Lennox Collection XC21 System Installation Instructions Manual

INSTALLATION

E2011 Lennox Industries Inc.

Dallas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

These instructions are intended as a general guide and do not supersede local codes in any way. Consult authorities having jurisdiction before installation.

NOTICE TO INSTALLER

It is critical for proper unit operation to place outdoor unit on an elevated surface as described in Unit Placement section on page 7.

BRAZING LINE SET TO SERVICE VALVES

It is imperative to follow the brazing technique illustrated starting on page 12 to avoid damaging the service valve’s internal seals.

UNIT PLACEMENT

NOTICE

A thermostat is not included and must be ordered separately.

D The Lennox icomfort Touch® thermostat must be used

in communicating applications.

D In non−communicating applications, the Lennox

ComfortSense® 7000 thermostat may be used, as well as other non−communicating thermostats.

In all cases, setup is critical to ensure proper system operation.

Field wiring examples for non−communicating applications begin on page 23.

See the icomfort Toucht thermostat Quick Start Guide for communicating and partial communicating field wiring connections.

INSTRUCTIONS

Dave Lennox Signature Collection XC21 System

AIR CONDITIONER

506587−01 06/11 Supersedes 10/10

TABLE OF CONTENTS

General 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Unit Dimensions 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Model Number Identification 2. . . . . . . . . . . . . . . . . . . .

Unit Parts Arrangement 3. . . . . . . . . . . . . . . . . . . . . . . .

Shipping and Packing List 4. . . . . . . . . . . . . . . . . . . . . .

Using Manifold Gauge Set 4. . . . . . . . . . . . . . . . . . . . . .

Operating Service Valves 4. . . . . . . . . . . . . . . . . . . . . . .

Recovering Refrigerant from Existing System 6. . . . .

Unit Placement 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removing and Installing Panels 9. . . . . . . . . . . . . . . . .

New or Replacement Line Set 10. . . . . . . . . . . . . . . . . . .

Brazing Connections 12. . . . . . . . . . . . . . . . . . . . . . . . . . .

Flushing Line Set and Indoor Coil 15. . . . . . . . . . . . . . . .

Installing Indoor Expansion Valve 16. . . . . . . . . . . . . . . .

Leak Test Line Set and Indoor Coil 17. . . . . . . . . . . . . . .

Evacuating Line Set and Indoor Coil 17. . . . . . . . . . . . .

Electrical 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air Conditioner Control (A175) Jumpers and

Terminals 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Field Control Wiring 23. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Servicing Unit Delivered Void of Charge 25. . . . . . . . . .

Unit Start−Up 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Refrigerant 25. . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating and Temperature Pressures 29. . . . . . . . . . .

System Operations 30. . . . . . . . . . . . . . . . . . . . . . . . . . . .

System Status, Fault and Lockout LED Codes 37. . . . .

Field Configuration and Testing 42. . . . . . . . . . . . . . . . . .

Maintenance (Dealer and Homeowner) 49. . . . . . . . . . .

SunSource® Home Energy System 50. . . . . . . . . . . . . .

Checklists 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General

This outdoor unit is designed for use with HFC−410A refrigerant only. This unit must be installed with an approved indoor air handler or coil. See the Lennox XC21 Engineering Handbook for approved indoor component matchups.

Litho U.S.A.

06/11 506587−01

*2P0611* *P506587-01*

Page 1

Unit Dimensions − Inches (mm) and Parts Arrangement

39−1/2 (1003)

DISCHARGE AIR

SIDE VIEW

UNIT SUPPORT FEET

SUCTIOn LINE INLET

LIQUID LINE INLET

ELECTRICAL

INLETS

(1194)

18−1/2

(470)

4−1/2 (114)

8 (203)

1 (25)

35−1/2

(902)

ACCESS VIEW

16−7/8

(429)

8−3/4 (222)

3−1/8

(79)

Model Number Identification

Refrigerant Type

X = R−410A

Unit Type

C = Air Conditioner

Series

30−3/4

(781)

BASE WITH ELONGATED LEGS

C 21

XXX

230

Nominal Cooling Capacity

024 = 2 tons 036 = 3 tons 048 = 4 tons 060 = 5 tons

26−7/8

(683)

3−3/4 (95)

4−5/8 (117)

Minor Revision Number

Voltage

230 = 208/230V−1ph−60hz

506587−01

Page 2

Typical Unit Parts Arrangement

WIRE TIE

OUTDOOR AMBIENT

TEMPERATURE SENSOR (RT13)

SECOND GROUND LUG FOR SOURCESOURCE

HIGH VOLTAGE FIELD

CONNECTIONS

GROUND LUG

AIR CONDITIONER

CONTROL (A175)

CONTACTOR−1 POLE (K1)

FAN MOTOR (A177) CONTROL

CAPACITOR (C12)

HIGH DISCHARGE LINE

TEMPERATURE SENSOR (RT28)

COMPRESSOR HARNESS

FIELD CONNECTION FOR

SUCTION LINE SERVICE

FIELD CONNECTION FOR

SUCTION LINE

VALVE PORT

LIQUID LINE SERVICE

VALVE PORT

LIQUID LINE

LIQUID LINE FILTER

DRIER (SINGLE FLOW)

LOW PRESSURE SWITCH

(S87)

HIGH PRESSURE SWITCH (S4)

CRANKCASE THERMOSTAT (S40)

Figure 1. Plumbing, Switches and Sensor Components

Page 3

XC21 SERIES

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause personal injury, loss of life, or damage to property.

Installation and service must be performed by a licensed professional installer (or equivalent) or a service agency.

1  Bushing (for low voltage wiring) 2  Isolation grommets for liquid and suction lines

Using Manifold Gauge Set

When checking the system charge, only use a manifold gauge set that features low−loss anti−blow back fittings.

IMPORTANT

CAUTION

Physical contact with metal edges and corners while applying excessive force or rapid motion can result in personal injury. Be aware of, and use caution when working near these areas during installation or while servicing this equipment.

IMPORTANT

The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFCs, HCFCs AND HFCs) as of July 1,

1992. Approved methods of recovery, recycling or reclaiming must be followed. Fines and/or incarceration may be levied for noncompliance.

WARNING

Electric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national and local codes.

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.

To prevent stripping of the various caps used, the appropriately sized wrench should be used and fitted snugly over the cap before tightening.

Manifold gauge set used with HFC−410A refrigerant systems must be capable of handling higher system operating pressures. The gauges should be rated for use with pressures of 0 − 800 psig on the high side and a low side of 30" vacuum to 250 psig with dampened speed to 500 psi. Gauge hoses must be rated for use at or up to 800 psig of pressure with a 4000 psig burst rating.

Table 1. Torque Requirements

Parts Recommended Torque

Service valve cap 8 ft.− lb. 11 NM

Sheet metal screws 16 in.− lb. 2 NM

Machine screws #10 28 in.− lb. 3 NM

Compressor bolts 90 in.− lb. 10 NM

Gauge port seal cap 8 ft.− lb. 11 NM

Operating Service Valves

The liquid and vapor line service valves are used for removing refrigerant, flushing, leak testing, evacuating, verifying charge and charging.

Each valve is equipped with a service port which has a factory−installed valve stem. Figure 2 provides information on how to access and operating both angle and ball service valves.

IMPORTANT

This model is designed for use in check expansion valve systems only. An indoor expansion valve approved for use with HFC−410A refrigerant must be ordered separately, and installed prior to operating the system.

Shipping and Packing List

Check unit for shipping damage. Consult last carrier immediately if damage is found.

1  Assembled outdoor unit. 1  Bag assembly which includes the following:

506587−01

IMPORTANT

Only use Allen wrenches of sufficient hardness (50Rc − Rockwell Harness Scale minimum). Fully insert the wrench into the valve stem recess.

Service valve stems are factory−torqued (from 9 ft−lbs for small valves, to 25 ft−lbs for large valves) to prevent refrigerant loss during shipping and handling. Using an Allen wrench rated at less than 50Rc risks rounding or breaking off the wrench, or stripping the valve stem recess.

See the Lennox Service and Application Notes #C−08−1 for further details and information.

Page 4

SERVICE VALVES

ANGLE AND BALL

Operating Angle Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use a service wrench with a hex−head extension (3/16" for liquid line valve sizes and 5/16" for vapor line valve sizes) to back the stem out counterclockwise as far as it will go.

SERVICE PORT CAP

SERVICE PORT CORE

(VALVE STEM SHOWN CLOSED) INSERT HEX WRENCH HERE

TO INDOOR

UNIT

(VALVE STEM SHOWN OPEN) INSERT HEX WRENCH HERE

STEM CAP

TO OUTDOOR UNIT

ANGLE−TYPE SERVICE VALVE

(BACK−SEATED OPENED)

When service valve is OPEN, the service port is open to linE set, indoor and outdoor unit.

Operating Ball Type Service Valve:

1. Remove stem cap with an appropriately sized wrench.

2. Use an appropriately sized wrenched to open. To open valve, rotate stem counterclockwise 90°. To close, rotate stem clockwise 90°.

TO INDOOR UNIT

TO OPEN ROTATE STEM COUNTERCLOCKWISE 90°.

TO CLOSE ROTATE STEM CLOCKWISE 90°.

SERVICE PORT

CORE

CAP

TO OUTDOOR

UNIT

BALL (SHOWN CLOSED)

VALV E STEM

STEM CAP

ANGLE−TYPE SERVICE VALVE

(FRONT−SEATED CLOSED)

WHEN SERVICE VALVE IS CLOSED, THE SERVICE PORT IS OPEN TO

THE LINE SET AND INDOOR UNIT.

To Access Service Port:

A service port cap protects the service port core from contamination and serves as the primary leak seal.

1. Remove service port cap with an appropriately sized wrench.

2. Connect gauge set to service port.

3. When testing is completed, replace service port cap and tighten as follows:

1/6 TURN

1/12 TURN

S With torque wrench: Finger tighten and

torque cap per table 1.

S Without torque wrench: Finger tighten and

use an appropriately sized wrench to turn an additional 1/6 turn clockwise.

Reinstall Stem Cap:

Stem cap protects the valve stem from damage and serves as the primary seal. Replace the stem cap and tighten as follows:

S With Torque Wrench: Finger tighten and then

torque cap per table 1.

S Without Torque Wrench: Finger tighten and use

an appropriately sized wrench to turn an additional 1/12 turn clockwise.

NOTE  A label with specific torque requirements may be affixed to the stem cap. If the label is present, use the specified torque.

Figure 2. Angle and Ball Service Valves

Page 5

XC21 SERIES

Recovering Refrigerant from Existing System

DISCOnNECT POWER

Disconnect all power to the existing outdoor unit at the disconnect

switch or main fuse box/breaker panel.

SERVICE DISCONNECT

SWITCH

COnNECT MANIFOLD GAUGE SET

Connect a gauge set, clean recovery cylinder and a recovery

machine to the service ports of the existing unit. Use the instruction provided with the recovery machine to make the connections.

