Fan Coil Units for Refrigerant Sizes 18 to 60

Safety Considerations

[Warning] Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock, or other conditions which may cause death, personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions packaged with kits or accessories when installing.

Follow all safety codes. Wear safety glasses, protective clothing and work gloves. Have a fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions included in literature and attached to the unit. Consult local building codes and the current editions of the National Electrical Code (NEC) NFPA 70. In Canada, refer to the current editions of the Canadian Electrical Code CSA C22.1.

Recognize safety information. This is the safety-alert symbol [Warning Symbol]. When you see this symbol on the unit and in instruction manuals, be alert to the potential for personal injury. Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

[Warning] PROPERTY OR PERSONAL INJURY HAZARD: Risk of fire. Flammable refrigerant used. To be repaired only by trained service personnel. Do not puncture refrigerant tubing. Auxiliary devices which may be ignition sources shall not be installed in the ductwork, other than auxiliary devices listed for use with the specific appliance. See instructions. Dispose of refrigerant properly in accordance with federal or local regulations. Failure to follow proper R-454B mitigation system installation instructions can result in property damage, personal injury, or death. If any fault codes are listed, please troubleshoot to prevent system malfunction.

[Warning] PERSONAL INJURY / PROPERTY DAMAGE HAZARD: Failure to follow this warning could result in property damage, personal injury, or death. For continued performance, reliability, and safety, the only approved accessories and replacement parts are those specified by the equipment manufacturer. The use of non-manufacturer approved parts and accessories could invalidate the equipment limited warranty and result in fire risk, equipment malfunction, and failure. Please review manufacturer's instructions and replacement part catalogs available from your equipment supplier.

Installation

Check Equipment

Unpack unit and move to final location. Remove carton taking care not to damage unit.

NOTE: Shipping block(s) that support the blower housing during transit will need to be removed (See Figure 1).

Figure 1: Diagram showing shipping blocks supporting the blower housing.

NOTE: If the door gasket is damaged or missing, the unit may not meet the ASHRAE 193 standard for cabinet air leakage. See the Product Data for this model or contact your supplier to order the gasket kit.

Inspect equipment for damage prior to installation. File claim with shipping company if shipment is damaged or incomplete. Locate unit rating plate which contains proper installation information. Check rating plate to be sure unit matches job specifications.

Mount Unit

Unit can stand or lie on floor, or hang from ceiling or wall. Allow space for wiring, piping, and servicing unit. The indoor equipment and pipes shall be securely mounted and guarded such that accidental rupture of equipment cannot occur from such events as moving furniture or reconstruction activities. When a Fresh Air Ventilator (HRV or ERV) is used, the air extraction opening from the room shall be located equal to or below the top of the unit. For floor mounted units, it shall be as low as practicable. The air extraction openings shall be located at a sufficient distance, BUT NOT LESS THAN 3ft 4in (3 m), from the air intake openings to prevent re-circulation to the space. When a Fresh Air Ventilator (HRV or ERV) is used, the lower edge of the air extraction opening where air is exhausted from the room SHALL NOT be more than 4in (100 mm) above the floor.

IMPORTANT: When unit is installed over a finished ceiling and/or living area, building codes may require a field-supplied secondary condensate pan to be installed under the entire unit. Some localities may allow as an alternative, the running of a separate, secondary condensate line. Consult local codes for additional restrictions or precautions.

Nuisance sweating may occur if the unit is installed in a high humidity environment with low airflow.

Upflow Installation

If return air is to be ducted through a floor, set unit on floor over opening and use 1/8" to 1/4" (3 to 6 mm) thick fireproof resilient gasket between duct, unit, and floor. Side return is a field option on slope coil models. Cut opening per dimensions (See Figure 3). A field-supplied bottom closure is required.

Figure 3: Diagram of a slope coil unit in an upflow application, indicating supply duct, return plenum, low volt entry, and power entry options.

Modular Units

Modular units (3, 4, and 5 ton) can be disassembled and components moved separately to the installation area for reassembly. This process accommodates small scuttle holes and limiting entrances to installation sites (See Figure 2). To disassemble the unit, disconnect the 4-pin sensor wire harness at the dissipation board and undo the wire routing in the cabinet. Remove the rear corner brackets by removing 2 screws which secure the brackets. Remove either 2 screws in each front corner of the coil box, or 2 screws in the blower box. Do not remove all 4 screws in each corner. Sections may now be separated by lifting the top section from the lower section. To reassemble, reverse above procedure. Be certain to reinstall all fasteners when reassembling.

