Lennox KDB024, KDB048, KDB036, KDB060 Installation Instructions Manual

2017

INSTALLATION

WARNING

Improper installation, adjustment, alteration, ser vice or maintenance can cause property damage, personal injury or loss of life. Installation and ser vice must be performed by a licensed professional HVAC installer or equivalent or service agency.

CAUTION

As with any mechanical equipment, contact with sharp sheet metal edges can result in personal in jury. Take care while handling this equipment and wear gloves and protective clothing.

Table Of Contents

Dimensions Page 2.................................

Shipping and Packing List Page 3....................

General Page 3....................................

Requirements Page 3...............................

Unit Support Page 4................................

Duct Connection Page 5............................

RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE

INSTRUCTIONS

KDB024 (2 TON) KDB036 (3 TON) KDB048 (4 TON) KDB060 (5 TON)

ROOFTOP PACKAGED UNITS

507626-01 04/2017 Supersedes 8/2016

Rigging Unit For Lifting Page 5.......................

Condensate Drains Page 6..........................

Electrical Connections Page 9.......................

Unit Power-Up Page 9..............................

Blower Operation and Adjustments Page 10............

Defrost Control Board Page 30........................

Service Page 33....................................

KDB024, 036, 048, 060 PARTS ARRANGEMENT

ECONOMIZER

(OPTIONAL)

INDOOR

TXV

CONDENSATE

DRAIN

FILTERS

COMBUSTION

AIR INDUCER

BURNERS

TB1 LOW VOLTAGE

TERMINAL BLOCK

EVAPORATOR

COIL

GAS VALVE

BLOWER

REVERSING

VALV E

CONDENSER

FAN

OUTDOOR

TXV

CONDENSER

COIL

COMPRESSOR

KDB024, 030, 036, 048, 060 DIMENSIONS

Model

KDB024, 036

KDB048, 060

2-1/4

(57)

(Overall dimensions same as end view without economizer)

No.

7/8

(22)

30-7/16

(773)

7/8

UNIT RETURN AIR DUCT

(22)

OPENING WITH HORIZONTAL

ECONOMIZER INSTALLED

END VIEW

in. mm

18-3/4 476

22-1/2 572

2-1/4

(57)

5-5/8 (143)

7 (178)

(737)

47 (1192)

BASE

3-1/2 (89)

LIFTING HOLES

(For rigging)

16-1/4

(413)

DD CC

(279)

26-1/2

(673)

6-5/8 (168)

BOTTOM

RETURN

AIR

OPENING

BOTTOM

SUPPLY

AIR

OPENING

(457)

5 (127)

(508)

BOTTOM

CONDENSATE

OUTLET

CENTER

GRAVITY

BOTTOM POWER ENTRY

3 X 8 (76 X 203)

25-3/4 (654) 024 thru 074

38-3/4 (984) 090

9-1/2 (241)

TOP VIEW (Base)

83-1/4 (2115) 024, 036 96-1/4 (2445) 048, 060

ELECTRICAL

INLET

GAS

INLET

(381)

(686)

CONDENSATE

OUTLET

(EITHER SIDE)

43-3/8 (1102) KDB048, 060

35-3/8 (899) KDB024, 036

26-1/2

(673)

FLUE/VENT

OUTLET

5-1/2 (140)

85-1/4 (2165) 024 thru 036 BASE

98-1/4 (2496) 060 BASE

SIDE VIEW

1 (25)

(1143)

1 (25)

47 (1194)

BASE

(Without Economizer)

END VIEW

38-7/8 (987) KDB024, 036

46-7/8 (1191) KDB048, 060

Page 2

FORKLIFT SLOTS

(Front, Back and

Blower End)

BACK VIEW

(508)

5-1/2 (140)

19-1/2

(495)

18-3/8

HORIZONTAL

SUPPLY AIR

OPENING

(467)

(279)

HORIZONTAL

RETURN AIR

OPENING

(Without Economizer)

2 (51)

(737)

5-1/2 (140)

Shipping and Packing List

Package 1 of 1 contains:

1- Assembled unit

Check unit for shipping damage. Receiving party should contact last carrier immediately if shipping damage is found.

