrated Heating Capacity = = kw Unit power required (heating) = = kw (plus any electric heat) Net Total Cooling Capacity = = kw Net Sensible Heat Capacity = = kw Total unit power required (cooling) = = kw 9

10 Selection procedure English I Determine job requirements. Estimated cooling requirements: Cooling load Total Capacity (TC)...112,000 Btuh Sensible Capacity (SHC)...90,000 Btuh Outdoor-Air Temperature (OAT)... 95F Temperature of Air Entering Indoor Coil Dry-bulb (Edb)...81F Wet-bulb (Ewb)... 67F Air Quantity (flow rate) cfm External Static Pressure (ESP) (loss in ducts and diffuser) in. wg Estimated heating requirements: Heating load...115,000 Btuh at Winter Design Temperature...17F Temperature of Air Entering Indoor Coil...70F Power Supply Options: Economizer, Electric Heat. II Determine unit size. Select unit on cooling capacity required. Enter cooling capacity table at required air quantity (5000 cfm) and indoor coil entering wet-bulb temperature (67 F). Read down table for gross total capacity (TC) and gross sensible capacity (SHC) opposite the condenser entering air temperature (95 F). Read a TC of 155,000 Btuh and SHC of 116,000 Btuh. Unit power requirements is 14.8 kw. (These gross capacities must be adjusted for the effects of indoor fan motor heat and the sensible heat capacity needs to be further adjusted for dry-bulb temperature other than 80 F. See sections IV and V.) To correct gross sensible heat capacity for an entering dry-bulb of 81 F, use the formula (Note 3, Cooling Capacity table). Corrected SHC Btuh = SHC + [1.10 x (1 BF) x (Fdb 80) x cfm] Btuh SHC = 116,000 + (1.10) x (1 0.05) x (81 80) x 5000 = 116, = 121,225 Btuh III Heating requirements. To obtain indoor fan motor heat (kw), all accessory pressure drops must be considered, including any requirement for accessory electric heat. Enter integrated heating ratings for the unit at 5000 cfm, 70 F Edb. At 17 F (air entering outdoor coil) find 79,000 Btuh integrated heating capacity at 9.8 kw input. The heating load requirement is 115,000 Btuh at 17 F. Thus 36,000 Btuh of supplementary electric heat is needed. The 36 kw (123,000 Btuh) heater will easily meet the requirements. IV Determine indoor fan performance. To obtain the ESP of the fan, the ESP of the ductwork must be added to the pressure drops of the accessories. Air requirement of system is 5000 cfm at 0.8 in. wg ESP (duct resistance). The electric heater pressure loss is 0.08 in. wg and loss in economizer option is 0.05 in. wg; the total fan ESP is the sum of these, or 0.93 in. wg. From the fan performance table, 0.93 in. wg ESP at 5000 cfm of air requires 2.50 Bhp at 1251 rpm (by interpolation). V Adjust capacities for effects of indoor fan motor heat. Net adjusted capacities are obtained by adding fan heat to integrated heating capacity and subtracting fan heat from gross cooling capacities. Total power requirements are increased by the fan kw. Bhp x kw/bhp kw input = motor efficiency 2.50 x = = 2.33 kw 0.80 Heat equivalent (Btuh) = 2.33 kw x 3412 Btuh per kw = 7950 Btuh Adjusted Integrated Heating Capacity = 79, = 86,950 Btuh Unit power required (heating) = = kw (plus any electric heat) Net Total Cooling Capacity = 155, = 147,050 Btuh Net Sensible Heat Capacity = 121, = 113,275 Btuh Total unit power required (cooling) = = kw 10