Figure 2: Diagram illustrating the removal of brackets on a modular unit, showing screw locations for blower box and coil box.

Manufactured and Mobile Home Housing Applications

1. Secure the fan coil to the structure using field-supplied hardware.
2. Allow a minimum of 24" (610 mm) clearance from access panels.
3. Recommended method of securing for typical applications:
1. If fan coil is away from wall, attach pipe strap to top of fan coil using no. 10 self-tapping screws. Angle strap down and away from back of fan coil, remove all slack, and fasten to wall stud of structure using 5/16" lag screws. Typical both sides of fan coil.
2. If fan coil is against wall, secure fan coil to wall stud using 1/8" (3 mm) thick right-angle brackets. Attach brackets to fan coil using no. 10 self-tapping screws and to wall stud using 5/16" lag screws (See Figure 2).

Downflow Installation

[Caution] PRODUCT OR PROPERTY DAMAGE HAZARD: Failure to follow this warning caution may result in product or property damage. The conversion of the fan coil to downflow requires special procedures for the condensate drains on both A-coil and Slope-coil units. The vertical drains have an overflow hole between the primary and secondary drain holes. This hole is plugged for all applications except downflow, and must be used for downflow. During conversion process, remove plastic cap covering vertical drains only and discard. Remove plug from overflow hole and discard. At completion of downflow installation, caulk around vertical pan fitting to door joint to retain low air leak performance of the unit.

In this application, field conversion of the evaporator is required using accessory downflow kit along with an accessory base kit. Use fireproof resilient gasket, 1/8" to 1/4" (3 to 6 mm) thick, between duct, unit, and floor.

NOTE: To convert units for downflow applications, refer to Installation Instructions supplied with kit for proper installation. See the Product Data or contact your supplier for the kit number. Use fireproof resilient gasket, 1/8" to 1/4" (3 to 6 mm) thick, between duct, unit, and floor.

NOTE: A gasket kit is also required for all downflow applications to maintain low air leak/low sweat performance. See the Product Data or contact your supplier for the kit number.

Horizontal Installation

Units must not be installed with access panels facing up or down. All other units are factory built for horizontal left installation (See Figures 4 and 5). When suspending unit from ceiling, dimples in casing indicate suitable location of screws for mounting metal support straps (See Figure 4). For horizontal applications having high return static and humid return air, the Water Management Kit may need to be used to assist in water management. See the Product Data or contact your supplier for the kit number.

NOTE: Modular units can be disassembled and components moved separately to installation area for reassembly. This process accommodates small scuttle holes and limiting entrances to installation sites (See Figure 9).

[Caution] PROPERTY DAMAGE HAZARD: Failure to follow this caution may result in product or property damage. For optimum condensate drainage performance in horizontal installations, unit should be leveled along its length and width.

Figure 4: Diagram of a slope coil unit in a horizontal left application (factory configuration), showing filter access clearance, front service clearance, power entry options, low volt entry options, primary and secondary drains.

Figure 5: Diagram showing an A-coil in a horizontal left application (factory configuration), detailing dissipation board, sensor cable routing, air seal assembly, horizontal drain pan, refrigerant connections, coil bracket, coil support rail, primary and secondary drains.

Horizontal Right Conversion of Units with Slope Coils

NOTE: A gasket kit is required for horizontal slope coil conversion to maintain low air leak/low sweat performance. See the Product Data or contact your supplier for the kit number.

1. Remove blower and coil access panels and fitting panel (See Figure 7).
2. Disconnect sensor on drain pan and cut wire tie securing sensor harness to the coil.
3. Undo sensor wire routing and place entire harness in the control box.
4. Remove coil mounting screw securing coil assembly to right side casing flange.
5. Remove coil assembly.
6. Lay fan coil on its right side and reinstall coil assembly with condensate pan down (See Figure 6).
7. Attach coil to casing flange using previously removed coil mounting screw.
8. Reconnect sensor wire harness by following routing shown (See Figure 6).

IMPORTANT: Sensor must be installed with the connector facing down or facing horizontally. Sensor should never be positioned with connector facing upward. Incorrect sensor position could result in premature failure.

9. Make sure pan cap in fitting door is properly seated on fitting door to retain low air leak rating of the unit.
10. Add gaskets from kit.
11. Align holes with tubing connections and condensate pan connections. Reinstall access panels and fitting panel.
12. Make sure liquid and suction tube grommets are in place to prevent air leaks and cabinet sweating. Install grommets after brazing.

