Installation, Start-Up and Service Instructions

OMNIZONE 50BYN006-024 Air-Cooled Indoor Self-Contained Systems Installation, Start-Up and Service Instructions CONTENTS Page SAFETY CONSIDERATIONS...1 GENERAL...1 INSTALLATION... 1-13 Step 1 Complete Pre-Installation Checks...1 Step 2 Rig and Place Unit...2 Splitting a 50BYN024...2 Unit Discharge...2 Vibration Isolation...2 Step 3 Install Accessories...2 Step 4 Install Ductwork...7 Step 5 Install Rain/Condensate Drain Line...11 Step 6 Complete Electrical Connections...13 START-UP... 13-20 General...13 Compressor Rotation...19 Operating Sequence...19 SERVICE...20,21 Cleaning Evaporator and Condenser Coils...20 Lubrication...20 Condenser Fan Adjustment...20 Pulley Alignment...20 Belt Tension Adjustment...20 Changing Fan Wheel...20 Fan Bearing Replacement...20 Concentric Alignment...20 MAINTENANCE...21,22 Cleaning...21 Inspection...21 Air Filters...21 Condensate Drain...21 Checking System Charge...21 Access Panel Removal...22 Evaporator-Fan Motor Removal...22 Pressure Relief Device...22 Cycle-LOC Protection Device...22 Time Guard II Control...22 High and Low Pressurestats...22 Oil Charge...22 TROUBLESHOOTING... 23-25 START-UP CHECKLIST... CL-1,CL-2 SAFETY CONSIDERATIONS Installing, starting up, and servicing air-conditioning components and equipment can be dangerous. Only trained, qualified installers and service mechanics should install, start-up, and service this equipment. When working on the equipment, observe precautions in the literature and on tags, stickers, and labels attached to the equipment. Follow all safety codes. Wear safety glasses and work gloves. Before performing service or maintenance operations on unit, turn off main power switch to unit. Electrical shock could cause personal injury. Use care in handling, rigging, and setting bulky equipment. GENERAL OMNIZONE indoor package units are designed to provide the flexibility required in replacement, renovation, and new construction. Units are available in 6 sizes from 5 tons to 20 tons. Belt-drive condensers provide adequate static to overcome ducting and louver static losses. This allows units to be positioned against an existing window or wall louver, or ducted to the outside as required. Convenient rear connections allow easy access for outside air connections and air side economizer. Unit supply air discharge may be vertical or horizontal front. These packaged vertical packaged units are fully piped and wired. Units are complete with a belt drive evaporator section and built-in ducted air-cooled condenser. Airflow is horizontal or vertical. All units are designed to fit through most standard doors. The 20 ton size may be easily field split to simplify moving the units into existing buildings. See Fig. 1-3 for unit dimensions and refer to Table 1 for unit operating weights. INSTALLATION OMNIZONE 50BY units are intended for indoor installation only. Determine building alterations required to run piping, wiring and ductwork. Follow dimensional drawings for ductwork, piping locations, electrical wiring (refer to Table 2 for electrical data) and overall unit dimensions. Read all installation instructions before installing the unit. Step 1 Complete Pre-Installation Checks Examine unit for damage incurred during shipment. File claim immediately with transit company if damage is found. Check the shipment for completeness. Verify that the nameplate electrical requirements match the available power supply. DO NOT place the unit in a horizontal position that would allow oil to drain into the top of the compressor. Do not allow refrigerant lines to come into contact with wiring or sharp objects or edges. Do not lift or move unit by putting pressure on refrigerant lines. Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations. Book 1 4 PC 111 Catalog No. 535-00136 Printed in U.S.A. Form 50BYN-1SI Pg 1 2-04 Replaces: 50BY-1SI Tab 2b 7a

Step 2 Rig and Place Unit Units are mounted on skids. Leave the unit on the skid until it is in the final position. While on the skid, the unit can be rolled, dragged or forklifted; do not apply force to the unit. Use a minimum of 3 rollers when rolling, and raise from above to remove the skid when unit is in the final position. See Fig. 4 for rigging details. PLACING THE UNIT The selected unit location should not be adjacent to an acoustically sensitive space. The best locations for these units are mechanical rooms, near elevator shafts, near restrooms, near stairwells or other similar locations. Position the unit where large supply of outdoor air is available for the unit inlet. Be sure to leave enough space for the return air inlet access to the evaporator and condenser coils for cleaning and maintenance. Units located on the same floor should have a minimum of 6 ft of clearance between condenser air openings. Units located floor-to-floor should have a minimum of 10 ft between units to prevent recirculation of conditioned air. DO NOT locate units where they will recirculate conditioned air. This will cause increased head pressure which can cause units to trip on high pressure. See Fig. 1-3 for recommended unit clearances and locations. Either provide inlet filters to protect the coils, or locate the unit in an area free from airborne dirt or other foreign material whichcouldclogthecoils. The units are designed to pass through most 36-in. door openings. The filter rack and duct mounting flanges may also be removed for additional clearance. Splitting a 50BYN024 The size 024 unit height exceeds 80 in. and may not clear all door openings. It may be necessary to split the unit in order to move it into the desired installation location. Refer to the following instructions to split the unit: NOTE: This unit and its 2 sections are heavy. Three people are required to move the sections safely. You will also need safety goggles, gloves and a dolly. 1. Move the unit to a work area close to the final installation location. 2. Be certain the service valves for all 3 circuits are in the OFF position. See Fig. 5. If any valves have been opened, the system must be evacuated. 3. Undo the suction line at the threaded fitting between the upper and lower sections of the unit. See Fig. 6. 4. Mark and undo each of the liquid lines for all 3 circuits at the threaded connections to the expansion valve and the connection to the filter drier. See Fig. 6. 5. Carefully move the liquid lines to the side, keeping them inside the unit. 6. You can now separate the upper and lower sections of the unit. Remove the 8 bolts that hold the two sections together. See Fig. 7. Once the bolts are removed, save the nuts, bolts and washers for use in re-assembly. 7. Carefully lift the fan/coil section from the base section and separate. 8. Move the separate sections to the installation location. 9. Place the bottom section first and then place the top section on top of it. 10. Bolt the sections together. 11. Reconnect the suction lines with the threaded fittings. 12. Reconnect the liquid lines to the expansion valve and filter drier. DO NOT mix circuits; be certain each line is returned to its original location. 13. Connect a vacuum pump to the service port by the compressor, on the suction line. 14. Pull a vacuum to 30 microns. 15. Pull the unit down and check to make sure all joints are tight and leak free. Open the discharge line service valve. See Fig. 6. 16. Open the liquid line service valve. See Fig. 6. 17. Follow the unit's start-up instructions. NOTE: Accessory items need to be installed before the ducts are attached. Unit Discharge Units are shipped from the factory configured for vertical discharge. The units (except the 50BYN014) can be converted to front or horizontal discharge by following these instructions: 1. Remove the screws (8) from the top front access panel to gain access to the fan section. 2. Loosen the supply fan mounting bolts (4) and slide the fan motor back until the belts (3) are loose. 3. Remove the belts (3). 4. Remove the screws (8) from the unit top panel that holds the fan. 5. Remove the top cover and fan. 6. Position fan where the top front access panel was mounted. 7. Secure the fan with the screws removed in Step 1. 8. Re-mount the belts. NOTE: Some units require different belts for different fan set ups. If this is the case, new belts are provided inside the fan enclosure. 9. Slide the fan motor back until the proper belt tension is obtained. Secure the motor with the mounting bolts (4). 10. Mount front access cover on top of the unit (where the top cover was originally) and secure with the screws (8) removedinstep4. Vibration Isolation Unit compressors are internally isolated and the compressor compartment is lined with acoustical insulation. If additional vibration isolation is desired, rubber pads may be located under each unit corner or unit may be mounted on rubber shear isolators. Spring isolators are not normally required. Ductwork attached to the unit should be isolated from the unit with a flexible collar on the inlet and outlet ducts. Step 3 Install Accessories (If Required) Refer to the following and the instructions provided with the individual accessory. Refer to Fig. 8 for typical system set up. HEATING COILS Accessory steam or hot water heating coils are mounted in the unit return air before the cooling coil. 1. Remove the filter rack provided with the unit. 2. Mount the filter rack on the coil. 3. Mount the coil in the position where the filter rack was. NOTE: The filter rack may be used with either ducted or free air return set ups. Make sure adequate air mixing occurs to prevent coil freeze-up. A 50BB900---001 freeze protection thermostat is recommended. LOW AMBIENT KIT If the unit will be operated with inlet air to the condenser below 50 F, a head pressure control low-ambient damper may be required. The low-ambient kit controls head pressure by discharge dampers on the condenser fan. The dampers are actuated by a refrigerant-operated piston connected to the discharge line of the condenser. If a lowambient accessory will be used, install it at this time (before final ductwork connections are made). INLET FILTER KIT An accessory filter rack may also be installed on the air inlet to help keep the coil clean. This filter rack should be installed before the ductwork is attached to the unit (if required in your specific application). Refer to installation instructions provided with the accessories for installation details. 2