MANIFOLD GAUGES

RECOVERY MACHINE

LOW

HIGH

RECOVERING REFRIGERANT

Remove existing HCFC−22 refrigerant using one of the following methods

below:

IMPORTANT  Some system configurations may contain higher than normal refrigerant charge due to either large internal coil volumes, and/or long line sets.

CLEAN RECOVERY CYLINDER

OUTDOOR UNIT

METHOD 1:

Us this method if the existing outdoor unit is not equipped with shut−off valves, or if the unit is not operational and you plan to use the existing HCFC−22 to flush the system.

Remove all HCFC−22 refrigerant from the existing system. Check gauges after shutdown to confirm that the entire system is completely void of refrigerant.

METHOD 2:

Use this method if the existing outdoor unit is equipped with manual shut−off valves, and you plan to use new HCFC−22 refrigerant to flush the system.

The following devices could prevent full system charge recovery into the outdoor unit:

S Outdoor unit’s high or low−pressure switches (if applicable) when tripped can cycle the compressor OFF.

S Compressor can stop pumping due to tripped internal pressure relief valve.

S Compressor has internal vacuum protection that is designed to unload the scrolls (compressor stops pumping) when the pressure ratio meets

a certain value or when the suction pressure is as high as 20 psig. (Compressor suction pressures should never be allowed to go into a vacuum. Prolonged operation at low suction pressures will result in overheating of the scrolls and permanent damage to the scroll tips, drive bearings and internal seals.)

Once the compressor can not pump down to a lower pressure due to one of the above system conditions, shut off the vapor valve. Turn OFF the main power to unit and use a recovery machine to recover any refrigerant left in the indoor coil and line set.

Perform the following task:

A Start the existing HCFC−22 system in the cooling mode and close the liquid line valve.

B Use the compressor to pump as much of the existing HCFC−22 refrigerant into the outdoor unit until the outdoor system is full (high pressure

switch will trip and shut the compressor off). Turn the outdoor unit main power OFF and use a recovery machine to remove the remaining refrigerant from the system.

NOTE  It may be necessary to bypass the low pressure switch (if equipped) to ensure complete refrigerant evacuation.

C When the low side system pressures reach 0 psig, close the vapor line valve.

D Check gauges after shutdown to confirm that the valves are not allowing refrigerant to flow back into the low side of the system.

Figure 3. Old Refrigerant Recovery Procedure

Page 6

506587−01

CLEARANCE ON ALL SIDES  INCHES (MILLIMETERS)

MINIMUM CLEARANCE

ABOVE UNIT

12 (305)

6 (152)

36 (914)

ACCESS PANEL

CONTROL PANEL

ACCESS

LOCATION

30 (762)

LINE SET CONNECTIONS

MINIMUM CLEARANCE BETWEEN

TWO UNITS

24 (610)

Figure 4. Installation Clearances

NOTES:

S CLEARANCE TO ONE OF THE

OTHER THREE SIDES MUST BE 36 INCHES (914MM).

S CLEARANCE TO ONE OF THE

REMAINING TWO SIDES MAY BE 12 INCHES (305MM) AND THE FINAL SIDE MAY BE 6 INCHES (152MM).

ACCESS PANEL

LINE SET

CONNECTIONS

48 (1219)

REAR VIEW OF UNIT

Unit Placement

CAUTION

In order to avoid injury, take proper precaution when lifting heavy objects.

See Unit Dimensions on page 3 for sizing mounting slab, platforms or supports. Refer to figure 4 for mandatory installation clearance requirements.

POSITIONING CONSIDERATIONS

Consider the following when positioning the unit:

S Some localities are adopting sound ordinances based

on the unit’s sound level registered from the adjacent property, not from the installation property. Install the unit as far as possible from the property line.

S When possible, do not install the unit directly outside

a window. Glass has a very high level of sound transmission. For proper placement of unit in relation to a window see the provided illustration in figure 5, detail A.

PLACING UNIT ON SLAB

When installing unit at grade level, the top of the slab should be high enough above grade so that water from higher ground will not collect around the unit. The slab should have a slope tolerance as described in figure 5, detail B.

NOTE  If necessary for stability, anchor unit to slab as described in figure 5, detail D.

ELEVATING THE UNIT

Units are outfitted with elongated support feet as illustrated in figure 5, detail C.

If additional elevation is necessary, raise the unit by extending the height of the unit support feet. This may be achieved by using a 2 inch (50.8mm) Schedule 40 female threaded adapter.

The specified coupling will fit snuggly into the recessed portion of the feet. Use additional 2 inch (50.8mm) Schedule 40 male threaded adaptors which can be threaded into the female threaded adaptors to make additional adjustments to the level of the unit.

NOTE  Keep the height of extenders short enough to ensure a sturdy installation. If it is necessary to extend further, consider a different type of field−fabricated framework that is sturdy enough for greater heights.

STABILIZING UNIT ON UNEVEN SURFACES

With unit positioned at installation site, perform the following:

1. Remove two side louvered panels to expose the unit base.

2. Install the brackets as illustrated in figure 5, detail D using conventional practices.

3. Replace the panels after installation is complete.

Page 7

XC21 SERIES

DETAIL A

 Outside Unit Placement

INSTALL UNIT AWAY FROM WINDOWS

DETAIL B

Install unit level or, if on a slope, maintain slope tolerance of two (2) degrees (or two inches per five feet [50 mm per 1.5 m]) away from building structure.

 Slab Mounting at Ground Level

BUILDING

STRUCTURE

MOUNTING SLAB

TWO 90° ELBOWS INSTALLED IN LINE SET WILL

REDUCE LINE SET VIBRATION.

DETAIL C

 Elevated Slab Mounting

using Feet Extenders

LEG DETAIL

2" (50.8MM) SCH 40

FEMALE THREADED

ADAPTER

BASE

GROUND LEVEL

STABILIZING UNIT ON UNEVEN SURFACES

DETAIL D

#10 1/2" LONG SELF−DRILLING

SHEET METAL SCREWS

STABILIZING BRACKET (18 GAUGE

METAL  2" WIDTH; HEIGHT AS

#10 1−1/4" LONG HEX HD SCREW

Concrete slab  use two plastic anchors (hole drill 1/4")

Wood or plastic slab  no plastic anchor (hole drill 1/8")

DETAIL E

Stabilizing bracket (18 gauge metal  2" (50.8mm) width; height as required); bend to form right angle as exampled below.

 Slab Side Mounting

REQUIRED)

AND FLAT WASHER

 Deck Top Mounting

MINIMUM ONE

PER SIDE

COIL

BASE PAN

CORNER POST

2" (50.8MM) SCH 40

MALE THREADED

ADAPTER

Use additional 2" SCH 40 male threaded adapters which can be threaded into the female threaded adapters to make additional adjustments to the level of the unit.

IMPORTANT  To help stabilize an outdoor unit, some installations may require strapping the unit to the pad using brackets and anchors commonly available in the marketplace.

IMPORTANT 

Unit Stabilizer Bracket Use (field−provided):

Always use stabilizers when unit is raised above the factory height. (Elevated units could become unstable in gusty wind conditions).

Stabilizers may be used on factory height units when mounted on unstable an uneven surface.

Figure 5. Placement and Slab Mounting

506587−01

SAME FASTENERS AS SLAB SIDE MOUNTING.

One bracket per side (minimum). For extra stability, two brackets per side, two inches (51mm) from each corner.

FOR EXTRA

STABILITY

Page 8

ROOF MOUNTING

Install the unit a minimum of six inches (152 mm) above the roof surface to avoid ice build−up around the unit. Locate the unit above a load bearing wall or area of the roof that

Removing and Installing Panels

See figure 6 for information on removing and installing unit panels.

can adequately support the unit. Consult local codes for rooftop applications.

To prevent personal injury, or damage to panels, unit or

NOTICE

Roof Damage! This system contains both refrigerant and oil. Some

rubber roofing material may absorbed oil and cause the rubber to swell when it comes into contact with oil. The rubber will then bubble and could 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.

Panel shown slightly rotated to allow top tab to exit (or enter) top slot for removing (or installing) panel.

structure, be sure to observe the following:

While installing or servicing this unit, carefully stow all removed panels out of the way, so that the panels will not cause injury to personnel, nor cause damage to objects or structures nearby, nor will the panels be subjected to damage (e.g., being bent or scratched).

While handling or stowing the panels, consider any weather conditions, especially windy conditions, that may cause panels to be blown around and battered.

LOUVERED PANEL REMOVAL

Remove the louvered panels as follows:

1. Remove two screws, allowing the panel to swing open slightly.

2. Hold the panel firmly throughout this procedure Rotate bottom corner of panel

away from hinged corner post until lower three tabs clear the slots as illustrated in detail B.

3. Move panel down until lip of upper tab clears the top slot in corner post as

illustrated in detail A.

LOUVERED PANEL INSTALLATION

Position the panel almost parallel with the unit as illustrated in detail D with the screw side as close to the unit as possible. Then, in a continuous motion:

1. Slightly rotate and guide the lip of top tab inward as illustrated in detail A and C;

then upward into the top slot of the hinge corner post.

2. Rotate panel to vertical to fully engage all tabs.

3. Holding the panel’s hinged side firmly in place, close the right−hand side of the panel, aligning the screw holes.

4. When panel is correctly positioned and aligned, insert the screws and tighten.

Detail A

LIP

WARNING

REMOVE 4 SCREWS TO REMOVE PANEL FOR ACCESSING COMPRESSOR AND CONTROLS.

Position panel with holes aligned; install screws and tighten.

Detail C

Maintain minimum panel angle (as close to parallel with the unit as possible) while installing panel.

IMPORTANT  Do not allow panels to hang on unit by top tab. Tab is for alignment and not designed to

support weight of panel.

Detail D

ANGLE MAY BE TOO EXTREME

PREFERRED

ANGLE FOR

INSTALLATION

HOLD DOOR FIRMLY ALONG

THE HINGED SIDE TO MAINTAIN

FULLY−ENGAGED TABS

Figure 6. Removing and Installing Panels

Page 9

SCREW

HOLES

Detail B

ROTATE IN THIS DIRECTION; THEN

DOWN TO REMOVE PANEL

XC21 SERIES

New or Replacement Line Set

REFRIGERANT LINE SET

This section provides information on installation or replacement of existing line set. If new or replacement line set is not being installed then proceed to Brazing Connections on page 12.

IMPORTANT

Lennox highly recommends changing line set when converting the existing system from HCFC−22 to HFC−410A. If that is not possible and the line set is the proper size as reference in table 2, use the procedure outlined under Flushing the System on page 13.

If refrigerant lines are routed through a wall, then seal and isolate the opening so vibration is not transmitted to the building. Pay close attention to line set isolation during installation of any HVAC system. When properly isolated from building structures (walls, ceilings. floors), the refrigerant lines will not create unnecessary vibration and subsequent sounds. See figure 7 for recommended installation practices. Also, consider the following when placing and installing a high−efficiency outdoor unit.

Liquid lines that meter the refrigerant, such as RFC1 liquid lines, must not be used in this application. Existing line set of proper size as listed in table 2 may be reused. If system was previously charged with HCFC−22 refrigerant, then existing line set must be flushed (see Flushing the System on page 15).