Figure 6: Diagram illustrating the conversion for horizontal right applications of a slope coil unit, showing coil mounting screw, coil support rail, dissipation sensor, drain pan, refrigerant connections, primary and secondary drains, dissipation sensor cable routing.

Horizontal Right Conversion of Units with A-Coils

1. Remove blower and coil access panels (See Figure 7).
2. Disconnect and remove sensor on delta plate and install on horizontal drain pan clip (See Figure 19).

IMPORTANT: Sensor must be installed with the connector facing down or facing horizontally. Sensor should never be positioned with connector facing upward. Incorrect sensor position could result in premature failure.

3. Undo sensor wire harness routing and place entire harness in the control box.
4. Remove metal clip securing fitting panel to condensate pan. Remove fitting panel.
5. Remove 2 snap-in clips securing A-coil in unit.
6. Slide coil and pan assembly out of unit.
7. Remove horizontal drain pan support bracket from coil support rail on left side of unit and reinstall on coil support rail on right side of unit (See Figure 8).
8. Convert air seal assembly for horizontal right.
1. Remove air seal assembly from coil by removing 4 screws (See Figure 7).
2. Remove air splitter (B) from coil seal assembly by removing 3 screws (See Figure 7 inset).
3. Remove filler plate (A) and install air splitter (B) in place of filler plate.
4. Install filler plate (A) as shown in horizontal right application.
5. Remove condensate troughs (C) and install on opposite tube sheets.
6. Install hose onto plastic spout.
9. Install horizontal pan on right side of coil assembly.
10. Slide coil assembly into casing. Be sure coil bracket on each corner of vertical pan engages coil support rails.
11. Reinstall 2 snap-in clips to correctly position and secure coil assembly in unit. Be sure clip with large offsets is used on right side of unit to secure horizontal pan.
12. Remove two oval fitting caps from left side of the coil, access panel, and fitting panel.
13. Remove insulation knockouts on right side of coil access panel.
14. Remove 2 oval coil access panel plugs and reinstall into holes on left side of coil access panel and fitting panel.
15. Install condensate pan fitting caps (from Step 12) in right side of coil door making sure that cap snaps and seats cleanly on back side of the coil door. Make sure no insulation interferes with seating of cap.
16. Reinstall access and fitting panels, aligning holes with tubing connections and condensate pan connections. Be sure to reinstall metal clip between fitting panel and vertical condensate pan.
17. Make sure liquid and suction tube grommets are in place to prevent air leaks and cabinet sweating.

Figure 7: Diagram showing the conversion for horizontal right applications of an A-coil unit, detailing dissipation board, dissipation sensor cable routing, air seal assembly, horizontal drain pan, dissipation sensor, refrigerant connections, coil bracket, coil support rail, drain pan support bracket, primary and secondary drains (horizontal right).

Figure 8: Diagram of a drain pan support bracket.

Air Ducts

Connect supply-air duct over the outside of 3½" (19 mm) flanges provided on supply-air opening. Secure duct to flange, using proper fasteners for type of duct used, and seal duct-to-unit joint. If return-air flanges are required, install factory-authorized accessory kit.

Use flexible connectors between ductwork and unit to prevent transmission of vibration. When electric heater is installed, use heat-resistant material for flexible connector between ductwork and unit at discharge connection. Ductwork passing through unconditioned space must be insulated and covered with vapor barrier.

Units equipped with 20-30kW electric heaters require a 1" (25 mm) clearance to combustible materials for the first 36" (914 mm) of supply duct. All 18,000 BTU units equipped with 8 or 10 kW electric heaters require a 1" (25.4 mm) clearance to combustible materials for the first 12" of supply duct.

If the appliance is connected via an air duct system to one or more rooms, the supply and return air shall be directly ducted to the space. Open areas such as false ceilings shall not be used as a return air duct. Any auxiliary devices installed in the ductwork should be approved by the manufacturer or declared suitable with the R-454B refrigerant.

[Warning] EXPLOSION AND PERSONAL HEALTH HAZARD: Failure to follow this warning could result in personal injury, death, and/or unit damage. Ensure to keep any required ventilation openings clear of obstruction. Air ducts connected to the appliance shall not contain a POTENTIAL IGNITION SOURCE. Auxiliary devices which may be a POTENTIAL IGNITION SOURCE shall not be installed in the duct work. Examples of such POTENTIAL IGNITION SOURCES are hot surfaces with a temperature exceeding 1292°F (700°C) and electric switching devices. Ensure only manufacturer approved auxiliary devices are installed.

Ductwork Acoustical Treatment

Metal duct systems that do not have a 90° elbow and 10 feet of main duct before first branch takeoff may require internal acoustical insulation lining. As an alternative, fibrous ductwork may be used if constructed and installed in accordance with the latest edition of SMACNA construction standard on fibrous glass ducts. Both acoustical lining and fibrous ductwork shall comply with National Fire Protection Association as tested by UL Standard 181 for Class 1 air ducts.

Electrical Connections

Units from the factory protect the low voltage circuit with a 3A automotive type fuse in-line on the wire harness. Motor speeds and time delay function are built into the motor. See (Minimum CFM and Motor Speed Selection on p9) for clarification.

When a factory-approved accessory control package has been installed, check all factory wiring per unit wiring diagram and inspect factory wiring connections to be sure none were loosened during transit or installation. If a different control package is required, see unit rating plate.

Before proceeding with electrical connections, make certain that supply voltage, frequency, phase, and ampacity are as specified on the unit rating plate. See unit wiring label for proper field high- and low-voltage wiring. Make all electrical connections in accordance with the NEC and any local codes or ordinances that may apply. Use copper wire only.

The unit must have a separate branch electric circuit with a field-supplied disconnect switch located within sight from, and readily accessible from, the unit. On units with a factory-installed disconnect with pull-out removed, service and maintenance can be safely performed on only the load side of the control package.

[Caution] Units may contain plastic plugs for the high and low voltage electrical connections. These plugs should only be removed when these ports are used for install or servicing and should be discarded after removal.

[Warning] PERSONAL OR EQUIPMENT DAMAGE HAZARD: Failure to follow this warning could result in personal injury, death, and/or unit damage. Provide training to installation personnel to follow national and local electrical codes.

Line Voltage Connections

If unit contains an accessory electric heater, remove and discard power plug from fan coil and connect male plug from heater to female plug from unit wiring harness. (See Electric Heater Installation Instructions.)

For units without electric heat:

1. Connect 208/230V power leads from field disconnect to yellow and black stripped leads.
2. Connect ground wire to unit ground lug.

NOTE: Units installed without electric heat should have a field-supplied sheet metal block-off plate covering the heater opening. This will reduce air leakage and formation of exterior condensation.

24V Control System

Connection To Unit

Wire low voltage in accordance with wiring label on the blower (See Figures 10 through 13). Use #18 AWG color-coded, insulated (35° C minimum) wire to make the low-voltage connections between the thermostat, the unit, and the outdoor equipment. If the thermostat is located more than 100' (30 m) from the unit (as measured along the low-voltage wire), use #16 AWG color-coded, insulated (35° C minimum) wire. All wiring must be NEC Class 1 and must be separated from incoming power leads. Refer to outdoor unit wiring instructions for any additional wiring procedure recommendations.

Figure 10: Wiring diagram for an air conditioning unit (cooling only), showing connections between thermostat, dissipation board, fan coil (control), and air conditioner.

Figure 11: Wiring diagram for an air conditioning unit (cooling and 1-stage heat), showing connections between thermostat, dissipation board, fan coil (control), and air conditioner.

Figure 12: Wiring diagram for a heat pump unit (cooling and 2-stage heat with no outdoor thermostat), showing connections between thermostat, dissipation board, fan coil (control), and heat pump (control).

Figure 13: Wiring diagram for a heat pump unit (cooling and 2-stage heat for manufactured housing), showing connections between thermostat, dissipation board, fan coil (control), and heat pump (control).

Transformer Information

The transformer is factory wired for 230V operation. For 208V applications, disconnect the black wire from the 230V terminal on transformer and connect it to the 208V terminal (See Figure 14).

Figure 14: Diagram illustrating transformer connections, showing primary and secondary wiring for 208V and 230V operation.

Heater Staging

If electric heat staging is required, a multi-stage heating room thermostat is required. Consult your equipment supplier for a suitable thermostat.

Manufactured Housing

In manufactured housing applications, the Code of Federal Regulations, Title 24, Chapter XX, Part 3280.714 requires that supplemental electric heat be locked out at outdoor temperatures above 40° F (4° C), except for a heat pump defrost cycle. See Figure 13 for typical low voltage wiring with outdoor thermostat.