General

These instructions are intended as a general guide and do not supersede local codes in any way. Authorities having jurisdiction should be consulted before installation.

KDB units have 2, 3, 4, and 5-ton cooling capacities. Units are available in three gas heating inputs.

KDB036, 048, and 060 3-phase units are equipped with two-speed, belt or direct drive supply air blowers. KDB024, 036, 048 and 060 1-phase units are equipped with variable speed, direct drive blowers. These units will provide supply air at lower speeds when cooling demand is low and increase to higher speeds when cooling demand is high. Refer to Blower Operation section.

Availability of units and options varies by brand.

Requirements

The KDB unit is ETL/CSA certified for outdoor installations only at the clearances to combustible materials listed on unit nameplate and in figure 1.

Installation of KDB dual fuel heat pumps must conform with standards in National Fire Protection Association (NFPA) “Standard for Installation of Air Conditioning and Ventilating Systems NFPA No. 90A,” “Standard for Installation of Residence Type Warm Air Heating and Air conditioning Systems NFPA No. 90B,” local municipal building codes and manufacturer's installation instructions.

NOTICE

Roof Damage! This system contains both refrigerant and oil. Some rubber roofing material may absorb oil, causing the rubber to swell. Bubbles in the rubber roofing material can cause leaks. Protect the roof surface to avoid exposure to refrigerant and oil during service and installation. Failure to follow this notice could result in damage to roof surface.

The National Electric Code (ANSI/NFPA No. 70-1984) is available from:

National Fire Protection Association 1 Batterymarch Park PO Box 9101 Quincy, MA 02269-9101

UNIT CLEARANCES

FIGURE 1

Unit

Clearance

Service

Clearance

Clearance to

Combustibles36(914)1(25)1(25)1(25)

Minimum Opera

tion Clearance36(914)36(914)36(914)36(914)

Note - Entire perimeter of unit base requires support when elevated above mounting surface.

Service Clearance - Required for removal of serviceable parts. Clearance to Combustibles - Required clearance to combustible

material. Minimum Operation Clearance - Required clearance for proper unit operation.

in.(mm)Bin.(mm)Cin.(mm)Din.(mm)

(1524)36(914)36(914)36(914)

WARNING

Electric shock hazard and danger of explosion. Can cause injury, death or product or property damage. Turn off gas and electrical power to unit before performing any maintenance or servicing operations on the unit. Follow lighting instructions attached to unit when putting unit back into operation and after service or maintenance.

The KDB unit is ETL/CSA certified as a dual fuel heat pump with cooling and auxiliary gas heat for non-residential use only at the clearances to combustible materials as listed on the unit nameplate and in figure 1.

Installation of ETL/CSA certified units must conform with current standard C273.5 “Installation Requirements for Heat Pumps” and applicable local codes. Authorities having jurisdiction should be consulted before installation.

Page 3

To p

Clearance

Unob

structed

Unob

structed

Unob

structed

Use of this unit as a construction heater or air conditioner

is not recommended during any phase of construction.

Very low return air temperatures, harmful vapors and

operation of the unit with clogged or misplaced filters will

damage the unit.

If this unit has been used for heating or cooling of

buildings or structures under construction, the following

conditions must be met or the warranty will be void:

 A room thermostat must control the unit. The use of

fixed jumpers that will provide continuous heating or

cooling is not allowed.

 A pre-filter must be installed at the entry to the return

air duct.

 The return air duct must be provided and sealed to

the unit.

 Return air temperature range between 55°F (13°C)

and 80°F (27°C) must be maintained.

 Air filters must be replaced and pre-filter must be

removed upon construction completion.

 The unit components, duct system, air filters and

evaporator coil must be thoroughly cleaned following

final construction clean-up.

 The unit operating conditions (including airflow,

cooling operation, and heating operation) must be

verified according to these installation instructions.

WARNING

Electric shock hazard and danger of explosion. Can cause injury, death or product or property damage. Turn off electrical power to unit before performing any maintenance or servicing operations on the unit.

