Loading...
BLD2023-1158_Manufacturer_Specifications_and_Installation_Instructions_9.14.2023_7.02.57_AM_3782189LENNOX UNIT INFORMATION ML18XC2 100051 Service Literaturep June 10, 2022 ML18XC2 (HFC-410A) SERIES OUTDOOR UNITS Table of Contents Installation Clearances...................................................2 Model Number Identification...........................................2 Dimensions..................................................................... 3 Specifications.................................................................4 Typical Unit Parts Arrangement......................................5 Operating Gauge Set and Service Valves......................5 Unit Placement..............................................................7 Removing and Installing Louvered Panels.....................8 New or Replacement Line Set........................................9 Brazing Connections................................................... 11 Flushing Line Set and Indoor Coil................................14 Installing Indoor Metering Device.................................15 Leak Test Line Set and Indoor Coil..............................16 Evacuating Line Set and Indoor Coil ...........................17 Electrical.......................................................................18 System Operation.......................................................20 Maintenance...............................................................20 Servicing Units Void of Charge...................................22 Start-Up......................................................................22 General Information These instructions are intended as a general guide and do not supersede national or local codes in any way. Consult authorities having jurisdiction before installation. The Merit° ML18XC2 model is designed for use with HFC- 410A refrigerant only. This unit must be installed with an approved indoor air handler or coil. For AHRI Certified system match -ups and expanded ratings, visit www.Len- noxPros.com. This outdoor unit is designed for use in systems that use the following refrigerant metering device: • Thermal expansion valve (TXV) IMPORTANT: Special procedures are required for clean- ing the all -aluminum coil in this unit. See page 21 in this instruction for information. Page 1 Installation Clearances F See NOTE See NOTES NOTES: Service clearance of 30 in. (762 mm) must be maintained on one of the sides adjacent to the control box. Clearance to one of the other three sides must be 36 in. (914 mm) :S Clearance to one of the remaining two sides may be 12 in. (305 mm) and the final side may be 6 in. (152 mm). A clearance of 24 in. must be maintained between two units. 48 in. (1219 mm) clearance required on top of unit. .. .JL v See NOTES BOX / Model Number Identification Product Tier ML = Merit® Series Nominal SEER Refrigerant Type X = R-410A Unit Type C = Air Conditioner Unit Cooling Stages 2 = Two Stage Compressor a AO1 Revision Level Ratings Revision Level Voltage 230 = 208/230V-1 phase-60hz Nominal Cooling Capacity 024 = 2 tons 036 = 3 tons 048 = 4 tons 060 = 5 tons Page 2 Dimensions INLET AIR INLET AIR INLET 4 AIR TOP VIEW 4-3/8 4-3/8 (111) 1.*- -0.1 (111) 4-3/8 I I 4-3/8 OPTIONAL UNIT INLET STAND-OFF KIT (4) (Field Installed) jj Cc MPRESS(PR AIR COIL DRAIN OUTLETS / (Around perimeter of base) SUCTION LINE 6-3/8162 \ 4-3/8 CONNECTION ( ) o (111) LIQUID LINE CONNECTION 6-3/8 4-3/8 (162) (111) W 2(51) SIDE VIEW TOP VIEW BASE SECTION AA OUTDOOR t DISCHARGE AIR COIL F COMPRESS SUCTION A LIQUID LI CONNECTI 2-: 11 OPTIONAL UNIT SIDE VIEW STANDOFF KIT (4) (FIELD INSTALLED) Model A B C inches mm inches mm inches mm ML18XC2-024 28-1/4 718 29-1/4 743 28-1/4 718 ML18XC2-036 28-1/4 718 33-3/4 857 33 838 ML18XC2-048 32-1/4 718 33-3/4 857 33 838 ML18XC2-060 32-1/4 819 r 43-1/4 1 1099 42-1/4 1 1073 Page 3 Specifications General Model No. All Regions Data Nominal Tonnage ML18XC2-024 ML18XC2-036 ML18XC2-048 ML18XC2-060 2 3 4 5 Indoor Unit Expansion Valve (TXV) (If needed) 12.1118 112,119 12.120 112,120 Connections Liquid line (o.d.) - in. (sweat) Suction line (o.d.) - in. 3/8 3/8 3/8 3/8 3/4 7/8 7/8 1-1/8 Refrigerant R-410A charge furnished 7 lbs. 1 oz. 8 lbs. 0 oz. 11 Ibs.1 oz. 12 lbs. 0 oz. Outdoor Net face area - sq. ft. Outer coil Coil Inner coil Tube diameter - in. and No. of rows Fins per inch 16.33 18.67 22.17 29.09 15.71 17.96 21.23 27.87 5/16 - 2 5/16 - 2 5/16 - 2 5/16 - 2 22 22 22 22 Outdoor Diameter - in. and No. of blades Fan Motor hp Cfm Rpm Watts 22-3 22-3 26 - 3 26 - 3 1/6 1/6 1/4 1/3 3160 3160 4100 3900 825 825 825 825 190 190 275 190 Shipping Data - lbs. 1 pkg. 166 187 231 283 ELECTRICAL DATA Line voltage data - 60 Hz 208/23OV-1 ph 208/23OV-1 ph 208/23OV-1 ph 208/23OV-1 ph ' Maximum Overcurrent Protection (MOCP) amps 25 35 45 50 ' Minimum circuit ampacity (MCA) 14.6 20.2 26.2 32.2 Compressor Rated load amps Locked rotor amps Power factor 10.9 15.4 19.9 23.7 61 92 127 151 0.97 0.94 0.93 0.92 Outdoor Fan Motor Full load amps Locked Rotor amps 1 1 1.4 2.6 1.9 1.9 3.2 --- CONTROLS - ORDER SEPARATELY M30 Smart Wi-Fi Thermostat 15Z69 Remote Outdoor Temperature Sensor X2658 OPTIONAL ACCESSORIES - ORDER SEPARATELY Blower Relay Kit 85W66 (for constant torque gas furnaces) Compressor Crankcase Heater 93M04 Compressor Hard Start Kit 10J42 Required if voltage is less than 230V 112,190 Compressor Low Ambient Cut -Off 45F08 Compressor Sound Cover 118,142 Compressor Time -Off Control 47,127 Freezestat 3/8 in. tubing 93G35 5/8 in. tubing 5OA93 Indoor Blower Off Delay Relay 58M81 Indoor Blower Speed Relay Kit 40K58 ° Low Ambient Kit (Fan Cycling) 34M72 Refrigerant L15-41-20, L15-41-40, L15-41-30, L15-41-50 Line Sets L15-65-30, L15-65-40, L15-65-50 Field Fabricate Unit Stand -Off Kit 94J45 NOTE -Extremes of operating range are plus 10% and minus 5% of line voltage. Refrigerant charge sufficient for 15 ft. length of refrigerant lines. For longer line set requirements see the Installation Instructions for information about line set length and additional refrigerant charge required. 