DIMENSIONAL CHART CORNER WEIGHTS 50BY 006 008 012 014 DIM mm ft-in. mm ft-in. mm ft-in. mm ft-in. A 1800 5-10 5 /8 1800 5-10 5 /8 1780 5-10 1780 5-10 B 1040 3-5 1231 4-0 1 /2 1613 5-3 1 /2 1804 5-11 C 690 2-3 1 /8 690 2-3 1 /8 745 2-5 3 /8 745 2-5 3 /8 D 765 2-6 1 /8 765 2-6 1 /8 825 2-8 1 /2 825 2-8 1 /2 E 355 1-2 420 1-4 1 /2 608 2-0 675 2-2 5 /8 F 170 0-6 3 /4 158 0-6 1 /4 191 0-7 1 /2 193 0-7 5 /8 G 320 1-0 5 /8 357 1-2 402 1-3 7 /8 452 1-5 3 /4 H 310 1-0 1 /4 350 1-1 3 /4 372 1-2 5 /8 424 1-4 3 /4 J 593 1-11 3 /8 593 1-11 3 /8 665 2-2 1 /4 665 2-2 1 /4 K 554 1-9 7 /8 554 1-9 7 /8 457 1-6 457 1-6 L 584 1-11 584 1-11 584 1-11 584 1-11 M 23 0-0 7 /8 23 0-0 7 /8 23 0-0 7 /8 23 0-0 7 /8 N 17 0-0 5 /8 17 0-0 5 /8 17 0-0 5 /8 17 0-0 5 /8 P 11.5 0-0 1 /2 11.5 0-0 1 /2 11.5 0-0 1 /2 11.5 0-0 1 /2 Q 43 0-1 3 /4 43 0-1 3 /4 43 0-1 3 /4 43 0-1 3 /4 R 605 1-11 3 /4 605 1-11 3 /4 605 1-11 3 /4 605 1-11 3 /4 S 50 0-2 55 0-2 1 /8 55 0-2 1 /8 55 0-2 1 /8 T 360 1-2 1 /8 400 1-3 3 /4 357 1-2 357 1-2 V 50 0-2 20 0-0 7 /8 24 0-1 24 0-1 W 660 2-2 660 2-2 660 2-2 660 2-2 X 535 1-9 1 /8 535 1-9 1 /8 590 1-11 1 /4 590 1-11 1 /4 Y 190 0-7 1 /2 190 0-7 1 /2 190 0-7 1 /2 190 0-7 1 /2 Z 124 0-4 7 /8 124 0-4 7 /8 124 0-4 7 /8 124 0-4 7 /8 AA 475 1-6 3 /4 475 1-6 3 /4 475 1-6 3 /4 475 1-6 3 /4 AB 140 0-5 1 /2 140 0-5 1 /2 140 0-5 1 /2 140 0-5 1 /2 AC 60 0-2 3 /8 60 0-2 3 /8 60 0-2 3 /8 60 0-2 3 /8 AD 21 0-0 7 /8 21 0-0 7 /8 21 0-0 7 /8 21 0-0 7 /8 AE 225 0-8 7 /8 225 0-8 7 /8 217 0-8 1 /2 217 0-8 1 /2 AF 155 0-6 1 /8 155 0-6 1 /8 155 0-6 1 /8 155 0-6 1 /8 AG 190 0-7 1 /2 190 0-7 1 /2 190 0-7 1 /2 190 0-7 1 /2 AH 73 0-2 7 /8 61 0-2 3 /8 59 0-2 3 /8 59 0-2 3 /8 AJ 895 2-11 1 /4 1110 3-9 3 /4 1495 4-10 7 /8 1686 5-6 3 /8 AK 386 1-3 1 /4 405 1-4 260 0-10 5 /8 356 1-2 AL 433 1-5 480 1-6 7 /8 433 1-5 433 1-5 AM 275 0-10 7 /8 275 0-10 7 /8 AN 433 1-5 433 1-5 AP 80 0-3 1 /8 80 0-3 1 /8 80 0-3 1 /8 80 0-3 1 /8 AQ 880 2-10 5 /8 1070 3-6 1 /8 1455 4-9 1 /4 1645 5-4 3 /4 AR 41 0-1 5 /8 41 0-1 5 /8 41 0-1 5 /8 41 0-1 5 /8 AS 533 1-9 605 1-11 7 /8 807 2-7 3 /4 920 3-0 1 /4 AT 347 1-1 5 /8 355 1-2 375 1-2 3 /4 395 1-3 1 /2 AV 50 0-2 50 0-2 50 0-2 50 0-2 AW 231 0-9 1 /8 231 0-9 1 /8 169 0-6 1 /2 169 0-6 1 /2 CORNER WEIGHTS 50BY 006 008 012 014 CORNER kg lb kg lb kg lb kg lb A 65.3 144 84 185 107 236 108 238 B 68.5 151 81 179 107 236 113 248 C 69.4 153 89 136 108 239 127 280 D 65.8 145 92 203 108 239 119 263 Fig. 1 Base Unit Dimensions 50BYN006-014 NOTES: 1. Dimensions in [ ] are in millimeters. 2. Center of gravity. 3. Direction of airflow. 4. One side of unit must have minimum of 3 [914] clearance for filter removal. 3