IMPORTANT

The Clean Air Act of 1990 bans the intentional vent ing of refrigerant (CFC's and HCFC's) as of July 1,

1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incar ceration may be levied for non-compliance.

Unit Support

NOTE - Securely fasten roof frame to roof per local codes.

CAUTION

To reduce the likelihood of supply / return air by pass and promote a proper seal with the RTU, duct work / duct drops / diffuser assemblies must be supported independently to the building structure.

A-Downflow Discharge Application

Roof Mounting with C1CURB

1- The C1CURB roof mounting frame must be installed,

flashed and sealed in accordance with the instructions provided with the frame.

2- The C1CURB roof mounting frame should be square

and level to 1/16” per linear foot (5mm per linear meter) in any direction.

3- Duct must be attached to the roof mounting frame

and not to the unit; supply and return plenums must be installed before setting the unit.

Installer's Roof Mounting Frame

Many types of roof frames can be used to install the unit, depending upon different roof structures. Items to keep in mind when using the building frame or supports are:

1- The unit base is fully enclosed and insulated, so an

enclosed frame is not required.

2- The frames or supports must be constructed with

non-combustible materials and should be square and level to 1/16” per linear foot (5mm per linear meter) in any direction.

3- Frame or supports must be high enough to prevent

any form of moisture from entering unit. Recommended minimum frame height is 14” (356mm).

4- Duct must be attached to the roof mounting frame

and not to the unit. Supply and return plenums must be installed before setting the unit.

5- Units require support along all four sides of unit base.

Supports must be constructed of steel or suitably treated wood materials.

NOTE-When installing unit on a combustible surface for downflow discharge applications, the C1CURB roof mounting frame is required.

B-Horizontal Discharge Applications

1- Units which are equipped with an optional

economizer and installed in horizontal airflow applications must use a horizontal conversion kit.

2- Specified installation clearances must be maintained

when installing units. Refer to figure 1.

Page 4

3- Top of support slab should be at least 4” (102mm)

above the finished grade and located so no run-off water from higher ground can collect around the unit.

4- Units require support along all four sides of unit base.

Supports must be constructed of steel or suitably treated wood materials.

Duct Connection

All exterior ducts, joints, and openings in roof or building walls must be insulated and weatherproofed with flashing and sealing compounds in accordance with applicable codes. Any duct passing through an unconditioned space must be insulated.

CAUTION

In downflow applications, do not drill or punch holes in base of unit. Leaking in roof may occur if unit base is punctured.

Rigging Unit For Lifting

1- Detach wooden base protection before rigging.

2- Connect rigging to the unit base using both holes in

each corner. See figure 2.

Horizontal Air Discharge

Unit is shipped with panels covering the horizontal supply and return air openings. Remove horizontal covers and place over downflow openings for horizontal air discharge. See figure 3. Secure in place with sheet metal screws.

Units Equipped With An Optional Economizer

1- Remove the horizontal supply air cover and position

over the downflow supply air opening. Secure with sheet metal screws.

2- Leave the horizontal return air cover in place.

3- Locate the separately ordered horizontal air

discharge kit. Place the kit panel over the downflow return air opening.

4- Remove and retain the barometric relief dampers and

lower hood.

5- Install return air duct beneath outdoor air intake. See

figure 4. Install barometric relief damper in lower hood and install in ductwork as shown in figure 4.

UNIT SUPPLY AND RETURN AIR OPENINGS

HORIZONTAL

RETURN AIR

OPENING

SUPPLY AIR

OPENING

3- All panels must be in place for rigging.

4- Place field‐provided H‐style pick in place just above

top edge of unit. Frame must be of adequate strength and length. (H-style pick prevents damage to unit.)

Unit

All

*Maximum weight with all avail able installed accessories.

CAUTION: DO NOT

WALK ON UNIT.

Weight*

Lbs. Kg.

894 406

Lifting Point Should

Be Directly Above Center Of Gravity.

