Page 1: Table Of Contents
RAS Series 7.5 to 12.5 Ton Package Electric Cooling Units With R−410A Refrigerant And Micro−channel Condenser Coils TABLE OF CONTENTS SAFETY CONSIDERATIONS ....
Page 2: Safety Considerations
SAFETY CONSIDERATIONS Installation and servicing of air-conditioning equipment WARNING can be hazardous due to system pressure and electrical components. Only trained and qualified service personnel ELECTRICAL OPERATION HAZARD should install, repair, service air-conditioning Failure to follow this warning could result in personal equipment.
Page 3: Unit Arrangement And Access
UNIT ARRANGEMENT AND ACCESS Air Conditioning S Condenser fan motor mounting bolts tightness General S Compressor mounting bolts FIGURE 1 and FIGURE 2 show general unit arrangement S Condenser fan blade positioning and access locations. S Control box cleanliness and wiring condition Typical Access Panel Location FIGURE 1 S Wire terminal tightness...
Page 4: Supply Fan (Blower) Section
washing with hot low−pressure water and soft detergent To remove the filter, open the spring clips. Re−install the and replace all screens before restarting the unit. Observe filter by placing the frame in its track, then closing the the flow direction arrows on the side of each filter frame. spring clips.
Page 5 3. Push the motor and its mounting plate towards the 5. Set movable flange at nearest keyway of pulley hub blower housing as close as possible to reduce the and tighten setscrew to torque specifications. center distance between fan shaft and motor shaft. To align fan and motor pulleys: 4.
Page 6: Cooling
To reduce vibration, replace the motor’s adjustable pitch balance adjustment). This will reduce the amount of pulley with a fixed pitch pulley (after the final airflow vibration generated by the motor/belt−drive system. COOLING Coil surfaces can be easily damaged (fin edges can be WARNING easily bent over and damage to the coating of a protected coil) if the tool is applied across the fins.
Page 7 Routine Cleaning of Evaporator Coil Surfaces 3. Thoroughly wet finned surfaces with clean water and a low velocity garden hose, being careful not Monthly cleaning with environmentally sound coil cleaner to bend fins. is essential to extend the life of coils. This cleaner is 4.
Page 8: R−410A Refrigerant
oil to the check valve core’s bottom O-ring. Install the fitting body with 96 +/ −10 in−lbs of torque; do not overtighten. R−410A REFRIGERANT This unit is designed for use with R−410A refrigerant. Do Because R−410A refrigerant is a blend, it is strongly not use any other refrigerant in this system.
Page 9: Cooling Charging Charts
Outdoor Temperature ... . 85_F (29_C) CAUTION Suction Pressure ..125 psig (860 kPa) UNIT DAMAGE HAZARD Suction Temperature should be .
Page 10 FIGURE 11 COOLING CHARGING CHARTS 10 Tons...
Page 11 Fig. 12 Cooling Charging Charts - 12.5 Ton Fig. 12 − Cooling Charging Chart (Circuit 1) Fig. 13 − Cooling Charging Chart (Circuit 2)
Page 12 Compressor Rotation Condenser−Fan Location On 3−phase units with scroll compressors, it is important See Fig.14. to be certain compressor is rotating in the proper 1. Shut off unit power supply. Install lockout tag. direction. To determine whether or not compressor is 2.
Page 13 Table 1 − Cooling Service Analysts PROBLEM CAUSE REMEDY Power failure. Call power company. Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker. Defective thermostat, contactor, transformer, Replace component. Compressor and Condenser Fan or control relay. Will Not Start. Insufficient line voltage.
Page 14: Convenience Outlets
CONVENIENCE OUTLETS Fig. 16 Weatherproof Cover Installation WARNING COVER - WHILE-IN-USE WEATHERPROOF ELECTRICAL OPERATION HAZARD Failure to follow this warning could result in personal injury or death. Units with convenience outlet circuits may use multiple disconnects. Check convenience outlet for power status before opening unit for service.
Page 15: Smoke Detectors
SMOKE DETECTORS The sampling tube varies in length depending on the size of the rooftop unit. The clear plastic cover permits visual Supply Smoke detectors available inspections without having to disassemble the sensor. factory−installed options models. Smoke The cover attaches to the sensor housing using four detectors may be specified for Supply Air only or for captive screws and forms an airtight chamber around the Return Air without or with economizer.