DIMENSIONAL CHART DIM UNIT 50BY016 mm ft-in. A 1980 6-6 B 1905 6-3 C 745 2-5 3 /8 D 825 2-8 1 /2 E 543 1-9 3 /8 F 257 0-10 1 /8 G 356 1-2 H 353 1-1 7 /8 J 665 2-2 1 /4 K 635 2-1 L 597 1-11 1 /2 M 19 0-0 3 /4 N 17 0-0 5 /8 P 17 0-0 5 /8 Q 43 0-1 3 /4 R 607 1-11 7 /8 S 84 0-3 3 /8 T 402 1-3 7 /8 V 22 0-0 7 /8 W 765 2-6 1 /8 X 603 1-11 3 /4 Y 190 0-7 1 /2 Z 124 0-4 7 /8 AA 432 1-5 AB 83 0-3 1 /4 AC 60 0-2 3 /8 AD 21 0-0 7 /8 AE 217 0-8 1 /2 AF 141 0-5 1 /2 AG 190 0-7 1 /2 AH 86 0-3 3 /8 AJ 1737 5-8 3 /8 AK 318 1-0 1 /2 AL 483 1-7 AM 311 1-0 1 /4 AN 483 1-7 AP 70 0-2 3 /4 AQ 1765 5-9 1 /2 AR 41 0-1 5 /8 AS 979 3-2 1 /2 AT 385 1-3 1 /8 AV 276 0-10 7 /8 AW 169 0-6 1 /2 AX 50 0-2 CORNER WEIGHTS UNIT 50BY016 kg lb A 119 263 B 142 312 C 152 334 D 128 281 Fig. 2 Base Unit Dimensions 50BYN016 NOTES: 1. Dimensions in [ ] are in millimeters. 2. Center of gravity. 3. Direction of airflow. 4. One side of unit must have minimum of 3 [914] clearance for filter removal. 4

DIMENSIONAL CHART DIM 50BYN024 mm ft-in. A 2341 7-8 1 /4 B 2108 6-11 C 794 2-7 1 /4 D 872 2-10 3 /8 E 581 1-10 7 /8 F 184 0-7 1 /4 G 406 1-4 H 379 1-3 J 830 2-8 5 /8 K 796 2-7 1 /4 L 584 1-11 M 28 0-1 1 /8 N 40 0-1 5 /8 P 51 0-2 Q 43 0-1 3 /4 R 805 2-7 3 /4 S 65 0-2 1 /2 T 457 1-6 V 16 0-0 5 /8 W 921 3-0 1 /4 X 610 2-0 Y 202 0-8 Z 86 0-3 3 /8 AA 422 1-4 5 /8 AB 140 0-5 1 /2 AC 60 0-2 3 /8 AD 21 0-0 7 /8 AE 226 0-8 7 /8 AF 184 0-7 1 /4 AG 220 0-8 3 /4 AH 62 0-2 1 /2 AJ 1984 6-6 1 /8 AK 345 1-1 5 /8 AL 530 1-8 7 /8 AM 356 1-2 AN 530 1-8 7 /8 AP 76 0-3 AQ 1956 6-5 AR 41 0-1 5 /8 AS 1085 3-6 3 /4 AT 399 1-3 3 /4 AV 314 1-0 3 /8 AW 236 0-9 1 /4 AX 50 0-2 AY 1471 4-10 CORNER WEIGHTS 50BYN024 CORNER kg lb A 183 403 B 194 428 C 192 424 D 181 400 Fig. 3 Base Unit Dimensions 50BYN024 NOTES: 1. Dimensions in [ ] are in millimeters. 2. Center of gravity. 3. Direction of airflow. 4. One side of unit must have minimum of 3 [914] clearance for filter removal. 5

LEGEND NPT National Pipe Thread BPS British Pipe Standard (NPT pipe will work with the type of fitting) Table 1 Physical Data UNIT 50BYN 006 008 012 014 016 024 NOMINAL CAPACITY (tons) 5 7 1 / 2 10 12 15 20 UNIT OPERATING WEIGHT (lb) 594 765 948 1036 1190 1654 COMPRESSOR Carrier Scroll Model SR58 SR75 SR58 SR58/SR75 SR75 SR75 Quantity 1 1 2 1/1 2 3 Rpm 3500 Oil Charge (oz) 44 50 44/44 50/44 50/50 50/50/50 Steps of Control 1 1 2 2 2 2* OPERATING CHARGE R-22 (lb) 8.6 10.1 8.0/8.8 8.8/10.6 9.9/9.9 9.9/9.9/9.9 EVAPORATOR FAN Adjustable, Belt-Driven, Centrifugal Nominal Cfm 2000 3000 4000 4800 6000 8000 Cfm Range 1,500-2,500 2,250-3,750 3,000-5,000 3,750-6,250 4,500-7,500 6,000-10,000 Available Static 1.2 1.25 2.25 2.25 2.0 2.0 Fan Size 10 1 / 2 x7 1 / 2 11 x 8 12 1 / 2 x9 1 / 2 14 x 12 12 1 / 2 x9 1 / 2 12 1 / 2 x9 1 / 2 Number of Fans 1 1 1 1 2 2 Standard Speed Range (Rpm) 1058-1449 950-1300 860-1120 849-1117 1045-1308 930-1160 Max Allowable Rpm 1900 1700 1500 1360 1900 1600 Motor Rpm 1725 Vertical Belt Quantity...Type 1...A33 1...A34 1...B41 1...B45 2...A42 2...B52 Horizontal Belt Quantity Type 1...A24 1...A24 1...B39 None 2...A32 2...B40 Fan Pulley (in.) 4 1 / 4 4 3 / 4 8 5 / 8 8 5 / 8 6 5 / 8 7 1 / 2 Motor Pulley (in.) 2 1 / 2-3 1 / 2 2 1 / 2-3 1 / 2 4 1 / 8-5 1 / 2 4 1 / 8-5 1 / 2 4-5 4-5 Nominal Hp...Frame Size 1 1 / 2...145T 2...145T 3...182T 5...184T 5...184T 7 1 / 2...184T Fan Shaft Size (mm) 20 20 20 20 25 25 Motor Shaft Size (in.) 7 / 8 7 / 8 1 1 / 8 1 1 / 8 1 1 / 8 1 1 / 8 Center Distance (in.) min/max 13.6-13.8 13.2-13.4 10.4-11.9 9.6-10.6 12.2-13.7 17.6-18.7 Center Distance (in.) min/max.** 6.6-7.7 6.4-7.4 N/A N/A 7-8 10.6-11.4 EVAPORATOR COIL 3 / 8-in. OD, Enhanced Copper Tube, Aluminum Fins Quantity Rows...Fin/in. 3...14 4...14 4...14 4...14 4...14 4...15 Face Area (sq ft) 5.7 7.0 9.5 10.8 12.2 17.6 RETURN AIR FILTERS 1 or 2 in. Disposable Type Quantity...Size 1...16 x 25 1...20 x 25 1...25 x 25 1...20 x 25 3...20 x 25 3...16 x 25 1...20 x 25 2...25 x 25 1...20 x 25 8...16 x 20 CONDENSER FAN Adjustable, Belt-Driven, Centrifugal Nominal Cfm 3000 4500 6000 7200 9000 12,000 Cfm Range 2,250-3,750 3,375-5,625 4,500-7,500 5,400-9,000 6,750-11,250 9,000-15,000 Available Static 1.0 1.0 1.0 1.0 1.0 1.0 Fan Size 11 x 11 12 1 / 2 x12 1 / 2 11 x 11 11 x 11 12 1 / 2 x12 1 / 2 14 x 14 Number of Fans 1 1 2 2 2 2 Standard Speed Range (Rpm) 952-1304 849-1117 1038-1305 1038-1305 903-1136 930-1150 Max Allowable Rpm 1700 1500 1700 1700 1500 1360 Motor Rpm 1725 Belt Quantity...Type 1...A65 1...B68 2...A67 2...A67 2...A78 2...B85 Fan Pulley (in.) 5 8 1 / 2 6 3 / 4 6 3 / 4 7 3 / 4 7 3 / 4 Motor Pulley (in.) 2 1 / 2-3 1 / 2 4 1 / 2-5 1 / 2 4-5 4-5 4-5 4-5 Nominal Hp...Frame Size 2...145T 3...182T 5...184T 5...184T 5...184T 7 1 / 2...184T Fan Shaft Size (mm) 20 20 25 25 25 25 Motor Shaft Size (in.) 7 / 8 1 1 / 8 1 1 / 8 1 1 / 8 1 1 / 8 1 1 / 8 Center Distance (in.) min/max 26.7-27.4 23.1-24.2 24.7-26.2 25.0-26.2 28.9-30.5 34.5-35.9 CONDENSER COIL 3 / 8-in. OD, Enhanced Copper Tube, Aluminum Fins Quantity Rows...Fins/in. 4...14 4...14 5...14 5...14 5...14 5...15 Face Area (sq ft) 6.4 7.7 10.5 11.8 14.2 19.4 CONTROLS 24 Volts Provided in Unit High Pressure Cutout (psig) 395 Cut-in (psig) 300 Low Pressure Cutout (psig) 27 Cut-in (psig) 67 Fusible Plug 203 F Time Guard II Devices 5 Minutes on Each Circuit CONDENSATE DRAIN LINE 2@ 3 / 4 BPS *The 20 ton unit is factory wired for 2 stages of capacity control. With the addition of a 3-stage thermostat or outdoor-air thermostat, the unit is capable of 3 stages of capacity control. Shaft center distances shown are for vertical discharge arrangement. **Shaft center distances shown are for horizontal discharge arrangement. 6