Ground Connections

NOTE: Use UL listed conduit and conduit connectors for connecting supply wire(s) to unit to obtain proper grounding. Grounding may also be accomplished by using grounding lugs provided in control box.

[Warning] ELECTRICAL SHOCK HAZARD: Failure to establish uninterrupted or unbroken ground could result in personal injury and/or death. According to NEC, NFPA 70, and local codes, the cabinet must have an uninterrupted or unbroken ground to minimize personal injury if an electrical fault should occur. The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes. If conduit connection uses reducing washers, a separate ground wire must be used.

Minimum CFM and Motor Speed Selection

The fan speed selection is done at the motor connector. Units with or without electric heaters require a minimum CFM. Refer to the unit wiring label to ensure that the fan speed selected is not lower than the minimum fan speed indicated.

Figure 15: Diagram showing motor speed selection, illustrating connection points on the motor or plug.

† electric heat airflow is same CFM as Tap 3, except 0 sec off delay

‡ high static applications, see airflow tables for max airflow

To change motor speeds disconnect the BLUE fan lead from motor connector terminal #2 (factory default position) and move to desired speed-tap; 1, 2, 3, or 5.

Speed-taps 1, 2, and 3 have a 90 second blower off time delay pre-programmed into the motor. Speed-tap 4 is used for electric heat only (with 0 second blower time delay) and the WHITE wire should remain on tap 4. Speed-tap 5 is used for high static applications, but has a 0 second blower time delay pre-programmed into the motor. See Airflow Performance tables for actual CFM. See Figure 15 for motor speed selection location.

NOTE: In low static applications, lower motor speed tap should be used to reduce possibility of water being blown off coil.

Refrigerant Tubing Connection and Evacuation

Use accessory tubing package or field-supplied tubing of refrigerant grade. Suction tube must be insulated. Do not use damaged, dirty, or contaminated tubing because it may plug refrigerant flow-control device. ALWAYS evacuate the coil and field-supplied tubing to 500 microns before opening outdoor unit service valves.

[Caution] PRODUCT DAMAGE HAZARD: Failure to follow this caution may result in product or property damage. A brazing shield MUST be used when tubing sets are being brazed to the unit connections to prevent damage to the unit surface and condensate pan fitting caps.

Units have sweat suction and liquid tube connections. Make suction tube connection first.

IMPORTANT: Federal regulations require that you do not vent refrigerant to the atmosphere. Recover during system repair or final unit disposal.

• Run refrigerant tubes as directly as possible by avoiding unnecessary turns and bends.
• Make provision for expansion and contraction of long piping runs.
• Protect piping and fittings as much as possible against adverse environmental effects; for example, the danger of water collecting and freezing in relief pipes or the accumulation of dirt and debris.
• Install piping to reduce the likelihood of hydraulic shock damaging the system.
• Always use certified steel piping and components to protect against corrosion.
• Protect flexible pipe elements against mechanical damage and excessive stress by torsion or other forces. Check flexible pipes for mechanical damage annually.

1. Cut tubing to correct length.
2. Insert tube into sweat connection on unit until it bottoms.
3. All fittings need to withstand 700 PSIG (Mechanical Fittings or Brazing). When brazing, use silver bearing or non-silver bearing brazing material. Do not use solder (materials which melt below 800° F / 427° C). Consult local code requirements.
4. Perform a pressure check of the unit with a nitrogen charge of about 200psi. The Nitrogen holding charge must not decrease in pressure for 1 hour.
5. Perform leak check on the unit. Vacuum unit to 500 microns. When isolating the unit from the pump, the pressure shall not rise above 1500 microns in 10 minutes.

Mechanical Line Set Connections

If using mechanical or crimp-type line set connections, follow crimp tool manufacturer's instructions.

NOTE: Should the use of mechanical fittings cause failure of the fittings or failure of the equipment, such would not be covered under the standard warranty.

[Caution] PRODUCT DAMAGE HAZARD: Failure to follow this caution may result in product or property damage. Wrap a wet cloth around rear of fitting to prevent damage to TXV and factory-made joints.

Refrigerant Flow-Control Device

The 18-60 size units come equipped with an R-454B refrigerant mechanical TXV. When tightening nuts on a TXV, do not exceed 20 ft-lbs.

Always use outdoor units designed to match indoor fan coil applications.