Page 16 Smoke Detector Locations Typical Supply Air Smoke Detector Sensor Fig. 19 Location Supply Air The Supply Air smoke detector sensor is located to the left of the unit’s indoor (supply) fan. (See Fig.19.) Access is through the fan access panel. There is no sampling tube used at this location.
Page 17 Using Remote Logic Dirty Controller Test Five conductors are provided for field use (see Highlight The dirty controller test checks the controller’s ability to F) for additional annunciation functions. initiate a dirty sensor test and indicate its results. Additional Application Data — Refer to Catalog No. CAUTION HKRNKA−1XA for discussions on additional control features of these smoke detectors including multiple unit...
Page 18 Remote Test/Reset Station Dirty Sensor Test CAUTION The test/reset station dirty sensor test checks the OPERATIONAL TEST HAZARD test/reset station’s ability to initiate a sensor dirty test and indicate the results. It must be wired to the controller as Failure to follow this caution may result in personnel shown in Fig.21 and configured to operate the controller’s and authority concern.
Page 19 Detector Cleaning 4. Gently remove dirt and debris from around the optic plate and inside the optic housing. Cleaning the Smoke Detector 5. Replace the optic housing and sensor cover. Clean the duct smoke sensor when the Dirty LED is 6.
Page 20: Indicators
Indicators Resetting Alarm and Trouble Condition Trips Normal State Manual reset is required to restore smoke detector systems to Normal operation. For installations using two The smoke detector operates in the normal state in the sensors, the duct smoke detector does not differentiate absence of any trouble conditions and when its sensing which sensor signals an alarm or trouble condition.
Page 21: Protective Devices
Sensor’s Trouble LED is On, But the Controller’s External motor overload device specially−calibrated circuit breaker that is UL recognized Trouble LED is OFF as a motor overload controller. It is an overcurrent device. Remove JP1 on the controller. When the motor current exceeds the circuit breaker setpoint, the device opens all motor power leads and the PROTECTIVE DEVICES motor shuts down.
Page 22 Typical Access Panel Location Typical Module Installation Fig. 24 Fig. 26 DISCONNECT MOUNTING LOCATION TRACK INDOOR UNIT BLOCK-OFF OUTDOOR ACCESS FLANGE PANEL ACCESS PANEL PANEL Typical Component Location Fig. 25 DISCONNECT EMT OR RIGID CONDUIT SINGLE CENTER MANUAL RESET MOUNTING (FIELD-SUPPLIED) POINT BOX POST...
Page 23 Typical Location of Heater Limit Typical Single Point Installation Fig. 27 Fig. 28 Switches (3−phase heater shown) CONTROL BUSHING SINGLE POINT BOX MOUNTING Line-Break SCREWS Limit Switches DRIP BOOT BRACKET MOUNTING SCREWS POWER WIRES FOAM BUSHING HEATER RELAYS HEATER MOUNTING SCREWS Low−Voltage Control Connections On RAS units, all fuses are 60−A.
Page 24: Economizer Systems
Avoid applying torch flame directly onto the aluminum ECONOMIZER SYSTEMS tubing. The RAS units may be equipped with a factory−installed or accessory (field−installed) economizer system. See Accessory Electric Heater Control Fig. 29 Fig.30 for component location See Fig. 31 for economizer Connections section wiring diagrams.
Page 25 Fig. 31 Economizer Wiring Table 6 − Economizer Input/Output Logic Enthalpy* Compressor N Terminal† Demand Control Occupied Unoccupied Stage Stage Ventilation (DCV) Outdoor Return Damper High Minimum position Closed (Free Cooling LED Off) Below set (DCV LED Off) Modulating** (between min. Modulating** (between position and full-open) closed and full-open)
Page 26 Economizer Functional View Fig. 32 Economizer The temperature sensor looks like an eyelet terminal with wires running to it. The sensor is located in the “crimp Table provides summary Economizer end” and is sealed from moisture. Troubleshooting instructions are enclosed. Outdoor Air Lockout Sensor A functional view of the Economizer is shown in Fig.32.
