Lennox 4HP18LT User manual

506470-01 Issue 1007

Save these instructions for future reference

INSTALLATION AND MAINTENANCE INSTRUCTIONS

4HP18LT Series

Split System Heat Pump

ManufacturedBy

AlliedAir Enterprises, Inc.

A Lennox International Inc. Company

215 Metropolitan Drive

West Columbia, SC 29170

TABLE OF CONTENTS

INSTALLATION ....................................................2

CONNECTION DIAGRAM....................................4

START-UP..........................................................13

OPERATION ......................................................18

MAINTENANCE .................................................23

*506470-01*

Page 1

The equipment covered in this manual is to be installed by trained and experienced service

and installation technicians. Improper installation, modification, service, or use can cause

electricalshock,fire,explosion,orotherconditionswhichmaycausepersonalinjury,death,

or property damage. Use appropriate safety gear including safety glasses and gloves

when installing this equipment.

WARNING

Installation and servicing of air conditioning equipment

can be hazardous due to internal refrigerant pressure

andlive electricalcomponents.Onlytrainedandqualified

servicepersonnelshouldinstallorservicethisequipment.

Installationandserviceperformedbyunqualified persons

canresultinpropertydamage,personalinjury, or death.

WARNING

Risk of electrical shock. Disconnect all remote power

supplies before installing or servicing any portion of the

system. Failureto disconnect powersuppliescan result

in property damage, personal injury, or death.

WARNING

Sharp metal edges can cause injury. When installing

the unit, use care to avoid sharp edges.

WARNING

506470-01 Issue 1007

INSTALLATION Inspection of Shipment

Upon receipt of equipment, carefully inspect it for possible

shipping damage. If damage is found, it should be noted on

the carrier’s freight bill. Take special care to examine the

unitinsidethecarton ifthe cartonisdamaged.Anyconcealed

damage discovered should be reported to the last carrier

immediately, preferably in writing, and should include a

request for inspection by the carrier’s agent.

If any damages are discovered and reported to the carrier

DO NOT INSTALL THE UNIT, as claim may be denied.

Check the unit rating plate to confirm specifications are

as ordered.

Location of Unit

Outdoor units operate under a wide range of weather

conditions; therefore, multiple factors must be considered

when positioning the unit. The unit must be positioned to

giveadequate clearances forsufficientairflowandservicing.

Refer to Figure 1 for installation clearances.

General

Read this entire instruction manual, as well as the

instructions supplied in separate equipment, before

starting the installation. Observe and follow all

warnings, cautions, instructional labels, and tags.

Failure to comply with these instructions could result

in an unsafe condition and/or premature component

failure.

These instructions are intended as a general guide only for

usebyqualifiedpersonnelanddonotsupersedeanynational

or local codes in any way. The installation must comply with

all provincial, state, and local codes as well as the National

ElectricalCode(U.S.)orCanadianElectricalCode(Canada).

Compliance should be determined prior to installation.

4HP18LT condensing units use R410A which is an ozone-

friendly HFC refrigerant. The unit must be installed with a

matching indoor coil and line set. Afilter drier approved for

use with R410Ais installed in the unit.

IMPORTANT: This product has been designed and

manufactured to meet ENERGY STAR criteria for energy

efficiencywhen matched with appropriate coil components.

However, proper refrigerant charge and proper air flow are

critical to achieve rated capacity and efficiency. Installation

of this product should follow the manufacturer’s refrigerant

chargingandairflowinstructions. Failureto confirmproper

charge and airflow may reduce energy efficiency and

shorten equipment life.

Whenservicing or repairingHVAC components,ensure the

fastenersareappropriatelytightened.Table1 shows torque

values for fasteners.

• Place a sound-absorbing material, such as Isomode

underthe unit ifitwillbe installedinalocation or position

that will transmit sound or vibration to the living area or

adjacentbuildings..

Page 2

Figure 1

Installation Clearances

* A service clearance of 30" must be maintained on

one of the sides adjacent to the control box.

Clearance to one of the other three sides must be

36".Clearance tooneof theremainingtwo sidesmay

be 12" and the final side may be 6".

Aclearance of 24" must be maintained between units.

48" clearance required on top of unit. Maximum soffit

overhang is 36".

36” *

36”

Table 1

Torque Table

Compressor Bolts 90 in. lbs.

#10 Machine Screws 28 in. lbs.

#8 Machine Screws 16 in. lbs.

Sheet Metal Screws 16 in. lbs.

Service Port Caps 8 ft. lbs.

Stem Caps 8 ft. lbs.