11 Performance data TEMP (C) AIR ENT OUTDOOR COIL GROSS COOLING CAPACITIES SI INDOOR AIR L/s / BF 2000/ / /0.07 Indoor Air Ewb (C) TC SHC kw TC SHC kw TC SHC kw TC SHC kw TC SHC kw TC SHC kw TC SHC kw TC SHC kw LEGEND BF Bypass Factor Ewb Entering Wet-Bulb Temperature (C) kw Compressor and Outdoor Fan Power Input TC Total Capacity (kw) SHC Sensible Heat Capacity (kw) NOTES: 1. Ratings are gross, and do not account for the effects of the indoor fan motor power and heat. 2. Direct interpolation is permissible. Do not extrapolate. 3. SHC is based on 26.7 C (80 F) db temperature of air entering the indoor unit. At any other temperature, correct the SHC read from the table of cooling capacities as follows: Corrected SHCkW = SHC + [1.23 x 10-3 x(1 BF) x(cdb 26.7) x L/s] Observe the rule of signs. Above 26.7 C (80 F), SHC correction will be positive; add it to SHC. Below 26.7 C (80 F), SHC correction will be negative; subtract it from SHC. 4. Formulas: SHCkW x 1000 Ldb C=Edb C 1.23 x L/s Leaving wet-bulb = wet-bulb temperature corresponding to enthalpy of air leaving coil (hlwb) TCkW x 1000 hlwb =hewb 1.20 x L/s Where hewb is enthalpy of air entering indoor coil (kj/kg). 11

12 Performance data (cont) TEMP (F) AIR ENT OUTDOOR COIL GROSS COOLING CAPACITIES ENGLISH INDOOR AIR CFM/BF 4400/ / /0.07 Indoor Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw TC SHC kw LEGEND BF Bypass Factor Ewb Entering Wet-Bulb Temperature (F) kw Compressor and Outdoor Fan Power Input (kw) TC Total Capacity (1000 Btuh) SHC Sensible Heat Capacity (1000 Btuh) NOTES: 1. Ratings are gross, and do not account for the effects of the indoor fan motor power and heat. 2. Direct interpolation is permissible. Do not extrapolate. 3. SHC is based on 80 F db temperature of air entering the indoor unit. At any other temperature, correct the SHC read from the table of cooling capacities as follows: Corrected SHCBtuh = SHC + [1.10 x (1 BF) x(fdb 80) x cfm] Observe the rule of signs. Above 80 F, SHC correction will be positive; add it to SHC. Below 80 F, SHC correction will be negative; subtract it from SHC. 4. Formulas: SHCBtuh Ldb (F)=Edb (F) 1.10 x cfm Leaving wet-bulb = wet-bulb temperature corresponding to enthalpy of air leaving coil (hlwb). TC Btuh hlwb =hewb 4.50 x cfm Where hewb is enthalpy of air entering indoor coil (Btu/lb). 12

13 FAN PERFORMANCE SI AIR VOLUME EXTERNAL STATIC PRESSURE (kpa) (L/s) r/s kw r/s kw r/s kw r/s kw r/s kw r/s kw r/s kw r/s kw r/s kw r/s kw LEGEND Standard Drive Field-Supplied Drive kw Fan Shaft Power r/s Fan Speed NOTES: 1. Fan performance based on wet coils and clean filters and includes casing losses. 2. Add option and accessory pressure losses to external static pressure required before entering table. 3. Minimum airflow for units with electric heat is 1900 L/s. 4. Conversion of shaft power to motor input heat value: kw (shaft) kw (heat) = kw (input) = motor efficiency 5. Motor size: 2.24 kw; average efficiency 80%. 6. Motor maximum allowable operating limit is 26.1 kw fan shaft power. FAN PERFORMANCE ENGLISH AIR VOLUME EXTERNAL STATIC PRESSURE (in. wg) (Cfm) Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp LEGEND Standard Drive Field-Supplied Drive Bhp Brake horsepower Rpm Revolutions per minute NOTES: 1. Fan performance based on wet coils and clean filters and includes casing losses. 2. Add option and accessory pressure losses to external static pressure required before entering table. 3. Minimum airflow for units with electric heat is 4026 cfm. 4. Conversion to motor input heat value: motor Bhp x W/Bhp Btuh = motor efficiency x W/Btuh motor Bhp x 2544 = motor efficiency 5. Motor size: 3 hp; average efficiency 80%. 6. Motor maximum allowable operating limit is 3.5 Bhp. 13