DOWNFLOW RETURN AIR

OPENING

DOWNFLOW SUPPLY AIR

OPENING

FIGURE 3

HORIZONTAL RETURN AIR DUCTWORK

WITH ECONOMIZER

HORIZONTAL

RETURN AIR

DUCT

UNITUNIT

FIGURE 2

INSTALL BAROMETRIC RELIEF DAMPERS

AND HOOD IN RETURN AIR DUCT

FIGURE 4

Page 5

Condensate Drains

Make drain connection to the 1” N.P.T. drain coupling provided on unit.

Note - The drain pan is made with a glass reinforced engineered plastic capable of withstanding typical joint torque but can be damaged with excessive force. Tighten pipe nipple hand tight and turn an additional quarter turn.

Units are shipped with the drain coupling facing the front

of the unit. Condensate can be drained from the back or

bottom of the unit with the following modifications. The

unit can be installed in either downflow or horizontal air

discharge regardless of condensate drain location.

Rear Drain Connection

A trap must be installed between drain connection and an open vent for proper condensate removal. See figure 5 or

6. It is sometimes acceptable to drain condensate onto the roof or grade; however, a tee should be fitted to the trap to direct condensate downward. The condensate line must be vented. Check local codes concerning condensate disposal. Refer to pages 2 for condensate drain location.

CONDENSATE SIDE DRAIN CONNECTION

CAULK AROUND CONDENSATE COUPLING

NOTE - Allow clearance to open doors when installing condensate piping.

Minimum Pitch

1” (25 mm) per

10' (3 m) of line

OPEN VENT

UNIT

MOUNTING

FRAME

1- Remove the condensate drain mullion. See figure 7.

Remove the two panels on each side of the mullion.

If the unit has hinged panels, two hinge screws must

be removed in addition to the mullion screws. See

figure 8.

CONDENSATE

DRAIN MULLION

FIGURE 7

FIGURE 5

CONDENSATE BOTTOM DRAIN CONNECTION

UNIT

DRAIN PAN

CAULK AROUND

CONDENSATE COUPLING

OPEN VENT

MOUNTING

FRAME

Minimum Pitch

1” (25 mm) per 10'

(3 m) of line

FIGURE 6

2- Lift the front edge of the drain pan and slide pan out

of unit. See figure 9.

3- Make sure the cap over the unit bottom drain hole is

secure.

UNITS WITH HINGED PANELS

CONDENSATE

DRAIN MULLION

REMOVE

TWO

SCREWS

FIGURE 8

Page 6

REMOVE DRAIN PAN

DRAIN PAN

BOTTOM CONDENSATE DRAIN

CAUTION: Be careful not to

damage the coupling threads

when drilling the hole.

DRILL A PILOT

HOLE IN CENTER

OF COUPLING

FIGURE 9

4- Rotate the drain pan until the downward slope is

toward the back of the unit. Slide the drain pan back into the unit. Be careful not to dislodge the cap over the bottom drain hole.

5- From the back side of the unit, pull the drain pan

coupling through the rear condensate opening.

6- Replace the condensate drain mullion and reinstall

screws.

7- Reinstall access doors.

Bottom Drain Connection

1- Remove the condensate drain mullion. See figure 7.

If the unit has hinged panels, two hinge screws must be removed in addition to the mullion screws. See figure 8.

2- Lift the front edge of the drain pan and slide pan out

of unit. See figure 9.

3- Turn the drain pan upside down and drill a pilot hole

through the bottom of the drain pan in the center of the coupling. See figure 10.

4- From the inside of the pan, use a Vari-Bit

bit to enlarge the hole to 7/8”. Do not damage coupling threads.

5- Remove the cap over the unit bottom drain hole.

6- Slide the drain pan back into the unit.

7- From the back side of the unit, pull the drain pan

coupling through the rear condensate opening.

8- From the front side of the unit, move the drain pan

until the bottom coupling settles into the unit bottom drain opening. Once in place, check to make sure the coupling is still positioned through the rear condensate drain hole.

After drilling the pilot

hole, drill a 7/8” hole from

the inside of the pan.