Fastener Torque

506470-01 Issue 1007

Roof Mounting

Install unit at a minimum of 6” above surface of the roof to

avoid ice buildup around the unit. Locate the unit above a

load bearing wall or area of the roof that can adequately

supportthe unit. Consultlocalcodesforrooftopapplications.

• Install the unit high enough above the ground or roof to

allow adequate drainage of defrost water and prevent

ice buildup.

• Inheavy snowareas,donotlocate theunitwheredrifting

snowwill occur. The unitbaseshouldbeelevated above

the depth of average snows.

NOTE: Elevation of the unit may be accomplished by

construction a frame using suitable materials. If a

support frame is constructed, it must not block drain

holes in unit base.

• Wheninstalledin areaswherelowambienttemperatures

exist, locate unit so winter prevailing winds do not blow

directly into outdoor coil.

• Locate unit away from overhanging roof lines which

would allow water or ice to drop on, or in front of, coil or

into unit.

Slab Mounting

When installing a unit at grade level, install on slab high

enough above grade so that water from higher ground will

notcollectaround the unit (See Figure 2). Slabshouldhave

a slope tolerance away from the building of 2° or 2” per 5’.

Thiswill prevent ice from building up under the unit during a

defrost cycle. Refer to following roof mounting section for

barrierconstructionif unit must face prevailingwinterwinds.

If unit coil cannot be mounted away from prevailing winter

winds, a wind barrier should be constructed (See Figure 3).

Size the barrier at least the same height and width as the

outdoor unit. Mount barrier 24” from the sides of the unit in

the direction of the prevailing winds.

Electrical Wiring

Allfieldwiring must be done inaccordancewiththe National

Electrical Code (NEC) recommendations, Canadian

Electrical Code (CEC) and CSA Standards, or local codes,

whereapplicable.

Refer to the furnace or blower coil installation instructions

for additional wiring application diagrams and refer to unit

rating plate for minimum circuit ampacity and maximum

overcurrent protection size.

Page 3

Line voltage is present at all components when unit is

not in operation on units with single pole contactors.

Disconnect all remote electric power supplies before

opening access panel. Unit may have multiple power

supplies. Failure to disconnect all power supplies could

result in personal injury or death.

WARNING

Unit must be grounded in accordance with national and

local codes. Failure to ground unit properly can result in

personal injury or death.

WARNING

Figure 2

Figure 3

Slab Mounting

Discharge Air

Mounting Slab

Ground Level

Building

Structure

506470-01 Issue 1007

1.Installlinevoltagepowersupply tounitfromaproperly

sized disconnect switch. Any excess high voltage field

wiringshould be trimmed or secured away from the low

voltage field wiring.

2. Ground unit at unit disconnect switch or to an earth

ground. To facilitate conduit, a hole is in the bottom of

the control box. Connect conduit to the control box

using a proper conduit fitting. Units are approved for

use only with copper conductors. 24V Class II circuit

connections are made in the low voltage junction box.

Refer to Figure 4 for high voltage field wiring diagram.

Acompleteunitwiring diagram is located inside the unit

control box cover.

3. Install room thermostat on an inside wall that is not

subjecttodrafts, direct sunshine, or other heatsources.

4. Install low voltage wiring from outdoor to indoor unit

andfromthermostatto indoor unit. (SeeWireDiagram

on page 27.)

5. Do not bundle any excess 24V control wire inside

control box. Run control wire through installed wire tie

and tighten wire tie to provide low voltage strain relief

andto maintainseperation of field-installedlow andhigh

voltage circuits.

Refrigerant Piping

If the 4HP18LT unit is being installed with a new indoor coil

and line set, the refrigerant connections should be made as

outlined in this section. If an existing line set and/or indoor

coilwillbeused to complete the system, refer to this section

as well as the section that follows entitled - Flushing

Existing Line Set and Indoor Coil.

If this unit is being matched with an approved line set or

indoor coil which was previously charged with R-22

refrigerant, the line set and coil must be flushed prior to

installation. Ifthe unit is being used with and existingindoor

coilwhich was equipped with a liquid linewhich served asa

meteringdevice (RFCI),theliquid linemustbe replacedprior

to the installation of the 4HP18LT unit.

Field refrigerant piping consists of liquid and suction lines

from the outdoor unit (sweat connections) to the indoor coil

(flare or sweat connections).

Select line set diameters from Table 2 to ensure that oil

returns to the compressor. Size vertical suction riser to

maintain minimum velocity at minimum capacity.

Recommended line length is 50’ or less. If more than 50’

line set is required, contact Technical Services. Table 2

showsthediameters for linesetsup to 100’althoughvertical

lift applications and trapping requirements need to be

reviewed with Technical Services for line sets over 50’.

Installing Refrigerant Line

During the installation of an air conditioning system, it is

important to properly isolate the refrigerant line to prevent

unnecessary vibration. Line set contact with the structure

(wall, ceiling, or floor) may cause objectionable noise when

vibration is translated into sound. As a result, more energy

or vibration can be expected. Close attention to line set

isolation must be observed.

Following are some points to consider when placing and

installing a high-efficiency outdoor unit:

Page 4

Figure 4

506470-01 Issue 1007

Placement

Beaware thatsome localitiesareadoptingsoundordinances

based on how noisy the unit is at the neighbor’s home, not

at the original installation. Install the unit as far as possible

fromthepropertyline. Whenpossible, do not install theunit

directly outside a bedroom window. Glass has a verry high

level of sound transmission. Figure 5 shows how to place

the outdoor unit and line set to reduce line set vibration.

Line Set Isolation

Illustrationson pages6and 7demonstrate procedureswhich

ensure proper refrigerant line set isolation. Figure 6 shows

how to install line sets on horizontal runs. Figure 7 shows

how to make a transition from horizontal to vertical. Figure

8 shows how to install line sets on vertical runs.

Brazing Connection Procedure

1. Cut ends of refrigerant lines square (free from nicks or

dents). Debur the ends. The pipe must remain round; do

not pinch end of line.

2. Before making line set connections, use dry nitrogen to

purge the refrigerant piping. This will help to prevent oxida-

tion and the introduction of moisture into the system.

3. Use silver alloy brazing rods (5% or 6% silver alloy for

copper-to-copper brazing or 45% silver alloy for copper-to-

brass or copper-to-steel brazing) which are rated for use

withR410Arefrigerant.

4. RemovetheSchradercoreassemblies before brazing to

protect them from damage due to extreme heat. Replace

the cores when brazing is complete.

5. Remove light maroon washers from service valves and

shield light maroon stickers to protect them during brazing.

Wrap a wet cloth around the valve body and copper tube

stub to protect it from heat damage.

Page 5

Table 2

Liquid Line

BTUH Line Set Length and Size

12 f t . 25 ft. 50 ft. 75 ft. 100 ft.

3/8 3/8 3/8 3/8 3/8

24,000

3/8 3/8 3/8 3/8

3/8 3/8 3/8 1/2

36,000

3/8 3/8 3/8 1/2

48,000

60,000 1/2

1/2

Refrigerant Line Set Diameters (in.)

S uction Line

BTUH Line Set Length and Size

12 f t . 25 ft. 50 ft. 75 ft. 100 ft.

3/4 3/4

24,000 7/8

36,000

7/8

1-1/8

7/8

1-1/8

48,000

7/87/8

7/8

1-1/8

60,000 1/8 1/8 1-1/8

1-1/8

3/4 3/4

For installations exceeding 50’, contact

Technical Services.

Install unit away

from windows

Two 90° elbows installed in lineset

will reduce lineset vibration

Figure 5

Outside Unit Placement & Installation

506470-01 Issue 1007

6. Brazethelinesettotheservicevalve. Quenchthejoints

with water or a wet cloth to prevent heat damage to the

valve core and opening port. The tube end must stay

bottomed in the fitting during final assembly to ensure

proper seating, sealing, and rigidity.

7. Install the thermal expansion valve which is sold

separately and which is approved for use with R410A

refrigerantin theliquidlineatthe indoorcoil(see Refrigerant

Metering Device on page 9).

Page 6

Whenflushingexistinglinesetand/orindoorcoil,besureto

empty all existing traps. Residual mineral oil can act as an

insulator, preventing proper heat transfer. It can also clog

thethermalexpansionvalve,reducingsystemperformance

andcapacity. Failureto properly flushsystemas explained

intheseinstructions will void warranty.

CAUTION

To hang line set from joist or rafter,

use either metal strapping material

or anchored heavy nylon wire ties.

Strapping Material

(around vapor line only)

8’

Tape or Wire Tie

Strap the vapor line to the joist or rafter

at 8 intervals then strap the liquid line

to the vapor line.

’

Floor Joist or

Roof Rafter

Metal Sleeve

Floor Joist or Roof Rafter

Tape or Wire Tie

Wire Tie

(around vapor line only)

Figure 6

Refrigerant Line Sets: Installing Horizontal Runs

506470-01 Issue 1007

Figure 8

Page 7

Figure 7

Anchored

Heavy Nylon

Wire Tie

Wall

Stud

Metal Sleeve Vapor Line Wrapped

in Armaflex

–

Liquid Line

Wall

Stud

Automotive

Muffler-Type

Hanger

Strap Liquid

Line to Vapor

Line

Metal Sleeve Vapor Line Wrapped

in Armaflex

–

Liquid Line

Strap Liquid

Line to Vapor

Line

Refrigerant Line Sets: Transition from Vertical to Horizontal

Outside Wall

Wood Block

Between Studs

IMPORTANT: Refrigerant

lines must not contact wall.

Vapor Line Liquid Line

Wire Tie

Inside Wall

Strap

Sleeve

Wire Tie

Strap

Wood Block

Sleeve

Vapor Line Wrapped

with Armaflex

Liquid Line

Caulk

PVC Pipe Fiberglass

Insulation

Outside Wall

IMPORTANT:

Refrigerant

lines must not

contact structure.

Refrigeraant Line Sets: Installing Vertical Runs (new construction shown)

NOTE: Similar installation practices

should be used if line set is to be

installed on exterior of outside wall.

506470-01 Issue 1007

Flushing Existing Line Set and Indoor Coil

This procedure should not be performed on systems

which contain contaminants, such as compressor burn

out.

Required Euipment

The following equipment is needed to flush the existing line

setandindoor coil (See Figure 9). Two cleanR-22recovery

bottles, an oil-less recovery machine with a “pump down”

feature, and two sets of gauges (one for use with R-22 and

one for use with R410A).

Flushing Procedure

IMPORTANT: The line set and/or indoor coil must be

flushed with at least the same amount of refrigerant that

previously charged the system. Check the charge in the

flushing cylinder before flushing the unit.

1. Remove existing R-22 refrigerant using the appropriate

procedure.

Ifthe existingoutdoorunitisnotequipped withshutoffvalves,

or if the unit is not operational AND the existing R-22

refrigerant will be used to flush the system:

Disconnect all power to the existing outdoor unit. Connect

theexistingunit, a clean recovery cylinder, and therecovery

machine according to the instructions provided with the

recovery machine. Remove all R-22 refrigerant

fromtheexistingsystem. Refer tothegaugesaftershutdown

to confirm that the entire system is completely void of

refrigerant. Disconnecttheliquidandsuctionlinesfromthe

existing outdoor unit.

If the existing outdoor unit is equipped with manual shutoff

valves AND new R-22 refrigerant will be used to flush the

system:

Start the existing R-22 refrigerant system in cooling mode

and close the liquid line valve. Pump all the existing R-22

refrigerant back into the outdoor unit.

(It may be necessary to bypass the low pressure switches

to ensure complete refrigerant evacuation.)

When the low side system pressures reach 0 psig, close

the suction line valve. Disconnect all power to the existing

outdoorunit. Refer to the gauges after shutdowntoconfirm

that the valves are not allowing refrigerant to flow back into

thelow side ofthesystem. Disconnect theliquidandsuction

lines from the existing outdoor unit.

2. Remove the existing outdoor unit. Set the new R410A

unit and follow the brazing connection procedure outlined

previously on this page to make line set connections. Do

not install the R410A thermal expansion valve at this

time.

3. Make low voltage and line voltage connections to the

new outdoor unit. Do not turn on power to the unit or

open the outdoor unit service valves at this time.

Page 8

Figure 9

Flushing Connections

506470-01 Issue 1007

4. RemovertheexistingR-22refrigerantflowcontrolorifice

or thermal expansion valve before continuing with flushing

procedures. R-22flowcontroldevicesarenotapprovedfor

usewith R410A refrigerantandmay preventproperflushing.

Use a field-provided fitting to reconnect the lines.

5. Removethe pressure tapvalve cores fromthe 4HP18LT

units service valves. Connect an R-22 cylinder with clean

refrigerant to the suction service valve. Connect the R-22

gauge set to the liquid line valve and connect a recovery

maching with an empty recovery tank to the gauge set.

6. Set the recovery machine for liquid recovery and start

the recovery machine. Open the gauge set valves to allow

therecoverymachinetopullavacuumontheexistingsystem

line set and indoor coil.

7. Invert the cylinder of clean R-22 and open its valve to

allow liquid refrigerant to flow in to the system through the

suction line valve. Allow the refrigerant to pass from the

cylinderandthroughthelineset and the indoor coil before it

enters the recovery machine.

8. Afterallof theliquid refrigeranthas beenrecovered,switch

the recovery machine to vapor recovery so that all of the R-

22vaporisrecovered. Allow the recovery machine to pulla

vacuum on the sytem.

NOTE: Asinglesystemflushshouldremoveallof themineral

oilfromtheexistingrefrigerantlinesandindoorcoil. Asecond

flushingmaybedone(usingclean refrigerant) if insufficient

amounts of mineral oil were removed during the first flush.

After each system flush, allow the recovery machine to

pulla vacuum onthe systemat the endof theprocedure.

9. Close the valve on the inverted R-22 cylinder and the

gauge set valves. Pump the remaining refrigerant out of

the recovery machine and turn the machine off.

10. Use nitrogen to break the vacuum on the refrigerant

linesandindoor coil before removing therecoverymachine,

gauges, and R-22 refrigerant drum. Re-install pressure tap

valve cores into the 4SHP18LT unit’s service valves.

11. Install the fixed orifice (or thermal expansion valve

approvedforusewithR410A refrigerant) in the liquid line at

the indoor coil.

Refrigerant Metering Device

4HP18LT units are designed for use with TXV systems.

Refertotheappropriatefollowingsectionforinformationon

installing the chosen refrigerant metering device.

An R410A system will not operate properly with an R-22

metering device.

Install the refrigerant metering device as shown in Figure

11. Do not twist cap tubes when loosening thesealnutfrom

the orifice housing. Use wrench to back up the distributor.

Expansion Valve Systems

Expansion valves equipped with Chatleff-type fittings are

available from the manufacturer. See Table 3 for proper

TXV for each unit.

To install an expansion valve (See Figure 10 above):

1. Separatethe distributor assembly and remove thepiston

orifice and used teflon seal. Insert nozzle end of the

expansion valve along with a new teflon seal into the

distributorandtighten to20-30 ft. lbs. Use backup wrench

on all wrench flats. Overtightening will crush the teflon

seal and may cause a leak.

2. Attach liquid line portion of distributor assembly along

with new teflon seal to the inlet of the expansion valve.

Tighten to 20 - 30 ft. lbs. Use backup wrench on all wrench

flats. Overtightening will crush the teflon seal and may

cause a leak.

Page 9

Figure 10

Table 3

MODEL PART NUMBER

4HP18LT- 24

4HP18LT - 36

H4TXV01

H4TXV02

4HP18LT - 48, -60 H4TXV03

TXV Data

506470-01 Issue 1007

3. Connect the external equalizer line to the equalizer port

on the suction line and tighten to 8 ft.lbs.

4. Strap the superheat sensing bulb to the suction header.

If installing an expansion valve on an indoor coil that

previouslyused afixedorifice, besuretoremovethe existing

fixedorifice. Failureto remove a fixedorificewheninstalling

an expansion valve to the indoor coil will result in improper

operation and damage to the system.

Manifold Gauge Set

Manifoldguage sets usedwithsystems charged withR410A

refrigerant must be capable of handling the higher system

operating pressures. The gauges should be rated for use

withpressures1-800onthehighside and a low side of 30”

vacuumto250psiwithdampenedspeed to 500 psi. Gauge

hoses must be rated for use at up to 800 psi of pressure

with a 4000 psi burst rating.

Liquid and Suction Line Service Valves

The liquid line and suction line service valves (See Figure

11) and service ports are used for leak teating, evacuation,

charging, and checking charge.

Each valve is equipped with a service port which has a

factory-installedSchradervalve. Aserviceportcap protects

the Schrader valve from contamination and serves as the

primary leak seal.

To Access the Schrader Port:

1. Remove the service port cap with an adjustable wrench.

2. Connect gauge to the service port.

3. When testing is completed, replace service port cap.

Tighten finger tight, then an additional 1/6 turn.

To Open Liquid or Suction Line Service Valve:

Remove stem cap with an adjustable wrench.

Use service wrench with a hex-head extension to back the

stem out counterclockwise as far as it will go. Use a 3/16”

hex head extension for liquid line service valves and a 5/

16” extension for suction line service valves.

Replace the stem cap. Tighten finger tight, then tighten an

additional 1/6 turn.

To Close Liquid or Suction Line Service Valve:

1. Remove the stem cap with an adjustable wrench.

2. Use a service wrench with a hex-head extension to turn

the stem clockwise to seat the valve. Tighten firmly.

3. Replace the stem cap. Tighten finger tight, then tighten

an additional 1/6 turn.

Suction Line (Ball Type) Service Valve

Suctionline(ball type) servicevalvesfunctionthe same way

astheother valves; thedifferenceisintheconstruction (See

Figure 12).

Theball valve is equipped with a service port with a factory-

installed Schrader valve. A service port cap protects the

Schrader valve from contamination and serves as the

primary seal.

Leak Testing

After the line set has been connected to the indoor and

outdoor units, the line set connections and indoor unit must

be checked for leaks.

Page 10

Figure 11

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