KHA/KHB Series Heat Pump Installation Instructions

Dimensions

Detailed dimensions are provided for KHA092, 102, 120 & KHB092, 102 units (Pages 2) and KHA150 & KHB122 units (Page 3). These pages include top, end, and side views with various measurements in inches and millimeters.

Shipping and Packing List

Package 1 of 1 contains: 1- Assembled unit. Check unit for shipping damage. Receiving party should contact the last carrier immediately if shipping damage is found.

General

These instructions are a general guide and do not supersede local codes. Authorities having jurisdiction should be consulted before installation. KHA units cover 7-1/2 to 12-1/2 ton cooling capacities, and KHB units cover 7-1/2 to 10-ton cooling capacities. Optional electric heat is available. Units are equipped with a supply air inverter; KHB122 units may have high efficiency direct drive blowers. Blower speed adjusts based on cooling demand.

Requirements

The KHA/KHB unit is ETL/CSA certified for outdoor installations only. Specific clearances to combustible materials are listed on the unit nameplate and in Figure 1. Installation must conform to NFPA standards (90A, 90B), local building codes, and manufacturer instructions. Use as a construction heater or air conditioner is not recommended. Proper return air temperatures (55-80°F) and pre-filters are required if used during construction to avoid voiding the warranty.

NOTICE: Roof Damage! System contains refrigerant and oil. Some rubber roofing material may absorb oil, causing swelling and leaks. Protect the roof surface during service and installation.

National Electric Code (ANSI/NFPA No. 70-1984) references are provided.

UNIT CLEARANCES

Figure 1 illustrates required unit clearances (Service Clearance, Minimum Operation Clearance) for different zones (A, B, C, D) and top clearance. Values are provided in inches (mm).

• Service Clearance: Required for removal of serviceable parts.
• Minimum Operation Clearance: Required clearance for proper unit operation.

Unit Support

Supports must be constructed of steel or suitably treated wood materials. For downflow discharge applications on combustible surfaces, the C1CURB roof mounting frame is required. Supports should be high enough to prevent moisture entry (minimum 14" frame height recommended). Units require support along all four sides of the unit base.

CAUTION: To reduce the likelihood of supply/return air bypass, ductwork/diffuser assemblies must be supported independently to the building structure.

Installer's Roof Mounting Frame

Various roof frames can be used. Key considerations include: unit base is enclosed and insulated, frames are non-combustible, square, and level (1/16" per linear foot), and high enough to prevent moisture entry.

A-Downflow Discharge Application

Roof Mounting with C1CURB: C1CURB frame installation, flashing, and sealing are required. Frame must be square and level. Ductwork attaches to the frame, not the unit.

B-Horizontal Discharge Applications: Requires a horizontal conversion kit (K1HECK00). Maintain specified clearances. Support slab should be at least 4" above finished grade.

Duct Connection

Exterior ducts, joints, and openings must be insulated and weatherproofed. Ducts passing through unconditioned spaces must be insulated.

CAUTION: In downflow applications, do not drill or punch holes in the unit base to avoid roof leaks.

Rigging Unit For Lifting

Detach wooden base protection. Connect rigging to unit base holes. Ensure all panels are in place. Use an H-style pick above the unit's top edge. The lifting point should be directly above the center of gravity. Do not walk on the unit.

Figure 2 shows the unit with lifting points indicated.

Condensate Drains

Connect to the 1" N.P.T. drain coupling. The drain pan is engineered plastic. Tighten pipe nipple hand-tight plus a quarter turn. A trap and vent are required for proper condensate removal. A tee can direct condensate downward. Check local codes for disposal. Units are shipped with the drain coupling facing front; rear or bottom drains are possible with modifications.

Rear Drain Connection involves removing access doors and a mullion.

Condensate Side Drain Connection (Figure 3) shows a side drain with a vent and required pitch.

Condensate Bottom Drain Connection (Figure 4) shows a bottom drain with a vent and required pitch.

Electrical Connections

A-Wiring: Route field wiring in conduit between the bottom power entry disconnect. Follow local codes.

B-Unbalanced Three-Phase Voltage - VFD Units Only: Units with VFDs require balanced three-phase power. Unbalanced power reduces reliability. If unbalanced power is supplied, an inverter with a higher current rating may be needed. Table 1 provides inverter up-sizing guidance.