FIGURE 10

9- Use a field-provided 1” plug to seal side drain

connection.

10- Replace the condensate drain mullion and reinstall

screws.

11- Reinstall access doors.

Connect Gas Piping

Before connecting field-provided piping, check with gas company or authorities having jurisdiction for local code requirements. When installing gas supply piping, length of run from gas meter must be considered in determining pipe size for 0.5” w.c. (.12kPa) maximum pressure drop. Do not use supply pipe smaller than unit gas connection. For natural gas units, operating pressure at the unit gas connection must be a minimum of 4.5” w.c. (1.12kPa) and a maximum of 10.5” (2.60kPa) w.c. For LP/propane gas units, operating pressure at the unit gas connection must be a minimum of 11” w.c. (2.74kPa) and a maximum of 13.0” w.c. (3.23kPa).

When making piping connections a drip leg should be installed on vertical pipe runs to serve as a trap for sediment or condensate. A 1/8” N.P.T. plugged tap is located on gas valve for test gauge connection. Refer to Heating Start-Up section for tap location. Install a ground joint union between the gas control manifold and the main manual shut-off valve. See figure 11 for gas supply piping entering outside the unit. Figure 12 shows bottom gas entry piping through the unit.

Compounds used on threaded joints of gas piping shall be resistant to the action of liquified petroleum gases.

Page 7

OUTSIDE OF UNIT GAS PIPE CONNECTION

TO GAS

VALV E

GROUND

JOINT UNION

TO GAS SUPPLY

After all connections have been made, check all piping connections for gas leaks. Also check existing unit gas connections up to the gas valve; loosening may occur during installation. Use a leak detection solution or other preferred means. Do not use matches candles or other sources of ignition to check for gas leaks.

CAUTION

Some soaps used for leak detection are corrosive to certain metals. Carefully rinse piping thoroughly after leak test has been completed. Do not use matches, candles, flame or othe sources of ignition to check for gas leaks.

WARNING

GAS PIPING

SUPPORT

MANUAL MAIN

SHUT-OFF VALVE

DRIP LEG

(REFER TO

LOCAL CODES)

FIGURE 11

BOTTOM ENTRY GAS PIPING COMPLETED

GROUND

JOINT UNION

STREET

ELBOW

7” NIPPLE

2-1/2” NIPPLE

DRIP LEG

Grommets for both gas pipe openings are field provided.

TO GAS

VALV E

TO GAS SUPPLY

MANUAL MAIN

SHUT-OFF VALVE

FIGURE 12

Pressure Test Gas Piping

When pressure testing gas lines, the gas valve must be disconnected and isolated. Gas valves can be damaged if subjected to more than 0.5 psig (3.48kPa). See figure 13.

NOTE-Codes may require that manual main shut-off valve and union (furnished by installer) be installed in gas line external to unit. Union must be of the ground joint type.

Danger of explosion. Can cause injury or product or property damage. Do not use matches, candles, flame or other sources of ignition to check for leaks.

NOTE-In case emergency shut down is required, turn off the main manual shut-off valve and disconnect main power to unit. These devices should be properly labeled by the installer.

PRESSURE TEST GAS LINE

MANUAL MAIN

SHUT-OFF VALVE

GAS VALVE

CAP

FIGURE 13

High Altitude Derate

Locate the high altitude conversion sticker in the unit literature bag. Fill out the conversion sticker and affix next to the unit nameplate.

Refer to table 1 for high altitude adjustments.

TABLE 1

HIGH ALTITUDE DERATE

Altitude Ft.* Gas Manifold Pressure

2000-4500 See Unit Nameplate

4500 And Above Derate 2% / 1000 Ft. Above Sea Level

*Units installed at 0-2000 feet do not need to be modified.

NOTE ‐ This is the only permissible derate for these units.

Page 8

Electrical Connections

POWER SUPPLY

Do not apply power or close disconnect switch until installation is complete. Refer to start-up directions.

Refer to unit nameplate for minimum circuit ampacity and maximum fuse size.

