KHA Series Heat Pump Installation Instructions

Important Safety Information

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 qualified installer, service agency, or the gas supplier.

CAUTION: Danger of sharp metallic edges. Can cause injury. Take care when servicing unit to avoid accidental contact with sharp edges.

NOTICE: Fiberglass wool insulation may cause respiratory, skin, and eye irritation. Consult material safety data sheets for proper handling.

Table of Contents

• Dimensions
• Shipping and Packing List
• General
• Requirements
• Unit Support
• Duct Connection
• Rigging Unit For Lifting
• Horizontal Air Discharge
• Condensate Drains
• Electrical Connections
• Blower Operation and Adjustments
• Start-Up
• Defrost Control Board
• Service

Unit Overview and Dimensions

The KHA series units are heat pump packaged units. Refer to the following diagrams for unit dimensions and configurations.

Top View (Base): Shows dimensions for bottom return air and supply air openings, center of gravity, and bottom condensate outlet.

End View: Shows overall unit height and depth.

Side View: Shows unit width, electrical inlet, and lifting holes.

Back View: Shows horizontal supply and return air openings.

Installation Requirements

General

These instructions are a general guide and do not supersede local codes. Consult authorities having jurisdiction before installation. Availability of units and options varies by brand.

Requirements

The KHA unit is ETL/CSA certified as a heat pump with cooling and with or without auxiliary electric heat for non-residential use only. Installation must conform to National Fire Protection Association (NFPA) standards (NFPA No. 90A, NFPA No. 90B), local building codes, and manufacturer's instructions.

Construction Site Use: Use as a construction heater or air conditioner is not recommended. If used, specific conditions must be met to avoid voiding the warranty, including thermostat control, pre-filter installation, sealed return air duct, maintained return air temperature range (55°F-80°F), filter replacement, thorough cleaning, and verification of operating conditions.

Unit Support

Securely fasten roof frame to roof per local codes. Units are installed on T1CURB or K1CURB frames. K1CURB is a full-perimeter curb for KH 072 units. Installer's roof mounting frames should be constructed with non-combustible materials, square, and level. Minimum frame height should be 14 inches (356mm). Units require support along all four sides of the base.

Duct Connection

All exterior ducts, joints, and openings must be insulated and weatherproofed. Any duct passing through an unconditioned space must be insulated.

Rigging Unit For Lifting

Detach wooden base protection before rigging. Remove all base protection brackets. Connect rigging to the unit base using holes in each corner. Ensure all panels are in place. Use a field-provided H-style pick placed just above the top edge of the unit. The frame must be of adequate strength and length.

Horizontal Air Discharge

Remove horizontal covers and place over downflow openings for horizontal air discharge. Secure with sheet metal screws.

Units Equipped With An Optional Economizer: Remove the horizontal supply air cover and position over the downflow supply air opening. Leave the horizontal return air cover in place. Install the horizontal air discharge kit panel over the downflow return air opening. Install return air duct beneath the outdoor air intake.

Condensate Drains

Make drain connection to the provided coupling (3/4” N.P.T. for older units, 1” N.P.T. for newer units). The drain pan is made of engineered plastic. Tighten pipe nipple hand tight and an additional quarter turn. A trap must be installed between the drain connection and an open vent. Check local codes for condensate disposal. Condensate can be drained from the front, back, or bottom of the unit with modifications.

Rear Drain Connection: Remove condensate drain mullion and side panels. Slide drain pan out, rotate for downward slope, and pull coupling through rear opening.

Bottom Drain Connection: Remove condensate drain mullion and slide pan out. Drill a pilot hole in the center of the coupling on the bottom of the drain pan, enlarge to 7/8". Remove cap over bottom drain hole, slide pan back in, pull coupling through rear opening, and align bottom coupling with unit bottom drain opening. Use a 3/4" plug to seal side drain connection.

Electrical Connections

Power Supply

Do not apply power until installation is complete. Refer to unit wiring diagram. Units are factory-wired for 240, 460, 575 volt supply. For 208V supply, move wire from 240V terminal to 208V terminal on control transformer.

Control Wiring

Thermostat Location: Mount thermostat vertically on a standard 2" x 4" handy box or non-conductive surface, approximately 5 feet (1524 mm) above the floor in an area with good air circulation. Avoid locations affected by drafts, hot/cold air from ducts, radiant heat, or pipes/chimneys.

Control Wiring: Route thermostat cable from subbase to control area above compressor. Use 18 AWG wire for electro-mechanical and electronic thermostats. Connect thermostat wiring to TB1 terminal control board. Refer to Figure 11 for wiring details. Ensure secure terminal connections.

Blower Operation and Adjustments

Blower Operation

Set thermostat fan switch to AUTO or ON. In ON position, blower operates continuously. In AUTO position, blower cycles with demand. Blower and unit are off when system switch is in OFF position.

Determining Unit CFM - Direct Drive Blowers

Measure static pressure external to the unit with air filters in place. Use Figure 13 to determine factory set blower speed. Use tables 2 through 7, measured static pressure, and factory-set blower speed to determine CFM. If CFM is lower than specified, move lead from speed tap 3 or 4 to speed tap 2 (See Figure 14). For 460/575V units, disconnect isolation lead before moving speed tap wire.

Determining Unit CFM - Belt Drive Blowers

Measure static pressure external to the unit and measure blower wheel RPM. Use tables 3 through 7, static pressure, and RPM readings to determine CFM. Blower RPM can be adjusted at the motor pulley. Loosen Allen screw and turn adjustable pulley clockwise to increase CFM, counterclockwise to decrease CFM (See Figure 16). Do not exceed minimum and maximum pulley turns (Table 1).