Control Wiring:

• Thermostat Location: Mount on a 2"x4" box or flat surface, approx. 5 ft above floor, in an area with good air circulation. Avoid drafts, heat sources, and chimneys. Route thermostat wires away from line voltage wiring.
• Use 18 AWG wire for thermostats.

Unit Power-Up:

• Ensure installation complies with instructions and codes.
• Inspect all electrical wiring for loose connections.
• Ensure refrigerant lines do not rub against the cabinet.
• Check main unit power connection voltage against the nameplate.
• Ensure filters are in place.
• Verify no heating, cooling, or blower demand from the thermostat before applying power.
• For KHB units, verify FCB (A191) fan control board DIP switch settings per model number (Figure 10).

Blower Operation and Adjustments

A-Three Phase Scroll Compressor Voltage Phasing: Compressors and blowers are factory wired in phase. Power wires are color-coded: line 1-red, line 2-yellow, line 3-blue. Observe pressures and blower rotation on start-up. If incorrect, disconnect power and reverse any two field-installed wires on the line side of K3, TB2, or F4 (not at blower contactor or compressors).

Belt-Driven Supply Air Inverter Units: Equipped with a phase monitor. An indicator LED turns red if power is out of phase or lost; it remains green for normal operation.

B-Blower Operation: Initiate blower demand via thermostat. Fan switch in ON position for continuous operation; AUTO position cycles with demand.

C-Blower Access: Blower assembly slides out for service (Figures 11 & 12).

Standard Blower Assembly (Figure 11): Instructions for adjusting belt tension by loosening/tightening motor mounting base bolts and adjusting bolts.

Direct Drive Blower Assembly (Figure 12): Shows blower housing and motor, with screws for sliding out the assembly.

Location of Static Pressure Readings (Figure 13): Illustrates where to take readings for ductwork and ceiling diffuser installations.

Belt Drive Blowers: Procedures for loosening wire ties, removing screws to slide frame, and reassembly.

Direct Drive Blowers: Similar procedures for loosening wire ties, removing screws, and reassembly.

Determining Unit CFM

Belt-driven units: CFM is factory-set. Adjust motor pulley for full load cooling/heating CFM. See Blower Operation section. Measurements require a dry indoor coil, blower running without cooling demand, and air filters in place. Static pressure is measured externally.

Direct drive units: CFM determined by Fan Control board.

Blower RPM Adjustment: Adjust at the motor pulley using the Allen screw. Clockwise increases CFM, counterclockwise decreases CFM. Refer to Table 2 for pulley turn limits.

E-Blower Belt Adjustment: Proper alignment and tension are crucial for belt and bearing life. Tension new belts after 24-48 hours. Ensure pulleys are aligned (Figure 14).

F-Check Belt Tension: Overtensioning shortens belt/bearing life. Measure span length (X) and apply force to deflect belt 1/64" per inch of span. Refer to Figure 15 for measurement and deflection guidance. Deflection force specifications are provided for 2, 3, and 5hp belts.

G-Field-Furnished Blower Drives: Use pages 14-17 for BHP, RPM, and drive number determination.

Blower Data Tables (Pages 14-17): These extensive tables provide detailed performance data (RPM, BHP, Watts) for various air volumes and static pressures for KHA092, KHA102, 120, 150, and KHB092, 102, 122 models, both belt and direct drive. They also list resistance values for factory-installed options and accessories.

Heating Start-Up

Set thermostat for first-stage heating (W1). This energizes compressors 1 & 2 and outdoor fans. For units with optional electric heat, W2 energizes electric heat, also during defrost.

Cooling Start-Up:

IMPORTANT: Ensure crankcase heater is energized 24 hours before start-up to prevent compressor damage.

Set thermostat fan switch to AUTO or ON for cooling demand (Y1). Y1 energizes reversing valve solenoid and compressor 1. Y2 energizes compressor 2. Optional economizer activates on Y1 cooling demand if outdoor air enthalpy is suitable.

Units contain two refrigerant circuits. Refrigerant charge is factory-set (HCFC-410A); do not exceed nameplate charge. System charging is not recommended below 60°F (15°C).

Figures 16 & 17 illustrate refrigerant stages and system configurations.