Field refrigerant piping consists of liquid and vapor lines from the outdoor unit to the indoor unit coil (braze connections). Use Lennox L15 (sweat, non−flare) series line set, or field−fabricated refrigerant line sizes as listed in table 2.

IMPORTANT

Mineral oils are not compatible with HFC−410A. If oil

must be added, it must be a Polyol Ester oil.

Table 2. Refrigerant Connections and Line Set

Requirements

Models Liquid

Line

−024, −036 and−048

−060 3/8 (10) 1−1/8 (29) Field Fabricated

NOTE  Some applications may required a field provided 7/8" to 1−1/8" adapter.

3/8 (10) 7/8 (22) L15 line set sizes are

Vapor/ Suction Line

L15 Line Set

dependent on unit match up. See XC21 Engineering Handbook to determine correct line set sizes.

NOTE  When installing refrigerant lines longer than 50 feet, see the Lennox Refrigerant Piping Design and Fabrication Guidelines, CORP. 9351−L9, or contact Lennox Technical Support Product Applications for assistance.

To obtain the correct information from Lennox, be sure to communicate the following information:

S Model (XC21) and size of unit (e.g. −036).

S Line set diameters for the unit being installed as listed

in table 2 and total length of installation.

S Number of elbows vertical rise or drop in the piping.

The compressor is charged with sufficient Polyol ester oil for line set lengths up to 50 feet. Recommend adding oil to system based on the amount of refrigerant charge in the system. No need to add oil in system with 20 pounds of refrigerant or less. For systems over 20 pounds − add one ounce of every five pounds of refrigerant.

Recommended topping−off POE oils are Mobil EAL ARCTIC 22 CC or ICI EMKARATEt RL32CF.

WARNING

Polyol Ester (POE) oils used with HFC−410A refrigerant absorb moisture very quickly. It is very important that the refrigerant system be kept closed as much as possible. DO NOT remove line set caps or service valve stub caps until you are ready to make connections.

506587−01

Page 10

Line Set Isolation  The following illustrations are examples of proper refrigerant line set isolation:

REFRIGERANT LINE SET  TRANSITION

FROM VERTICAL TO HORIZONTAL

ANCHORED HEAVY NYLON

WIRE TIE OR AUTOMOTIVE

MUFFLER-TYPE HANGER

WALL STUD

NON−CORROSIVE

METAL SLEEVE

AUTOMOTIVE

MUFFLER-TYPE HANGER

STRAP LIQUID LINE TO VAPOR LINE

LIQUID LINE

VAPOR LINE − WRAPPED IN ARMAFLEX

REFRIGERANT LINE SET  INSTALLING

HORIZONTAL RUNS

To hang line set from joist or rafter, use either metal strapping material or anchored heavy nylon wire ties.

WIRE TIE (AROUND VAPOR LINE ONLY)

8 FEET (2.43 METERS)

STRAPPING

MATERIAL (AROUND

VAPOR LINE ONLY)

TAPE OR WIRE TIE

FLOOR JOIST OR

ROOF RAFTER

8 FEET (2.43 METERS)

NON−CORROSIVE METAL SLEEVE

STRAP THE VAPOR LINE TO THE JOIST OR RAFTER AT 8 FEET (2.43 METERS) INTERVALS THEN STRAP THE LIQUID LINE TO THE VAPOR LINE.

TAPE OR WIRE TIE

REFRIGERANT LINE SET  INSTALLING

VERTICAL RUNS (NEW CONSTRUCTION SHOWN)

NOTE  Insulate liquid line when it is routed through areas where the surrounding ambient temperature could become higher than the temperature of the liquid line or when pressure drop is equal to or greater than 20 psig.

OUTSIDE WALL

WOOD BLOCK

BETWEEN STUDS

VAPOR LINE WRAPPED

WITH ARMAFLEX

OUTSIDE

WALL

PVC

PIPE

FIBERGLASS

INSULATION

VAPOR LINE

SLEEVE

CAULK

LIQUID LINE

NOTE  Similar installation practices should be used if line set is to be installed on exterior of outside wall.

LIQUID LINE

WIRE TIE

INSIDE WALL

STRAP

NON−CORROSIVE METAL SLEEVE

WIRE TIE

WOOD BLOCK

WIRE TIE

STRAP

FLOOR JOIST OR

ROOF RAFTER

Figure 7. Line Set Installation

Page 11

XC21 SERIES

Brazing Connections

Use the procedures outline in figures 8 and 9 for brazing line set connections to service valves.

WARNING

Danger of fire. Bleeding the refrigerant charge from only the high side may result in pressurization of the low side shell and suction tubing. Application of a brazing torch to a pressurized system may result in ignition of the refrigerant and oil mixture − Check the high and low pressures before applying heat.

IMPORTANT

Connect gauge set low pressure side to vapor line service valve and repeat procedure starting at paragraph 4 for brazing the liquid line to service port valve.

IMPORTANT

Allow braze joint to cool before removing the wet rag from the service valve. Temperatures above 250ºF can damage valve seals.

WARNING

When using a high pressure gas such as dry nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

CAUTION

Brazing alloys and flux contain materials which are hazardous to your health.

Avoid breathing vapors or fumes from brazing operations. Perform operations only in well−ventilated areas.

Wear gloves and protective goggles or face shield to protect against burns.

Wash hands with soap and water after handling brazing alloys and flux.

IMPORTANT

Use silver alloy brazing rods with 5% minimum silver alloy for copper−to−copper brazing. Use 45% minimum alloy for copper−to−brass and copper−to−steel brazing.

WARNING

Fire, Explosion and Personal Safety Hazard.

Failure to follow this warning could result in damage, personal injury or death.

Never use oxygen to pressurize or purge refrigeration lines. Oxygen, when exposed to a spark or open flame, can cause fire and/or an explosion, that could result in property damage, personal injury or death.

506587−01

Page 12

PIPING PANEL REMOVAL AND PREPARING LINE SET

Remove piping panel for easier access to service valves. Cut ends of the refrigerant lines square (free from nicks or dents) and debur the ends. The pipe must remain round. Do not crimp end of the line.

CUT AND DEBUR

LINE SET SIZE MATCHES

SERVICE VALVE CONNECTION

SERVICE VALVE

COPPER TUBE

REDUCER

STUB

CONNECTION

LINE SET SIZE IS SMALLER

THAN CONNECTION

CAP AND CORE REMOVAL

Remove service cap and core from both the suction / vapor and

liquid line service ports.

SERVICE PORT CAP

SERVICE PORT CORE

LIQUID LINE SERVICE VALVE

REFRIGERANT LINE

DO NOT CRIMP SERVICE VALVE

CONNECTOR WHEN PIPE IS

SMALLER THAN CONNECTION

ATTACH THE MANIFOLD GAUGE SET FOR BRAZING LIQUID AND SUCTION / VAPOR LINE SERVICE VALVES

A Connect gauge set low pressure side to liquid line

service valve (service port).

B Connect gauge set center port to bottle of nitrogen with

regulator.

C With valve core removed from the suction / vapor line

service port, nitrogen flow will have an exit point.

ATTACH

GAUGES

SUCTION / VAPOR SERVICE PORT MUST BE

OPEN AND SERVICE PORT CORE REMOVED

TO ALLOW EXIT POINT FOR NITROGEN FLOW

SUCTION / VAPOR

LINE

INDOOR

UNIT

SUCTION /

VAPOR LINE

SERVICE

VALV E

SUCTION / VAPOR LINE

SERVICE VALVE

HIGHLOW

OUTDOOR

UNIT

SERVICE PORT CORE

SERVICE PORT CAP

LIQUID LINE

LIQUID LINE SERVICE

VALV E

Figure 8. Brazing Procedures

Page 13

NITROGEN

XC21 SERIES

WRAP SERVICE VALVES

To help protect service valve seals during brazing, wrap water saturated cloths around service valve bodies and copper tube stubs. Use

additional water saturated cloths underneath the valve body to protect the base paint.

FLOW NITROGEN

Flow regulated nitrogen (at 1 to 2 psig) through the refrigeration

gauge set into the valve stem port connection on the liquid service valve and out of the suction / vapor valve stem port. See steps 3A, 3B and 3C on previous page and below for manifold gauge setup.

BRAZE LINE SET

Water saturated cloths must remain water saturated throughout

the brazing and cool−down process.

A Braze liquid line to liquid line service valve.

B Braze suction / vapor line to suction / vapor service

valve.

1. FIRE, PERSONAL INJURY, OR PROPERTY DAMAGE will result if you do not wrap a water saturated cloth around both liquid and suction line service valve bodies and copper tube stub while brazing in the line set! The braze, when complete, must be quenched with water to absorb any residual heat.

2. Do not open service valves until refrigerant lines and indoor coil have been leak−tested and evacuated. Refer to procedures provided in this supplement.

WHEN BRAZING LINE SET TO

SERVICE VALVES, POINT FLAME AWAY

FROM SERVICE VALVE.

WARNING

SUCTION / VAPOR LINE

WATER SATURATED CLOTHS

IMPORTANT  Allow braze joint to cool. Apply

additional water saturated cloths to help cool brazed joints. Do not remove water saturated cloths until piping has cooled. Temperatures above 250ºF will damage valve seals.

SUCTION / VAPOR SERVICE PORT

MUST BE OPEN AND SERVICE PORT

CORE REMOVED TO ALLOW EXIT

POINT FOR NITROGEN FLOW

LIQUID LINE

WATER SATURATED

PREPARATION FOR NEXT STEP

After all connections have been brazed, disconnect manifold gauge set from service ports. Apply additional water saturated cloths to both services

valves to cool piping. Once piping is cool, remove all water saturated cloths. Refer to the unit installation instructions for the next step in preparing the unit.

CLOTHS

Figure 9. Brazing Procedures (Continued)

506587−01

Page 14

Flushing Line Set and Indoor Coil

TYPICAL EXISTING FIXED ORIFICE

DISTRIBUTOR

ASSEMBLY

A On fully cased coils, remove the coil access and plumbing panels. B Remove any shipping clamps holding the liquid line and distributor as-

sembly.

C Using two wrenches, disconnect liquid line from liquid line orifice hous-

ing. Take care not to twist or damage distributor tubes during this process.

D Remove and discard fixed orifice, valve stem assembly if present and

Teflon® washer as illustrated above.

E Use a field−provided fitting to temporary reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

COIL SHOWN)

DISTRIBUTOR TUBES

LIQUID LINE ORIFICE HOUSING

REMOVE AND DISCARD

WHITE TEFLON

(IF PRESENT)

TEFLON® RING

FIXED ORIFICE

SEAL

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

REMOVAL PROCEDURE (UNCASED

BRASS NUT

TWO PIECE PATCH PLATE

(UNCASED COIL ONLY)

CONNECT GAUGES AND EQUIPMENT FOR FLUSHING PROCEDURE

INVERTED HCFC−22 CYLINDER CONTAINS CLEAN HCFC−22 TO BE USED FOR FLUSHING.