2 HACR type breaker or fuse. Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements. ° Freezestat is recommended with Low Ambient Kit Page 4 Typical Unit Parts Arrangement COMPRESSOR UTDOOR COIL i HIGH PRESSURE SWITCH LOW PRESSURE SWITCH LIQUID LINE SERVICE VALVE SUCTION LINE SERVICE VALVE FIGURE 1. Typical Plumbing Arrangement Operating Gauge Set and Service Valves TORQUE REQUIREMENTS When servicing or repairing HVAC components, ensure the fasteners are appropriately tightened. Table 1 provides torque values for fasteners. TABLE 1. Torque Requirements Parts Recommended Torque Service valve cap 8 ft.- lb. 11 NM Sheet metal screws 16 ft.- lb. 2 NM Machine screws #10 28 ft.- lb. 3 NM Compressor bolts 90 in.- lb. 10 NM Gauge port seal cap 8 ft.- lb. 11 NM USING MANIFOLD GAUGE SET When checking the system charge, only use a manifold gauge set that features low loss anti -blow back fittings. Manifold gauge set used with HFC-410A refrigerant sys- tems must be capable of handling the higher system oper- ating pressures. The gauges should be rated for use with pressures of 0 - 800 psig on the high side and a low side of 30" vacuum to 250 psig with dampened speed to 500 psi. Gauge hoses must be rated for use at up to 800 psig of pressure with a 4000 psig burst rating. OPERATING SERVICE VALVES The liquid and vapor line service valves are used for re- moving refrigerant, flushing, leak testing, evacuating, checking charge and charging. Each valve is equipped with a service port which has a factory -installed valve stem. Figure 2 provides information on how to access and operating both angle and ball service valves Page 5 SERVICE VALVES ANGLE AND BALL Operating Angle Type Service Valve: 1. Remove stem cap with an appropriately sized wrench. 2. Use a service wrench with a hex -head extension (3/16" for liquid line valve sizes and 5/16" for vapor line valve sizes) to back the stem out counterclockwise as far as it will go. / SERVICE PORT CAP SERVICE PORT CORE (VALVE STEM SHOWN TO INDOOR CLOSED) INSERT HEX UNIT (VALVE STEM SHOWN OPEN) WRENCH HERE INSERT HEX WRENCH HERE SERVICE PORT STEM CAP CORE TO OUTDOOR UNIT ANGLE -TYPE SERVICE VALVE ANGLE -TYPE SERVICE VALVE (FRONT -SEATED CLOSED) (BACK -SEATED OPENED) When service valve is OPEN, the service port is WHEN SERVICE VALVE IS CLOSED, THE SERVICE PORT IS OPEN open to IinE set, Indoor and outdoor unit. TO THE LINE SET AND INDOOR UNIT. Operating Ball Type Service Valve: To Access Service Port: A service port cap protects the service port core from contamination and 1. Remove stem cap with an appropriately sized wrench. serves as the primary leak seal. 2. Use an appropriately sized wrenched to open. To open valve, 1. Remove service port cap with an appropriately sized wrench. roate stem counterclockwise 90°. To close rotate stem clockwise 901. 2. Connect gauge set to service port. 3. When testing is completed, replace service port cap and tighten as follows: TO INDOOR UNIT • With torque wrench: Finger tighten and 1/6TURN torque cap per table 3. 11 2 / • Without torque wrench: Finger tighten and 10 TO OPEN ROTATE STEM BALL (SHOWN use an appropriately sized wrench to turn 9 COUNTERCLOCKWISE 90°. CLOSED) an additional 1/6 turn clockwise. g 5 TO CLOSE ROTATE STEM VALVE � STEM % 6 R i enstall Stem Ca p: CLOCKWISE 90°. � Stem cap protects the valve stem from damage and serves as the SERVICE PORT primary seal. Replace the stem cap and tighten as follows: 1/12 TURN SERVICE PORT • With Torque Wrench: Finger tighten and �j CORE SERVICE PORT CAP then torque cap per table 3. 11 2 1 • Without Torque Wrench: Finger tight- 10 2 en and use an appropriately sized 9 3 TO OUTDOOR STEM CAP wrench to turn an additional 1/12 turn 8 4 UNIT clockwise. '� 6 5 NOTE — A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque. FIGURE 2. Angle and Ball Service Valves Page 6 DETAIL A DETAIL B INSTALL UNIT AWAY FROM WINDOWS TWO 90' ELBOWS INSTALLED IN LINE SET WILL REDUCE LINE SET VIBRATION INSTALL UNIT LEVEL OR, IF ON A SLOPE, MAINTAIN SLOPE TOLERANCE OF 2 DEGREES (OR 2 INCHES PER 5 FEET [50 MM PER 1.5 M]) AWAY FROM BUILDING STRUCTURE. DISCHARGE AIR BUILDING 4 STRUCTURE A J�- L FIGURE 3. Placement and Slab Mounting Unit Placement See Unit Dimensions on page 3 for sizing mounting slab, platforms or supports. Refer to page 2 for mandatory in- stallation clearance requirements. A CAUTION liftingIn order to avoid injury, take proper precaution when heavy objects.. POSITIONING CONSIDERATIONS Consider the following when positioning the unit: • Some localities are adopting sound ordinances based on the unit's sound level registered from the adjacent property, not from the installation property. Install the unit as far as possible from the property line. • When possible, do not install the unit directly outside a window. Glass has a very high level of sound trans- mission. For proper placement of unit in relation to a window see the provided illustration in figure 3, detail A. PLACING UNIT ON SLAB When installing unit at grade level, the top of the slab should be high enough above grade so that water from higher ground will not collect around the unit. The slab should have a slope tolerance as described in figure 3, detail B. ROOF MOUNTING MOUNTING SLAB GROUND LEVEL Install the unit a minimum of 6 inches (152 mm) above the roof surface to avoid ice build-up around the unit. Locate the unit above a load bearing wall or area of the roof that can adequately support the unit. Consult local codes for rooftop applications. If unit coil cannot be mounted away from prevailing winter winds, a wind barrier should be constructed. Size barrier at least the same height and width as outdoor unit. Mount barrier 24 inches (610 mm) from the sides of the unit in the direction of prevailing winds. Page 7 WARNING To prevent personal injury, or damage to panels, unit or structure, be sure to observe the following: While installing or servicing this unit, carefully stow all removed panels out of the way, so that the panels will not cause injury to personnel, nor cause damage to objects or