[Caution] PRODUCT OPERATION HAZARD: Failure to follow this caution may result in improper product operation. If using a TXV in conjunction with a single-phase reciprocating compressor, a compressor start capacitor and relay are required. Consult outdoor unit pre-sale literature for start assist kit part number.

Disassembly

[Warning] PERSONAL INJURY HAZARD: Failure to follow this warning could result in personal injury. Remove refrigerant charge from system and ensure there is no pressure before servicing the TXV.

NOTE: For Item #1 (See Figure 16): Use an adjustable wrench with a backup adjustable wrench to loosen the brass nut (TXV outlet). Then use both wrenches to loosen Item # 2 (TXV inlet).

1. Use an adjustable wrench with a backup adjustable wrench to loosen Item # 3 (TXV equalizer line).
2. For Item #4 - Cut the wire tie and remove the black insulation. Remove the band from around the TXV bulb.
3. Cut the wire tie that holds the TXV equalizer line and bulb from the aluminum vapor header tube.
4. Remove 2 screws from the TXV bracket. Remove the TXV from the coil unit.

Figure 16: Diagram illustrating mechanical TXV removal, numbering connection points for disassembly and assembly.

Assembly

1. Mount the TXV bracket and TXV with the 2 screws removed during disassembly.
2. Connect Items #1 and #2 (TXV outlet and inlet respectively) and use an adjustable wrench with a backup wrench to tighten each nut. Tighten to between 10 and 20 ft-lbs.
3. Connect Item #3 and use an adjustable wrench with a backup adjustable wrench to tighten the flare nut. Tighten to approximately 12 ft-lbs.
4. Item # 4 - Reconnect the TXV bulb with a clamp and reinstall insulation around the TXV bulb and vapor tube.

[Caution] UNIT DAMAGE HAZARD: Failure to follow this Caution may result in unit damage. Failure to place insulation between copper tubes and aluminum parts will lead to galvanic corrosion, which will result in a refrigerant leak in the future.

5. Use a wire tie to mount the 1/8" TXV equalizer and bulb tubes to the vapor header tube. Make sure that there is insulation between the aluminum vapor tube and copper tube.
6. Leak test the TXV fittings, then evacuate and charge the system to the required subcooling per the outdoor unit rating plate.

Condensate Drains

To connect drains, the cap openings must be removed. Use a knife to start the opening near the tab and using pliers, pull the tab to remove the disk. Clean the edge of the opening if necessary and install the condensate line. Finally caulk around the lines where they exit the fitting to retain the low leak rating of the unit.

Units are equipped with primary and secondary ¾" FPT drain connections. For proper condensate line installations see Figures 3 through 7. To prevent property damage and achieve optimum drainage performance, BOTH primary and secondary drain lines should be installed and include properly-sized condensate traps (See Figures 17 and 22). Factory-approved condensate traps are available. It is recommended that PVC fittings be used on the plastic condensate pan. Finger-tighten plus 1-1/2 turns. Do not over-tighten. Use pipe dope.

NOTE: Do not use CPVC in field drain lines due to potential reaction with POE oil.

NOTE: When connecting condensate drain lines, avoid blocking filter access panel, thus preventing filter removal. After connection, prime both primary and secondary condensate traps.

[Caution] PRODUCT DAMAGE HAZARD: Failure to follow this caution may result in product or property damage. Use only full size P-traps in the condensate line (See Figure 17). Shallow running traps are inadequate and DO NOT allow proper condensate drainage (See Figure 18).

Figure 17: Diagram of a recommended condensate trap, showing proper P-trap configuration.

Figure 18: Diagram illustrating an insufficient condensate trap, highlighting why shallow traps are inadequate.

[Caution] UNIT OR PROPERTY DAMAGE HAZARD: Failure to follow this warning caution may result in product or property damage. The conversion of the fan coil to downflow requires special procedures for the condensate drains on both A-coil and Slope-coil units. The vertical drains have an overflow hole between the primary and secondary drain holes. This hole is plugged for all applications except downflow, and must be used for downflow. During conversion process, remove plastic cap covering vertical drains only and discard. Remove plug from overflow hole and discard. At completion of downflow installation, caulk around vertical pan fitting to door joint to retain low air leak performance of the unit.

