Lennox Merit CBA25UHE Installation Instructions Manual

Lennox Merit CBA25UHE Installation Instructions Manual

Air handler units

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©2023 Lennox Industries Inc.
Dallas, Texas, USA
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for noncompliance.
WARNING
To prevent serious injury or death:
1. Lock-out/tag-out before performing maintenance.
2. If system power is required (e.g., smoke detector
maintenance), disable power to blower, remove fan
belt where applicable, and ensure all controllers
and thermostats are set to the "OFF" position before
performing maintenance.
3. Always keep hands, hair, clothing, jewelry, tools, etc.
away from moving parts.
INSTALLATION
INSTRUCTIONS
Merit
Series
®
CBA25UHE Air Handler Units
MULTI-POSITION AIR HANDLERS
508370-01
6/2023

Table of Contents

Unit Dimensions - Upflow Position.................................2
Unit Dimensions - Horizontal Position ..........................3
General Information .......................................................4
Requirements ................................................................4
Installation Clearances ..................................................5
Installation .....................................................................5
Condensate Drain...........................................................8
Duct System and Filters ...............................................9
Brazing Refrigerant Lines ............................................10
Sealing the Unit ...........................................................13
Electrical Connections .................................................13
Air Flow - Cooling Blower Speed ................................16
Blower Data ................................................................17
Check-out Procedures .................................................18
Operation ....................................................................18
Homeowner Maintenance ............................................19
Professional Maintenance ...........................................19
Use of Air Handler During Construction .......................19
Shipping and Packing List
Package 1 of 1 contains:
1 - Assembled air handler unit factory-equipped for upflow
or horizontal air discharge application (includes upflow
and horizontal drain pans and preinstalled air filter).
Check the air handler for shipping damage; if found, im-
mediately contact the last carrier. Check the unit rating
plate to confirm that delivered unit matches order.
IMPORTANT: Special procedures are required for clean-
ing the all-aluminum coil in this unit. See page 19 in this
instruction for information.
Page 1

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Summary of Contents for Lennox Merit CBA25UHE

  • Page 1: Table Of Contents

    INSTALLATION INSTRUCTIONS ©2023 Lennox Industries Inc. Merit Series ® Dallas, Texas, USA CBA25UHE Air Handler Units MULTI-POSITION AIR HANDLERS 508370-01 6/2023 Table of Contents Unit Dimensions – Upflow Position.........2 Unit Dimensions – Horizontal Position ......3 General Information ............4 Requirements ..............4 Installation Clearances ..........5...
  • Page 2: Unit Dimensions - Upflow Position

    Unit Dimensions – Upflow Position 1 (25) DETAIL OF PIPING PLATE 4-3/4 3/4 (19) (121) SUCTION LINE SUPPLY AIR LIQUID OPENING CONDENSATE LINE 14-1/2 DRAINS (2) (368) 2-3/8 (Horizontal) (60) 1 (25) 1 (25) CONDENSATE DRAINS (2) 4-3/8 (Upflow and (111) 2-3/4 Downflow)
  • Page 3: Unit Dimensions - Horizontal Position

    Unit Dimensions – Horizontal Position 1-1/8 (29) DETAIL OF PIPING PLATE CONDENSATE CONDENSATE DRAINS (2) DRAINS (2) (Upflow and 4-3/4 3-1/2 (Horizontal) Downflow) (121) (89) 20-3/8 (518) OPENING (559) 1-3/4 (44) (19) SUCTION 2-3/4 LINE LIQUID (70) LINE 2-3/8 4-3/8 (60) (111) LOW VOLTAGE INLETS...
  • Page 4: General Information

    Lennox air handler units (with or without optional elec- The air handler must be installed so that free access is tric heat), MUST conform with National Fire Protection As- allowed to the coil/filter compartment and blower/control sociation (NFPA) standards: “Standard for Installation of...
  • Page 5: Installation Clearances

    2 - If installing a unit in an upflow application, remove Installation Clearances the horizontal drain pan. IMPORTANT - The horizontal drain pan is not required in upflow NON-DUCTED RETURN CLOSET INSTALLATION air discharge installations; its removal provides The air handler can be installed in a closet with a false the best efficiency and air flow.
  • Page 6 RIGHT-HAND DISCHARGE IMPORTANT 1 - Determine which plugs are required for drain line After removal of drain pan plug(s), check drain hole(s) connections. to verify that drain opening is fully open and free of any 2 - With access door removed, remove drain line plugs debris.
  • Page 7 12 - If suspending the unit, it must be supported along the entire length of the cabinet. If using chain or strap, use a piece of angle iron or sheet metal attached to the unit (either above or below) so that the full length of the cabinet is supported.
  • Page 8: Condensate Drain