structures nearby, nor will the panels be subjected to damage (e.g., being bent or scratched). While handling or stowing the panels, consider any weather conditions, especially windy conditions, that may cause panels to be blown around and battered. New or Replacement Line Set This section provides information on new installation or re- placement of existing line set. If a new or replacement line set is not required, then proceed to Brazing Connections on page 11. If refrigerant lines are routed through a wall, seal and isolate the opening so vibration is not transmitted to the building. Pay close attention to line set isolation during installation of any HVAC system. When properly isolated from building structures (walls, ceilings. floors), the refrig- erant lines will not create unnecessary vibration and sub- sequent sounds. REFRIGERANT LINE SET Field refrigerant piping consists of liquid and suction lines from the outdoor unit (braze connections) to the indoor unit coil (flare or braze connections). Use Lennox L15 (braze, non -flare) series line set, or use field -fabricated refrigerant lines as listed in table 2. TABLE 2. Refrigerant Line Set — in. (mm) Field Recommended Line Set Model Connections Liquid Suction Liquid Suction L15 Line Set Line Line Line Line -024 3/8" 3/4" 3/8" 3/4" L15-41: 15 ft. 50 ft. 00 mm) (19 mm) (10mm) (19 mm) (4.6 m-15 m) -036 3/8" (10mm) 7/8" (22mm) 3/8" (10mm) 7/8" (22 mm) L 15-65: 15 ft.— 50 ft. (4.6 m-15 m) -048 -060 3/8" 1-1/8" 3/8" 1-1/8" Field -Fabricated (10mm) (29 mm) (10mm) (29 mm) NOTE - Some applications may require a field -provided 7/8" to 1-1/8" adapter. NOTE — When installing refrigerant lines longer than 50 feet, contact Lennox Technical Support Product Applica- tions for assistance or Lennox piping manual. To obtain the correct information from Lennox, be sure to communi- cate the following points: • Model (ML18XC2) and size of unit (e.g. -060). • Line set diameters for the unit being installed as listed in table 4 and total length of installation. • Number of elbows and if there is a rise or drop of the piping. A IMPORTANT Mineral oils are not compatible with HFC-410A. If oil must be added, it must be a Polyol ester oil. The compressor is charged with sufficient Polyol ester oil for line set lengths up to 50 feet. Recommend adding oil to system based on the amount of refrigerant charge in the system. No need to add oil in system with 20 pounds of refrigerant or less. For systems over 20 pounds - add one ounce for every five pounds of refrigerant. Recommended topping -off POE oils are Mobil EAL ARC- TIC 22 CC or ICI EMKARATE RL32CF. MATCHING WITH NEW OR EXISTING INDOOR COIL AND LINE SET The RFC1-metering line consisted of a small bore copper line that ran from condenser to evaporator coil. Refrig- erant was metered into the evaporator by utilizing tem- perature/pressure evaporation effects on refrigerant in the small RFC line. The length and bore of the RFC line cor- responded to the size of cooling unit. If the ML18XC2 is being used with either a new or existing indoor coil which is equipped with a liquid line which served as a meter- ing device (RFCI), the liquid line must be replaced prior to the installation of the ML18XC2 unit. Typically a liquid line used to meter flow is 1/4" in diameter and copper. LINE SET ISOLATION Page 9 1.INF ET INSTALLATION Line Set Isolation — The following illustrations are examples of proper refrigerant line set isolation: REFRIGERANT LINE SET — TRANSITION FROM VERTICAL TO HORIZONTAL ANCHORED HEAVY NYLON WIRE TIE OR AUTOMOTIVE AUTOMOTIVE MUFFLER -TYPE HANGER MUFFLER -TYPE HANGER REFRIGERANT LINE SET — INSTALLING VERTICAL RUNS (NEW CONSTRUCTION SHOWN) NOTE — Insulate liquid line when it is routed through areas where the surrounding ambient temperature could become higher than the temperature of the liquid line or when pressure drop is equal to or greater than 20 psig. OUTSIDE WALL VAPOR LINE LIQUID LINE WALL STUD WIRE TIE NSIDE WALL STRAP STRAP LIQUID LINE TO WOOD BLOCK VAPOR LINE BETWEEN STUDS NON -CORROSIVE METAL SLEEVE \LIQUID LINE WIRE TIE NON -CORROSIVE METAL SLEEVE WOOD BLOCK VAPOR LINE - WRAPPED IN ARMAFLEX WIRE TIE STRAP REFRIGERANT LINE SET — INSTALLING HORIZONTAL RUNS To hang line set from joist or rafter, use either metal strapping material or anchored heavy nylon wire ties. 8 FEET (2.43 METERS) I STRAPPING L ( MATERIAL VAPOR LINE ONLY) FLOOR JOIST OR / ROOF RAFTER 7/ WIRE TIE (AROUND VAPOR LINE ONLY) TAPE OR WIRE TIE 8 FEET (2.43 METERS) NON -CORROSIVE METAL SLEEVE TAPE OR STRAP THE VAPOR LINE TO THE JOIST WIRE TIE OR RAFTER AT 8 FEET (2.43 METERS) INTERVALS THEN STRAP THE LIQUID LINE TO THE VAPOR LINE. FLOOR JOIST ROOF RAFTER I SLEEVE VAPOR LINE WRAPPED \ WITH ARMAFLEX OUTSIDE WALL LIQUID LINE PVC \ CAULK PIPE FIBERGLASS INSULATION i NOTE — Similar installation practices should be used if line set is to be installed on exterior of outside wall. FIGURE 5. Line Set Installation Page 10 Danger of fire. Bleeding the refrigerant charge from only the high side may result in pressurization of the low side shell and suction tubing. Application of a brazing torch to a pressurized system may result in ignition of the refrigerant and oil mixture. Check the high and low pressures before applying heat. When using a high pressure gas such as nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa). Brazing alloys and flux contain materials which are hazardous to your health. Avoid breathing vapors or fumes from brazing operations. Perform operations only in well -ventilated areas. Wear gloves and protective goggles or face shield to protect against burns. Wash hands with soap and water after handling brazing alloys and flux. Allow braze joint to cool before removing the wet rag from the service valve. Temperatures above 250OF can damage valve seals. Use silver alloy brazing rods with 5% minimum silver alloy for copper -to -copper brazing. Use 45% minimum alloy for copper -to -brass and copper -to -steel brazing. Fire, Explosion and Personal Safety hazard. Failure to follow this warning could result in damage, personal injury or death. Never use oxygen to pressurize or purge refrigeration lines. Oxygen, when exposed to a spark or open flame, can cause fire and/ or an explosion, that could result in property damage, personal injury or death. 