VAPOR LINE

SERVICE VALVE

EXISTING

INDOOR

UNIT

LIQUID LINE SERVICE

VALV E

VAPOR

LIQUID

RECOVERY

CYLINDER

A Inverted HCFC−22 cylinder with clean refrigerant to the vapor service

valve.

B HCFC−22 gauge set (low side) to the liquid line valve. C HCFC−22 gauge set center port to inlet on the recovery machine with an

empty recovery tank to the gauge set.

D Connect recovery tank to recovery machines per machine instructions.

OUTDOOR

NEW

UNIT

OPENED

RECOVERY MACHINE

GAUGE

MANIFOLD

LOW HIGH

CLOSED

TANK RETURN

INLET

DISCHARGE

TYPICAL EXISTING EXPANSION VALVE REMOVAL PROCEDURE (UNCASED COIL SHOWN)

ORIFICE

HOUSING

EQUALIZER LINE

STUB END

TEFLOn RING

VAPOR

CHECK

EXPANSION

VALV E

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

LINE

TEFLON

RING

SENSING

LINE

LIQUID

LINE

LIQUID LINE

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER

LINE FITTING

SENSING BULB

A On fully cased coils, remove the coil access and plumbing panels. B Remove any shipping clamps holding the liquid line and distributor

assembly.

C Disconnect the equalizer line from the check expansion valve

equalizer line fitting on the vapor line.

D Remove the vapor line sensing bulb. E Disconnect the liquid line from the check expansion valve at the liquid

line assembly.

F Disconnect the check expansion valve from the liquid line orifice

housing. Take care not to twist or damage distributor tubes during this process.

G Remove and discard check expansion valve and the two Teflon® rings. H Use a field−provided fitting to temporary reconnect the liquid line to the

indoor unit’s liquid line orifice housing.

FLUSHING LINE SET

The line set and indoor unit coil must be flushed with at least the

same amount of clean refrigerant that previously charged the system. Check the charge in the flushing cylinder before proceeding.

A Set the recovery machine for liquid recovery and start the

recovery machine. Open the gauge set valves to allow the recovery machine to pull a vacuum on the existing system line

set and indoor unit coil.

B Invert the cylinder of clean HCFC−22 and open its valve to allow

liquid refrigerant to flow into the system through the vapor line valve. Allow the refrigerant to pass from the cylinder and through the line set and the indoor unit coil before it enters the recovery machine.

C After all of the liquid refrigerant has been recovered, switch the

recovery machine to vapor recovery so that all of the HCFC−22 vapor is recovered. Allow the recovery machine to pull down to 0 the system.

D Close the valve on the inverted HCFC−22 drum and the gauge

set valves. Pump the remaining refrigerant out of the recovery machine and turn the machine off.

Figure 10. Flushing Line Set and Indoor Coil

Page 15

XC21 SERIES

Installing Indoor Expansion Valve

INDOOR EXPANSIOn VALVE INSTALLATIOn

TWO PIECE

PATCH PLATE

(UNCASED

COIL ONLY)

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER LINE

FITTING (SEE

EQUALIZER LINE INSTALLATION FOR FURTHER DETAILS)

(Uncased Coil Shown)

LIQUID LINE

ORIFICE

HOUSING

STUB

END

TEFLON RING

EQUALIZER LINE

VAPOR

CHECK

EXPANSION

VALV E

LIQUID LINE

ASSEMBLY WITH

LINE

TEFLON

RING

SENSING

BRASS NUT

LIQUID LINE

Sensing bulb insulation is required if mounted external to the coil casing. sensing bulb installation for bulb positioning.

EQUALIZER LINE INSTALLATIOn

A Remove and discard either the flare seal cap or flare nut

with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right.

B Remove and discard either the flare seal cap or flare nut

with copper flare seal bonnet from the equalizer line port on the vapor line as illustrated in the figure to the right.

LINE

A Remove the field−provided fitting that temporary

reconnected the liquid line to the indoor unit’s distributor assembly.

B Install one of the provided Teflon® rings around the

stubbed end of the check expansion valve and lightly lubricate the connector threads and expose surface of the Teflon

ring with refrigerant oil.

C Attach the stubbed end of the check expansion valve to

the liquid line orifice housing. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above, or 20 ft−lb.

D Place the remaining Teflon

washer around the other end of the check expansion valve. Lightly lubricate connector threads and expose surface of the Teflon ring with refrigerant oil.

E Attach the liquid line assembly to the check expansion

valve. Finger tighten and use an appropriately sized wrench to turn an additional 1/2 turn clockwise as illustrated in the figure above or 20 ft−lb.

SENSING BULB INSTALLATIOn

A Attach the vapor line sensing bulb in the proper

orientation as illustrated to the right using the clamp and screws provided.

NOTE  Confirm proper thermal contact between vapor line and check expansion bulb before insulating the sensing bulb once installed.

B Connect the equalizer line from the check expansion

valve to the equalizer vapor port on the vapor line. Finger tighten the flare nut plus 1/8 turn (7 ft−lbs) as illustrated below.

VAPOR LINE

BULB

ON LINES SMALLER THAN 7/8", MOUNT SENSING BULB AT EITHER THE 3 OR 9 O’CLOCK POSITION.

BULB

1/2 Turn

1/8 Turn

FLARE SEAL CAP

506587−01

FLARE NUT

COPPER FLARE SEAL BONNET

MALE BRASS EQUALIZER LINE FITTING

VAPOR LINE

BULB

NOTE  NEVER MOUNT ON BOTTOM OF LINE.

Figure 11. Installing Indoor Expansion Valve

Page 16

ON 7/8" AND LARGER LINES, MOUNT SENSING BULB AT EITHER THE 4 OR 8 O’CLOCK POSITION. NEVER MOUNT ON BOTTOM OF LINE.

BULB

IMPORTANT

Leak Test Line Set and Indoor Coil

The Environmental Protection Agency (EPA) prohibits the intentional venting of HFC refrigerants during maintenance, service, repair and disposal of appliance. Approved methods of recovery, recycling or reclaiming must be followed.

IMPORTANT

If this unit is being matched with an approved line set or indoor unit coil which was previously charged with mineral oil, or if it is being matched with a coil which was manufactured before January of 1999, the coil and line set must be flushed prior to installation. Take care to empty all existing traps. Polyol ester (POE) oils are used in Lennox units charged with HFC−410A refrigerant. Residual mineral oil can act as an insulator, preventing proper heat transfer. It can also clog the expansion device, and reduce the system performance and capacity. Failure to properly flush the system per the instructions below will void the warranty.

CONNECT GAUGE SET

A Connect an HFC−410A manifold gauge set high pressure

hose to the vapor valve service port.

NOTE  Normally, the high pressure hose is connected to the liquid line port. However, connecting it to the vapor port better protects the manifold gauge set from high pressure damage.

B With both manifold valves closed, connect the cylinder of

HFC−410A refrigerant to the center port of the manifold gauge set.

NOTE  Later in the procedure, the HFC−410A container will be replaced by the nitrogen container.

IMPORTANT

Leak detector must be capable of sensing HFC refrigerant.

WARNING

When using a high pressure gas such as dry nitrogen to pressurize a refrigeration or air conditioning system, use a regulator that can control the pressure down to 1 or 2 psig (6.9 to 13.8 kPa).

WARNING

Refrigerant can be harmful if it is inhaled. Refrigerant must be used and recovered responsibly.

Failure to follow this warning may result in personal injury or death.

HIGHLOW

MANIFOLD GAUGE SET

OUTDOOR UNIT

TO VAPOR

SERVICE VALVE

NITROGEN

HFC−410A

TEST FOR LEAKS

After the line set has been connected to the indoor and outdoor units, check the line set connections and indoor unit for leaks. Use the

following procedure to test for leaks:

A With both manifold valves closed, connect the cylinder of HFC−410A refrigerant to the center port of the manifold gauge set. Open the valve

on the HFC−410A cylinder (vapor only).

B Open the high pressure side of the manifold to allow HFC−410A into the line set and indoor unit. Weigh in a trace amount of HFC−410A. [A

trace amount is a maximum of two ounces (57 g) refrigerant or three pounds (31 kPa) pressure]. Close the valve on the HFC−410A cylinder

and the valve on the high pressure side of the manifold gauge set. Disconnect the HFC−410A cylinder.

C Connect a cylinder of dry nitrogen with a pressure regulating valve to the center port of the manifold gauge set.

D Adjust dry nitrogen pressure to 150 psig (1034 kPa). Open the valve on the high side of the manifold gauge set in order to pressurize the line set

and the indoor unit.

E After a few minutes, open one of the service valve ports and verify that the refrigerant added to the system earlier is measurable with a leak

detector.

F After leak testing disconnect gauges from service ports.

Figure 12. System Leak Test

Page 17

XC21 SERIES

Evacuating Line Set and Indoor Coil

CONNECT GAUGE SET

NOTE  Remove cores from service valves (if not already done).

A Connect low side of manifold gauge set

with 1/4 SAE in−line tee to vapor line service valve

B Connect high side of manifold gauge

set to liquid line service valve

C Connect micron gauge available

connector on the 1/4 SAE in−line tee.

D Connect the vacuum pump (with

vacuum gauge) to the center port of the manifold gauge set. The center port line will be used later for both the HFC−410A and nitrogen containers.

NITROGEN

HFC−410A

VACUUM PUMP

OUTDOOR

UNIT

A34000 1/4 SAE TEE WITH SWIVEL COUPLER

500

MICRON

GAUGE

GAUGE SET

TO VAPOR

SERVICE VALVE

TO LIQUID LINE SERVICE VALVE

LOW

MANIFOLD

EVACUATE THE SYSTEM

A Open both manifold valves and start the vacuum pump.

B Evacuate the line set and indoor unit to an absolute pressure of 23,000 microns (29.01 inches of mercury).

NOTE  During the early stages of evacuation, it is desirable to close the manifold gauge valve at least once. A rapid rise in pressure indicates a relatively large leak. If this occurs, repeat the leak testing procedure.

NOTE  The term absolute pressure means the total actual pressure within a given volume or system, above the absolute zero of pressure. Absolute pressure in a vacuum is equal to atmospheric pressure minus vacuum pressure.

C When the absolute pressure reaches 23,000 microns (29.01 inches of mercury), perform the following:

S Close manifold gauge valves S Close valve on vacuum pump S Turn off vacuum pump S Disconnect manifold gauge center port hose from vacuum pump S Attach manifold center port hose to a dry nitrogen cylinder with pressure regulator set to 150 psig (1034 kPa) and purge the hose. S Open manifold gauge valves to break the vacuum in the line set and indoor unit. S Close manifold gauge valves.

D Shut off the dry nitrogen cylinder and remove the manifold gauge hose from the cylinder. Open the manifold gauge valves to release the

dry nitrogen from the line set and indoor unit.

E Reconnect the manifold gauge to the vacuum pump, turn the pump on, and continue to evacuate the line set and indoor unit until the

absolute pressure does not rise above 500 microns (29.9 inches of mercury) within a 20−minute period after shutting off the vacuum pump and closing the manifold gauge valves.

F When the absolute pressure requirement above has been met, disconnect the manifold hose from the vacuum pump and connect it to an

upright cylinder of HFC−410A refrigerant. Open the manifold gauge valve 1 to 2 psig in order to release the vacuum in the line set and indoor unit.

G Perform the following:

S Close manifold gauge valves. S Shut off HFC−410A cylinder. S Reinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core

tool while maintaining a positive system pressure.

S Replace stem caps and secure finger tight, then tighten an additional one−sixth (1/6) of a turn as illustrated.

RECOMMEND

MINIMUM 3/8" HOSE

1/6 TURN

HIGH

506587−01

Figure 13. Evacuating System

Page 18

IMPORTANT

Use a thermocouple or thermistor electronic vacuum gauge that is calibrated in microns. Use an instrument capable of accurately measuring down to 50 microns.

WARNING

Danger of Equipment Damage. Avoid deep vacuum operation. Do not use compressors to evacuate a system. Extremely low vacuums can cause internal arcing and compressor failure. Damage caused by deep vacuum operation will void warranty.

Evacuating the system of non−condensables is critical for proper operation of the unit. Non−condensables are

defined as any gas that will not condense under temperatures and pressures present during operation of an air conditioning system. Non−condensables and water suction combine with refrigerant to produce substances that corrode copper piping and compressor parts.

Electrical

In the U.S.A., wiring must conform with current local codes and the current National Electric Code (NEC). In Canada, wiring must conform with current local codes and the current Canadian Electrical Code (CEC).

Refer to the furnace or blower coil installation instructions for additional wiring application diagrams and refer to unit nameplate for minimum circuit ampacity and maximum overcurrent protection size.

24VAC TRANSFORMER

Use the transformer provided with the furnace or air handler for low-voltage control power (24VAC − 40 VA minimum)

SIZE CIRCUIT AND INSTALL DISCOnNECT SWITCH

Refer to the unit nameplate for minimum circuit ampacity, and maximum fuse or circuit breaker (HACR per NEC). Install power wiring and properly sized disconnect switch.

SERVICE

DISCONNECT

SWITCH

NOTE  Units are approved for use only with copper conductors. Ground unit at disconnect switch or to an earth ground.

WARNING

Electric Shock Hazard. Can cause injury or death. Unit must be grounded in accordance with national and local codes.

INSTALL THERMOSTAT

Install room thermostat (ordered separately) on an inside wall

approximately in the center of the conditioned area and 5 feet (1.5m) from the floor. It should not be installed on an outside wall or where it can be affected by sunlight or drafts.

THERMOSTAT

5 FEET

(1.5M)

NOTE  24VAC, Class II circuit connections are made in the control box.

CAUTION

ELECTROSTATIC DISCHARGE

(ESD)

Precautions and Procedures

Page 19

XC21 SERIES

A. ROUTE COnTROL WIRES  NOn−COMMUNICATING

Install low voltage control wiring from outdoor to indoor unit and from

thermostat to indoor unit.

A Run 24VAC control wires through hole with grommet.

B Make 24VAC control wire connections to heat pump control (A175) .

NOTE  Do not bundle any excess 24VAC control wires inside control box.

NOTE  Wire tie provides low voltage wire strain relief and to maintain

separation of field installed low and high voltage circuits.

NOTE  For proper voltages, select control wires gauge per table below.

WIRE RUN LENGTH AWG# INSULATION TYPE

LESS THAN 100’ (30 METERS) 18 TEMPERATURE RATING

MORE THAN 100’ (30 METERS) 16 35ºC MINIMUM.

CONTROL (A175)

B. ROUTE COnTROL WIRES  COMMUNICATING

Maximum length of wiring (18 gauge) for all connections on the RSBus is limited to 1500 feet (457 meters). Color−coded, temperature rating 95ºF (35ºC) minimum, solid core. (Class II Rated Wiring)

HEAT PUMP

HOLE

COnTROL BOX

ROUTE HIGH VOLTAGE AND GROUND WIRES

Any excess high voltage field wiring should be trimmed and secured away from any low voltage field wiring. To facilitate a conduit, a

cutout is located in the bottom of the control box. Connect conduit to the control box using a proper conduit fitting.

HIGH VOLTAGE

CONDUIT HOLE

WATERTIGHT

CONDUIT

FITTING

WATERTIGHT

FLEXIBLE CONDUIT

TO SERVICE

DISCONNECT BOX

PIPING PANEL

GROUND LUG

CONTACTOR

COnTROL BOX

ELECTRICAL INLET

(HIGH VOLTAGE)

WIRING ENTRY POINTS

ELECTRICAL INLET (CONTROL WIRING  LOW VOLTAGE). USE BUSHING PROVIDED IN BAG ASSEMBLY HERE.

ACCESS VIEW

506587−01

Page 20

Figure 14. Typical XC21 Wiring

Page 21

XC21 SERIES

Air Conditioner Control (A175) Jumpers and Terminals

AIR COnDITIOnER COnTROL − TWO−STAGE

Table 3 provides additional information concerning jumpers, links, and connections for the air conditioner control.

FIELD TEST

PINS (E33)

DS11 and DS14

LED ALERT CODES

DS13 and DS15

LED ALERT CODES

DS12

COMMUNICATING

STATUS INDICATOR

FOR HUMIDITROL (EDA) APPLICATION (TWO−STAGE UNITS

ONLY)

Figure 15. Air Conditioner Control

Table 3. Air Conditioner Control Jumpers and

Terminals

Board ID Label Description

E12 PSC Fan 240 VAC output connection for outdoor fan.

E16 PSC Fan 240 VAC input connection for outdoor fan.

W 24VAC output for defros t auxiliary heat output.

L Thermostat service light connection.

E18

E21 and E22 LO−PS

E31 and E32 Y1 OUT

E24 and E25 HS−PS

E26 Y1 FAN

E27 Y2 FAN

E28 FAN C ECM common connection for ECM fan.

E30

E33 Field Test

E34

DS Humiditrol Input

C 24VAC system common

i−

R 24VAC system power input

Six position square pin header E30 provides connections for the temperature sensors.

DIS (YELLOW) PINS 5 and 6 (RT28)

AMB (BLACK) Pins 3 and 4 (RT13)

COIL (BROWN) Pins 1 and 2

Y2 Solenoid

Short DS To R

24VAC thermostat input/output for second stage operation of the unit.

24VAC thermostat input for first stage operation of the unit.

24VAC thermostat input for reversing valve operation

Input/Output − RSBus data low. Used in communicating mode only with compatible indoor thermostat.

Input/Output − RSBus data high. Used in communicating mode only with compatible indoor thermostat.

S4 connection for low−pressure switch (2.4 milliamps @ 18VAC)

24VAC common output, switched for enabling compressor contactor.

S87 connection for high−pressure switch (E25) and 24VAC (E24) to A177 R" input.

First Stage and second stage basic and precision dehumidification ECM fan motor 24VDC output connection 1.

Second stage basic and precision dehumidification ECM fan motor 24VDC output connection 2.

DIS 5  Discharge line temperature sensor supply.

DIS 6

 Discharge line temperature sensor return.

Range is 35ºF to 310ºF. Sensor is clipped on a 1/2" copper tube.

AMB 3  Outdoor ambient temperature sensor supply.

AMB 4  Outdoor ambient temperature return. Range is 40ºF to +140ºF

Not Used.

This jumper allows service personnel to defeat the timed off control, initiate or terminate a defrost and field programming of unit capacity feature.

Second−stage compressor output.

Cut for Humiditrol (EDA) application. This sets the outdoor fan speed to predefined speed. See table 11 for set speed based on unit capacity size. Use only in two−stage units.

506587−01

Page 22

Field Control Wiring

The following two illustrations provide examples on how to install control wiring using a non−communicating thermostat. For

examples of how to install control wiring in complete or partial communicating systems, see the icomfort Touch

thermostat

Quick Start Guide which is provided with the thermostat.

Air Handler

ComfortSense[ 7000 Thermostats

Catalog # Y0349 or Y2081

On−board link

Low voltage thermostat wiring

Flat metal jumper

XC21 Two−Stage

Air Conditioner Control

1. Thermostat T terminals are used for outdoor sensor input. Use for thermostat’s outdoor temperature display (optional).

2. R to L connection is required for this model when using the ComfortSense

required and ordered separately.

3. Air handler control ships from factory with metal jumpers installed across W1, W2 and W3. For one−stage electric heat, do not remove factory

installed metal jumpers.

4. Air handler control ships from factory with metal jumpers installed across W1, W2 and W3. For two−stage electric heat, remove factory installed metal jumper between W1 to W2. Then connect thermostat wire between the air handler control’s W2 and the thermostat’s W2 terminal.

5. Cut on−board link (clippable wire) from Y1−Y2 2 STAGE COMPR for two−stage compressor and two−speed fan operation.

6. Cut loop jumper (clippable wire) DS to R on two−stage units for Humiditrol® applications. This will slow the outdoor unit’s fan speed to a specific RPM. A wire must be installed between the DS terminals on the air handler and outdoor unit controls. See table 11 for fan speed based on unit capacity.

7. Cut on−board link (clippable wire) DS−R for Humiditrol setting. See air handler installation instruction or engineering handbook for lowest fan speed information.

7000 − catalog number Y0349 only. Resistor Kit (catalog number 47W97)

or Harmony IIIt applications. This will slow the indoor blower motor to the lowest speed

Figure 16. ComfortSense® 7000 Series Thermostat  Air Hander/Two−Stage Air Conditioner

Page 23

XC21 SERIES

XC21 Two−Stage Air

Conditioner Control

Furnace

ComfortSense[ 7000 Thermostats

Catalog # Y0349 or Y2081

On−board link

Low voltage thermostat wiring

1. Thermostat T terminals are used for outdoor sensor input. Use for thermostat’s outdoor temperature display (optional).

2. R to L connection is required for this model when using the ComfortSense

47W97) required and ordered separately.

3. Cut on−board link W915 (clippable wire) for two−stage operation.

4. Cut loop jumper (clippable wire) DS to R on two−stage units for Humiditrol® applications. This will slow the outdoor unit’s fan speed to a specific RPM. A wire must be installed between the DS terminals on the furnace and outdoor unit controls. See table 11 for fan speed based on unit capacity.

5. Cut on−board link (clippable wire) DS−R for Humiditrol

setting. See furnace installation instruction or engineering handbook for lowest fan speed information.

or Harmony IIIt applications. This will slow the indoor blower motor to the lowest speed

7000 − catalog number Y0349 only. Resistor Kit (catalog number

Figure 17. ComfortSense® 7000 Series Thermostat  Furnace/Two−Stage Air Conditioner

506587−01

Page 24

Servicing Units Delivered Void of Charge

If the outdoor unit is void of refrigerant, clean the system using the procedure described below.

1. Leak check system using procedure outlined on page

17.

2. Evacuate the system using procedure outlined on page 18.

3. Use nitrogen to break the vacuum and install a new filter drier in the system.

4. Evacuate the system again using procedure outlined on page 18.

5. Weigh in refrigerant using procedure outlined in figure

21.

6. Monitor the system to determine the amount of moisture remaining in the oil. It may be necessary to replace the filter drier several times to achieve the required dryness level. If system dryness is not

verified, the compressor will fail in the future.

Unit Start−Up

3. After evacuation is complete, open both the liquid and vapor line service valves to release the refrigerant charge contained in outdoor unit into the system.

4. Replace the stem caps and tighten to the value listed in table 1.

5. Check voltage supply at the disconnect switch. The voltage must be within the range listed on the unit’s nameplate. If not, do not start the equipment until you have consulted with the power company and the voltage condition has been corrected.

6. Set the thermostat for a cooling demand. Turn on power to the indoor indoor unit and close the outdoor unit disconnect switch to start the unit.

7. Recheck voltage while the unit is running. Power must be within range shown on the nameplate.

8. Check system for sufficient refrigerant by using the procedures listed under System Refrigerant.

System Refrigerant

This section outlines procedures for:

IMPORTANT

If unit is equipped with a crankcase heater, it should be energized 24 hours before unit start−up to prevent compressor damage as a result of slugging.

1. Rotate fan to check for binding.

2. Inspect all factory− and field−installed wiring for loose connections.

GAUGE SET

COnNECTIOnS FOR TESTING AND CHARGING

SUCTION LINE

SERVICE PORT CONNECTION

LIQUID PHASE

REFRIGERANT TANK

CHARGE IN

DIGITAL SCALE

1. Connecting gauge set for testing and charging (see figure 18.

2. Checking and adjusting indoor airflow as described in figure 19.

3. Adding or removing refrigerant. Use figure 20 to determine the best method for charging the system. When using weigh in method use procedure provided in figure 21, and verifying charge using methods described in figures 22 or 23.

LOW

HIGH

MANIFOLD GAUGE SET

OUTDOOR UNIT

VAPOR LINE

SERVICE VALVE

TEMPERATURE

SENSOR

AClose manifold gauge set valves and connect the center hose to a cylinder of HFC−410A. Set for liquid phase charging.

BConnect the manifold gauge set’s low pressure side to the suction line service port.

CConnect the manifold gauge set’s high pressure side to the liquid line service port.

DPosition temperature sensor on liquid line near liquid line service port.

Figure 18. Gauge Set Setup and Connections

LINE SERVICE

Page 25

TO LIQUID

VALV E

TEMPERATURE SENSOR

(LIQUID LINE)

LIQUID LINE

SERVICE VALVE

XC21 SERIES

ADDING OR REMOVING REFRIGERANT

This system uses HFC−410A refrigerant which operates at much higher pressures than HCFC−22. The pre−installed liquid line filter drier is approved for use with HFC−410A only. Do not replace it with components designed for use with HCFC−22. This unit is NOT approved for use with coils which use capillary tubes or fixed orifices as a refrigerant metering device.

Check airflow using the Delta−T (

DT) process using the illustration in figure 19.

AIRFLOW

DRY

BULB

53º

All temperatures are expressed in ºF

DROP

19º

INDOOR COIL

TEMPERATURE OF AIR ENTERING INDOOR COIL ºF

WET−BULB ºF

80 24 24 24 23 23 22 22 22 20 19 18 17 16 15 78 23 23 23 22 22 21 21 20 19 18 17 16 15 14 76 22 22 22 21 21 20 19 19 18 17 16 15 14 13 74 21 21 21 20 19 19 18 17 16 16 15 14 13 12

DRY−BULB

72 20 20 19 18 17 17 16 15 15 14 13 12 11 10 70 19 19 18 18 17 17 16 15 15 14 13 12 11 10

57 58 59 60 61 62 63 64 65 66 67 68 69 70

AIR FLOWAIR FLOW

64º

INDOOR COIL

WET BULB

72º

DRY BULB

Use the following procedure to adjust for optimal air flow across the indoor coil:

1. Determine the desired DT  Measure entering air temperature using dry bulb (A) and wet bulb (B). DT is the intersecting value of A and B in the

table (see triangle).

2. Find temperature drop across coil  Measure the coil’s dry bulb entering and leaving air temperatures (A and C). Temperature Drop Formula:

) = A minus C.

Drop

3. Determine if fan needs adjustment  If the difference between the measured T

is needed. See example below:

ASSUME DT = 15 AND A TEMP. = 72º, THESE C TEMPERATURES WOULD NECESSITATE STATED ACTIONS:

Cº T

53º 19 – 15 = 4 INCREASE THE AIRFLOW 58º 14 – 15 = −1 (WITHIN +3º RANGE) NO CHANGE 62º 10 – 15 = −5 DECREASE THE AIRFLOW

4. ADJUST THE FAN SPEED  See indoor unit instructions to increase/decrease fan speed.

– DT = ºF ACTION

DROP

Changing air flow affects all temperatures; recheck temperatures to confirm that the temperature drop and DT are within +3º.

and the desired DT (T

Drop

–DT) is within +3º, no adjustment

Drop

Figure 19. Checking Indoor Airflow over Evaporator Coil using Delta−T Chart

506587−01

Page 26

Use WEIGH IN to initially charge a system when the outdoor unit is void of charge. To verify charge and add or

remove refrigerant use either

APPROACH or SUBCOOLING methods.

START: Determine the correct charge method:

TXV

WHEN TO CHARGE?

S Warm weather best S Can charge in colder weather

CHARGE METHOD? Determine by:

S Outdoor ambient temperature

REQUIREMENTS:

65ºF (18.3ºC)

AND ABOVE

64ºF (17.7ºC) AND BELOW

S Sufficient heat load in structure S Indoor temperature between 70-80ºF (21−26ºC) S Manifold gauge set connected to unit S Thermometers:

− to measure outdoor ambient temperature

APPROACH OR

SUBCOOLING

WEIGH-IN

Figure 20. Determining Charge Method

WEIGH IN

If the system is void of refrigerant, first, locate and repair any leaks and then weigh in the refrigerant charge into the unit. To calculate the total refrigerant charge:

Amount specified on

nameplate

CHARGING METHOD

Adjust amount. for variation in line set

length listed on line set length table below.

+ =

− to measure liquid line temperature

− to measure suction line temperature

Total Charge

Refrigerant Charge per Line Set Length

LIQUID LINE SET DIAMETER

3/8" (9.5 MM)

*If line length is greater than 15 ft. (4.6 m), add this amount. If line length is less than 15 ft. (4.6 m), subtract this amount.

NOTE  The above nameplate is for illustration purposes only. Go to actual nameplate on outdoor unit for charge information.

OUNCES PER 5 FEET (G PER 1.5 M) ADJUST FROM 15 FEET (4.6 M)

3 OUNCE PER 5’ (85 G PER 1.5 M)

LINE SET*

Figure 21. Using HFC−410A Weigh In Method

Page 27

XC21 SERIES

1. Confirm proper airflow across coil using figure 19.

APPROACH

TEST AND CHARGE METHOD

65ºF (18.3ºC) AND ABOVE

If refrigerant added or removed, retest to confirm that unit is properly charged

If value is greater than shown (high approach), add refrigerant; if less than shown (liquid temp too close to ambient temp, low approach), remove refrigerant.

APPº (APPROACH) VALUES(F:+/−1.0° [C: +/−0.6°])*

Models ºF (ºC)* −024 −036 −048 −060 Any 3.5 (1.9) 6.0(3.3) 6.0 (3.3) 13.0 (7.2) *Temperature of air entering outdoor coil

Figure 22. Using Approach Test and Charge Method

2. Compare unit pressures with table 4, Normal Operating Pressures.

3. Use APPROACH to correctly charge unit or to verify the charge is correct.

4. Set thermostat to call for heat (must have a cooling load between 70-80ºF (21−26ºC).

5. Connect gauge set.

6. When heat demand is satisfied, set thermostat to call for cooling.

7. Allow temperatures and pressures to stabilize.

8. Record outdoor ambient temperature:

AMBº =_________

9. Record line temperature:

LIQº = __________

10. Subtract to determine approach (APPº):

LIQº_____ − AMBº _____ = APPº_____

11. Compare results with table to the left.

SUBCOOLING

TEST AND CHARGE METHOD

65ºF (18.3ºC) AND ABOVE

BLOCK OUTDOOR COIL: [sometimes necessary with lower temperatures] Use cardboard or plastic sheet to restrict the airflow through the outdoor coil to achieve pressures from 325−375 psig (2240−2585 kPa). Higher pressures are needed to check charge. Block equal

CARDBOARD OR

PLASTIC SHEET

If refrigerant added or removed, verify charge using the approach method

If value is greater than shown, remove refrigerant; if less than shown, add refrigerant

SCº (Subcooling) Values (F:+/−1.0° [C: +/−0.6°])

ºF (ºC)* −024 −036 −048 −060 Any 4.0 (2.2) 2.5 (1.4) 4.0 (2.2) 3.0 (1.7) *Temperature of air entering outdoor coil

sections of air intake panels and move coverings sideways until the liquid pressure is in the above noted ranges.

Models

1. Confirm proper airflow across coil using figure 19.

2. Compare unit pressures with table 4, Normal Operating Pressures.

3. Use SUBCOOLING to correctly charge unit or to verify the charge is correct.

4. Set thermostat to call for heat (must have a cooling load between 70-80ºF (21−26ºC)

5. Connect gauge set

6. Measure outdoor ambient temperature

7. When heat demand is satisfied, set thermostat to call for cooling

8. Allow temperatures and pressures to stabilize.

NOTE − If necessary, block outdoor coil to maintain 325 − 375 psig.

9. Record liquid line temperature:

LIQº = ______

10. Measure liquid line pressure and use the value to determine saturation temperature (see table 5):

SATº = ______

11. Subtract to determine subcooling (SCº):

SATº_____ − LIQº _____ = SCº _____

12. Compare results with table to the left.

Figure 23. Using Subcooling Test and Charge Method

506587−01

Page 28

Operating and Temperature Pressures

Minor variations in these pressures may be expected due to differences in installations. Significant differences could mean that the system is not properly charged or that a problem exists with some component in the system.

Table 4. Normal Operating Pressures (Liquid +10 and Suction +5 psig)*

Use this table to perform maintenance checks; it is not a procedure for charging the

IMPORTANT

XC21 −024 −036 −048 −060

5F (5C)** Liquid Vapor Liquid Vapor Liquid Vapor Liquid Vapor

65 (18.3)

75 (23.9)

85 (29.4)

95 (35.0)

105 (40.6)

115 (46.1)

65 (18.3)

75 (23.9)

85 (29.4)

95 (35.0)

105 (40.6)

115 (46.1)

* Typical pressures only, expressed in psig (liquid +/− 10 and vapor+/− 5 psig); indoor match up, indoor air quality, and indoor load will cause the pressures to vary. These operating pressures are also listed on the unit charging sticker (401104S) located on the unit access panel. ** Temperature of air entering outdoor coil.