    TRAPS MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES — FEET (25MM PER 3 GENERALLY, TWO INCHES (51MM). METERS) LENNOX P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90. FIGURE 6. Typical Main and Overflow Drain IMPORTANT THIS CORNER SHOULD BE 5/8" (+/- 1/8") HIGHER...
  • Page 9: Duct System And Filters

    NOTE - Do not operate air handler without a trap in the appropriate Lennox Product Specifications bulletin. main (primary) drain. The condensate drain is on the Additional information is provided in Service and negative pressure side of the blower;...
  • Page 10: Brazing Refrigerant Lines

    INSTALLING DUCT SYSTEM WARNING Connect supply air duct to the flange on top of the air han- dler. If an isolation connector is used, it must be nonflam- Polyol ester (POE) oils used with HFC-410A refrigerant mable. absorb moisture very quickly. It is very important that the refrigerant system be kept closed as much as possible.
  • Page 11 Technical Support Product Applications for assistance. 5 - Braze using an alloy of silver or copper and To obtain the correct information from Lennox, be sure to phosphorus with a melting point above 1,100°F communicate the following information: Model and capac- (593°C).
  • Page 12 PLEASE READ IMPORTANT ISSUES CONCERNING BRAZING OPERATIONS ON PREVIOUS PAGES BEFORE PROCEEDING. NOTE - REFER TO OUTDOOR UNIT INSTALLATION INSTRUCTIONS FOR REFRIGERANT PIPING SIZE REQUIREMENTS. NOTE - Use silver alloy brazing rods with five or six percent minimum silver alloy for copper-to-copper brazing, 45 percent alloy for copper-to-brass and copper-to-steel brazing.
  • Page 13: Sealing The Unit

    WARNING Sealing the Unit Seal the unit so that warm air is not allowed into the cabi- Electric Shock Hazard. net. Warm air introduces moisture, which results in water Can cause injury or death. blow-off problems. This is especially important when the Foil-faced insulation conductive...
  • Page 14 WARNING USE COPPER CONDUCTORS ONLY 1 - Disconnect all power supplies. 2 - Remove the air handler access panel. 3 - Route the field supply wires to the air handler electrical connection box. 4 - Use UL-listed wire nuts to connect the field supply conductors to the unit black and yellow leads, and the ground wire to ground terminal marked GND.
  • Page 15 Cut size: 7" Wide x 9-1/2" Tall PART NO. 537981-03 WIRING DIAGRAM - ELECTRIC HEAT 20KW HTR 3 HTR 2 HTR 1 HTR 4 SEC L SEC L SEC L SEC L HTR 4 HTR 3 HTR 2 HTR 1 PRI LS PRI LS PRI LS...
  • Page 16: Air Flow - Cooling Blower Speed

    WARNING Thermostat Indoor Unit Outdoor Unit Electric shock hazard! - Disconnect all power supplies before servicing. Replace all parts and panels before operating. Failure to do so can result in death or electrical shock. Auxiliary Heat Auxiliary Heat ADJUSTING BLOWER SPEED (Heat Pump) (Heat Pump) Motor Speed Taps...
  • Page 17: Blower Data

    Blower Data CBA25UHE-024 PERFORMANCE External Air Volume / Watts at Various Blower Speeds Static Tap 1 Tap 2 Tap 3 Tap 4 Tap 5 Pressure in. w.g. Watts Watts Watts Watts Watts 0.10 1040 1160 0.20 1020 1140 0.30 1120 0.40 1080 0.50...
  • Page 18: Check-Out Procedures

    Check-out Procedures Operation Cooling (Cooling Only or Heat Pump) NOTE – Refer to outdoor unit installation instructions for sys- tem start-up instructions and refrigerant charging instructions. On all models, the 24 volt line will go directly to the termi- PRE-START-UP CHECKS nal board from the transformer.
  • Page 19: Homeowner Maintenance

    Lennox does not recommend the use of its air handler unit The temperature/humidity difference between the inside during any phase of construction. Very low return air tem-...
  • Page 20 Installing Contractor’s Name_______________________ Installing Date_______________________________ Installing Contractor’s Phone_______________________ Air Handler Model #___________________________ Job Address____________________________________ Thermostat Line Voltage SUPPLY Disconnect Switch Integrated Control Temperature Duct Blower Motor Amps System Electric Heat Amps Duct Static RETURN Filter Drain Line DUCT SYSTEM TOTAL EXTERNAL STATIC (dry coil) dry coil wet coil SUPPLY AIR DUCT...
  • Page 21 Installing Contractor’s Name_______________________ Installing Date_______________________________ Installing Contractor’s Phone_______________________ Air Handler Model #___________________________ Job Address____________________________________ Line Voltage Disconnect Switch Thermostat Integrated Control Duct System Duct System Filter RETURN SUPPLY Electric Heat Amps Blower motor Amps Drain Line Duct Static Temperature DUCT SYSTEM TOTAL EXTERNAL STATIC (dry coil) dry coil wet coil...

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Merit seriesCba25uheCba25uh

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