NOTE: If unit is located in or above a living space where damage may result from condensate overflow, a field-supplied, external condensate pan should be installed underneath the entire unit, and a secondary condensate line (with appropriate trap) should be run from the unit into the pan. Any condensate in this external condensate pan should be drained to a noticeable place. As an alternative to using an external condensate pan, some localities may allow the use of a separate ¾" (19 mm) condensate line (with appropriate trap) to a place where the condensate will be noticeable. The owner of the structure must be informed that when condensate flows from the secondary drain or external condensate pan, the unit requires servicing or water damage will occur.

Install traps in the condensate lines as close to the coil as possible (See Figure 22). Make sure that the outlet of each trap is below its connection to the condensate pan to prevent condensate from overflowing the drain pan. Prime all traps, test for leaks, and insulate traps if located above a living area. Condensate drain lines should be pitched downward at a minimum slope of 1" (25 mm) for every 10' (3 m) of length. Consult local codes for additional restrictions or precautions.

Figure 22: Diagram of a condensate drain, indicating primary and secondary drain connections and the requirement for primary and secondary traps.

Leak Dissipation System

[Warning] PERSONAL INJURY OR PROPERTY DAMAGE HAZARD: Failure to follow proper R-454B mitigation system installation instructions can result in property damage, personal injury, or death. If any fault codes are listed, please troubleshoot to prevent system malfunction.

The 18-60 size units come equipped with a factory wired R-454B leak detection and dissipation system to ensure safe operation during a leak. The system consists of a bracket, a PCB, a A2L Detection Sensor, and a drain pan clip. Failure to install this system will result in potentially hazardous conditions and improper equipment operation, and void all system warranties and liabilities.

All units are shipped with the A2L Detection Sensor located in the upflow position. For sizes 18-24, the sensor will always be installed on the drain pan clip.

Figure 19: Diagram showing a dissipation sensor mounted on a drain clip.

For sizes 30-60, the sensor comes factory installed on the delta plate (See Figures 20, 21). For horizontal right and left, the sensor will need to be moved to the drain pan clip (See Figures 19, 5, 6, 7).

[Warning] PRODUCT OPERATION / INJURY HAZARD: Failure to follow this warning could cause product damage or personal injury. Make sure the sensor is not exposed to significant amounts of dust/dirt contamination. This could clog the sensor and prevent proper functioning. For sensor cleaning instructions, refer to service manual.

IMPORTANT: Sensor must be installed with the connector facing down or facing horizontally. Sensor should never be positioned with connector facing upward. Incorrect sensor position could result in premature failure.

Figure 20: Diagram showing the factory location of an A-coil vertical dissipation sensor.

Figure 21: Diagram showing the factory location of a slope coil vertical dissipation sensor.

The A2L Detection Sensor is attached to a wiring harness that connects the sensor to the dissipation board. In upflow, the routing of the wire harness is up the right side of the unit behind the wire retainers for the cabinet insulation. At each wire retainer, the harness is attached using two wire ties. When converting unit to horizontal or downflow, follow routing shown in Figures 5, 6, or 7. When converting the unit to any orientation, ensure the sensor wiring harness is disconnected and the wire harness has been placed in the control box before any components are moved.

Refer to Figures 10 through 13 for low voltage field connections between the dissipation board and the thermostat. All control wires are labeled with the wire function and landing point.

Leak Dissipation System Self-Test

Power on the unit and verify proper functioning of equipment. The yellow LED on the dissipation board should be steady. If flash codes are present, see (Troubleshooting on p12).

NOTE: Operation of the Test Mode is only possible if no faults exist on the dissipation board.

IMPORTANT: Press the Test button for roughly ONE SECOND to enter Test Mode. Pressing the Test button for longer periods enables different functions (Table 2).

Press the Test button on the dissipation system control board to ensure proper dissipation system operation under each test condition listed below. After pressing the Test button, system will enter Dissipation Mode for 60 seconds to help verify correct operation.

Ensure that the fan coil is able to meet the minimum required dissipation mode airflows. These required minimum airflow rates during Dissipation Mode are listed in Table 4. They are based on the total system refrigerant charge quantity.

Troubleshooting

For all flash codes, first try power cycling the system to remove the code.

No power

Verify the wiring to/from pins 1 and 8 on the power harness plug. Check the 24V system wiring from the transformer.

Flashing 1

Check for refrigerant leaks using an independent R-454B detector. If no leaks are present, replace the sensor.

Flashing 2

Check both ends of the sensor wire harness to ensure proper attachment. Power cycle the system to check whether the flash code has been removed. If the flash code is still present, replace the sensor.