209 144 211 142 215 140 229 134 242 145 244 144 250 142 264 137 281 146 285 146 288 144 306 140 324 148 330 149 338 146 353 144 372 151 380 151 387 149 405 146 426 152 436 154 459 152 468 146

213 138 214 137 217 124 238 130 245 142 247 140 251 133 276 133 285 142 288 141 289 138 317 135 329 144 330 143 336 141 368 139 376 147 384 145 385 144 420 141 432 151 445 148 437 146 478 143

system. Minor variations in these pressures may be due to differences in installations. Significant deviations could mean that the system is not properly charged or that a problem exists with some component in the system.

First Stage (Low Capacity)

Second Stage (High Capacity)

Table 5. HFC−410A Temperature (°F) − Pressure (Psig)

°F °C Psig °F °C Psig

−40 −40.0 11.6 60 15.6 170

−35 −37.2 14.9 65 18.3 185

−30 −34.4 18.5 70 21.1 201

−25 −31.7 22.5 75 23.9 217

−20 −28.9 26.9 80 26.7 235

−15 −26.1 31.7 85 29.4 254

−10 −23.3 36.8 90 32.2 274

−5 −20.6 42.5 95 35.0 295 0 −17.8 48.6 100 37.8 317 5 −15.0 55.2 105 40.6 340

10 −12.2 62.3 110 43.3 365 15 −9.4 70.0 115 46.1 391 20 −6.7 78.3 120 48.9 418 25 −3.9 87.3

125 51.7 446 30 −1.1 96.8 130 54.4 476 35 1.7 107 135 57.2 507 40 4.4 118 140 60.0 539 45 7.2 130 50 10.0 142

145 62.8 573

150 65.6 608 55 12.8 155

Page 29

XC21 SERIES

INSTALLING ISOLATION GROMMETS

Locate the isolation grommets (provided). Slide grommets onto vapor and liquid lines. Insert grommets into piping panel to isolate refrigerant lines from sheet metal edges.

SUCTION LINE

LIQUID LINE

TWO ISOLATION GROMMETS ARE PROVIDE FOR THE LIQUID AND SUCTION LINE PIPE PANEL PASS THROUGH.

REAR VIEW OF UNIT EXTERIOR

PIPING PANEL

Figure 24. Isolation Grommets

System Operation

In non−communicating systems the delay is set for 300 seconds (five minutes) and can not be changed. To override timer when active or inactive, place a jumper on the field test pins between 1 and 2 seconds.

In communicating system, the icomfort Touch® thermostat has a separate built−in 5−minute non−adjustable short cycle protection.

Resetting Anti−Short Cycle Delay

The E33 pins on the air conditioner control can be jumpered between 1 to 2 seconds to reset the anti−short cycle delay sequence.

HIGH (S4) AND LOW (S87) PRESSURE SWITCHES Low Pressure Switch (LO−PS)  See figure 27 for low

pressure switch sequence of operation.

High Pressure Switch (HI−PS)  See figure 28 for high pressure switch sequence of operation.

Pressure Switch Event Settings

The following pressures are the auto reset event value triggers for low and high pressure thresholds:

S High Pressure (auto reset) − trip at 590 psig; reset at

418.

S Low Pressure (auto reset) − trip at 25 psig; reset at 40.

IMPORTANT

Some scroll compressor have internal vacuum protector that will unload scrolls when suction pressure goes below 20 psig. A hissing sound will be heard when the compressor is running unloaded. Protector will reset when low pressure in system is raised above 40 psig. DO NOT REPLACE COMPRESSOR.

The air conditioner control (A175) provides the following system functions:

S Compressor anti−short−cycle delay. S High (S4) and low (S87) pressure switches S Ambient (RT13) and Discharge Line (RT28)

Temperature Sensors Monitoring and Protection.

S Five strikes lockout safety feature for High/Low

Pressure Switches and High Discharge Line Temperature. See figures 27, 28 and 29 feature function.

COMPRESSOR PROTECTION  ANTI−SHORT CYCLE DELAY

The air conditioner control protects the compressor from:

S Short cycling (five minutes) when there is initial power

S Interruption in power to the unit S High or low pressure switch or discharge line sensor

trips

S Delay after Y1 demand is removed.

COMPRESSOR PROTECTION  FIVE−STRIKE LOCKOUT SAFETY FUNCTION

The five−strike lockout safety function is designed to protect the unit’s compressor from damage. The five−strike feature is used for high pressure (S4) and low (S87) pressure switch trips and high discharge temperature (RT28).

Resetting Five−Strike Lockout

Once the condition has been rectified, power to the heat pump control’s R terminal must be cycled OFF, or a jumper placed on the FIELD TEST pins between 1− to 2−seconds to reset the heat pump control.

UNIT SENSORS

Sensors connect to the heat pump control through a field-replaceable harness assembly that plugs into the control. Through the sensors, the control detects outdoor ambient, coil, and discharge temperature fault conditions. As the detected temperature changes, the resistance across the sensor changes. Tables 7 and 8 shows how the resistance varies as the temperature changes for both type of sensors. Sensor resistance values can be checked by ohming across pins listed in table 6.

NOTE  When checking the ohms across a sensor, be aware that a sensor showing a resistance value that is not within the range shown in table 6, may be performing as designed. However, if a shorted or open circuit is detected, then the sensor may be faulty and the sensor harness will need to be replaced.

506587−01

Page 30

High Discharge Line Temperature Sensor (RT28)

Ambient Air

Temperature Sensor

10K resistor

See table 6 for sensor range. The high discharge line temperature sensor (location shown in figure 1 monitors temperature range and open/short conditions. See figure 29 for the high discharge line temperature sensor sequence of operation.

Coil Temperature Sensor

This model does not use a coil temperature sensor. The

High Discharge Line Temperature Sensor

cable assembly attached to the air conditioner control’s E30 connection has a 10K resister installed between pins 5 and 6 as illustrated in figure 25.

SECOND−STAGE OPERATION

Figure 25. 10k Resistor Location

If the control receives a call for second−stage compressor operation Y2 and the first-stage compressor output is

Ambient Temperature Sensor (RT13)

See table 6 for sensor range. If the ambient sensor is detected as being open, shorted or out of the temperature range of the sensor, the control will not perform demand defrost operation. The control will revert to time/temperature defrost operation and will display the appropriate alert code. Heating and cooling operation will be allowed in this fault condition.

active, the second-stage compressor solenoid output will be energized by the air conditioner control system operation function.

NOTE  Figure 14 illustrates the correct Y2 field wiring configuration.

NOTE  The heat pump control system operation monitor has a five second delay between Y2 being powered and the solenoid energizing.

Table 6. Sensor Temperature / Resistance Range

Sensor Temperature Range °F (°C) Resistance values range (ohms)

Outdoor (Ambient) −40ºF to 140ºF (−40ºC to 60ºC) 280,000 to 3750 3 and 4 (Black)

Discharge −35ºF to 310ºF (−37ºC to 154ºC) 41,000 to 103 1 and 2 (Yellow)

Note: Sensor resistance decreases as sensed temperature increases (see tables 7 and 8.

Pins/ Wire Color

E33 JUMPER (TEST) PINS

Placing the JUMPER On the E33 jumper pins (see page 22 for location of E33 jumper pins) allows the technician to

S Clear compressor anti−short cycle delay. S Clear five−strike fault lockouts  High / Low pressure switches and High Discharge Temperature Sensor. S Set the unit capacity code (procedure provided on page 42).

Y1 Active

PLACE A JUMPER ON1 THE E33 PINS FOR LONGER THAN ONE SECOND JUMPER OFF POSITION.

CLEARS ANY SHORT CYCLE LOCKOUT AND FIVE STRIKE FAULT LOCKOUT FUNCTION, IF APPLICABLE. NO OTHER FUNCTIONS WILL BE EXECUTED AND UNIT WILL CONTINUE IN THE MODE IT WAS OPERATING.

NOTES: 1  Placing a JUMPER On the E33 pins will not reset (reboot) the air conditioner control (A175). The only way to reset the outdoor unit is to cycle the

24VAC power to the outdoor unit’s air conditioner control. 2  If the jumper remains on the E33 pins for longer than five seconds, the air conditioner control will ignore the JUMPER On E33 pins and revert to

normal operation.

. THEN REMOVE JUMPER AND PLACE IN

FACTORY DEFAULT

JUMPER SETTING

Figure 26. Multi−Function E33 Jumper (Test) Pin

JUMPER

OFF

JUMPER

Page 31

XC21 SERIES

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

CLOSED

COMPRESSOR

COnTACTOR

ENERGIZED

INITIAL TRIP

SWITCH IS

IGNORED FOR

90 SECOnDS

OPEN

COMPRESSOR

COnTACTOR

DE−ENERGIZED

COMPRESSOR

ANTI−SHORT

CYCLE TIMER

BEGINS

INCREMENT

5−STRIKE

COUNTER

LED ALERT CODE / OR

MODERATE

ALERT 410

DISPLAYED

LOW

PRESSURE

SWITCH (S87)

If 5−strike counter has four or less strikes when Y1 demand is

CLOSED

terminated or satisfied, the strike counter will reset to zero. In a icomfort Touch® thermostat enabled setup, the thermostat will terminate demand when the compressor contactor is de−energized. If demand is satisfied when alarm is not active, the 5−strike counter will reset.

Lockouts can be reset by either cycling power off to the air conditioner

control’s (A175) R terminal, or placing a jumper on the field test pins (E33) between 1 to 2 seconds.

5−STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

LOCKOUT

SWITCH IS CLOSED OR OUTDOOR

AMBIENT TEMPERATURE IS 15ºF

OR BELOW

REQUIRED

506587−01

SERVICE

OPEN

ANTI−SHORT

CYCLE TIMER

ENDS

COMPRESSOR

COnTACTOR

ENERGIZED

LOW

PRESSURE

SWITCH (S87)

WAITING FOR

PRESSURE SWITCH TO

LED ALERT CODE / OR

CRITICAL

ALERT 411

SERVICE

REQUIRED

DISPLAYED

LED ALERT

CODE / OR

CLOSED

MODERATE

ALERT 410

DISPLAYED

CLOSED

Figure 27. Low Pressure (S87) Switch Operation

Page 32

NORMAL

OPERATIOn

Y1 DEMAND

HIGH

PRESSURE

SWITCH (S4)

OPEN

CLOSED

HIGH

PRESSURE

SWITCH (S4)

COMPRESSOR

COnTACTOR ENERGIZED

CLOSED

OPEN

COMPRESSOR

COnTACTOR

DE−ENERGIZED

COMPRESSOR

ANTI−SHORT

CYCLE TIMER

BEGINS

INCREMENT

5−STRIKE

COUNTER

LED ALERT CODE / OR

MODERATE

ALERT 412

DISPLAYED

ANTI−SHORT

CYCLE TIMER

ENDS

If 5−strike counter has four or less strikes when Y1 demand is terminated or satisfied, the strike counter will reset to zero. In a icomfort Touch thermostat enabled setup, the thermostat will terminate demand when the compressor contactor is de−energized. If demand is satisfied when alarm is not active, the 5−strike counter will reset.

Lockouts can be reset by either cycling power off to the air conditioner

control’s (A175) R terminal, or placing a jumper on the field test pins (E33) between 1 to 2 seconds.