Step 4 Install Ductwork The 50BYN unit is designed for use either with or without ductwork or rain louvers. If either is used, care must be taken to eliminate air recirculation. Recirculation can be minimized by discharging through an extension elbow. When properly designed, single deflection discharge louvers can be applied to ductwork and to the unit air discharge. Fixed rain louvers over discharge outlets can cause excessive recirculation and nuisance high-pressure switch cutouts. Obstructions closer than 10 ft to the discharge air pattern can also cause significant recirculation. NOTE: See Fig. 9 for recommended duct sizing The 50BYN016 and 024 units are shipped with the condenser flanges stored inside the condenser section. Before attaching ductwork, mount the flanges to the condenser as shown in Fig. 10. CONDENSER AIR DUCT The condenser supply and discharge air duct should be as short and straight as possible. The cross section area of the duct should never be less than the face area of the unit openings. Ductwork should be insulated to prevent moisture condensation on the unit panels during cold weather. (See Fig. 11.) Insulate as follows: 1. If metal ductwork is used, insulation may be applied on the inside of the duct. This installation should be extended to cover the inside of the duct flanges. It is necessary to insulate the inside of the ducts at the duct flanges to reduce heat loss from the metal cabinet by conduction through the duct flanges and into the cold duct. Interior insulation allows the metal duct to approach room temperature. It also prevents condensation from forming and collecting under the insulation which will occur with exterior duct insulation. NOTE: Fiberglass duct board may also be used if permitted by local codes. 2. If insulation is applied to the outside of the metal duct, the inside must be insulated for a length of 10 in. from the unit (including the duct flanges) or up to the flexible duct vapor barrier on the outside, which must be tightly sealed to prevent condensation under the insulation. SERVICE VALVE Fig. 5 50BYN024 Unit (Service Panels Removed) SPREADER BAR SUPPORTS UNDER SKID Fig. 4 50BYN Unit Rigging 7

THREADED LIQUID LINE FITTING ON TXV (3 CIRCUITS) THREADED SUCTION CONNECTION (3 CIRCUITS) LIQUID LINE THREADED CONNECTIONS AND SERVICE VALVES (3 CIRCUITS) SUCTION LINE SERVICE PORT DISCHARGE LINE SERVICE VALVE DISCHARGE LINE SERVICE PORT Fig. 6 50BYN024 Front View UNITS SPLIT AT THIS POINT Fig. 7 Splitting the 50BYN024 Unit 8

SUCTION LINE EVAP TXV THREADED CONNECTION THREADED CONNECTION SERVICE PORT DISCHARGE LINE SERVICE PORT LIQUID LINE FILTER DRIER COMP COND SERVICE VALVE Fig. 8 Typical System Setup SERVICE VALVE THREADED CONNECTION 9

50BYN A DISCHARGE LOUVER 50BYN DIMENSIONS (in.) 4 3/4" 1" * C B F D UNIT 50BYN A B C D F G 006 24 14 1 / 8 6 20 1 / 8 26 34 5 / 8 008 24 15 3 / 4 6 21 3 / 4 26 41 1 / 8 012 24 14 6 20 26 57 1 / 4 014 24 14 6 20 26 64 3 / 4 016 30 15 7 / 8 6 21 7 / 8 30 1 / 8 69 1 / 2 024 30 18 6 24 36 1 / 4 78 INLET LOUVER G *Access panel for condenser coil cleaning. INLET LOUVER DETAIL DISCHARGE LOUVER DETAIL 5" 4" 14 GAGE ALUMINUM OR 18 GAGE GALVANIZED STEEL 4" 5 5/8" 3" 4" 1/2" 1" 45 30 FLANGE NOT PERMISSIBLE BLADE STIFFENER FOR LOUVER WIDTHS OVER 30" DEFLECTOR DETAIL EXHAUST VANE DEFLECTOR CONDENSER INTAKE Fig. 9 Typical Recommended Condenser Duct Dimensions 10

DUCT FLANGE Fig. 10 Placement of Duct Flanges (50BY016,024) CONDENSER AIRFLOW LOUVERS The proximity of the condenser air inlet and discharge airstreams makes the possibility of air recirculation quite high. It is possible to use one louver to route inlet and discharge airstreams but it is not recommended. Separate inlet and discharge louvers are recommended (see Fig. 9) to avoid air leakage from discharge to inlet. A baffle may also be used on the outside of the building to direct discharge away from the air inlet. Louvers should be selected with sufficiently strong blades for the application. Louver blades should be at least 30-in. wide and constructed of a minimum of 18-gage metal. EVAPORATOR DUCTWORK Supply duct should be properly supported and the aspect ratio as close to square as possible. Duct should be sized for a maximum of 2000 feet per minute velocity in areas outside the equipment room. The duct should be lined with acoustical insulation for a minimum of 10 ft beyond the equipment room. A flexible duct connection should be used on the connection to the unit to prevent transmission of any unit vibrations into the duct. Return duct may be attached to the unit, but is not necessary. The return to the unit should prevent line of sight visibility to the space. Insulated return duct is also recommended for acoustically sensitive spaces. Maximum velocity should not exceed 1000 ft per minute over occupied spaces. Adequate return area is essential for proper operation. Step 5 Install Rain/Condensate Drain Line IMPORTANT: A rain drain connection MUST BE USED if any possibility exists of rain water entering the unit. The 50BYN unit has a drain connection for evaporator condensate and a connection on the unit base to drain any rain water that may accumulate. Rain drain connection can be made on either side of the unit. Block whichever drain is not being used, but DO NOT BLOCK BOTH drain locations.when connecting rain drains and condensate drains from the unit to floor drains, sinks, or hoppers, connect drains downstream of trap to ensure that condensate does not drain back into the unit. A drain kit is provided (shipped in the fan section). This kit consists of PVC drain fittings to adapt to field-supplied threaded pipe. Make connections through the unit side panel. Some applications may require connection to either galvanized steel or copper drain pipe; consult local code requirements for details. IMPORTANT: NEVER use pipe smaller than 3 / 4 inches in the drain run. Pitch drain pipe downward at a slope of at least 1 / 4 -in. per ft for proper drainage. Provide tees plugged on one side for cleanouts. Leave clearance for servicing, and observe all local sanitary codes. The condensate trap should have a depth adequate to allow 3-in. of water in the trap (see Fig. 12) with the unit running. 11