1 CUT AND DEBUR CAP AND CORE REMOVAL Cut ends of the refrigerant lines square (free from nicks or dents) 2 Remove service cap and core from and debur the ends. The pipe must remain round. Do not crimp end both the suction / vapor and liquid line of the line. service ports. CUT AND DEBUR 01' LINE SET SIZE MATCHES SERVICE VALVE CONNECTION SERVICE VALVE CONNECTION COPPERTUBE -� STUB \ REDUCER O LINE SET SIZE IS SMALLER THAN CONNECTION REFRIGERANT LINE SERVICE PORT CAP ci "r SERVICE PORT CORE LIQUID LINE SERVICE VALVE DO NOT CRIMP SERVICE VALVE CONNECTOR WHEN PIPE IS SMALLER THAN CONNECTION SERVICE PORT OCORE SERVICE PORT CAP SUCTION / VAPOR LINE SERVICE VALVE 3 ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE VALVES Flow regulated nitrogen (at 1 to 2 psig) through the low -side refrigeration gauge set into the liquid line service port valve, and out of the suction / vapor line service port valve. A Connect gauge set low pressure side to liquid line service valve (service port). USE REGULATOR TO FLOW B Connect gauge set center port to bottle of LOW HIGH NITROGEN AT 1 TO 2 PSIG. nitrogen with regulator. O / C Remove core from valve in suction / vapor O line service port to allow nitrogen to escape. ATTACH _ o GAUGES SUCTION / VAPOR SERVICE PORT MUST BE OPEN TO ALLOW EXIT POINT FOR NITROGEN C SUCTION / VAPOR LINE SERVICE VALVE VAPOR LINE V/ INDOOR OUTDOOR UNIT UNIT I NITROGEN LIQUID LINE LIQUID LINE SERVICE O WHEN BRAZING LINE SET TO VALVE SERVICE VALVES, POINT FLAME AWAY FROM SERVICE VALVE. FIGURE 6. Brazing Procedures Page 12 4 WRAP SERVICE VALVES To help protect service valve seals during brazing, wrap water saturated cloths around service valve bodies and copper tube stubs. Use additional water saturated cloths underneath the valve body to protect the base paint. 5 FLOW NITROGEN Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration gauge set into the valve stem port connection on the liquid service valve and out of the suction / vapor valve stem port. See steps 3A, 313 and 3C on manifold gauge set connections 6 BRAZE LINE SET Wrap both service valves with water saturated cloths as illustrated here and as mentioned in step 4, before brazing to line set. Water saturated cloths must remain water saturated throughout the brazing and cool -down process. M �k LIQUID LINE SERVICE VALVE WHEN BRAZING LINE SET TO SERVICE VALVES, POINT FLAME AWAY FROM SERVICE VALVE. IMPORTANT — Allow braze joint to cool. Apply additional water saturated cloths to help cool brazed joint. Do not remove water saturated cloths until piping has cooled. Temperatures above 250°F will damage valve seals. �=11 SUCTION / VAPOR LINE Q WATER SATURATED CLOTH LIQUID LINE SUCTION / VAPOR LINE SERVICE VALVE WHEN BRAZING LINE SET TO SERVICE VALVES, POINT FLAME AWAY FROM SERVICE VALVE. WATER SATURATED CLOTH 7 PREPARATION FOR NEXT STEP After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water saturated cloths to both services valves to cool piping. Once piping is cool, remove all water saturated cloths. Refer to the unit installation instructions for the next step in preparing the unit. FIGURE 7. Brazing Procedures (continued) Page 13 Flushing Line Set and Indoor Coil TYPICAL EXISTING FIXED ORIFICE TYPICAL EXISTING EXPANSION VALVE REMOVAL 1 A REMOVAL PROCEDURE (UNCASED OR PROCEDURE (UNCASED COIL SHOWN) COIL SHOWN) 1B STUB END DISTRIBUTOR TUBES TWO PIECE PATCH PLATE LIQUID LINE CHECK (UNCASED COIL ONLY) ORIFICE EXPANSION LIQUID LINE ORIFICE HOUSING DISTRIBUTOR HOUSING VALVE � TUBES TEFLON" ® TEFLON@ RING p RING / FIXED ORIFICE �\ p l ® BRASS NUT � O TEFLON ®RING SENSING � LINE DISTRIBUTOR a NE v ASSEMBLY DISTRIBUTOR EQUA\ LIZER REMOVE AND DISCARD 1 ASSEMBLY6 LINE WHITE TEFLON@ SEAL (IF PRESENT) LIQUID LINE ASSEMBLY (INCLUDES STRAINER) LIQUID LINE / ASSEMBLY WITH A On fully cased coils, remove the coil access and plumbing panels. / BRASS NUT B Remove any shipping clamps holding the liquid line and distributor as- p I sembly. MALE EQUALIZER / C Using two wrenches, disconnect liquid line from liquid line orifice hous- LINE FITTING VAPOR ing. Take care not to twist or damage distributor tubes during this pro- SENSING BULB LINE \ LIQUIDLINE cess. D Remove and discard fixed orifice, valve stem assembly if present and A On fully cased coils, remove the coil access and plumbing panels. Teflon® washer as illustrated above. B Remove any shipping clamps holding the liquid line and distributor E Use a field -provided fitting to temporarily reconnect the liquid line to the assembly indoor unit's liquid line orifice housing. C 2 CONNECT GAUGES AND EQUIPMENT FOR D FLUSHING PROCEDURE E INVERTED CYLINDER GAUGE F CONTAINS CLEAN HCFC22* TO BE USED MANIFOLD A FOR FLUSHING. �� LOW HIGH 7 H VAPOR LINE NEWTOPENEDCLOSED SERVICE VALVE\ OUTDOOR �� UNIT EXISTING INDOOR UNIT LIQUID LINE SERVICE VALVE TANK \ RETURN D p - CIE INLET o DISCHARGE RECOVERY CYLINDER RECOVERY MACHINE A Inverted HCFC-22 cylinder with clean refrigerant* to the vapor service valve. B HCFC-22 gauge set (low side) to the liquid line valve. C HCFC-22 gauge set center port to inlet on the recovery machine with an empty recovery tank to the gauge set. D Connect recovery tank to recovery machines per machine instructions. Disconnect the equalizer line from the check expansion valve equalizer line fitting on the vapor line. Remove the vapor line sensing bulb. Disconnect the liquid line from the check expansion valve at the liquid line assembly. Disconnect the check expansion valve from the liquid line orifice housing. Take care not to twist or damage distributor tubes during this process. Remove and discard check expansion valve and the two Teflon® rings. Use a field -provided fitting to temporary reconnect the liquid line to the indoor unit's liquid line orifice housing. 