Flashing 3

Check for refrigerant leaks using an independent R-454B detector.

Flashing 4

If the code does not clear after power cycling the system, replace the dissipation board.

Flashing 5

If the code does not clear after power cycling the system, replace the sensor.

Flashing 6

Press the test button repeatedly. Power cycle the system. If the button cannot be reset, replace the dissipation board.

Flashing 7

Verify wiring of all "Y" and "W" wires in the applicable wiring diagram.

Flashing 8

Verify wiring of all "Y" and "W" wires in the applicable wiring diagram.

Accessories

Humidifier

Connect the humidifier and humidistat to the fan coil unit as shown in Figures 23 and 24. The cooling lockout relay is optional.

Figure 23: Wiring diagram of a humidifier to a heat pump.

Figure 24: Wiring diagram of a humidifier to a fan coil with electric heat.

Sequence of Operation

Continuous Fan

Thermostat closes the R to G connection. G passes through the dissipation board and energizes the fan relay on the PCB which completes the circuit to the indoor blower motor. When G is de-energized, there is a 90-second delay before the relay opens.

Cooling Mode

Thermostat energizes R to G, R to Y, and R to O (heat pump only). G and Y pass through the dissipation board to their respective outputs. G energizes the fan relay on the PCB which completes the circuit to the indoor blower motor. When G is de-energized, there is a 90-second delay before the fan relay opens.

Heat Pump Heating with Auxiliary Electric Heat

Thermostat energizes R to G, R to Y, and R to W connections. G and Y pass through the dissipation board to their respective outputs. G energizes the fan relay on the PCB which completes the circuit to the indoor blower motor. W energizes the electric heat relay(s) which completes the circuit to the heater element(s). When W is de-energized, the electric heat relay(s) open, turning off the heater elements. When G is de-energized there is a 90-second delay before the fan relay opens.

Electric Heat or Emergency Heat Mode

Thermostat closes R to W connection. W passes through the dissipation board and energizes the electric heat relay(s) which completes the circuit to the heater element(s). Blower motor is energized through the normally-closed contacts on the fan relay. When W is de-energized, the electric heat relay(s) opens.

Leak Dissipation Mode

Thermostat energizes appropriate signals to the dissipation board based on operation mode. The dissipation board energizes G output, which energizes the fan relay on the PCB to complete the circuit to the indoor blower motor. The dissipation board opens switches for W and Y. This de-energizes signals going to electric heat and outdoor compressor which opens the electric heat relay(s).

Start-up Procedures

Refer to outdoor unit Installation Instructions for system start-up instructions and refrigerant charging method details.

When charging unit, ensure your conditioned space is larger than the minimum floor area shown in Table 6. For charging quantities outside of the range of the table, use the following equation to determine your minimum area: A_min = 15 x Total Charge (lbs) - ft².

Care and Maintenance

[Caution] PRODUCT DAMAGE HAZARD: Failure to follow this caution may result in poor unit performance and/or product damage. Never operate unit without a filter. Factory authorized filter kits may be used when locating the filter inside the unit. For those applications where access to an internal filter is impractical, a field-supplied filter must be installed in the return air duct system.

To continue high performance and minimize possible equipment failure, it is essential that periodic maintenance be performed on this equipment. Consult your local dealer as to the proper frequency of maintenance contract.

The ability to properly perform maintenance on this equipment requires certain mechanical skills and tools. If you do not possess these, contact your dealer for maintenance. The only consumer service recommended or required is filter replacement or cleaning on a monthly basis.

NOTE: Servicing the blower assembly requires the removal of two screws that attach the blower housing to the fan deck. It is not necessary to reinstall of these screws after service.

Figure 25: Diagram showing shipping screws.

Tables

Table 7 - Electric Heater Static Pressure Drop (in. wc)

Table 8 - Airflow Performance (CFM) Wet

Table 9 - Airflow Performance (CFM) Dry

NOTES: 1.Airflow based upon dry coil at 230V with factory-approved filter and electric heater (2 element heater sizes 18 through 36, 3 element heater sizes 42 through 60). 2.To avoid potential for condensate blowing out of drain pan prior to making drain trap: Return static pressure must be less than 0.40 in. wc. Horizontal applications of 42 - 60 sizes must have supply static greater than 0.20 in. wc. Airflow above 400 cfm/ton on 48-60 size could result in condensate blowing off coil or splashing out of drain pan.