*Provide access for cleaning condenser coil. Fig. 11 50BYN Applications 12

MINIMUM PITCH ONE IN. PER 10 FT. OF LINE OPEN VENT SEE NOTE Step 6 Complete Electrical Connections GENERAL Verify that nameplate electrical requirements match available power supply. Voltage at condenser must be within the minimum and maximum shown in Table 2 and phases must be balanced within 2%. Contact local power company for line voltage corrections. 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: UNBALANCED 3-PHASE SUPPLY VOLTAGE Use the following formula to determine the percent of voltage imbalance. Percent Voltage Imbalance max voltage deviation from average voltage = 100 x average voltage Example: Supply voltage is 460-3-60. AB = 452 v BC = 464 v AC = 455 v 452 + 464 + 455 Average Voltage = 1371 = 3 = 457 Determine maximum deviation from average voltage: (AB) 457 452 = 5 v (BC) 464 457 = 7 v (AC) 457 455 = 2 v Maximum deviation is 7 v. Determine percent of voltage imbalance: % Voltage Imbalance = 100 x 7 457 = 1.53% This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%. IMPORTANT: If supply voltage phase imbalance is more than 2%, contact your local electric utility company immediately. Unit operation on improper line voltage or excessive phase imbalance may be considered abuse and any resulting damage may not be covered by Carrier warranty. All wiring must be in accordance with local or NEC (National Electrical Code) regulations. POWER WIRING The units must have adequate overcurrent protection, fuses, or HACR (Heating, Air Conditioning and Refrigeration) breakers, according to the national and applicable local codes. 3 TO UNIT DRAIN PLUG NOTE: Trap should be deep enough to offset maximum unit static difference. A 4-in. trap is recommended. Fig. 12 External Trap Condensate Drain For field power connections, all main power wiring enters the unit through a factory-punched access hole under the control box. Attach power wires to the power connections on the main power terminal block in the unit control box. Be sure to install a ground wire. CONTROL WIRING All units require an accessory thermostat package to complete the unit control system. Any of the following controls systems can be used: 1. Room-mounted thermostat. Thermostat may be mounted in an appropriate location in the conditioned space. Route the wires from the thermostat to the low voltage connection of the control box. Connect wires to the low voltage terminal block. The fan switch on the thermostat will control fan operations. 2. Carrier TEMP thermostat. Mount relay pack for the Carrier TEMP thermostat in the low voltage section of the control box. Wire from the relay pack to the low voltage terminal strip and from the relay pack to the thermostat. FREEZE PROTECTION THERMOSTAT An accessory freeze protection thermostat is required when a liquid line lossof-charge switch is installed or when the unit is equipped with an airside economizer for intermediate or cold weather operation. Refer to Fig. 13 and 14 and the installation instructions included with the thermostat. Field installation of an evaporator freeze-up thermostat (50BB900001) is required. WINTER START MODIFICATIONS When starting aircooled units under low-ambient temperature conditions, the compressor may pull suction pressure down below the lowpressure cutout switch setting causing the compressor to shut off. At extremely low temperatures, the low-pressure switch may open during the off cycle, preventing the compressor from starting. In these cases, winter start control is required as follows: If 50BZ unit has a low-pressure switch, the use of the winterstart kit (part no. CRWINSTR01A00) is recommended. This kit bypasses the low-pressure switch on start-up. START-UP To prevent injury, ensure that ducting or wire fan guards are installed on the condenser fan before starting the unit. General Complete the start up checklist on page CL-1 before attempting system start-up. 1. Set indoor thermostat system switch to OFF position and fan switch to AUTO position. 2. Check all electrical connections, fuses, starter and pressure control resets. 3. Check operation of evaporator fan motor and ensure fan rotation is correct. If rotation needs to be reversed, disconnect main power and switch any 2 leads on the load side of the disconnect switch. 4. Adjust fan speed. Units are belt-driven condenser units and allow for a wide range of inlet static and condenser airflow requirements. It may be necessary to adjust the condenser airflow to account for these inlet conditions. Inadequate airflow will result in poor unit performance and possible nuisance tripping of high-pressure switches. If an airflow is not specified, use the nominal airflow from Tables 3 and 4 and adjust the fan speed to compensate for actual job conditions. Use Table 1 to determine proper fan speed. If the unit trips on high pressure due to high condensing temperature it may be necessary to increase the fan speed and condenser airflow. 5. The outdoor-air fans cycle with the compressor Be sure fans are running during compressor rotation. 13

UNIT 50BYN 006 008 012 014 016 024 LEGEND FLA Full Load Amps LRA Locked Rotor Amps MCA Minimum Circuit Amps MOCP Table 2 Electrical Data V-PH-Hz VOLTAGE RANGE COMPRESSOR NO. 1 COMPRESSOR NO. 2 COMPRESSOR NO. 3 CONDENSER FAN INDOOR-FAN MOTOR POWER SUPPLY* Min Max RLA LRA RLA LRA RLA FLA Hp FLA Hp FLA MCA MOCP 208/230-3-60 187 253 18.3 125 2.0 7.5 1.5 6.6 37.0 50 460-3-60 414 506 9.2 67 2.0 3.4 1.5 3.0 17.8 25 575-3-60 518 632 7.3 27 2.0 2.7 1.5 2.4 14.3 20 208/230-3-60 187 253 20.4 146 3.0 10.6 2.0 7.5 43.6 60 460-3-60 414 506 10.2 73 3.0 4.8 2.0 3.4 21.0 30 575-3-60 518 632 8.2 50 3.0 3.9 2.0 2.7 16.8 20 208/230-3-60 187 253 17.7 125 17.7 125 5.0 16.7 3.0 10.6 67.1 80 460-3-60 414 506 8.9 67 8.9 67 5.0 7.6 3.0 4.8 32.3 40 575-3-60 518 632 7.1 27 7.1 27 5.0 6.1 3.0 3.9 25.9 30 208/230-3-60 187 253 17.7 125 20.9 146 5.0 16.7 5.0 16.7 76.4 90 460-3-60 414 506 8.9 67 10.5 73 5.0 7.6 5.0 7.6 36.7 45 575-3-60 518 632 7.1 27 8.4 50 5.0 6.1 5.0 6.1 29.4 35 208/230-3-60 187 253 20.9 146 20.9 146 5.0 16.7 5.0 16.7 80.4 100 460-3-60 414 506 10.5 73 10.5 73 5.0 7.6 5.0 7.6 38.7 45 575-3-60 518 632 8.4 50 8.4 50 5.0 6.1 5.0 6.1 31.0 35 208/230-3-60 187 253 20.9 146 20.9 146 20.1 146 7.5 24.2 7.5 24.2 116.8 125 460-3-60 414 506 10.5 73 9.9 73 9.5 73 7.5 11.0 7.5 11.0 56.0 60 575-3-60 518 632 8.4 50 8.4 50 8.4 50 7.5 9.0 7.5 9.0 45.2 50 Maximum Overcurrent Protective Device (see Note 1) NEC National Electrical Code RLA Rated Load Amps *Minimum Ckt Amps and MOCP Amps values per NEC (see Note 1). The overcurrent protective device for the unit shall be fuse or HACR circuit breaker (see Note 1). NOTES: 1. In compliance with NEC requirements for multimotor and combination load equipment (NEC Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR circuit breaker. Canadian units may be fuse or circuit breaker. 2. Wire sizing amps are a sum of 125% of the compressor RLA plus 100% of indoor fan motor FLA. 3. Motors are protected against primary single phasing condition. 4. Indoor-fan motors are 3-phase motors of same voltage as unit. 14

W1 Y1 50BYN TB2 G W3 CK1 CK2 R C W2 Y2 RS2 (012 SIZE UNIT AND LARGER) WIRE NUT SHIELD (CUT AND TAPE BACK) R UNIT GROUND G T1 Y1 X C Y2 T2 RS+5 RS1 RS GND 33CS250-01 REMOTE ROOM SENSOR (P/N ZONECCORRS01) NOTE: Remote sensor is field-installed option. Fig. 13 Thermostat Connection Diagram with 33CS250-01 Thermostat 50BYN O/W2 TB2 Y1 R G Y/Y2 W/W1 C (012 SIZE UNIT AND LARGER) R G T1 Y1 X C Y2 T2 B L DO NOT USE S1 S2 33CSPTN-01 WIRE NUT SHIELD (CUT AND TAPE BACK) REMOTE ROOM SENSOR (P/N ZONECCORRS01) UNIT GROUND NOTE: Remote sensor is field-installed option. Fig. 14 Thermostat Connection Diagram with 33CSPTN-01 Thermostat 15

50BYN 006 008 012 014 016 024 LEGEND Bhp Brake Horsepower Shaded areas require field-supplied drive. Table 3 Condenser Fan Performance STATIC PRESSURE (in. wg) Cfm 0.0 0.2 0.4 0.6 0.8 1.0 Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp 2,000 566 0.18 710 0.30 846 0.40 972 0.46 1070 0.61 1130 0.72 2,500 753 0.40 880 0.59 927 0.63 1020 0.79 1105 1.10 1184 1.35 3,000 940 0.83 985 0.90 1080 1.00 1122 1.10 1200 1.29 1320 1.46 3,500 1047 1.20 1140 1.47 1173 1.50 1250 1.70 1292 1.40 1360 1.59 4,000 1250 1.94 1257 2.00 1333 2.10 1390 2.41 1410 2.60 1470 2.76 3,000 547 0.30 670 0.54 751 0.60 840 0.80 920 1.10 995 1.50 3,750 760 0.89 824 1.10 920 1.25 964 1.30 1040 1.53 1110 2.10 4,500 910 1.53 940 1.70 1020 1.90 1090 2.08 1173 2.40 1240 2.59 5,250 1020 2.00 1095 2.40 1170 2.90 1180 3.00 1240 3.10 1300 3.53 6,000 1180 3.10 1195 3.20 1260 3.70 1320 4.16 1380 4.80 1440 5.60 4,000 665 0.40 803 0.65 920 0.97 989 1.20 1080 1.48 1163 1.90 5,000 830 0.82 912 1.20 1010 1.55 1088 1.70 1170 2.00 1246 2.50 6,000 976 1.70 1070 2.16 1131 2.30 1210 2.66 1318 2.90 1390 3.36 7,000 1120 2.85 1198 3.00 1273 3.20 1343 3.70 1410 4.21 1474 4.90 8,000 1282 3.90 1353 4.50 1420 5.06 1517 5.30 1580 5.93 1640 6.70 4,800 703 0.62 840 1.05 860 1.10 950 1.29 1090 1.62 1172 2.02 6,000 853 1.12 902 1.60 1060 2.10 1130 2.30 1210 2.66 1290 3.20 7,200 1045 2.40 1140 3.00 1191 3.20 1270 3.62 1290 3.79 1357 4.60 8,400 1190 3.60 1270 4.20 1340 4.89 1421 5.10 1490 5.85 1560 6.70 9,600 1380 5.70 1452 6.50 1520 7.13 1550 7.20 1611 7.50 1670 8.23 6,000 600 0.60 720 1.02 820 1.51 910 2.10 950 2.20 1025 2.80 7,500 736 1.50 833 1.86 920 2.50 1015 2.80 1040 3.08 1106 3.80 9,000 942 3.20 1030 3.60 1040 4.20 1110 4.50 1141 4.80 1230 5.03 10,500 1075 5.10 1150 6.25 1220 6.80 1280 6.72 1340 7.50 1400 8.50 12,000 1230 7.10 1310 8.20 1350 8.96 1410 9.20 1465 9.80 1470 10.10 8,000 560 1.68 640 2.04 705 2.40 770 3.00 850 3.60 920 3.98 10,000 710 3.36 760 3.72 820 4.20 870 4.80 930 5.40 975 6.00 12,000 845 5.28 890 5.70 945 6.20 975 6.71 1025 7.26 1090 7.70 14,000 960 8.14 1020 8.80 1076 9.24 1090 9.90 1125 10.50 1150 11.00 16,000 1090 11.60 1150 12.50 1190 12.80 1200 13.20 1230 13.70 1250 14.00 16

1500 1750 2000 2250 2500 2250 2625 3000 3375 3750 3000 3500 4000 4500 5000 CFM LEGEND Bhp Brake Horsepower 1. Shaded areas require field-supplied drive. 2. Italics require field-supplied motor. Table 4 Evaporator Fan Performance EXTERNAL STATIC PRESSURE (in. wg) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 50BYN006 Rpm 690 860 978 1100 1210 1310 1400 Bhp 0.20 0.30 0.35 0.47 0.44 0.56 0.69 Rpm 800 950 1080 1140 1240 1340 1430 Bhp 0.22 0.36 0.53 0.60 0.68 0.90 1.10 Rpm 953 1090 1140 1240 1340 1430 1520 Bhp 0.44 0.61 0.65 0.80 0.86 1.04 1.23 Rpm 1040 1160 1270 1340 1430 1480 1550 Bhp 0.58 0.80 0.97 1.10 1.23 1.30 1.33 Rpm 1209 1324 1430 1460 1550 1640 1720 Bhp 0.84 1.10 0.38 1.40 1.56 1.85 2.13 50BYN008 Rpm 683 827 950 980 1100 1130 1180 Bhp 0.24 0.43 0.66 0.73 0.76 0.83 0.94 Rpm 845 980 990 1100 1150 1220 1320 Bhp 0.57 0.83 0.88 1.03 1.18 1.23 1.32 Rpm 930 1046 1150 1210 1270 1340 1500 Bhp 0.71 1.01 1.34 1.37 1.59 1.64 1.94 Rpm 1060 1172 1270 1350 1380 1400 1505 Bhp 1.07 1.42 1.81 1.91 2.04 2.13 2.29 Rpm 1250 1350 1370 1390 1440 1520 1550 Bhp 1.72 2.10 2.27 2.37 2.63 2.70 2.89 50BYN012 Rpm 710 790 870 930 980 1060 1100 1180 1240 1290 1390 1400 Bhp 0.66 0.77 0.91 0.97 1.14 1.23 1.38 1.44 1.67 1.88 2.04 1.99 Rpm 720 820 920 920 1050 1120 1190 1240 1280 1320 1400 1410 Bhp 0.70 0.86 1.21 1.40 1.65 1.69 1.98 1.98 2.17 2.33 2.50 2.45 Rpm 852 960 1050 1090 1180 1200 1240 1320 1330 1440 1410 1420 Bhp 0.95 1.35 1.80 2.02 2.28 2.40 2.30 2.60 2.70 2.80 2.90 2.96 Rpm 946 1042 1130 1210 1220 1320 1330 1340 1420 1430 1500 1550 Bhp 1.32 1.76 2.25 2.76 2.83 3.10 3.20 3.34 3.45 3.53 4.07 4.49 Rpm 1040 1125 1205 1280 1320 1340 1430 1470 1500 1520 1580 1610 Bhp 1.75 2.22 2.73 3.21 3.40 3.75 3.97 4.41 4.68 4.87 4.76 5.03 17