3FLUSHING LINE SET The line set and indoor unit coil must be flushed with at least the same amount of clean refrigerant* that previously charged the system. Check the charge in the flushing cylinder before proceeding. A Set the recovery machine for liquid recovery and start the recovery machine. Open the gauge set valves to allow the recovery machine to pull a vacuum on the existing system line set and indoor unit coil. B Invert the cylinder of clean HCFC-22* and open its valve to allow liquid refrigerant to flow into the system through the vapor line valve. Allow the refrigerant to pass from the cylinder and through the line set and the indoor unit coil before it enters the recovery machine. C After all of the liquid refrigerant has been recovered, switch the recovery machine to vapor recovery so that all of the HCFC-22 vapor is recovered. Allow the recovery machine to pull the system down to 0. D Close the valve on the inverted HCFC-22 drum and the gauge set valves. Pump the remaining refrigerant out of the recovery machine and turn the machine off. *IMPORTANT - Clean refrigerant is any refrigerant in a system that has not had compressor burn out. If the system has experienced burn out, it is recommended that the existing line set and indoor coil be replaced. FIGURE 8. Removing Metering Device and Flushing Page 14 Installing Indoor Metering Device This outdoor unit is designed for use in systems that use a In applications where an uncased coil is being installed in check expansion valve metering device at the indoor coil. a field -provided plenum, install the expansion valve in a See the Lennox ML18XC2 Product Specification bulletin manner that will provide access for field servicing of the for approved expansion valve kit match -ups. The expan- expansion valve. Refer to below illustration for reference sion valve unit can be installed internal or external to the during installation of expansion valve unit. indoor coil. INDOOR EXPANSION VALVE INSTALLATION TWO PIECE PATCH PLATE (Uncased Coil Shown) (UNCASED COIL ONLY) LIQUID LINE STUB ORIFICE END EXPANSION HOUSING \ VALVE DISTRIBUTOR TUBES TEFLON@ /\ 0 I\ RING o ' TEFLON®, \ ® RING SENSING LINE 11 DISTRIBUTOR EQUALIZER ASSEMBLY LINE LIQUID LINE / ASSEMBLY WITH / BRASS NUT A Remove the field -provided fitting that temporary 1/2 Turn reconnected the liquid line to the indoor unit's distributor assembly. 11 B Install one of the provided Teflon® rings around the 10 stubbed end of the expansion valve and lightly lubricate q 4 the connector threads and expose surface of the Teflon® 8 7 5 ring with refrigerant oil. C Attach the stubbed end of the expansion valve to the liquid line orifice housing. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above, or 20 ft-lb. D Place the remaining Teflon® washer around the other end of the expansion valve. Lightly lubricate connector threads and expose surface of the Teflon® ring with refrigerantoil. E Attach the liquid line assembly to the expansion valve. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above or 20 ft-lb. SENSING BULB INSTALLATION A Attach the vapor line sensing bulb in the proper orientation as illustrated to the right using the clamp and MALE EQUALIZER LINE VAPOR screws provided. 1/8 Turn FITTING (SEE LINE I EQUALIZER LINE NOTE — Confirm proper thermal contact between vapor line 1 INSTALLATION FOR and expansion bulb before insulating the sensing bulb once 10 FURTHER DETAILS) LIQUID LINE installed. q B Connect the equalizer line from the expansion valve to 8 4 Sensing bulb insulation is required if the equalizer vapor port on the vapor line. Finger tighten 7 6 5 mounted external to the coil casing. sensing the flare nut plus 1/8 turn (7 ft-lbs) as illustrated below. bulb installation for bulb positioning. ON LINES SMALLER THAN EQUALIZER LINE INSTALLATION VAPOR LINE 7/8", MOUNT SENSING BULB AT EITHER THE 3 OR A Remove and discard either the flare seal cap or flare nut ICJ 9 O'CLOCK POSITION. with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right. BULB BULB B Remove and discard either the flare seal cap or flare nut with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right. FLARE SEAL CAP FLARE NUT VAPOR LINE ON 7/8" AND LARGER LINES, MOUNT SENSING BULB AT OR COPPER FLARE EITHER THE 4 OR 8 O'CLOCK SEAL BONNET POSITION. NEVER MOUNT ON BOTTOM OF LINE. MALE BRASS EQUALIZER BULB BULB LINE FITTING VAPOR LINE NOTE— NEVER MOUNT ON BOTTOM OF LINE. FIGURE 9. Installing Indoor Expansion Valve Page 15 1 CONNECT GAUGE SET A Connect an HFC-410A manifold gauge set high pressure hose to the vapor valve service port. NOTE — Normally, the high pressure hose is connected to the liquid line port. However, connecting it to the vapor port better protects the manifold gauge set from high pressure damage. B With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set. Leak Test Line Set and Indoor Coil A IMPORTANT Leak detector must be capable of sensing HFC refrigerant. MANIFOLD GAUGE SET NOTE — Later in the procedure, the HFC-410A container will be replaced by the nitrogen I k �� B A container. TO VAPOR SERVICE VALV NITROGEN HFC-410A OUTDOOR UNIT 2 TEST FOR LEAKS After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit for leaks. Use the following procedure to test for leaks: A With both manifold valves closed, connect the cylinder of HFC-410A refrigerant to the center port of the manifold gauge set. Open the valve on the HFC-410A cylinder (vapor only). B Open the high pressure side of the manifold to allow HFC-410A into the line set and indoor unit. Weigh in a trace amount of HFC-410A (A trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure]. Close the valve on the HFC-410A cylinder and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC-410A cylinder. C Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge set. D Adjust dry nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize the line set and the indoor unit. E After a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak detector. F After leak testing disconnect gauges from service ports. FIGURE 10. Leak Test Page 16 Evacuating Line Set and Indoor