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second heat sequencer can be connected with the first Matt‐ or foil-faced insulation is installed in indoor sequencer to W1 on the thermostat. They may also be equipment to provide a barrier between outside air connected to a second heating stage W2 on the conditions (surrounding ambient temperature and thermostat subbase. humidity) and the varying conditions inside the unit. If the insulation barrier is damaged (wet, ripped, torn or EMERGENCY HEAT (HEATING HEAT PUMP) separated from the cabinet
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Installing Contractor’s Name_______________________ Installing Date_______________________________ Installing Contractor’s Phone_______________________ Air Handler Model #___________________________ Job Address____________________________________ Thermostat 9 Line Voltage SUPPLY Disconnect AIR Switch 3 8 2 Temperature Integrated Control 1 Duct 6 Blower Motor Amps 5 System Electric Heat Amps 7 Duct Static RETURN Filter AIR 4 Drain Line DUCT SYSTEM TOTAL EXTERNAL STATIC (dry coil) 1 5 dry coil
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Installing Contractor’s Name_______________________ Installing Date_______________________________ Installing Contractor’s Phone_______________________ Air Handler Model #___________________________ Job Address____________________________________ Line Voltage Disconnect Switch Thermostat 2 Integrated 9 3 Control 1 Duct System 1 Duct System Filter RETURN SUPPLY AIR AIR 6 Electric Heat Amps Blower motor Amps 7 5 4 Drain Line 8 Duct Static Temperature DUCT SYSTEM 5 TOTAL EXTERNAL STATIC (dry coil)
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INSTALLATION
INSTRUCTIONS
2012 Lennox Industries Inc.
Dallas, Texas, USA
®
Merit CBX25UH Series
Units
AIR HANDLERS
Litho U.S.A.
506757-01 (0659371-80)
10/2012
Table of Contents
Shipping and Packing List ...................... 1
CBX25UH Series Units ......................... 1
Requirements ................................. 3
Installation Clearances ......................... 3
Installation .................................... 4
Condensate Drain ............................. 6
Duct System and Filt
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CBX25UH Unit Dimensions - inches (mm) B C 3/4 (19) LINE VOLTAGE Right, Left and Top LOW VOLTAGE Right Side Only AIR FLOW A CONDENSATE DRAIN PIPING PLATE (4) (2 −1/4 x 3 −3/4) FILTER ACCESS SUCTION LINE F LIQUID LINE J E 3/4 (19) D H G (Opening) (Opening) 2 −1/2 1 −3/4 2 −1/2 2 −1/2 (44) (64) (64) (64) SIDE VIEW FRONT VIEW −024 −030 −036 −042 −048 / −060 −018 Dimension inches mm inches mm inches mm inches mm inches mm inches mm A 38 965 40 −1/2 1029 43 1092 48 1219 48 1219 52 −1/2 1334 B 15 381 1
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Do not remove the cabinet knockouts until it has been Requirements determined which knockouts will need to be removed for the installation. WARNING Select the final air discharge position which best suits the site conditions. Consider required clearances, space, Excessive Weight Hazard - Use two or more people routing requirements for refrigerant line, condensate when moving and installing the unit. Failure to do so can disposal, filters, duct system, wiring, and accessibility for result in back
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If a return air plenum is used, the return air grille should be HORIZONTAL APPLICATIONS immediately in front of the opening in the plenum to allow for the free flow of return air. When not installed in front of IMPORTANT the opening, there must be adequate clearance around the air handler to allow for the free flow of return air. When removing the coil, there is possible danger of equipment damage and personal injury. Be careful when Installation removing the coil assembly from a unit installed
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5. If the unit is suspended, the entire length of the cabinet 3. Remove coil assembly, bottom drain pan and must be supported. If you use a chain or strap, use a horizontal drain pan as one assembly from the air piece of angle iron or sheet metal attached to the unit handler. (either above or below) to support the length of the 4. Move the horizontal drain pan to the opposite side of cabinet. Use securing screws no longer than 1/2 inch the coil. Be sure drain holes toward the back of the unit to
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HORIZONTAL RIGHT HORIZONTAL LEFT REMOVE 2 SCREWS (FACTORY DEFAULT) SECURING BLOW OFF PREVENTION BRACKET ROTATE BRACKET TO THIS POSITION AND REINSTALL Figure 8. Blow-Off Prevention Plate Condensate Drain IMPORTANT On units of this type, where the blower “draws” rather than “blows” air through the coil, traps must be installed in the con densate drain lines (primary and auxiliary, if used). Traps prevent the blower from drawing air through the drain lines into the air supply. OVERFLOW DRAIN LINE
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5. Make sure drain ports and drain pan are free of all IMPORTANT debris. 6. Plug and check any unused drain pan openings for A field-fabricated secondary drain pan, with a drain pipe tightness. Torque plugs to 30 in. lb. to prevent water to the outside of the building, is required in all installa leaks or seepage from the drain pan. tions over a finished living space or in any area that may be damaged by overflow from the main drain pan. In 7. Install a 2” trap in the primary drain lines as clo
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2. Make sure that the suction line is insulated over the entire exposed length and that neither suction nor IMPORTANT liquid lines are in direct contact with floors, walls, duct If a highefficiency filter is being installed as part of this system, floor joists, or other piping. system to ensure better indoor air quality, the filter must 3. Connect the suction and liquid lines to the evaporator be properly sized. Highefficiency filters have a higher coil. static pressure drop than standardeffi
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1. Disconnect all power supplies. Electrical Connections 2. Remove the air handler access panel. 3. Route the field supply wires to the air handler electrical WARNING connection box. Electric shock hazard! - Disconnect all 4. Use UL-listed wire nuts to connect the field supply power supplies before servicing. conductors to the unit black and yellow leads, and the ground wire to ground terminal marked GND. Replace all parts and panels before op erating. 5. Replace the air handler access panel. F
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THERMOSTAT AIR HANDLER THERMOSTAT AIR HANDLER R R G G SEE BU NOTE BU SEE NOTE W Y HEAT‐ONLY APPLICATION AIR CONDITIONER THERMOSTAT HEAT PUMP UNIT UNIT AIR HANDLER R COOLING‐ONLY APPLICATION THERMOSTAT AIR HANDLER G R CONNECT COMMON BU WIRE ONLY IF G REQUIRED (REFER TO THE W APPROPRIATE THERMOSTAT INSTALLATION BK INSTRUCTIONS) BK W SEE BU Y NOTE HEAT PUMP APPLICATION WITH AIR CONDITIONER ELECTRIC HEAT UNIT COOLING APPLICATION WITH ELECTRIC HEAT NOTE - Connect common wire only if required (Refer t
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BLOWER RELAY CHANGING BLOWER SPEED PLASTIC CAPS 5 BLOWER RELAY HARNESS BLUE (MED) RED (L0) 2 BLACK (HI) YELLOW (COM) 4-PIN BLOWER CONNECTOR Figure 13. Changing Blower Speed NOTE — Refer to wiring diagram located on the unit access panel (or figure 13 above) and blower performance (table 2). All air data measured external to unit with 1 inch non-pleated air filter in place. All factory settings are medium speed except the -48 which is set to low speed from the factory. All data given while
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Set the thermostat so that it does not call for heat. Check-out Procedures Allow up to 5 minutes for all sequencers to cycle off. NOTE - Refer to outdoor unit installation instructions for Operation system start-up instructions and refrigerant charging TIME DELAY RELAY instructions. Blower time delay operation: PRE‐START‐UP CHECKS 1. When cooling demand is initiated, there is a 1 second Is the air handler properly and securely installed? motor-on delay. If horizontally configured, is the