3,600 4,200 4,800 5,400 6,000 4,500 5,250 6,000 6,750 7,500 6,000 7,000 8,000 9,000 10,000 CFM LEGEND Bhp Brake Horsepower 1. Shaded areas require field-supplied drive. 2. Italics require field-supplied motor. Table 4 Evaporator Fan Performance (cont) EXTERNAL STATIC PRESSURE (in. wg) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 50BYN014 Rpm 580 640 710 780 845 910 975 1040 1080 1130 1180 1280 Bhp 0.67 0.80 0.94 1.06 1.25 1.49 1.63 1.76 1.97 2.30 2.50 2.70 Rpm 670 730 760 900 915 935 1040 1050 1100 1150 1215 1285 Bhp 1.03 1.18 1.40 1.63 1.72 1.83 2.13 2.20 2.34 2.70 2.80 3.30 Rpm 760 840 850 930 940 1035 1060 1090 1130 1205 1280 1330 Bhp 1.50 1.79 1.86 2.12 2.15 2.48 2.67 2.80 2.95 3.30 3.70 3.80 Rpm 850 880 955 1005 1050 1060 1115 1160 1205 1270 1340 1360 Bhp 2.10 2.40 2.64 2.87 3.05 3.14 3.40 3.70 3.92 4.35 4.56 4.76 Rpm 955 980 1035 1060 1110 1150 1170 1220 1240 1285 1360 1380 Bhp 2.98 3.22 3.35 3.60 3.80 4.00 4.22 4.40 4.60 4.75 5.60 5.80 50BYN016 Rpm 676 840 970 940 1037 1092 1170 1251 1320 1370 1432 1462 Bhp 0.60 1.04 1.35 1.50 1.60 1.72 1.80 1.85 1.90 2.54 2.90 3.20 Rpm 731 865 980 1083 1100 1180 1210 1280 1370 1434 1490 1550 Bhp 0.80 1.20 1.65 2.00 2.20 2.35 2.47 2.70 2.98 3.42 3.50 3.67 Rpm 891 1020 1134 1140 1217 1240 1313 1327 1400 1450 1514 1580 Bhp 1.44 2.16 2.80 2.90 3.00 3.18 3.40 3.50 3.70 4.25 4.50 4.80 Rpm 950 1060 1160 1240 1280 1350 1390 1450 1514 1540 1590 1640 Bhp 1.80 2.50 3.18 3.70 3.80 4.10 4.30 4.70 5.10 5.30 5.90 6.30 Rpm 1060 1160 1290 1330 1350 1420 1488 1540 1600 1650 1707 1760 Bhp 2.50 3.27 4.37 4.50 4.70 5.02 5.40 5.68 6.20 6.50 6.90 7.40 50BYN024 Rpm 670 786 890 915 990 1090 1120 1180 1270 1310 1360 1470 Bhp 0.85 1.32 1.92 2.10 2.31 2.64 2.86 3.30 3.49 4.00 4.30 4.60 Rpm 820 930 980 1035 1070 1140 1225 1270 1290 1330 1380 1480 Bhp 1.75 2.46 2.60 3.01 3.40 3.52 4.00 4.30 4.50 4.80 5.30 5.66 Rpm 980 1033 1080 1150 1170 1250 1290 1310 1365 1410 1460 1522 Bhp 3.30 3.50 3.65 4.13 4.35 5.00 5.20 5.35 5.90 6.30 6.64 7.20 Rpm 1105 1120 1200 1240 1300 1330 1385 1430 1460 1510 1590 1620 Bhp 4.80 4.90 5.20 5.40 6.20 6.40 7.00 7.20 7.50 8.30 9.26 10.40 Rpm 1230 1250 1320 1326 1390 1415 1460 1515 1530 1580 1625 Bhp 6.00 6.80 7.03 6.80 7.80 8.20 8.46 9.45 9.70 10.50 10.90 18

Compressor Rotation To determine whether or not compressor is rotating in the proper direction: 1. Connect service gages to suction and discharge pressure fittings. 2. Energize the compressor. 3. The suction pressure should drop and the discharge pressure should rise, as is normal on any start-up. 4. If the suction pressure does not drop and the discharge pressure does not rise to normal levels. 5. Note that the evaporator fan is probably also rotating in the wrong direction. 6. Turn off power to the unit and tag disconnect. 7. Reverse any two of the unit power leads. 8. Reapply power to the unit. 9. The suction and discharge pressure levels should now move to their normal start-up levels. NOTE: When the compressor is rotating in the wrong direction, the unit makes an elevated level of noise and does not provide cooling. Operating Sequence All units require the addition of a thermostat accessory package to complete the control circuit. The sequence of operation may vary depending on which package is selected. ROOM-MOUNTED THERMOSTAT These units use an electronic, communicating electronic, or mechanical thermostat mounted in the conditioned space. FAN CIRCULATION When the fan selector switch is set to the ON position, the indoor-fan motor is energized through G on the thermostat and the indoor-fan contactor is energized. This starts the indoor fan motor (IFM). The fan will operate to provide continuous air circulation. COOLING The indoor fan will operate continuously or when the compressor runs, depending on the setting of the thermostat fan selector switch. When the thermostat closes (on a call for cooling Y1 on the thermostat), the control relay (CR), outdoor-fan contactor (OFC) and compressor contactor(s) (C1 and C2 on 20 ton) close. The control relay will start the indoor fan if it is not already running. The outdoor-fan contactor will start the condenser fan and the compressor contactors will immediately start the first stage compressor(s). The 50BYN024 unit as wired from the factory has two compressors on first stage and one on second stage. This may be altered (see application data section of the product data catalog). A second stage on 50BYN012-024 units will close if additional cooling demand is required, and will then start the second-stage compressor. When the thermostat is satisfied, the second stage compressor will stop first, and then the first stage compressors will stop when cooling demand is satisfied. The outdoor fan will also stop as soon as the first stage cooling is satisfied. HEATING The indoor fan will operate continuously or when the heater runs, depending on the setting of the thermostat fan selector switch. When the thermostat closes (on a call for heating), the thermostat activates the water or steam control valve or electric heater to meet heating requirements. CARRIER TEMP THERMOSTAT The Carrier TEMP System is a control system which includes a relay pack, TEMP system thermostat, sensors and appropriate wiring. The TEMP thermostat is the system controller and works much like a room thermostat, but provides for communicating control. The TEMP thermostat requires the addition of an accessory relaypacktointerfacewiththeunit.thisrelaypackmaybe mounted in the low-voltage control compartment. The system operation is the same as stated in the Room-Mounted Thermostat section above. CARRIER VARIABLE VOLUME AND TEMPERATURE (VVT) SYSTEM The VVT system is a control system that includes a relay pack (which may be mounted in the low voltage control compartment); monitor thermostat; zone controllers modulating supply duct dampers; modulating bypass controller sensors; and appropriate wiring. The VVT thermostat is the system controller. It sends messages to the relay pack which then sends the appropriate signals to the 50BYN unit for fan, heating and cooling. The monitor thermostat also gathers information from the zone controllers, which control the zone supply dampers. It provides a zoned, all-air system for both heating and cooling which supplies variable volume, variable temperature air to the zones conditioned. ALL UNITS The control circuit incorporates a currentsensing lockout relay (Cycle-LOC device) that locks off the compressor(s) when any safety device is activated (low or high pressure switches, outdoor-fan motor overload, or compressor internal overload). If any compressor safety device opens, the compressor(s) will stop and a 24-v signal will be sent to the X connection of the low-voltage terminal strip. The signal may be used to light an indicator light on the thermostat to show that service is required on the unit. Since the unit is protected by the Cycle-LOC device, the compressor(s) will not restart following a safety interruption unless the thermostat is satisfied without cooling operation. To reset the Cycle-LOC control device, manually turn the control power to the OFF, then back to the ON position. High- and low-pressure switches and motor overload protectors will reset automatically when the condition which caused the device to trip has dropped below the reset condition. A 5-minute timer (Time-Delay Relay [TDR]) will prevent the compressor(s) from restarting for 5 minutes after any compressor has stopped. If the condenser-fan motor overheats due to motor over-load or lack of cooling air, the internal fan protector will open the circuit internally in the motor, and the fan will stop. If a safety control in the unit opens, the condenser fan will also stop. ACCESSORIES Low ambient control on 50BYN units is accomplished with a refrigerant operated damper located on the condenser fan discharge. Low ambient operation does not affect operating sequence. WINTERSTART Since these units are equipped with a 27 psig low-pressure switch, a 3-minute low-pressure switch bypass is recommended for operation below 50 F. Order Winter Start Control accessory no. CRWINSTR01A00 and install according to the instructions supplied with the kit. DEFROST THERMOSTAT (50BB-900- - -001) This thermostat is installed on the evaporator coil and is recommended with Winter Start control. Install thermostat according to instructions supplied with the kit. ECONOMIZER When the thermostat turns the indoor fan on, the economizer relay is energized and the actuator is powered on. The actuator moves the dampers to the minimum position as determined by the adjustment potentiometer on the actuator. If the system uses a CO 2 sensor, the minimum position is determined by the potentiometer on the required field-supplied adapter. On a call for heating from the thermostat (W1 and/or W2 energized), the economizer remains at the minimum position. NOTE: If a CO 2 sensor is used, the economizer can modulate based on the carbon dioxide level in the space. There is no low leaving-air temperature limit control. Controls to accomplish this must be field-supplied and installed. 19