Coil CONNECT GAUGE SET NOTE — Remove cores from service valves (if 1 not already done). A Connect low side of manifold gauge set with 1/4 SAE in -line tee to vapor line service valve B Connect high side of manifold gauge set to liquid line service valve OUTDOOR C Connect micron gauge available UNIT connector on the 1/4 SAE in -line tee. A D Connect the vacuum pump (with vacuum gauge) to the center port of the manifold gauge set. The center port line will be used later for both the HFC-410Aand nitrogen containers. NITROGEN HFC-410A VACUUM PUMP LOW MANILD A34000 1/4 SAE TEE WITHJGAUG2SET SWIVEL COUPLER 500 GAUGE t TO VAPOR SERVICE VALVE 13 TO LIQUID LINE SERVICE VALVE HIGH 2 EVACUATE THE SYSTEM RECOMMEND A Open both manifold valves and start the vacuum pump. MINIMUM 3/8" HOSE B Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury). NOTE— During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. A rapid rise in pressure indicates a relatively large leak. If this occurs, repeat the leak testing procedure. NOTE — The term absolute pressure means the total actual pressure within a given volume or system, above the absolute zero of pressure. Absolute pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure. C When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), perform the following: • Close manifold gauge valves • Close valve on vacuum pump • Turn off vacuum pump • Disconnect manifold gauge center port hose from vacuum pump • Attach manifold center port hose to a dry nitrogen cylinder with pressure regulator set to 150 psig (1034 kPa) and purge the hose. • Open manifold gauge valves to break the vacuum in the line set and indoor unit. • Close manifold gauge valves. D Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the dry nitrogen from the line set and indoor unit. E Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the absolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20-minute period after shutting off the vacuum pump and closing the manifold gauge valves. F When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to an upright cylinder of HFC-410A refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and indoor unit. G Perform the following: • Close manifold gauge valves. 1/6 TURN • Shut off HFC-410A cylinder. 1h� • Reinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core 11 10 2 tool while maintaining a positive system pressure. 9 3 • Replace stem caps and secure finger tight, then tighten an additional one -sixth (1/6) of a turn as illustrated. g 4 7 5 FIGURE 11. Evacuating the System Page 17 A IMPORTANT Use a thermocouple or thermistor electronic vacuum gauge that is calibrated in microns. Use an instrument capable of accurately measuring down to 50 microns. Evacuating the system of non-condensables is critical for proper operation of the unit. Non-condensables are de- fined as any gas that will not condense under tempera- tures and pressures present during operation of an air conditioning system. Non-condensables and water suc- tion combine with refrigerant to produce substances that corrode copper piping and compressor parts. SIZE CIRCUIT AND INSTALL SERVICE DISCONNECT SWITCH Refer to the unit nameplate for minimum circuit ampacity, and maximum fuse or circuit breaker (HACR per NEC). Install power wiring and properly si7arl rliscnnnant switch NOTE— Units are approved foruse only with copper conductors Ground unit at disconnect switch or to an earth ground. Electrical In the U.S.A., wiring must conform with current local codes and the current National Electric Code (NEC). In Canada, wiring must conform with current local codes and the cur- rent Canadian Electrical Code (CEC). Refer to the furnace or air handler installation instructions for additional wiring application diagrams and refer to unit nameplate for minimum circuit ampacity and maximum overcurrent protection size. 24VAC TRANSFORMER Use the transformer provided with the furnace or air han- dler for low -voltage control power (24VAC - 40 VA mini- mum). INSTALL THERMOSTAT Install room thermostat (ordered separately) on an inside wall approximately in the center of the conditioned area and 5 feet (1.5m) from the floor. It should not be installed on an outside wall or where it can be affected by sunlight or drafts. THERM NOTE— 24VAC, Class 11 circuit connections are made in the control panel. Page 18 ML18XC2-024 I START ML18XC2-036 O O CAPACITOR ML18XC2-048 B4 4 K31 OUTDOOR FAN F C H POTENTIAL (LEADED) RELAY ORANGE -RUN 3O 1 5 (OPTIONAL) BLACK -COMMON PURPLE- C12 CAPACITOR DUAL CAPACITOR 587 LOW S1 PRESSURE COMPRESSOR© SWITCH S4 © OS R HIGH PRESSURE 'AL34 SWITCH GROUND K1-1 LUG COMPRESSOR R(S) CONTACTOR RED K1 COMPRESSOR CONTACTOR EQUIPMENT 06 GROUND L2� RED EC MOTOR CONNECTION (ML18XC2-060) K1-1 COMPRESSOR CONTACTOR ® S11 D4 L1 S4 U YELLOW a g Y1 ¢ m B4 FAN MOTOR �J BLUE V2 ¢ y gq0 C B7 (LEADED) S87 Y z ¢ OMPRESSOR © BLACK C ¢ K 5 K1 BLUE K31 S 2 ELEO w z w ® Nw z Q O K ® m O 0 zw C7 H qQ ¢ HR1 RED o i C F C12 DUAL CAPACITOR w CBA25UH,CBA27UHE m & CBA36MV L2 INDOOR EQUIPMENT UNIT THERMOSTAT GROUND SLP99V SL297V SL280V ML296V TB1 ML180V EL280E EL 296E SLP99 frR R INDOOR EL1WE ML1WEML193E UNITA92 THERMOSTAT 0 W3 EL180E EL195E ML196E INDOOR ®T61 W2 UNIT THERMOSTAT W914 DS D W1 TB1 A2 R R R R G G W W95 O O E) W1 O G G W2 DS D G G O QS YELLOW V V YELL YELLOW BLUE BLUE n Y1 • BLUE 4 V1 y V2 • V2 BLACK C C BLACK BLACK C C � C C FIGURE 12. Typical Wiring Diagram Q NOTE - FOR USE WITH COPPER CONDUCTORS ONLY. REFER TO UNIT RATING PLATE FOR MINIMUM CIRCUIT AMPACITY AND MAXIMUM OVERCURRENT PROTECTION SIZE © REFER TO COMPRESSOR IN UNIT FOR ACTUAL TERMINAL ARRANGEMENT © WARNING - ELECTRIC SHOCK HAZARD,CAN CAUSE INJURY OR DEATH.UNIT MUST BE GROUNDED IN ACCORDANCE WITH NATIONAL AND LOCAL CODES. REMOVE JUMPER FOR TWO STAGE COOL ® ON A92 CUT ONBOARD W914 JUMPER FROM D5 TO R, WHEN HUMIDITY CONTROL IS USED ® ON A92 DO NOT CUT ONBOARD W951 JUMPER FROM R TO O. IT IS USED FOR APPLICATIONS FOR CONDENSING UNITS e FOR CONDENSING UNIT APPLICATIONS USE R TO O JUMPER. REMOVE IN HEAT PUMP APPLICATIONS