Page 27 and D. See Fig.35 for the corresponding temperature accessory bulb sensor (part number changeover values. DNTEMPSN002A00). The accessory sensor must be mounted in the return airstream. (See Fig.37.) Wiring is Economizer Controller Potentiometer and provided in the Economizer wiring harness. Fig.
Page 28 Enthalpy Changeover Setpoints Fig. 38 CONTROL CONTROL POINT CURVE APPROX. deg. F (deg. C) AT 50% RH HIGH LIMIT CURVE APPROXIMATE DRY BULB TEMPERATURE--degrees F (degrees C) return air duct. The Economizer controller compares the Economizer Control Fig. 39 outdoor air enthalpy to the return air enthalpy to determine Economizer use.
Page 29 Adjust the DCV potentiometers to correspond to the DCV requirements. The maximum demand ventilation position voltage output of the indoor air quality sensor at the is used for fully occupied ventilation. user-determined setpoint. (See Fig.40.) When demand ventilation control is not being used, the minimum position potentiometer should be used to set the Sensor Maximum Range Settings Fig.
Page 30 potentiometer to the P and P1 terminals on the Typically the maximum ventilation rate will be about 5 to Economizer controller. (See Fig.39) 10% more than the typical cfm required per person, using normal outside air design criteria. Damper Movement A proportional anticipatory strategy should be taken with Damper movement from full open to full closed (or vice the following conditions: a zone with a large area, varied...
Page 31 Once the fully occupied damper position has been Economizer Preparation determined, set the maximum damper demand control This procedure is used to prepare the Economizer for ventilation potentiometer to this position. Do not set to the troubleshooting. No troubleshooting or testing is done by maximum position as this can result in over-ventilation to performing the following procedure.
Page 32: Wiring Diagrams
2. Ensure terminals AQ and AQ1 are open. The LED for 8. Return Economizer settings and wiring to normal both DCV and Exhaust should be off. The actuator +after completing troubleshooting. should be fully closed. Supply−Air Sensor Input 3. Connect a 9−v battery to AQ (positive node) and AQ1 To check supply−air sensor input: (negative node).
Page 33 Typical Unit Wiring Diagram−Power (208/230−3−60) Fig. 42...
Page 34 Typical Unit Wiring Diagram−Control (208/230−3−60) Fig. 43...
Page 35: Pre Start−Up
PRE−START−UP WARNING WARNING ELECTRICAL OPERATION HAZARD PERSONAL INJURY HAZARD Failure to follow this warning could result in personal Failure to follow this warning could result in personal injury or death. injury or death. Relieve pressure and recover all refrigerant before 1.
Page 36: Start−Up, General
START−UP, GENERAL Unit Preparation Check unit charge. Refer to Refrigerant Charge section. Make sure that unit has been installed in accordance with Reset thermostat at a position above room temperature. installation instructions and applicable codes. Both compressors will shut off. Evaporator fan will shut off after a 30−second delay.
Page 37 does not satisfy the space load, the space temperature Heating With Economizer will drop until thermostat calls for Stage 2 heating (W2 During Occupied mode operation, indoor fan operation Closes). Heater contactor No. 2 (HC2) will be energized will be accompanied by economizer dampers moving to and heater module No.
Page 38: Fastener Torque Values
FASTENER TORQUE VALUES See Table 8 for torque values. Table 8− Torque Values Supply fan motor mounting 120 12 in−lbs 13.5 1.4 Nm Supply fan motor adjustment plate 120 12 in−lbs 13.5 1.4 Nm Motor pulley setscrew 72 5 in−lbs 8.1 0.6 Nm Fan pulley setscrew...
Page 39: Appendix Ii. Physical Data
APPENDIX II. PHYSICAL DATA Physical Data (Cooling) 7.5 − 12.5TONS RAS090 RAS120 RAS150 Refrigeration System # Circuits / # Comp. / Type 2 / 2 / Scroll 2 / 2 / Scroll 2 / 2 / Scroll R−410a charge A/B (lbs) 4−6 / 4−6 6−0 / 6−0 7−6/8−0...
Page 40 RAS090 3 PHASE 7.5 TON HORIZONTAL SUPPLY AVAILABLE EXTERNAL STATIC PRESSURE (IN. WG) Field Supplied Drive Standard Static Option Medium Static Option 2250 0.43 0.64 0.86 1.10 1.34 2438 0.51 0.73 0.97 1.21 1.47 2625 0.60 0.84 1.09 1.34 1.62 2813 0.70 0.95...