14 Performance data (cont) TEMP (C) AIR ENT OUTDOOR COIL INTEGRATED HEATING CAPACITIES SI AIRFLOW (L/s) Return Air Temp Edb (C) Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw LEGEND Cap. Capacity kw Edb Entering air dry-bulb temperature (C) Ldb Leaving air dry-bulb temperature (C) kw Compressor and Outdoor-Fan Power Input NOTES: 1. Integrated heating capacity ratings shown are not adjusted for the effects of the indoor-fan motor power and heat. A deduction has been made for defrosting the outdoor coils at temperatures below 4 C. 2. Direct interpolation is permissible. Do not extrapolate. 3. When using auxiliary and/or supplementary heating, the maximum allowable leaving-air temperature is 60 C. Ldb C= Total heating cap. kw x 1000 Edb C x airflow L/s 4. For supplementary glycol coil: Fluid flow L/s fluid capacity kw = x fluid temperature drop (C) TEMP (F) AIR ENT OUTDOOR COIL INTEGRATED HEATING CAPACITIES ENGLISH AIRFLOW (Cfm) Return Air Temp Edb (F) Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw Cap kw LEGEND Cap. Capacity (1000 Btuh) Edb Entering air dry-bulb temperature (F) Ldb Leaving air dry-bulb temperature (F) kw Compressor and Outdoor-Fan Power Input NOTES: 1. Integrated heating capacity ratings shown are not adjusted for the effects of the indoor-fan motor power and heat. A deduction has been made for defrosting the outdoor coils at temperatures below 40 F. 2. Direct interpolation is permissible. Do not extrapolate. 3. When using auxiliary and/or supplementary heating, the maximum allowable leaving-air temperature is 140 F. Ldb F= Total heating cap. (Btuh) Edb F x airflow cfm 4. For supplementary glycol coil: Fluid flow Gpm fluid capacity (Btuh) = 500 x fluid temperature drop (F) 14

15 GLYCOL COIL DATA SI L/s EGT EDB % Glycol kw L/s Ldb kw L/s Ldb kw L/s Ldb kw L/s Ldb kw L/s Ldb kw L/s Ldb LEGEND EDB Entering Dry-Bulb Temperature (C) EGT Entering Glycol Temperature (C) kw Heating Capacity (kw) Ldb Leaving Dry-Bulb Temperature (C) L/s Liters per Second NOTES: 1. Fluid t =11C. 2. This accessory glycol coil is intended for use with a MINIMUM of 25% glycol solution. It IS NOT intended for use solely with water due to freeze-up conditions and the resulting water damage to the conditioned space. GLYCOL COIL DATA ENGLISH Cfm EGT EDB % Glycol Cap. Gpm Ldb Cap. Gpm Ldb Cap. Gpm Ldb Cap. Gpm Ldb Cap. Gpm Ldb Cap. Gpm Ldb LEGEND Cap. Btuh x 1000 EDB Entering Dry-Bulb Temperature (F) EGT Entering Glycol Temperature (F) Gpm Gallons per Minute Ldb Leaving Dry-Bulb Temperature (F) NOTES: 1. Fluid t =20F. 2. This accessory glycol coil is intended for use with a MINIMUM of 25% glycol solution. It IS NOT intended for use solely with water due to freeze-up conditions and the resulting water damage to the conditioned space. ACCESSORY STATIC PRESSURE LOSSES SI AIRFLOW (L/s) ACCESSORY Pressure Drop (kpa) Electric Heater Economizer Glycol Coil NOTE: Add these pressure losses to the external static pressure before entering the Fan Performance table. ACCESSORY STATIC PRESSURE LOSSES ENGLISH AIRFLOW (Cfm) ACCESSORY Pressure Drop (in. wg) Electric Heater Economizer Glycol Coil NOTE: Add these pressure losses to the external static pressure before entering the Fan Performance table. 15

16 Electrical data SI and English NOMINAL V-PH-HZ VOLTAGE RANGE Min Max Qty COMPRESSOR FLA (each) RLA (each) Qty OUTDOOR-FAN MOTOR FLA (each) RLA (each) kw (each) INDOOR-FAN MOTOR ELECTRIC HEATER* POWER SUPPLY V-Ph-Hz kw Hp FLA kw FLA WSA ICF LEGEND FLA Full Load Amps Hp Nominal Horsepower ICF Maximum Instantaneous Current Flow during starting. (Any point in the starting sequence where the sum of LRA for the starting compressor plus FLA for all other running compressors is maximum.) kw Power Output (motors) LRA Locked Rotor Amps RLA Rated Load Amps WSA Wire Sizing Amps. One terminal block for each unit. To size wires, use 125% of the largest motor FLA plus 100% of the FLA for the other motors and heaters in the unit. *Indoor airflow when electric heat is used must not be less than 1900 L/s (4026 cfm). Four-wire circuit with grounded neutral required to provide source for 230-v motors. Typical piping and wiring NEC National Electrical Code (U.S.A. Standard) 16

17 Typical wiring schematic AHA Adjustable Heat Anticipator BRK W/AT Breaks with Amp Turns C Contactor, Compressor CAP Capacitor CB Circuit Breaker CC Cooling Compensator CH Crankcase Heater CLO Compressor Lockout CLS Cooling Lockout Switch COMP Compressor Motor CR Control Relay DFR Defrost Relay DFT Defrost Thermostat DM Damper Motor DR Damper Relay DT Defrost Timer EC Enthalpy Control EQUIP Equipment FL Fuse Link FPT Freeze Protection Thermostat FU Fuse GND Ground LEGEND HC Heater Contactor HPS High-Pressure Switch HR Heater Relay HTR Heater IFC Indoor-Fan Contactor IFM Indoor-Fan Motor IP Internal Protector L Light LOR Lockout Relay LPS Low-Pressure Switch LS Limit Switch MAT Mixed Air Thermostat OFC Outdoor-Fan Contactor OFM Outdoor-Fan Motor OP Overcurrent Protector PL Plug Assembly PRI Primary QT Quadruple Terminal RVR Reversing Valve Relay RVS Reversing Valve Solenoid TB Terminal Block TC Thermostat Cooling TDR Time-Delay Relay TH Thermostat Heating TRAN Transformer Terminal (Marked) Terminal (Unmarked) Terminal Block Splice Splice (Marked) Factory Wiring Field Control Wiring Field Power Wiring Accessory Wiring or Optional Wiring Accessory To indicate common potential only; not to represent wiring 17

18 Controls Base unit operating sequence Cooling With unit main power on, set thermostat at COOL position and desired room temperature. Set fan switch at AUTO. position. On a rise in room temperature, cooling contact no. 1 in thermostat closes, energizing compressor no. 1 contactor on all units. Compressor no. 1 and indoor and outdoor fan motors start. Compressor no. 1 cycles on demand of thermostat to satisfy room conditions. With an additional rise in room temperature, cooling contact no. 2 in thermostat closes, energizing compressor contactor no. 2. Compressor no. 2 starts. Compressor no. 2 cycles on demand of the thermostat to satisfy room conditions. Heating Turn unit power on and set thermostat at HEAT position and desired temperature. Set fan at AUTO. position. On a drop in room temperature, heating contact no. 1 in the thermostat closes, energizing compressor contactor no. 1 and reversing valve and starting compressor no. 1. Indoor blower contactors and outdoor-fan contactors energize at the same time for heat pump cycle. When thermostat second-stage heating contacts close, compressor contactor no. 2 energizes and compressor no. 2 starts. Units have a built-in electric resistance heat lock-out through the defrost thermostat. Above 4.4 C (40 F) (approximate) outdoor temperature, electric resistance heat is locked out and second-stage heat is from compressor no. 2. Below 4.4 C (40 F) (approximate) ambient, when thermostat first-stage heating contacts close, compressor contacts no. 1 and no. 2 energize sequentially through a time delay and both compressors are brought on to satisfy heating requirements. On a further drop in room temperature (outdoor ambient below 4.4 C [40 F]), thermostat second-stage heating contacts close, energizing electric resistance heat contactor and second-stage heat operates. Electric heaters with 2 or more contactors can have outdoor thermostats wired into the control circuit for additional staging. Automatic changeover When system selection switch is set at AUTO. position, unit automatically changes from heating operation to cooling operation when temperature of the conditioned space rises to cooling lever setting. When temperature of conditioned space falls to heating lever setting, unit automatically changes from cooling to heating operation (with a 1.67 C [3 F] deadband in between). Continuous air circulation Turn unit power on. Set system control at OFF position, and set fan switch at ON position. Indoor fan contactor is energized through the thermostat switch, and indoor fan runs continuously. NOTE: If controls are set at HEAT, COOL, or AUTO. position, unit operation is as described in Cooling, Heating and Automatic Changeover sections above, except indoor fan runs continuously. Defrost cycle The defrost thermostat on the outdoor coil activates a defrost timer which energizes electric resistance heaters and deenergizes reversing valve relays and outdoor-fan motors. When defrost thermostat is satisfied or when 10 minutes have elapsed, reversing valve solenoids energize and electric heaters deenergize. The defrost timer prevents defrost again for 90 minutes. The defrost thermostat, in conjunction with a time-delay relay, prevents electric heat operation above an approximate ambient temperature of 4.4 C (40 F) (depends on coil frost conditions). If defrost thermostat closes, time-delay relay energizes and pulls in compressor contactor no. 2. Both compressors are now operated by W1, and W2 controls electric heat. Economizer operation Turn unit power on, and set thermostat at COOL or AUTO. position. If outside temperature is below setting of outdoor-air changeover thermostat, then: Upon a rise in room temperature, cooling contact no. 1 in the thermostat closes. Indoor-fan motor starts and outdoorair damper modulates to maintain mixture of outdoor air and return air at present temperature. Cooling is provided using outdoor air. Mechanical cooling is locked out. At temperature above outdoor air changeover thermostat setting, outdoor-air damper moves to VENT position whenever fan is running, and cooling operation is as described in Cooling section above. When heat is energized, outdoor-air damper moves to vent position. Outdoor-air damper closes when fan is not operating. 18

19 Application data Ductwork Ductwork must be attached to the curb on all units. Interior installation may proceed before unit is set in place on the roof. If ductwork is to be attached to the unit, do not drill in condensate drain pan area leaks may result. Field power connection Factory- and field-installed electric heat allows single power entry to the unit for both heating and cooling. Condensate traps Evaporator coil is draw-through configuration. Trap (minimum 100 mm [4 in.] deep) must be field provided prior to start-up on cooling cycle. Install a plug in condensate drain on opposite side of unit from trap. Static pressure limits When return-air ductwork systems are used, return-side static pressures should be limited to 0.10 kpa (0.4 in. wg). Operating limits Airflow and other values in this literature indicate the operating range of the equipment. Operation outside these limits is not recommended. Low ambient cooling operation Units are designed to operate at outdoor temperatures down to 1.7 C (35 F). At temperatures below 1.7 C (35 F), accessory Motormaster Head Pressure Control will permit operation at outdoor temperatures as low as 29 C ( 20 F). Roof curb All curb installations must be counterflashed to prevent water leakage. Power supply Electric power may be brought to the unit within curb perimeter through fittings provided in the basepan. Provide power supply in accordance with local codes. Control wiring 24-v wiring to thermostat. Remote control panel When use is required with emergency heat (in addition to accessory emergency-heat components), field-supplied emergency heat switch (DPST toggle switch) must be used. Emergency heat subbase cannot be used with the remote control panel. Unit selection Select unit based on cooling only. Do not select heat pumps on heating capacity. Add auxiliary resistance heat if required. CONCENTRIC DUCT AIR DISTRIBUTION CONCENTRIC DUCT DETAILS NOTE: Do not drill in this area; damage to basepan may result in water leak. area indicates block-off panels. NOTES: 1. Dimension A, A and B, B are obtained from field-supplied ceiling diffuser. 2. Dimensions are in millimeters. 19

20 Application data (cont) TYPICAL FIELD THERMOSTAT WIRING LEGEND COMM Communications TB Terminal Block 20

21 Guide specifications Packaged Rooftop Air-to-Air Heat Pump Constant Volume Application Size Range: 52.8 kw (15 tons), Nominal Cooling Carrier Model Number: 50PQ Part 1 General 1.01 SYSTEM DESCRIPTION A. Outdoor, rooftop mounted, electrically controlled, airto-air heat pump utilizing reciprocating type compressors for heating and cooling duty. Unit shall discharge supply air vertically as shown on contract drawings QUALITY ASSURANCE A. Unit shall be designed to conform to ASHRAE 15 latest revision (U.S.A.). B. Unit shall be ETL listed (U.S.A.) and CSA certified (Canada) as a total package for safety requirements. C. Roof curb shall be designed to conform to NRCA Standards (U.S.A.). D. Insulation and adhesive shall meet NFPA 90A requirements for flame spread and smoke generation (U.S.A.) DELIVERY, STORAGE, AND HANDLING A. Unit shall be stored and handled per manufacturer s recommendations. Part2Products 2.01 EQUIPMENT A. General: Factory-assembled, single-piece, air-to-air heat pump. Contained within the unit enclosure shall be all factory wiring, piping, controls, refrigerant charge (R-22), and special features required prior to field start-up. B. Unit Cabinet: 1. Unit cabinet shall be constructed of galvanized steel, bonderized, and coated with a prepainted baked enamel finish. 2. Indoor blower compartment interior cabinet surfaces shall be insulated with a minimum 1 2-in. thick, flexible fiberglass insulation, and shall be coated on the air side. Aluminum foil faced fiberglass insulation shall be used in the heating compartment. 3. Cabinet panels shall be easily removable for servicing. 4. Filters will be accessible through a sliding filter rack. 5. Holes shall be provided in the base rails for rigging shackles to facilitate overhead rigging. 6. Unit shall have a factory-installed, sloped condensate pan. C. Fans: 1. Indoor blower: a. Fan shall be belt drive, as shown on the equipment drawings. Belt drive shall include an adjustable-pitch motor pulley. b. Fan wheel shall be made from steel, be double inlet type with forward curved blades with a corrosion resistant finish and shall be dynamically balanced. c. Bearings shall be sealed and permanently lubricated. 2. Outdoor fan shall be of the direct drive propeller type with aluminum blades, riveted to corrosionresistant steel spiders, dynamically balanced, and discharge air vertically upwards. D. Compressors: 1. Semi-hermetic type with internal and external vibration isolation. 2. Equipped with factory-installed crankcase heater to prevent refrigerant dilution of oil. E. Coils: 1. Indoor and outdoor coils shall have aluminum plate fins mechanically bonded to seamless copper tubes with all joints brazed. 2. Tube sheet openings shall be belled to prevent tube wear. F. Refrigerant Components: 1. Expansion device. 2. Filter drier. 3. Reversing valve. 4. Accumulator. G. Filter Section: 1. Standard filter section shall consist of one size of factory-installed, low-velocity, 50 mm (2 in.) thick throwaway fiberglass filters of commercially available sizes. 2. Filter face velocity shall not exceed 1.6 m/s (320 fpm) at nominal airflows. H. Controls and Safeties: 1. Unit Controls: a. Unit shall be complete with self-contained lowvoltage control circuit. b. Unit shall incorporate an outdoor coil defrost system to prevent excessive frost accumulation during heating duty, and shall be controlled as follows: 1) Defrost shall be initiated on the basis of time and coil temperature. 2) A 90-minute timer shall activate defrost cycle only if coil temperature is low enough to indicate a heavy frost condition. 3) Defrost cycle shall terminate when defrost thermostat is satisfied and shall have a positive termination time of 10 minutes. 2. Safeties: Unit shall incorporate a solid-state compressor protector which provides reset capability at the space thermostat, should any of the following safety devices trip and shut off compressor: a. Compressor overtemperature, overcurrent. b. Low-pressure switch. 21

22 Guide specifications (cont) c. Freezestat, indoor. d. High-pressure switch. I. Operating Characteristics: 1. Unit shall be capable of starting and running at 46 C (115 F) ambient outdoor temperature per maximum load criteria of ARI Standard 340 (U.S.A.). 2. Compressor with standard controls shall be capable of operation down to 1.7 C (35 F) ambient outdoor temperature in cooling duty. 3. Compressor shall be capable of operation in heating duty down to 29 C ( 20 F) ambient outdoorair temperature. 4. Unit shall be capable of simultaneous heating duty and defrost cycle operation when using electric heaters indicated in Section L, Special Features. J. Electrical Requirements: All unit power wiring shall enter unit cabinet at a single location. K. Motors. 1. Compressor motors shall be of the refrigerantcooled type with line break thermal and current overload protection. 2. All fan motors shall have permanently lubricated bearings and inherent automatic reset thermal overload protection. L. Special Features: Certain standard features are removed and replaced by those features designated by *. Consult your local Carrier Sales office for amending specifications. * 1. Roof Curbs (Vertical and Horizontal): a. Formed galvanized steel with wood nailer strip and shall be capable of supporting entire unit weight. 2. Horizontal Adapter: Includes factory-assembled adapter and duct to substantially improve fan static performance. * 3. Integrated Economizer: a. Integrated type capable of simultaneous economizer and compressor operation. b. Includes all hardware and controls to provide cooling with outdoor air. c. Equipped with low-leakage dampers not to exceed 3% leakage at 248 Pa (1.0 in. wg) pressure differential. d. Capable of introducing up to 100% outdoor air. e. Equipped with gravity relief damper. f. Capable of going to fully-closed position in the defrost mode. * 4. Two-Position Damper: a. Two-position damper package shall include motor and single-blade damper, and admits up to 100% outdoor air. b. Damper shall close upon unit shutoff. * 5. Electric Resistance Heater: a. Open wire nichrome elements with all necessary safety and operating controls. b. UL and CSA listed (U.S.A.) and indicated on basic unit informative plate. c. The heater assembly shall include the following safety features: 1) Automatic reset switches. 2) Heat limiters for primary, secondary, overcurrent, and thermal protection. 3) Branch circuit protection. d. Unit shall have a single power wiring entry location for the heating section. * 6. Remote Control Panel: Panel shall be a decorative, indoor, wall-mounted panel consisting of: a. Two-stage heat/2-stage cool thermostat with automatic changeover. b. System switch with HEAT-COOL-AUTO.- OFF settings. c. Fan switch with ON-AUTO. settings. d. Indicator lights for HEAT-COOL-FAN operation. e. Three unused indicator lights for field use. * 7. Thermostat and Subbase: Provides staged cooling and heating, automatic (or manual) changeover, fan control, and indicator light. 8. Compressor Cycle Delay: Compressor shall be prevented from restarting for a minimum of 5 minutes after shutdown. * 9. Head Pressure Control Package: a. Consists of solid-state control and condenser coil temperature sensor for head pressure control. b. Capable of controlling outdoor-fan motor cycling to maintain condensing temperature between 32.2 C and 43.3 C (90 F and 110 F) at outdoor ambient temperatures down to 29 C ( 20 F). * 10. Power Exhaust Package: Package shall include an exhaust fan, motor, and damper for vertical flow units with economizer to ensure proper building pressurization. * 11. Barometric Relief Damper Package: a. Package shall include damper, seals, hardware, and hoods to relieve excess internal pressure. b. Damper shall close due to gravity upon unit shutdown. 22