REMOVE DS TO Y1 JUMPER WHEN HUMIDITY CONTROL IS USED ® WHEN TWO STAGE THERMOSTAT IS USED, CONNECT SECOND STAGE HEAT BULB TO TERMINAL "W2", AND REMOVE JUMPER BETWEEN"R"AND"W2" ® L34 SOLENOID IS LOCATED IN COMPRESSOR. COIL IS 24VDC. DO NOT CONNECT 24VAC TO COIL TERMINALS ® S11 IS OPTIONAL LOW AMBIENT SWITCH ® OPTIONAL HARD START KIT MAY BE REQUIRED ON APPLICATIONS WHERE VOLTAGES ARE LESS THAN 230 VOLT KIT ICLUDES K31 AND C7 WITH ALL NECESSARY WIRING. ® S40 AND HRI ARE USED ON 048 AND 060 UNITS ONLY NOTE - IF ANY WIRE IN THIS APPLIANCE IS REPLACED,IT MUST BE REPLACED WITH WIRE OF LIKE SIZE, RATING, INSULATION THICKNESS, AND TERMINATION. NOTE -MINIMUM TRANSFORMER REQUIRED IN INDOOR UNIT-40 VA LINE VOLTAGE FIELD INSTALLED CLASS II VOLTAGE FIELD WIRING DENOTES OPTIONAL COMPONENTS LENNOX COOLING - CONDENSING ML18XC2-024 ML18XC2-048 ML18XC2-036 ML18XC2-060 �vene e: Form No. '• 538238-01 02011 Ltho U.SA. Page 19 System Operation UNIT COMPONENTS The outdoor unit and indoor blower cycle on demand from the room thermostat. If the thermostat blower switch is in the ON position, the indoor blower operates continuously. Liquid line Filter Drier The unit is equipped with a large -capacity filter drier which keeps the system clean and dry. If replacement is neces- sary, order another of the same design and capacity. The replacement filter drier must be suitable for use with HFC- 410A refrigerant. Low Pressure Switch (S87) The ML18XC2 is equipped with an auto -reset low pres- sure switch which is located on the vapor line. The switch shuts off the compressor when the vapor pressure falls below the factory setting. This switch, which is ignored during defrost operation, closes at pressures at or above 40 ± 5 psig (276 ± 34 kPa) and opens at 25 ± 5 psig (172 ± 34 kPa). It is not adjustable. High Pressure Switch (S4) The ML18XC2 is equipped with an auto -reset high pres- sure switch (single -pole, single -throw) which is located on the liquid line. The switch shuts off the compressor when discharge pressure rises above the factory setting. The switch is normally closed and is permanently adjusted to trip (open) at 590 ± 15 psig (4068 ± 103 kPa). NOTE — A Schrader core is under the pressure switches. Crankcase Heater (HR1) and Thermostat Switch (S40) All models sizes are equipped with a belly band type crankcase heater. HR1 prevents liquid from accumulating in the compressor. The HR1 is controlled by a single pole, single throw thermostat switch (S40) located on the liquid line. On all units, the heater is on when there is no com- pressor operation. Thermal Protection Switch (S173) — Compressor Mounted Some ML18XC2 units are equipped with a compressor mounted normally closed temperature switch that pre- vents compressor damage due to overheating caused by internal friction. The switch is located on top of the compressor casing (see figure 1). This switch senses the compressor casing temperature and opens at 239- 257°F (115°C-125°C) to shut off compressor operation. The auto -reset switch closes when the compressor cas- ing temperature falls to 151-187°F (66°C-86°C), and the compressor is re -energized. This single -pole, single -throw (SPST) bi-metallic switch is wired in series with the 24V Y input signal to control compressor operation. Maintenance DEALER Maintenance and service must be performed by a quali- fied installer or service agency. At the beginning of each cooling season, the system should be checked as follows: Outdoor Unit 1 - Clean and inspect outdoor coil (may be flushed with a water hose). Ensure power is off before cleaning. 2 - Outdoor unit fan motor is pre -lubricated and sealed. No further lubrication is needed. 3 - Visually inspect all connecting lines, joints and coils for evidence of oil leaks. 4 - Check all wiring for loose connections. 5- Check for correct voltage at unit (unit operating). 6 - Check amp draw on outdoor fan motor. Motor Nameplate: Actual: 7 - Inspect drain holes in coil compartment base and clean if necessary. NOTE — If insufficient cooling occurs, the unit should be gauged and refrigerant charge should be checked. Outdoor Coil It may be necessary to flush the outdoor coil more fre- quently if it is exposed to substances which are corrosive or which block airflow across the coil (e.g., pet urine, cot- tonwood seeds, fertilizers, fluids that may contain high levels of corrosive chemicals such as salts) • Outdoor Coil — The outdoor coil may be flushed with a water hose. Outdoor Coil (Sea Coast) — Moist air in ocean locations can carry salt, which is corrosive to most metal. Units that are located near the ocean require frequent inspections and maintenance. These inspections will determine the necessary need to wash the unit including the outdoor coil. Consult your installing contractor for proper intervals/ procedures for your geographic area or service contract. Page 20 NOTICE! Failure to follow instructions will cause damage to the unit. This unit is equipped with an aluminum coil. Alu- minum coils may be damaged by exposure to solu- tions with a pH below 5 or above 9. The aluminum coil should be cleaned using potable water at a mod- erate pressure (less than 50psi). If the coil cannot be cleaned using water alone, Lennox recommends use of a coil cleaner with a pH in the range of 5 to 9. The coil must be rinsed thoroughly after cleaning. In coastal areas, the coil should be cleaned with po- table water several times per year to avoid corrosive buildup (salt). Indoor Unit 1. Clean or change filters. 2. Lennox blower motors are prelubricated and perma- nently sealed. No more lubrication is needed. 3. Adjust blower speed for cooling. Measure the pressure drop over the coil to determine the correct blower CFM. Refer to the unit information service manual for pressure drop tables and procedure. 4. Belt Drive Blowers - Check belt for wear and proper tension. 5. Check all wiring for loose connections. 6. Check for correct voltage at unit. (blower operating) 7. Check amp draw on blower motor. Motor Nameplate: Actual: Indoor Coil 1 - Clean coil if necessary. 