1- 230,460,575 volt units are factory wired. For 208V

supply, disconnect the pink wire (230V) at all control power transformer(s). insulated terminal cover from the 208V terminal on the control transformer. Move the wire from the transformer 240V terminal to the 208V terminal. Place the insulated terminal cover on the unused 240V terminal.

2- Route power through the bottom power entry area

and connect to the top of K1 compressor contactor or factory-installed disconnect or circuit breaker. Secure power wiring with factory-installed wire ties provided in control box. See unit wiring diagram.

CONTROL WIRING

A-Thermostat Location

Room thermostat mounts vertically on a standard 2” X 4” handy box or on any non-conductive flat surface.

Locate thermostat approximately 5 feet (1524 mm) above the floor in an area with good air circulation at average temperature. Avoid locating the room thermostat where it might be affected by:

-drafts or dead spots behind doors and in corners

-hot or cold air from ducts

-radiant heat from sun or appliances

-concealed pipes and chimneys

IMPORTANT - Unless field thermostat wires are rated for maximum unit voltage, they must be routed away from line voltage wiring.

B-Control Wiring

1- Route thermostat cable or wires from subbase to

unit control box (refer to unit dimensions to locate bottom and side power entry).

IMPORTANT - Unless field thermostat wires are rated for maximum unit voltage, they must be routed away from line voltage wiring. Use wire ties located near the front of the control section to secure thermostat cable.

Use18 AWG wire for all applications using remotely installed electro-mechanical and electronic thermostats.

2- Install thermostat assembly in accordance with

instructions provided with thermostat.

3- Connect thermostat wiring to TB1 terminal board on

the lower side of the controls hat section. Wire as shown in figure 14 for electro-mechanical and

electronic thermostats. If using other temperature control devices or energy management systems see instructions and wiring diagram provided by manufacturer.

24 VOLT FIELD WIRING WITH ELECTRONIC AND

ELECTRO-MECHANICAL THERMOSTATS

TB1

NOT ALL TERMINALS

ARE FOUND ON ALL

THERMOSTATS

Jumper terminals R and OC when thermostat has no night setback terminals

A2 THERMOSTAT

Note - On electro-mechanical thermo stats set anticipator at 0.1 amps.

on units equipped with an economizer.

FIGURE 14

IMPORTANT-Terminal connections at the wall plate or subbase must be made securely. Loose control wire connections may allow unit to operate but not with proper response to room demand.

Unit Power-Up

A-General

1- Make sure that unit is installed in accordance with the

installation instructions and applicable codes.

2- Inspect all electrical wiring, both field and factory

installed, for loose connections. Tighten as required.

3- Check to ensure that refrigerant lines do not rub against

the cabinet or against other refrigerant lines.

4- Check voltage at main unit power connection.

Voltage must be within range listed on nameplate. If not, consult power company and have voltage condition corrected before starting unit.

5- Make sure filters are in place before start‐up.

6- Make sure there is no heating, cooling, or blower

demand from thermostat. Apply power to unit.

Page 9

Blower Operation and Adjustments

KD 024 units are equipped with multi-tap ECM, direct drive blowers only.

KD 036, 048 and 060 units are equipped with either multi-tap ECM, direct drive or two-stage belt drive blowers.

The blower will operate at high speed with Y2 thermostat demand and low speed with a Y1 thermostat demand. Low speed operation delivers approximately 2/3 of air volume of high speed. Two-speed blower operation results in lower energy consumption.

IMPORTANT

Three phase scroll compressors must be phased sequentially for correct compressor and blower rotation. Follow “COOLING START-UP” section of installation instructions to ensure proper compres sor and blower operation.

A-Blower Operation

Initiate blower demand at thermostat according to instructions provided with thermostat. Unit will cycle on thermostat demand. The following steps apply to applications using a typical electro-mechanical thermostat.

1- Blower operation is manually set at the thermostat

subbase fan switch. With fan switch in ON position, blowers will operate continuously.

2- With fan switch in AUTO position, the blowers will

cycle with demand. Blowers and entire unit will be off when system switch is in OFF position.