On a call for cooling from the thermostat (Y1 energized), the actuator logic module determines if the outdoor air enthalpy is acceptable according to the set point on the actuator. If the outdoor air enthalpy is acceptable, the economizer begins to modulate open and is controlled to maintain a 56 F leaving air temperature. If outdoor air enthalpy is unacceptable, the logic module bypasses the use of outdoor air and energizes Y1 of the unit. On a call for a second stage of cooling (Y2 energized), the actuator energizes Y1 on the unit if the outdoor air enthalpy is acceptable. If the outdoor air is unacceptable, the actuator logic module energizes Y2 of the unit. When the system is equipped with a CO 2 sensor in a modulating configuration, the following applies: If the system is operating in the Cooling mode and the demand for fresh air to reduce the carbon dioxide level in the space is greater than the cooling load demand, the actuator modulates to reduce the carbon dioxide level and does not modulate towards closed if the leaving-air temperature is below 56 F. If, however, the cooling demand is greater than the demand to reduce the carbon dioxide level, the actuator modulates open and controls to a 56 F leaving-air temperature. The damper modulates open when the leaving-air temperature demand is greater than the airflow demand required for the CO 2 sensor to reduce carbon dioxide levels. When the CO 2 sensor is installed, there is no minimum leaving air temperature control at the economizer. USING A CO 2 SENSOR WITH THE ECONOMIZER A separately ordered carbon dioxide sensor can be used to signal the economizer to open the outdoor-air dampers to admit fresh air and dilute the indoor CO 2 level. Sensor descriptions and part numbers are shown below. CO 2 SENSOR ACCESSORIES Part Numbers Description CGCDXSEN001A00 Wall Mount Sensor (No Display) CGCDXSEN002A00 Wall Mount Sensor With Display Duct Mount Sensor CGCDXSEN003A00 (No Display) CGCDXGAS001A00 Sensor Calibration Service Kit CGCDXPRM001A00 User Interface Program (UIP) The CO 2 sensors listed above are all factory set for a range of 0 to 2000 ppm and a linear voltage output of 2 to 10 vdc. The relay normally open dry contacts (TB-3 and TB-4) are factory set to close at 1000 ppm. Refer to the installation instructions with the CO 2 sensor for electrical ratings of contacts and information on connecting to power supply. Switch contacts can be used to set off an alarm or light to indicate CO 2 levels higher than the switch set point. Any changes to the factory configuration require the purchase of the User Interface Program (UIP) or Sensor Calibration Service Kit, which also contains the UIP. For correct modulation of the economizer actuator motor, a separately ordered adapter (Honeywell part no. Q769C1007) is required. SERVICE Cleaning Evaporator and Condenser Coils Do not use high-pressure water or air. Damage to fins may result. Clean coils with a vacuum cleaner, fresh water, compressed air, or a bristle brush (not wire). Backflush coil to remove debris. Commercial coil cleaners may also be used to help remove grease and dirt. Steam cleaning is NOT recommended. Units installed in corrosive environments should be cleaned as part of a planned maintenance schedule. In this type of application, all accumulations of dirt should be cleaned off the coil. Take care not to get water in the system ducts or unit insulation. Lubrication Fan motors have permanently lubricated bearings. Condenser Fan Adjustment To prevent personal injury, be sure wire fan guards are secured in place over each fan discharge (or that fans are ducted) before starting the unit. TO CHANGE FAN SPEED 1. Shut off unit power supply. 2. Loosen fan belt by loosening fan motor from mounting bracket. Do not loosen fan motor mounting bracket from unit. 3. Loosen movable pulley flange setscrew (Fig. 15). 4. Screw movable flange toward fixed flange to increase fan speed and away from fixed flange to decrease speed. Increasing fan speed increases load on motor. Do not exceed maximum allowable fan speed or motor full load amps indicated on motor nameplate and in Table 2. 5. Set movable flange setscrew at nearest flat of pulley hub and tighten setscrew. 6. Check pulley alignment and belt tension adjustment as described below. 7. Check fan operation. Repeat above procedure as required. Pulley Alignment Shut off unit power supply. Loosen fan motor pulley setscrews and slide fan pulley along fan shaft. Make angular alignment by loosening motor from mounting bracket (see Fig. 15). Check alignment with a straightedge. Belt Tension Adjustment Shut off unit power supply. Loosen fan motor mounting plate bolts. Do not loosen motor mounting bracket from unit. Move fan motor mounting plate until proper belt tension is achieved (approximately 1 / 2-in. deflection with 8-lb tension at midpoint of belt span). Changing Fan Wheel If a fan wheel should fail, it may be replaced as follows: 1. Remove belts from fan pulley. 2. Loosen locking collars on the fan bearings and set screws on the fan wheels. 3. Remove the shaft through the access panel on either side of the unit. 4. Remove the fan cut-off plate in the fan discharge. 5. Remove the fan wheel through the fan discharge opening. 6. Replace the wheel, and reverse Steps 1-4 above. Fan Bearing Replacement If a fan bearing fails, replace it as follows: 1. Remove belts from the fan pulley. 2. Support fan shaft. 3. Loosen locking collar on fan bearing. 4. Remove bearing from the shaft. 5. Install new bearing onto the shaft, and reverse Steps 1-3 above. Concentric Alignment Shaft and wheels must be concentrically centered with the venturi or air inlet of the fan housing (see Fig. 16). Shaft bearings are supports by bearing supports (Fig. 17). If shaft and wheels are concentrically misaligned from shipping shock, it is possible to rebend the bearing support arms to the original positions. Replace the bearing support if it has extensive damage. 20