2 - Check connecting lines, joints and coil for evidence of oil leaks. 3 - Check condensate line and clean if necessary. HOMEOWNER Cleaning of the outdoor unit's coil should be performed by a trained service technician. Contact your dealer and set up a schedule (preferably twice a year, but at least once a year) to inspect and service your outdoor unit. The follow- ing maintenance may be performed by the homeowner. A IMPORTANT Sprinklers and soaker hoses should not be installed where they could cause prolonged exposure to the outdoor unit by treated water. Prolonged exposure of the unit to treated water (i.e., sprinkler systems, soakers, waste water, etc.) will corrode the surface of the steel and aluminum parts, diminish performance and affect longevity of the unit. Outdoor Coil • Make sure no obstructions restrict airflow to the outdoor unit. • Grass clippings, leaves, or shrubs crowding the unit can cause the unit to work harder and use more energy. • Keep shrubbery trimmed away from the unit and peri- odically check for debris which collects around the unit. Routine Maintenance In order to ensure peak performance, your system must be properly maintained. Clogged filters and blocked airflow prevent your unit from operating at its most efficient level. 1 - Air Filter — Ask your Lennox dealer to show you where your indoor unit's filter is located. It will be either at the indoor unit (installed internal or external to the cabinet) or behind a return air grille in the wall or ceiling. Check the filter monthly and clean or replace it as needed. 2 - Disposable Filter — Disposable filters should be replaced with a filter of the same type and size. NOTE— If you are unsure about the filter required for your system, call your Lennox dealer for assistance. 3 - Reusable Filter — Many indoor units are equipped with reusable foam filters. Clean foam filters with a mild soap and water solution; rinse thoroughly; allow filter to dry completely before returning it to the unit or grille. NOTE — The filter and all access panels must be in place any time the unit is in operation. 4 - Electronic Air Cleaner — Some systems are equipped with an electronic air cleaner, designed to remove airborne particles from the air passing through the cleaner. If your system is so equipped, ask your dealer for maintenance instructions. 5- Indoor Unit — The indoor unit's evaporator coil is equipped with a drain pan to collect condensate formed as your system removes humidity from the inside air. Have your dealer show you the location of the drain line and how to check for obstructions. (This would also apply to an auxiliary drain, if installed.) Thermostat Operation See the thermostat homeowner manual for instructions on how to operate your thermostat. Preservice Check If your system fails to operate, check the following before calling for service: • Verify room thermostat settings are correct. • Verify that all electrical disconnect switches are ON. • Check for any blown fuses or tripped circuit breakers. • Verify unit access panels are in place. The outdoor unit must be properly maintained to ensure • Verify air filter is clean. its proper operation. • If service is needed, locate and write down the unit • Please contact your dealer to schedule proper inspec- model number and have it handy before calling. tion and maintenance for your equipment. Page 21 Accessories For update -to -date information, see any of the following publications: • Lennox ML18XC2 Product Specification bulletin • Lennox Product Catalog • Lennox Price Book Servicing Units Void of Charge If the outdoor unit is void of refrigerant, clean the system using the procedure described below. 1 - Leak check system using procedure outlined on page 15. 2 - Evacuate the system using procedure outlined on page 16. 3 - Use nitrogen to break the vacuum and install a new filter drier in the system. 1 - Rotate fan to check for binding. 2 - Inspect all factory and field -installed wiring for loose connections. 3 - After evacuation is complete, open the liquid line and suction line service valves to release the refrigerant charge (contained in outdoor unit) into the system. 4 - Replace the stem caps and tighten as specified in Operating Service Valves on page 7. 5 - Check voltage supply at the disconnect switch. The voltage must be within the range listed on the unit's nameplate. If not, do not start the equipment until you have consulted with the power company and the voltage condition has been corrected. 6 - Set the thermostat for a cooling demand. Turn on power to the indoor indoor unit and close the outdoor unit disconnect switch to start the unit. 4 - Evacuate the system again using procedure 7 - Recheck voltage while the unit is running. Power outlined on page 16. must be within range shown on the nameplate. 5 - Weigh in refrigerant. 8 - Check system for sufficient refrigerant by using Start -Up the procedures listed under Start -Up and Charging Procedures. A IMPORTANT 9- Recheck voltage while the unit is running. Power must be within range shown on the nameplate. If unit is equipped with a crankcase heater, it should be energized 24 hours before unit start-up to prevent compressor damage as a result of slugging. Page 22 ML18XC2 Start -Up and Performance Checklist Customer Address Indoor Unit Model Serial Outdoor Unit Model Serial Notes: START UP CHECKS Refrigerant Type: Rated Load Amps: Actual Amps_ Rated Volts Actual Volts Condenser Fan Full Load Amps Actual Amps: COOLING MODE Suction Pressure: Liquid Pressure: Supply Air Temperature: Ambient Temperature: Return Air: Temperature: System Refrigerant Charge (Refer to manufacturer's information on unit or installation instructions for required subcooling and approach temperatures.) Subcooling: A — B = SUBCOOLING Saturated Condensing Temperature (A) minus Liquid Line Temperature (B) Approach: A — B = APPROACH Liquid Line Temperature (A) minus Outdoor Air Temperature (B) Indoor Coil Temperature Drop (18 to 22°F) A — B = COIL TEMP DROP Return Air Temperature (A) minus Supply Air Temperature (B) Page 23