Belt Drive Blowers

2- Remove and retain screws on either side of sliding

frame. Pull frame toward outside of unit.

3- Slide frame back into original position when finished

servicing. Reattach the blower wiring in the previous location on the blower motor base using the wire tie.

4- Replace retained screws on either side of the

sliding frame.

Direct Drive Blowers

1- Loosen the reusable wire tie which secures the

controls and high voltage blower wiring to the blower housing.

2- Remove and retain screws in front and on either side

of blower housing. Pull frame toward outside of unit.

3- Slide frame back into original position when finished

servicing. Reattach the blower wiring in the previous location on the blower motor base using the wire tie.

4- Replace retained screws in front and on either side of

the blower housing.

B-Determining Unit CFM - Direct Drive Blowers

1- The following measurements must be made with air

filters in place.

2- With all access panels in place, measure static

pressure external to unit (from supply to return). Add any additional air resistance for options and accessories shown in accessory air resistance tables. Blower performance data is based on static pressure readings taken in locations shown in figure 15.

Note - Static pressure readings can vary if not taken where shown.

1- Loosen the reusable wire tie which secures the

blower wiring to the blower motor mounting plate.

LOCATION OF STATIC PRESSURE READINGS

INSTALLATIONS WITH DUCTWORK

ROOFTOP UNIT

RETURN AIR

READING LOCATION

SUPPLY

MAIN

DUCT RUN

RE

TURN

FIRST BRANCH

OFF OF MAIN RUN

SUPPLY AIR

READING

LOCATION

FIGURE 15

SUPPLY AIR

Page 10

3- Use figure 16 to determine the factory-set blower

speed.

INSTALLATIONS WITH CEILING DIFFUSERS

ROOFTOP UNIT

RETURN AIR

READING

RE

TURN

LOCATION

READING

SUPPLY

DIFFUSER

LOCATION

4- Use direct drive blower tables, the measured static

pressure and the factory-set blower speed to determine CFM. If CFM is lower or higher than the design specified CFM, move the leads as shown in figure 16.

BLOWER SPEED FACTORY SETTINGS

Gray

Pink

Green/Yellow

Yellow

Common

GND

High

Green

White

Brown

4- The blower RPM can be adjusted at the motor pulley.

Loosen Allen screw and turn adjustable pulley clockwise to increase CFM. Turn counterclockwise to decrease CFM. See figure 18. Do not exceed minimum and maximum number of pulley turns as shown in table 2.

TABLE 2

MINIMUM AND MAXIMUM PULLEY ADJUSTMENT

Belt

A Section 0 5

*No minimum number of turns open when B belt is used on pulleys 6” O.D. or larger.

Minimum

Turns Open

Maximum

Turns Open

D-Blower Belt Adjustment

FIGURE 16

C-Determining Unit CFM - Belt Drive Blowers

IMPORTANT - Direct drive multi-tap ECM blower unit CFM is determined by the blower motor speed tap. Refer to the Direct Drive Variable Speed Start-Up section.

1- The following measurements must be made with a

dry indoor coil. Run blower without a cooling demand. Measure the indoor blower shaft RPM. Air filters must be in place when measurements are taken.

2- With all access panels in place, measure static

pressure external to unit (from supply to return). Blower performance data is based on static pressure readings taken in locations shown in figure 15.

Note - Static pressure readings can vary if not taken where shown.

3- Referring to pages 17 to 22, use static pressure and

RPM readings to determine unit CFM. Use page 23 when installing units with any of the optional accessories listed.

Maximum life and wear can be obtained from belts only if proper pulley alignment and belt tension are maintained. Tension new belts after a 24-48 hour period of operation. This will allow belt to stretch and seat in the pulley grooves. Make sure blower and motor pulleys are aligned as shown in figure 17.

1- Loosen four bolts securing motor base to mounting

frame. See figure 18.

PULLEY ALIGNMENT

ALIGNED

MOTOR PULLEY

BELT

NOT ALIGNED

BLOWER

PULLEY

FIGURE 17

Page 11

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Lennox KDB024, KDB048, KDB036, KDB060 Installation Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual