Product Data. Features/Benefits. 50ZP Single-Package Electric Cooling Units. 2 to 5 Nominal Tons

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1 Product Data 50ZP Single-Package Electric Cooling Units 2 to 5 Nominal Tons Single Package Air-Conditioning Units with: easy installation design corrosion-proof basepan pre-painted steel cabinet sloped drain pan for improved indoor air quality top cover service access lightweight, compact construction Features/Benefits Compact, horizontal supply and return unit, combining easy installation and maintenance with efficient performance. Easy to install The 50ZP units are small, compact, and easy to handle. Every 50ZP unit has an identical 32 x 51-in. footprint to make jobsite planning simple. The concise design uses less sheet metal and makes the 50ZP units lighter than other units. The unit can be easily positioned on the jobsite with the hand holds built into the unit basepan. Drop-in cartridge style heaters are utilized to minimize installation time. The 50ZP unit was designed with potential safety hazards in mind. There are no sharp edges or corners which could injure a worker. Top cover service access The 50ZP units are designed to be serviced from the top. The split-top design allows easy access for installation and maintenance procedures on the unit. Routine maintenance tasks such as coil cleaning are sped up with through-the-top access. Multiple side panels do not need to be removed as with other units. Copyright 1997 Carrier Corporation Form 50ZP-1PD

2 No-rust basepan with integrated drain pan The 50ZP units feature a tough, hightech, composite material basepan with integrated drain pan. The composite material eliminates the potential problems of rust and premature replacement which are common with standard metal basepans. Each 50ZP basepan is sloped to eliminate standing water per ASHRAE Standard Durable pre-painted steel cabinet The watertight construction and corrosion-resistant finish of the 50ZP unit will keep it looking like new for years. Carrier s paint treatment process ensures quality protection against the elements. A compact, low-profile design utilizes a louvered coil enclosure for protection against vandalism and hail damage. Indoor-air quality A sloped drain pan minimizes the amount of standing water inside the unit, which limits algae growth. The drain pan is made of a rust-proof material and will not deteriorate or release foreign matter into the conditioned air. Lightweight, compact construction The 50ZP unit is the lightest, most compact packaged unit that Carrier has ever designed. Its light weight (222 lbs for the 50ZP024 unit) makes the unit easier to handle. The low height (22-in. for 50ZP , 30-in. for 50ZP042, 048, and 34-in. for 50ZP060 units) keeps ductwork to a minimum and makes the unit less visible. Efficient, dependable performance The 50ZP units offer 10.0 SEER (Seasonal Energy Efficiency Rate) cooling performance efficiencies. This high performance level can reduce cooling expenses by as much as 25% compared to older cooling equipment (depending on local climate conditions). A highefficiency, multi-speed blower motor system ensures quality performance with most duct systems. The computerdesigned blower wheel is balanced for quiet operation. Rugged, reliable construction The 50ZP units utilize a structural beam design to form the four sides of the cabinet. Only 12 different pieces of sheet metal are used in the unit construction to simplify the unit for greater reliability. The 50ZP units are built to last. Durable, dependable components Compressors are designed for high efficiency. Each compressor is hermetically sealed against contamination to help promote longer life and dependable operation. Vibration isolation provides quiet operation. Reciprocating compressors have internal high-pressure and overcurrent protection. Direct-drive multispeed, PSC (permanent split capacitor) blower motor is standard on all models. Direct-drive, PSC condenser-fan motors are designed to help reduce energy consumption and provide for cooling operation down to 40 F. Refrigerant system is designed to provide dependability. Liquid refrigerant strainers are used to promote clean, unrestricted operation. Each unit leaves the factory with a full refrigerant charge. Refrigerant service connections make checking operating pressures easier. Model number nomenclature Table of contents Page Features/Benefits...1,2 Model Number Nomenclature...2 ARI Capacity Ratings...3 Physical Data...3 Accessories...4,5 Base Unit Dimensions Selection Procedure...9 Performance Data Electrical Data...15 Controls...16 Typical Installation...17 Typical Wiring Diagram...17,18 Guide Specifications...19,20 2

3 ARI* capacity ratings UNIT 50ZP NET COOLING CAPACITY (Btuh) STANDARD CFM SEER** SOUND RATING (db) , , , , , , db Dry Bulb db decibels (10 decibels = 1 bel) SEER Seasonal Energy Efficiency Ratio wb Wet Bulb *Air Conditioning and Refrigeration Institute. Rated in accordance with U.S. Government DOE (Department of Energy) test procedures and/or ARI Standard 210/ **All units have factory-installed time-delay relay. Rated in accordance with ARI Standard NOTES: 1. Ratings are net values, reflecting the effects of circulating fan heat. 2. Cooling Capacity Ratings are based on cooling standard: 80 F db/67 F wb indoor air entering temperature 95 F db air entering outdoor unit Physical data UNIT 50ZP OPERATING WEIGHT (lb) COMPRESSOR TYPE Reciprocating REFRIGERANT R-22 Charge (lb) REFRIGERANT METERING DEVICE Acutrol System CONDENSER Copper Tubes, Aluminum Plate Fins Rows...Fins/in Total Face Area (sq ft) CONDENSER FAN Propeller CFM Nominal Rpm Motor Hp Diameter (in.) EVAPORATOR COIL Copper Tubes, Aluminum Plate Fins Rows...Fins/in Total Face Area (sq ft) EVAPORATOR FAN MOTOR Direct Drive Blower Motor Size (in.) 10x8 10x8 10x8 10x9 10x9 10x10 Nominal Cfm Rpm Range Number of Speeds * Factory Speed Setting Low Med Low Med Low Low Motor Hp CONNECTING DUCT SIZES Round Square Supply Air (in.) x 13.9 Return Air (in.) x 27.8 FIELD-SUPPLIED RETURN AIR FILTER Throwaway (in.) 24x24 24x24 24x24 24x24 24x30 24x30 *460-v motors are 2-speed only. Required filter sizes shown are based on the ARI (Air Conditioning and Refrigeration Institute) rated airflow at a velocity of 300 ft/min for throwaway type or 450 ft/min for high capacity type. Recommended filters are 1-in. thick. 3

4 Accessories ACCESSORY Outdoor Thermostat Crankcase Heater ( ) Thermostat and Subbase Electronic Programmable Thermostat Controls Upgrade Kit Time Guard II Kit Low-Ambient Kit Electric Heat with Single-Point Kit (5.0 to 20.0 kw) Electronic programmable thermostat provides 2-stage heating and 2-stage cooling control with remote communication ability. Thermostat and subbase provide heating and cooling unit control. The subbase provides system and fan switching at the thermostat location. Low-ambient kit (Motormaster II device) allows the use of mechanical cooling down to outdoor ambient temperatures as low as 0 F. Solid-state Time Guard II device protects compressor by preventing short cycling. Crankcase heater warms crankcase oil to reduce refrigerant migration and ensure proper compressor lubrication. (Recommended on 208/230-v single-phase units in sizes only.) Electric heaters provide heat in the unit when required. Each package has a heater module that slides into keyed mounting slots in the fan inlet. Heater sizes range from 5.0 to 20.0 kw. The electric heater design allows the use of a single-point power supply for the entire unit, resulting in lower installed costs. Controls upgrade kit includes high- and low-pressure switches which provide additional safety features and protect the unit from running at unsuitable pressures. Outdoor thermostat brings second stage of 2-stage electric heater on line when the outdoor-air temperature falls below the set point. ODS CATALOG ORDERING NO. ELECTRIC HEATERS NOMINAL USED WITH SIZES CAPACITY (kw) ELECTRIC HEATERS (208/230 SINGLE PHASE 60 Hz) CPHEATER026A X X X X CPHEATER039A X X X X CPHEATER025A X X X X CPHEATER027A X X X X ELECTRIC HEATERS (208/230 V 3PHASE 60 Hz) CPHEATER029A X X X X CPHEATER030A X X X X CPHEATER031A X X X X CPHEATER033A X X X X ELECTRIC HEATERS (460 V 3PHASE 60 Hz) CPHEATER034A X CPHEATER035A X CPHEATER036A X CPHEATER037A X ODS Order Distribution System NOTE: Electric heaters are rated at 240 v and 480 v. Refer to Multiplication Factors table on page 5 for other voltages. 4

5 THERMOSTATS AND SUBBASES ODS CATALOG ORDERING NO. TSTATCCN2S01-A TSTATCCP2S01-A 33CSPTN-01 --HH01AD-45 DESCRIPTION Automatic Changeover 3 Heat/2 Cool (Programmable Residential Thermostat) Automatic Changeover 3 Heat/2 Cool (Non-Programmable Residential Thermostat) Automatic Changeover 2 Heat/2 Cool (Programmable Commercial Thermostat) Manual Changeover 2 Heat/1 Cool (Non-Programmable Thermostat) ODS Order Distribution System MULTIPLICATION FACTORS HEATER kw RATING VOLTAGE DISTRIBUTION V/3/60 MULTIPLICATION FACTOR Example: 15.0 kw (at 240 v) heater on 208 v = 15.0 (.75 mult factor) = capacity at 208 v 5

6 Base unit dimensions 50ZP REQUIRED CLEARANCES TO COMBUSTIBLE MAT L Millimeters (in.) Top of Unit...0 Duct Side of Unit...0 Side Opposite Ducts...0 Bottom of Unit...0 NEC REQUIRED CLEARANCES Millimeters (in.) Between Units, Power Entry Side (42.00) Unit and Ungrounded Surfaces, Power Entry Side (36.00) Unit and Block or Concrete Walls and Other Grounded Surfaces, Power Entry Side (42.00) REQUIRED CLEARANCES FOR SERVICING Millimeters (in.) Condenser Coil Access Side (30.00) Power Entry Side (30.00) (Except for NEC Requirements) Unit Top (36.00) Side Opposite Ducts (30.00) CG Center of Gravity NEC National Electrical Code NOTES: 1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (914 mm [36 in.]). A removable fence or barricade requires no clearance. 2. Dimensions are in millimeters. Dimensions in ( ) are in inches. UNIT ELECTRICAL UNIT WT CENTER OF GRAVITY mm (in.) CHARACTERISTICS Lb Kg X Y Z 50ZP / (14.00) (20.00) (9.50) 50ZP / (14.00) (20.00) (9.50) 50ZP / , 208/ (14.00) (20.00) (9.50) 6

7 Base unit dimensions 50ZP042,048 REQUIRED CLEARANCES TO COMBUSTIBLE MAT L Millimeters (in.) Top of Unit...0 Duct Side of Unit...0 Side Opposite Ducts...0 Bottom of Unit...0 NEC REQUIRED CLEARANCES Millimeters (in.) Between Units, Power Entry Side (42.00) Unit and Ungrounded Surfaces, Power Entry Side (36.00) Unit and Block or Concrete Walls and Other Grounded Surfaces, Power Entry Side (42.00) REQUIRED CLEARANCES FOR SERVICING Millimeters (in.) Condenser Coil Access Side (30.00) Power Entry Side (30.00) (Except for NEC Requirements) Unit Top (36.00) Side Opposite Ducts (30.00) CG Center of Gravity NEC National Electrical Code NOTES: 1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (914 mm [36 in.]). A removable fence or barricade requires no clearance. 2. Dimensions are in millimeters. Dimensions in ( ) are in inches. UNIT ELECTRICAL UNIT WT CENTER OF GRAVITY mm (in.) CHARACTERISTICS Lb Kg X Y Z 50ZP / , 208/ (14.00) (20.00) (12.00) 50ZP / , 208/ (14.00) (20.00) (12.00) 7

8 Base unit dimensions 50ZP060 REQUIRED CLEARANCES TO COMBUSTIBLE MAT L Millimeters (in.) Top of Unit...0 Duct Side of Unit...0 Side Opposite Ducts...0 Bottom of Unit...0 NEC REQUIRED CLEARANCES Millimeters (in.) Between Units, Power Entry Side (42.00) Unit and Ungrounded Surfaces, Power Entry Side (36.00) Unit and Block or Concrete Walls and Other Grounded Surfaces, Power Entry Side (42.00) REQUIRED CLEARANCES FOR SERVICING Millimeters (in.) Condenser Coil Access Side (30.00) Power Entry Side (30.00) (Except for NEC Requirements) Unit Top (36.00) Side Opposite Ducts (30.00) CG Center of Gravity NEC National Electrical Code NOTES: 1. Clearances must be maintained to prevent recirculation of air from outdoorfan discharge, with the exception of the condenser coil (914 mm [36 in.]). A removable fence or barricade requires no clearance. 2. Dimensions are in millimeters. Dimensions in ( ) are in inches. ELECTRICAL UNIT WT CENTER OF GRAVITY mm (in.) UNIT CHARACTERISTICS Lb Kg X Y Z 50ZP , 208/ , (14.00) (20.00) (14.00) 8

9 Selection procedure I Determine cooling and heating requirements at design conditions. Given: Required Cooling Capacity (TC)... 34,000 Btuh Sensible Heat Capacity (SHC)...25,000 Btuh Required Heating Capacity...15,000 Btuh Outdoor Entering-Air Temperature...95F Indoor Entering-Air Temperature... 80Fedb; 67 F ewb Indoor-Air Quantity cfm External Static Pressure in. wg Electrical Characteristics (V-Ph-Hz) II Select unit based on required cooling capacity. Enter Cooling Capacities table at condenser entering temperature of 95 F, indoor air entering at 1200 cfm and 67 F ewb. The 50ZP036 unit provides a total cooling capacity of 34,200 Btuh and a sensible heat capacity of 25,300 Btuh. For indoor-air temperature other than 80 F edb, calculate sensible heat capacity correction, as required, using the formula found in Note 4 following the Cooling Capacities tables. NOTE: Unit ratings are net capacities. III Select electric heat. The required heating capacity is 15,000 Btuh (given). Determine the electric heat capacity in kw. 15,000 Btuh = 4.4 kw of heat required 3414 Btuh/kW Enter the Electric Heaters table on page 4 for 208/ 240, single-phase, 50ZP036 unit. The 5-kW heater at 240 v most closely satisfies the heating required. To calculate kw at 230 v, multiply the heater kw by multiplication factor 0.92 found in the Multiplication Factors table on page 5. 5 kw x 0.92 = 4.6 kw 4.6 kw x 3414 Btuh/kW = 15,704 Btuh IV Determine fan speed and power requirements at design conditions. Before entering the air delivery tables, calculate the total static pressure required. From the given, Filter Pressure Drop table, the Accessory Electric Heat Pressure Drop table, and the Wet Coil Pressure Drop table, find: External static pressure 0.20 in. wg Filter 0.10 in. wg Electric Heat 0.13 in. wg Wet Coil 0.09 in. wg Total static pressure 0.52 in. wg Enter the table for Dry Coil Air Delivery Horizontal Discharge. At 0.5 in. wg external static pressure and high speed, the motor delivers 1297 cfm. Interpolating for 0.52 in. wg delivers 1276 cfm, which satisfies the job requirements. 9

10 Performance data 50ZP024 TEMP (F) AIR ENT COND COOLING CAPACITIES EVAP AIR CFM/BF 700/ / /0.15 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw ZP030 TEMP (F) AIR ENT COND EVAP AIR CFM/BF 875/ / /0.09 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw BF Bypass Factor Ewb Entering Wet Bulb kw Total Unit Power Input SHC Sensible Heat Capacity, 1000 Btuh TC Total Cooling Capacity, 1000 Btuh (net) NOTES: 1. Ratings are net; they account for the effects of the indoor-fan motor power and heat. 2. Direct interpolation is permissible. Do not extrapolate. 3. The following formulas may be used: sensible capacity (Btuh) t ldb = t edb 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving indoor coil (h lwb) h = h total capacity (Btuh) lwb ewb 4.5 x cfm Where: h ewb = Enthalpy of air entering indoor coil 4. The SHC is based on 80 F edb temperature of air entering indoor coil. Below 80 F edb, subtract (corr factor x cfm) from SHC. Above 80 F edb, add (corr factor x cfm) to SHC. Correction Factor = 1.10 x (1 BF) x (edb 80). 10

11 50ZP036 TEMP (F) AIR ENT COND COOLING CAPACITIES (cont) EVAP AIR CFM/BF 1050/ / /0.11 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw ZP042 TEMP (F) AIR ENT COND EVAP AIR CFM/BF 1225/ / /0.14 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw BF Bypass Factor Ewb Entering Wet Bulb kw Total Unit Power Input SHC Sensible Heat Capacity, 1000 Btuh TC Total Cooling Capacity, 1000 Btuh (net) NOTES: 1. Ratings are net; they account for the effects of the indoor-fan motor power and heat. 2. Direct interpolation is permissible. Do not extrapolate. 3. The following formulas may be used: sensible capacity (Btuh) t ldb = t edb 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving indoor coil (h lwb) h = h total capacity (Btuh) lwb ewb 4.5 x cfm Where: h ewb = Enthalpy of air entering indoor coil 4. The SHC is based on 80 F edb temperature of air entering indoor coil. Below 80 F edb, subtract (corr factor x cfm) from SHC. Above 80 F edb, add (corr factor x cfm) to SHC. Correction Factor = 1.10 x (1 BF) x (edb 80). 11

12 Performance data (cont) 50ZP048 TEMP (F) AIR ENT COND COOLING CAPACITIES (cont) EVAP AIR CFM/BF 1400/ / /0.08 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw ZP060 TEMP (F) AIR ENT COND EVAP AIR CFM/BF 1750/ / /0.08 Evap Air Ewb (F) TC SHC kw TC SHC kw TC SHC kw TC SHC kw BF Bypass Factor Ewb Entering Wet Bulb kw Total Unit Power Input SHC Sensible Heat Capacity, 1000 Btuh TC Total Cooling Capacity, 1000 Btuh (net) NOTES: 1. Ratings are net; they account for the effects of the indoor-fan motor power and heat. 2. Direct interpolation is permissible. Do not extrapolate. 3. The following formulas may be used: sensible capacity (Btuh) t ldb = t edb 1.10 x cfm t lwb = Wet-bulb temperature corresponding to enthalpy of air leaving indoor coil (h lwb) h = h total capacity (Btuh) lwb ewb 4.5 x cfm Where: h ewb = Enthalpy of air entering indoor coil 4. The SHC is based on 80 F edb temperature of air entering indoor coil. Below 80 F edb, subtract (corr factor x cfm) from SHC. Above 80 F edb, add (corr factor x cfm) to SHC. Correction Factor = 1.10 x (1 BF) x (edb 80). 12

13 WET COIL PRESSURE DROP UNIT SIZE 50ZP AIRFLOW (cfm) PRESSURE DROP (in. wg) UNIT SIZE 50ZP FILTER SIZE (in.) FILTER PRESSURE DROP (in. wg) CFM , ACCESSORY ELECTRIC HEAT PRESSURE DROP (in. wg) CFM Heater kw

14 Performance data (cont) DRY COIL AIR DELIVERY* HORIZONTAL DISCHARGE (Deduct 10% for 208 Volt Operation) UNIT 50ZP MOTOR SPEED Low Med High Low Med High Low Med High Low Med High Low High Low Med High AIR DELIVERY 208 AND 460 VOLT HORIZONTAL DISCHARGE External Static Pressure (in. wg) Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM Watts CFM *Air delivery values are based on operating voltage of 230 v or 460 v, dry coil, without filter or electric heater. Deduct wet coil, filter, and electric heater pressure drops to obtain external static pressure available for ducting. 460-v motors have 2 speeds (size 060 only). NOTES: 1. Do not operate the unit at a cooling airflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator-coil frosting may occur at airflows below this point. 2. Dashes indicate portions of the table that are beyond the blower motor capacity or are not recommended. 14

15 Electrical data UNIT 50ZP NOMINAL VOLTAGE (V-Ph-Hz) VOLTAGE RANGE COMPRESSOR OFM IFM ELECTRIC HEAT POWER SUPPLY DISCONNECT SIZE Min Max RLA LRA FLA FLA Nominal kw* FLA MCA MOCP FLA LRA / / 16.9/ / 20 16/ / / / / / 30 24/ / / / / 60 44/ / / / / / / / / / / 22.9/ / 30 22/ / / / / 30 24/ / / / / 60 44/ / / / / 90 65/ 75 / / 24.2/ / 30 23/ / / / / 30 24/ / / / / 60 45/ / / / / 90 66/ / / / /110 86/ 99 / / 15.4/ / 20 15/ / / / / 20 15/ / / / / 35 27/ / / / / 50 39/ / / / / 70 51/ 59 / / 27.4/ / 35 26/ / / / / 35 26/ / / / / 60 45/ / / / / 90 66/ / / / /110 86/ 99 / / 17.9/ / 25 17/ / / / / 25 17/ / / / / 35 27/ / / / / 50 39/ / / / / 70 51/ 59 / / 32.3/ / 40 31/ / / / / 90 67/ / / / /110 88/101 / / 21.1/ / 25 21/ / / / / 25 21/ / / / / 40 29/ / / / / 60 41/ / / / / 70 53/ / / 29.7/ / 35 29/ / / / / 35 29/ / / / / 40 31/ / / / / 60 43/ / / / / 70 55/ FLA Full Load Amps HACR Heating, Air Conditioning and Refrigeration IFM Indoor (Evaporator) Fan Motor LRA Locked Rotor Amps MCA Minimum Circuit Amps MOCP Maximum Overcurrent Protection NEC National Electrical Code OFM Outdoor (Condenser) Fan Motor RLA Rated Load Amps *Heater capacity (kw) is based on heater voltage of 208 v, 240 v, or 480 v. If power distribution voltage to unit varies from rated heater voltage, heater kw will vary accordingly. Fuse or HACR circuit breaker. NOTES: 1. In compliance with NEC requirements for multimotor and combination load and equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. 2. Unbalanced 3-Phase Supply Voltage Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to determine the percentage of voltage imbalance. % Voltage Imbalance max voltage deviation from average voltage = 100 x average voltage Example: Supply voltage is AB = 452 v BC = 464 v AC = 455 v Average voltage = 3 = 457 Determine maximum deviation from average voltage: (AB) =5v (BC) =7v (AC) =2v Maximum deviation is 7 v. Determine percentage of voltage imbalance: 7 % Voltage imbalance = 100 x 457 = 1.53% This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%. IMPORTANT: If the supply voltage phase imbalance is more than 2% contact your local electric utility company immediately. 15

16 Controls Sequence of operation Cooling NOTE: With the FAN switch in the ON position, 24 v is supplied to the indoor-fan relay (IFR) through the G terminal on the thermostat. This voltage energizes the coil of the contactor, closing the normally-open set of contracts which provide continuous power to the indoor-fan motor (IFM). Moving the FAN switch back to the AUTO. position, providing there is not a call for cooling, deenergizes the IFR, opens the IFR contacts, and deenergizes the IFM. The FAN switch in AUTO. position cycles upon a call for cooling. On a call for cooling, 24 v is supplied to the compressor contactor (C) and IFR simultaneously through the Y and G terminals of the thermostat, respectively. On units with a compressor time delay relay, there is a built-in, 5-minute (± 45 seconds) delay between compressor starts. Energizing the contactor closes the normally-open set of contacts supplying power to both the compressor and outdoor-fan motor (OFM). Energizing the IFR closes the normally-open set of contacts providing power to the IFM. On the loss of the call for cooling, 24 v is removed from both the contactor and IFR and opening both the contacts supplying power to compressor/ofm and IFM. Heating If accessory electric heaters are installed, on a call for heat, circuit R-W is made through the thermostat contacts. Circuit R-G is made which energizes the IFR. If the heaters are staged, then the thermostat closes a second set of contacts (W2) when second stage is required. When thermostat is satisfied, contacts open, deenergizing the heater relay and the IFR. 16

17 Typical installation Power Wiring Control Wiring Outdoor Airflow Indoor Airflow *Separate disconnect per NEC (National Electrical Code) required for electric heater when singlepoint connection is not used. Typical wiring diagram ELECTRIC HEATER WIRING 17

18 Typical wiring diagram (cont) AWG American Wire Gage C Contactor, Compressor CAP Capacitor COMP Compressor Motor EQUIP Equipment FL Fuse Link FU Fuse GND Ground HR Heater Relay (Strip Heat) IFM Indoor Fan Motor IFR Indoor-Fan Relay IP Internal Protector OFM Outdoor-Fan Motor QT Quadruple Terminal TDR Time Delay Relay TRAN Transformer Field Splice Marked Wire Terminal (Marked) Terminal (Unmarked) Terminal Block Splice Splice (Marked) Factory Wiring Field Control Wiring Field Power Wiring Accessory or Optional Wiring To indicate common potential only, not to represent wiring 18

19 Guide specifications Packaged Rooftop Cooling Unit with Electric Heat Constant Volume Application HVAC Guide Specifications Size Range: 2 to 5 Tons, Nominal Cooling Carrier Model Number: 50ZP Part 1 General 1.01 SYSTEM DESCRIPTION Outdoor rooftop/slab mounted, electrically controlled cooling unit utilizing a reciprocating compressor for cooling duty and optional electric heaters for heating duty. Unit shall discharge supply air horizontally as shown on contract drawings QUALITY ASSURANCE A. Unit shall be rated in accordance with ARI Standards 210/ and Designed in accordance with UL Standard. B. Unit shall be UL listed as a total package for safety requirements. C. Roof curb shall be designed to conform to NRCA Standards. D. Insulation and adhesive shall meet NFPA 90A requirements for flame spread and smoke generation DELIVERY, STORAGE AND HANDLING Unit shall be stored and handled per manufacturer s recommendations. Part2 Products 2.01 EQUIPMENT A. General: Factory assembled single piece cooling unit. 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 phosphated, bonderized, zinc-coated pre-painted steel. 2. Basepan made of a single-piece, non-corrosive, composite material. 3. Indoor blower compartment interior cabinet surfaces shall be insulated with a minimum 1 2-in. thick, flexible fiberglass insulation, coated on the air side with aluminum foil. 4. Cabinet panels shall be easily removable for servicing. 5. Unit shall have a sloped non-corrosive drain pan that conforms to ASHRAE Standard Unit insulation conforms to ASHRAE Standard 62P. C. Fans: 1. Indoor Blower (Evaporator Fan): a. Fan shall be 2- or 3-speed direct drive as shown on the equipment drawings. b. Fan wheel shall be made from steel, be double inlet type, have forward curved blades with a corrosion resistant finish, and be dynamically balanced. 2. Outdoor (condenser) fan shall be of the directdriven propeller type with aluminum blades riveted to corrosion resistant steel spiders. It shall be dynamically balanced, and discharge air vertically upwards. D. Compressor: Fully hermetic; reciprocating type with internal and external vibration isolation. E. Coils: 1. Evaporator and condenser 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. 3. Outdoor coil shall be protected by metal louvered panels. F. Refrigerant Components: 1. Refrigerant components shall be of the Acutrol feed system type. 2. Service gage connections on suction, discharge, and liquid lines. 3. Ability to route gage hoses through unit side panel. G. Controls: Unit shall be complete with self-contained low-voltage control circuit. H. Operating Characteristics: 1. Unit shall be capable of starting and running at 115 F ambient outdoor temperature per maximum load criteria of ARI Standard Compressor with standard controls shall be capable of operation down to 40 F ambient outdoor temperature. I. Electrical Requirements: All unit power wiring shall enter unit cabinet at a single location. J. Motors: 1. Compressor motors shall be of the refrigerant cooled type with line break thermal and current overload protection. 19

20 Guide specifications (cont) 2. All fan motors shall have permanently lubricated bearings, and inherent automatic reset thermal overload protection. 3. Outdoor (condenser) fan motor shall be totally enclosed. K. Special Features: 1. Low Ambient Package: Package shall consist of a solid-state control and condenser coil temperature sensor for controlling outdoor-fan motor operation, which shall allow unit to operate down to 0 F outdoor ambient temperature. 2. Heating Section: a. Equipped with field-installed electric resistance heater(s) of the characteristics shown in the equipment schedule. b. Heater elements shall be open wire type, adequately supported and insulated with ceramic bushings. c. Electric heater packages must provide singlepoint power connection capability. 3. Compressor Short Cycle Device: Solid-state control shall protect compressor by preventing short cycling. 4. Controls Upgrade Kit: Contains high and low pressure switches. Kits shall protect unit from operating at unacceptable pressures. 5. Outdoor Thermostat: Allows for staging of electric heaters based on outdoor-air temperature. 6. Crankcase Heater: Warms crankcase oil to reduce refrigerant migration and ensure proper compressor lubrication. 7. Thermostat and Subbase: Provides staged cooling and heating, automatic (or manual) changeover, fan control. 8. Electronic Programmable Thermostat: Thermostat provides 2-stage heating and 2-stage cooling control with remote communication ability. Book 1 4 Tab 1b 6b Carrier Corporation Syracuse, New York Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Page 20 Catalog No Printed in U.S.A. PC 111 Form 50ZP-1PD Replaces: 50ZP-1APD