Page 41 APPENDIX III. FAN PERFORMANCE (cont.) RAS120 3 PHASE 10 TON HORIZONTAL SUPPLY AVAILABLE EXTERNAL STATIC PRESSURE (IN. WG) Field Supplied Drive Standard Static Option 3000 0.58 0.73 0.88 1.05 1.22 3250 0.71 0.87 1.04 1.21 1.39 3500 0.86 1.03 1.21 1.39 1.58 3750...
Page 42 FAN PERFORMANCE (cont.) RAS150 3 PHASE 12.5 TON HORIZONTAL SUPPLY Available External Static Pressure (in. wg) Field Supplied Drive Standard Static Option 3438 0.82 0.99 1.16 1.34 1.53 3750 1.03 1.21 1.40 1.59 1.79 4063 1.28 1.47 1.67 1.88 2.09 4375 1.56 1.77...
Page 43 APPENDIX III. FAN PERFORMANCE (cont.) Pulley Adjustment MOTOR PULLEY TURNS OPEN MOTOR/DRIVE COMBO Standard Static Medium Static High Static 1102 1083 1063 1044 1025 1006 Standard Static Medium Static 1084 1059 1035 1010 High Static 1240 1218 1196 1175 1153 1131 1109 1087...
Page 44 APPENDIX IV. ELECTRICAL DATA RAS090 VOLTAGE COMP (Cir 1) COMP (Cir 2) OFM (ea) RANGE V−Ph−Hz WATTS TYPE EFF at Full Load WATTS AMP Draw 1448 2278 208−3−60 13.6 13.6 HIGH 4400 15.0 15.0 1448 230−3−60 13.6 13.6 2278 HIGH 4400 15.0 15.0...
Page 45: Appendix Iv. Electrical Data
APPENDIX IV. ELECTRICAL DATA (cont) MCA/MOCP DETERMINATION NO C.O. OR UNPWRD C.O. ELECTRIC HEATER NO C.O. or UNPWRD C.O. NO P.E. w/ P.E. (pwrd fr/unit) TYPE DISC. SIZE DISC. SIZE (kW) MOCP MOCP − − 39.5 43.3 7.8/10.4 21.7/25.0 39.5/39.5 60/60 38/38 191/191...
Page 46 APPENDIX IV. ELECTRICAL DATA (cont) MCA/MOCP DETERMINATION NO C.O. OR UNPWRD C.O. (cont) ELECTRIC HEATER NO C.O. or UNPWRD C.O. NO P.E. w/ P.E. (pwrd fr/unit) TYPE DISC. SIZE DISC. SIZE (kW) MOCP MOCP − − 45.8 49.6 7.8/10.4 21.7/25.0 45.8/45.8 60/60 44/44...
Page 47 MCA/MOCP DETERMINATION NO C.O. OR UNPWRD C.O. (cont) ELECTRIC HEATER NO C.O. or UNPWRD C.O. NO P.E. w/ P.E. (pwrd fr/unit) Nom* TYPE DISC. SIZE DISC. SIZE (kW) MOCP MOCP − − 60.7 64.5 7.8/10.4 21.7/25.0 60.7/60.7 80/80 63/63 360/360 64.5/64.5 80/80 68/68...
Page 48: Appendix V. Motormaster Sensor Locations
APPENDIX V. MOTORMASTER SENSOR LOCATIONS Fig. 44 RAS090 and RAS120...
Page 49: Unit Start-Up Checklist
START-UP CHECKLIST (Remove and Store in Job File) PRELIMINARY INFORMATION MODEL NO.: SERIAL NO.: DATE: TECHNICIAN: PRE-START-UP (insert checkmark in box as each item is completed) j VERIFY THAT JOBSITE VOLTAGE AGREES WITH VOLTAGE LISTED ON RATING PLATE j VERIFY THAT ALL PACKAGING MATERIALS HAVE BEEN REMOVED FROM UNIT j REMOVE ALL SHIPPING HOLD DOWN BOLTS AND BRACKETS PER INSTALLATION INSTRUCTIONS j VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTALLATION INSTRUCTIONS j CHECK REFRIGERANT PIPING FOR INDICATIONS OF LEAKS;...

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