Blower Belt Adjustment

Ensure proper pulley alignment and belt tension. Tension new belts after 24-48 hours of operation. To increase belt tension, loosen motor base bolts and slide motor downward. To decrease belt tension, slide motor upward. Tighten motor base bolts.

Check Belt Tension

Measure span length X. Deflect belt 1/64” per inch of span length. Measure belt deflection force (5 lbs for used belt, 7 lbs for new belt). Refer to Figure 17.

Field-Furnished Blower Drives

Use tables 3 through 7 to determine BHP and RPM required. Reference table 10 for drive kit number and Figure 11 for drive kit specifications.

Table 2: Direct Drive Blower Performance

Table 3: Belt Drive Blower Performance (3 Ton)

Table 4: Belt Drive Blower Performance (4 Ton)

Table 5: Belt Drive Blower Performance (5 Ton)

Table 6: Belt Drive Blower Performance (6 Ton Downflow)

Table 7: Belt Drive Blower Performance (6 Ton Horizontal)

Start-Up

Heating

Set thermostat to initiate a first-stage heating demand. This will energize compressors and outdoor fan. For units with optional electric heat, increased demand (W2) will energize electric heat.

Cooling

Set thermostat to initiate a first-stage cooling demand. This will energize the reversing valve solenoid and compressor.

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 suction and discharge pressures and blower rotation on start-up. If pressure differential is not observed or blower rotation is incorrect, disconnect power and reverse any two field-installed wires connected to the line side of the K1 contactor.

Refrigerant Charge and Check

WARNING: Do not exceed nameplate charge. Unit is factory charged. If system requires charge, reclaim, evacuate, and add required nameplate charge. Charging is not recommended below 60°F (15°C). Weigh charge into system if below this temperature.

Procedure: Attach gauge manifolds, operate unit in cooling mode until system stabilizes. Compare operating pressures to normal operating pressures in tables 12-17. Minor variations are expected; significant differences may indicate improper charge or system problems.

Table 12: TH 024S R22 Normal Operating Pressures

Table 13: KH 030S R410A Normal Operating Pressures

Table 14: KH R410A 036S Normal Operating Pressures

Table 15: KH 048S R410A Normal Operating Pressures

Table 16: KH 060S R410A Normal Operating Pressures

Table 17: KH 072S R410A Normal Operating Pressures

Approach Method: Compare liquid temperature to outdoor ambient temperature. Approach temperature should match values in Table 18. Greater approach indicates undercharge; lesser approach indicates overcharge. This method is not valid if system pressures do not match tables 12-17.

Table 18: Approach Temperature

Compressor Controls

Freezestat (S49): De-energizes compressor when indoor coil temperature falls below 29°F (-2°C) to prevent freeze-up. Resets when indoor coil temperature reaches 58°F (15°C).

Defrost Switch (S6): Closes to initiate defrost when liquid line temperature falls to 42°F (5.6°C). Opens when liquid line temperature reaches 70°F (21°C) to terminate defrost. CMC1 terminates defrost after 14 minutes if switch remains closed.

Defrost Control (CMC1): Liquid line temperature initiated, operates for 14 minutes unless terminated by defrost switch. Electric heat is energized during defrost.

Defrost Control Board

The defrost thermostat and control board work together to prevent excessive icing. The defrost control will not energize a defrost cycle unless the unit has operated in heating mode for an accumulated 60 or 90 minutes (default, depending on board model). Run time interval can be changed by moving the jumper on the CMC board timing pins (See Figure 18).

Defrost Interval Adjustment: Interval can be adjusted to 30, 60, or 90 minutes. Factory default is 60 minutes. If timing jumper is not in place, control defaults to 90 minutes.

Defrost Test Option: For troubleshooting, start TEST mode when unit is in heating mode and defrost thermostat is closed or jumpered. If timing jumper is in TEST position at power-up, control ignores test pins. Place jumper across TEST pins for two seconds to enter defrost mode. If jumper is removed before an additional 5-second period, unit remains in defrost until defrost pressure switch opens or 14 minutes pass. If jumper is removed after the additional period, defrost terminates.

Diagnostic LEDs: The defrost board uses two LEDs (DS2 - Green, DS1 - Red) for diagnostics. LED flash sequences indicate various conditions (See Table 19).

Table 19: Defrost Control Board Diagnostic LED

Service

The unit should be inspected once a year by a qualified service technician.

Maintenance

Indoor Coil

Inspect and clean coil at the beginning of each cooling and heating season. Clean using mild detergent or commercial coil cleanser. Flush coil and condensate drain with water, avoiding insulation, filters, and return air ducts.

Outdoor Coil

Clean outdoor coil annually with detergent or commercial coil cleaner. Inspect monthly during the cooling season. For units with two slabs, clean between slabs carefully and wash thoroughly. Flush coils with water.

Filters

WARNING: Units are shipped with temporary filters. Replace filters before building is occupied. Damage to the unit could result if filters are not replaced with approved filters.

Check filters monthly and replace when necessary. Note air flow direction marking on filter frame when reinstalling. See Figure 19.

Table 20: Unit Filters

Supply Air Blower Wheel

Annually inspect supply air blower wheel for accumulated dirt or dust. Turn off power before cleaning.

Filter Drier

The unit is equipped with a biflow filter drier. Replace if necessary with one of like design.