Refrigerant Charge and Check

Do not exceed nameplate charge. If adjustment is needed, reclaim, evacuate, and recharge. System charging is not recommended below 60°F (15°C); weigh charge if needed. Use gauge manifolds, disable economizer, and check systems. Compare operating pressures to Tables 4-10 based on outdoor coil entering air temperature. Approach method (Table 11) can be used for charge verification, but is not valid for over/undercharged systems.

Compressor Controls

• High Pressure Switches (S4, S7): Protect compressors, cut out at 640 psig ± 10 psig.
• Freezestats (S49, S50): Prevent coil freeze-up by de-energizing compressors below 29°F (-2°C) indoor coil temperature. Reset at 58°F (15°C).
• Crankcase Heater (HR1, HR2): Must be on 24 hours before running compressors. Energize via thermostat with no cooling demand.
• Defrost Switches (S6, S9): Initiate defrost when liquid line temperature drops to 35°F (1.7°C).
• Defrost Termination Switches (S46, S104): Terminate defrost when vapor pressure reaches 450 psig (3103 kPa).
• Defrost Controls (CMC1): Liquid line temperature initiated, operates for 14 minutes unless terminated by pressure drop. Electric heat is energized during defrost.

Defrost Control Board

The defrost thermostat, pressure switch, and control work together to prevent outdoor coil icing. Compressor Accumulated Run-Time Interval: Defrost cycle requires accumulated heating mode time (60 or 90 mins, adjustable via jumper). Defrost Test Option: Allows manual entry into defrost mode for troubleshooting.

Diagnostic LEDs (Table 12) indicate unit status (normal operation, board failure).

Defrost Control Board CMC1 (Figure 18) shows timing jumper and diagnostic LEDs.

KHA Belt Drive Supply Air Inverter Start-Up

A-General: Units have VFDs for two blower speeds, adjusting to cooling demand for energy savings. Low speed is approx. 2/3 of full RPM.

B-Set Maximum Blower CFM: Adjust blower pulley for full speed CFM.

C-Set Blower Speed During Ventilation: Set ventilation speed switch on VFD control board to "LO" to save energy.

D-Set Damper Minimum Position (Units W/ Economizer): Set minimum ventilation air volumes using high and low speed potentiometers on the VFD control board (Figure 19). Adjust potentiometers to achieve specified intake air CFM.

Figure 19 shows the LVC2 (A183) VFD Control Board with speed switch and potentiometers.

KHB092H & 102H Belt Drive Supply Air Inverter Start-Up

Similar to KHA units, these units use VFDs for two blower speeds. Procedures for setting maximum blower CFM, blower speed during ventilation, and damper minimum positions (using FCB (A191) Fan Control Board, Figure 21) are provided.

Direct Drive Supply Air Blower Start-Up

A-General: Units use direct drive blowers with adjustable high and low speeds.

B-Set Blower CFM: Initiate blower signal, measure RPM and static pressure to calculate CFM. Adjust potentiometer on FCB board (Figure 22) for desired CFM.

C-Set Blower Speed During Ventilation: Set ventilation speed switch on FCB control board to "LO" for energy savings.

D-Set Damper Minimum Position (Units W/ Economizer): Adjust minimum damper positions using potentiometers on the FCB board for high and low speed settings.

Troubleshoot FCB Board (A191): Provides guidance on checking board components, connections, and signals (Figure 22, 23, 24). Table 13 lists LVC2 Board Blower Outputs.

Service

Units should be inspected annually by a qualified technician.

CAUTION: Label all wires before disconnection during servicing. Verify proper operation afterward.

• Lubrication: Motors are factory lubricated; no further lubrication needed.
• Filters: Equipped with four 20 X 25 X 2" filters. Check monthly and replace with like kind/size. Note airflow direction. (Figure 25)
• Supply Air Blower Wheel: Inspect annually for dirt/dust. Turn off power before cleaning.
• Indoor Coil: Inspect and clean annually using mild detergent or commercial cleanser. Flush with water, avoiding insulation and filters.
• Outdoor Coil: Clean annually with detergent or commercial cleaner. Inspect monthly. Clean between slabs if necessary (Figure 26).
• Filter Drier: Bi-flow filter drier; order like design for replacement.

Start-Up Report

A Start-Up Report form is provided on Page 28 for recording installation checks, cooling checks, blower checks, heating checks (electric/gas), and accessory checks. It includes sections for job details, inspections, compressor data, pressures, fan amps, and voltage readings.