5−STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

HIGH

PRESSURE

SWITCH (S4)

LOCKOUT

LED ALERT

CODE / OR

CRITICAL

ALERT 413

SERVICE

REQUIRED

CLEARED

COMPRESSOR

COnTACTOR

ENERGIZED

HIGH

PRESSURE

SWITCH (S4)

SERVICE

REQUIRED

WAITING FOR

OPEN

PRESSURE SWITCH TO

Figure 28. High Pressure (S4) Switch Operation

CLOSED

LED ALERT CODE / OR

MODERATE

ALERT 412

DISPLAYED

Page 33

NORMAL

OPERATIOn

XC21 SERIES

If temperature is at or above 279ºF.

Y1 DEMAND

OPEN

DISCHARGE

SENSOR

(RT28)*

OPEN

COMPRESSOR

COnTACTOR

DE−ENERGIZED

COMPRESSOR

ANTI−SHORT

CYCLE TIMER

BEGINS

INCREMENT

5−STRIKE

COUNTER

CLOSED

COMPRESSOR

COnTACTOR

ENERGIZED

HIGH

PRESSURE

SWITCH (S4)

If 5−strike counter has four or less strikes when Y1 demand is terminated

CLOSED

or satisfied, the strike counter will reset to zero. In a icomfort Touch thermostat enabled setup, the thermostat will terminate demand when the compressor contactor is de−energized. If demand is satisfied when alarm is not active, the 5−strike counter will reset.

Lockouts can be reset by either cycling power off to the air conditioner

control’s (A175) R terminal, or placing a jumper on the field test pins (E33) between 1 to 2 seconds.

5−STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

DISCHARGE

SENSOR (RT28)

IS AT OR

BELOW 225ºF

LED ALERT

CODE / OR

MODERATE

ALERT 414

DISPLAYED

ANTI−SHORT

CYCLE TIMER

ENDS

YES

COMPRESSOR

COnTACTOR

ENERGIZED

WAITING FOR

TEMPERATURE

DROP TO OR

BELOW 225ºF

DISCHARGE

SENSOR (RT28)

LOCKOUT

LED ALERT

CODE / OR

CRITICAL

ALERT 415

CLEARED

LED ALERT CODE / OR

MODERATE

ALERT 414

CLEARED

SERVICE

REQUIRED

NORMAL

OPERATIOn

Figure 29. High Discharge Temperature (RT28) Sensor Operation

506587−01

Page 34

Table 7. Ambient Sensor (RT13) Temperature / Resistance Range

Degrees

Fahrenheit

136.3 2680 56.8 16657 21.6 44154 −11.3 123152

133.1 2859 56.0 16973 21.0 44851 −11.9 125787

130.1 3040 55.3 17293 20.5 45560 −12.6 128508

127.3 3223 54.6 17616 20.0 46281 −13.2 131320

124.7 3407 53.9 17942 19.4 47014 −13.9 134227

122.1 3592 53.2 18273 18.9 47759 −14.5 137234

119.7 3779 52.5 18607 18.4 48517 −15.2 140347

117.5 3968 51.9 18945 17.8 49289 −15.9 143571

115.3 4159 51.2 19287 17.3 50074 −16.5 146913

113.2 4351 50.5 19633 16.8 50873 −17.2 150378

111.2 4544 49.9 19982 16.3 51686 −17.9 153974

109.3 4740 49.2 20336 15.7 52514 −18.6 157708

107.4 4937 48.5 20695 15.2 53356 −19.3 161588

105.6 5136 47.9 21057 14.7 54215 −20.1 165624

103.9 5336 47.3 21424 14.1 55089 −20.8 169824

102.3 5539 46.6 21795 13.6 55979 −21.5 174200

100.6 5743 46.0 22171 13.1 56887 −22.3 178762

99.1 5949 45.4 22551 12.5 57811 −23.0 183522

97.6 6157 44.7 22936 12.0 58754 −23.8 188493

96.1 6367 44.1 23326 11.5 59715 −24.6 193691

94.7 6578 43.5 23720 11.0 60694 −25.4 199130

93.3 6792 42.9 24120 10.4 61693 −26.2 204829

92.0 7007 42.3 24525 9.9 62712 −27.0 210805

90.6 7225 41.7 24934 9.3 63752 −27.8 217080

89.4 7444 41.1 25349 8.8 64812 −28.7 223677

88.1 7666 40.5 25769 8.3 65895 −29.5 230621

86.9 7890 39.9 26195 7.7 67000 −30.4 237941

85.7 8115 39.3 26626 7.2 68128 −31.3 245667

84.5 8343 38.7 27063 6.7 69281 −32.2 253834

83.4 8573 38.1 27505 6.1 70458 −33.2 262482

82.3 8806 37.5 27954 5.6 71661 −34.1 271655

81.2 9040 37.0 28408 5.0 72890 −35.1 281400

80.1 9277 36.4 28868 4.5 74147 −36.1 291774

79.0 9516 35.8 29335 3.9 75431 −37.1 302840

78.0 9757 35.2 29808 3.4 76745 −38.2 314669

77.0 10001 34.7 30288 2.8 78090 −39.2 327343

76.0 10247 34.1 30774 2.3 79465

75.0 10496 33.5 31267 1.7 80873

74.1 10747 33.0 31766 1.2 82314

73.1 11000 32.4 32273 0.6 83790

72.2 11256 31.9 32787 0.0 85302

71.3 11515 31.3 33309 −0.5 86852

70.4 11776 30.7 33837 −1.1 88440

69.5 12040 30.2 34374 −1.7 90068

68.6 12306 29.6 34918 −2.2 91738

67.7 12575 29.1 35471 −2.8 93452

66.9 12847 28.6 36031 −3.4 95211

66.0 13122 28.0 36600 −4.0 97016

65.2 13400 27.5 37177 −4.6 98870

64.4 13681 26.9 37764 −5.2 100775

63.6 13964 26.4 38359 −5.7 102733

62.8 14251 25.8 38963 −6.3 104746

62.0 14540 25.3 39577 −6.9 106817

61.2 14833 24.8 40200 −7.5 108948

60.5 15129 24.2 40833 −8.2 111141

59.7 15428 23.7 41476 −8.8 113400

59.0 15730 23.2 42130 −9.4 115727

58.2 16036 22.6 42794 −10.0 118126

57.5 16345 22.1 43468 −10.6 120600

Resistance

Degrees

Fahrenheit

Resistance

Degrees

Fahrenheit

Resistance

Degrees

Fahrenheit

Resistance

Page 35

XC21 SERIES

Table 8. High Discharge (RT28) Sensor Temperature / Resistance Range

Degrees

Fahrenheit

303.1 183 186.1 1052 136.8 2656 94.5 6613

298.1 195 185.0 1072 136.0 2698 93.6 6739

293.4 207 183.9 1093 135.2 2740 92.8 6869

289.0 220 182.8 1114 134.5 2783 92.0 7002

284.8 232 181.8 1135 133.7 2827 91.2 7139

280.9 245 180.7 1157 132.9 2872 90.3 7281

277.1 258 179.6 1179 132.2 2917 89.5 7426

273.6 270 178.6 1201 131.4 2963 88.6 7575

270.2 283 177.6 1223 130.6 3010 87.8 7729

267.0 297 176.6 1245 129.9 3057 86.9 7888

263.9 310 175.5 1268 129.1 3105 86.0 8051

260.9 323 174.6 1291 128.4 3154 85.2 8220

258.1 336 173.6 1315 127.6 3204 84.3 8394

255.3 350 172.6 1338 126.8 3255 83.4 8574

252.7 364 171.6 1362 126.1 3307 82.5 8759

250.1 378 170.6 1386 125.3 3359 81.6 8951

247.7 391 169.7 1411 124.6 3413 80.7 9149

245.3 405 168.7 1435 123.8 3467 79.8 9354

243.0 420 167.8 1460 123.1 3523 78.8 9566

240.8 434 166.9 1486 122.3 3579 77.9 9786

238.6 448 165.9 1511 121.6 3637 76.9 10013

236.5 463 165.0 1537 120.8 3695 76.0 10250

234.4 478 164.1 1563 120.1 3755 75.0 10495

232.4 492 163.2 1590 119.3 3816 74.1 10749

230.5 507 162.3 1617 118.5 3877 73.1 11014

228.6 523 161.4 1644 117.8 3940 72.1 11289

226.7 538 160.5 1672 117.0 4005 71.1 11575

224.9 553 159.7 1699 116.3 4070 70.0 11873

223.2 569 158.8 1728 115.5 4137 69.0 12184

221.5 584 157.9 1756 114.8 4205 68.0 12509

219.8 600 157.1 1785 114.0 4274 66.9 12848

218.1 616 156.2 1815 113.2 4345 65.8 13202

216.5 632 155.3 1845 112.5 4418 64.7 13573

214.9 649 154.5 1875 111.7 4491 63.6 13961

213.4 665 153.6 1905 111.0 4567 62.5 14368

211.9 682 152.8 1936 110.2 4644 61.3 14796

210.4 698 152.0 1968 109.4 4722 60.2 15246

208.9 715 151.1 1999 108.7 4802 59.0 15719

207.5 732 150.3 2032 107.9 4884 57.8 16218

206.0 750 149.5 2064 107.1 4968 56.6 16744

204.6 767 148.7 2098 106.4 5054 55.3 17301

203.3 785 147.9 2131 105.6 5141 54.0 17891

201.9 803 147.1 2165 104.8 5231 52.7 18516

200.6 821 146.2 2200 104.0 5323 51.4 19180

199.3 839 145.4 2235 103.3 5416 50.0 19887

198.0 857 144.6 2270 102.5 5512 48.6 20641

196.8 876 143.8 2306 101.7 5610 47.2 21448

195.5 894 143.0 2343 100.9 5711 45.7 22311

194.3 913 142.3 2380 100.1 5814

193.1 932 141.5 2418 99.3 5920

191.9 952 140.7 2456 98.5 6028

190.7 971 139.9 2495 97.7 6139

189.5 991 139.1 2534 96.9 6253

188.4 1011 138.3 2574 96.1 6370

187.2 1031 137.6 2615 95.3 6489

Resistance

Degrees

Fahrenheit

Resistance

Degrees

Fahrenheit

Resistance

Degrees

Fahrenheit

Resistance

506587−01

Page 36

System Status, Fault and Lockout LED Codes

LED codes are displayed using various LEDs located on the air conditioner control (A175). See figure 15 for location of air conditioner control LEDs.

DS11 AND DS14  SYSTEM STATUS, FAULT AND LOCKOUT LED CODES

DS11 (Green) and DS14 (Red) LEDs indicate non−communicating mode diagnostics conditions that are listed in table 9.

These LEDs display fault conditions in system cooling capacity, dehumidification mode, anti−short cycle lockout, high and low pressures, high discharge line temperature, outdoor ambient temperature, and discharge sensor failures.

DS15 AND DS13  COMPRESSOR FAULT AND LOCKOUT LED CODES

DS15 (Yellow) and DS13 (Red) LEDs indicate non−communicating mode diagnostics conditions that are listed in table 10.

These LEDs display the most common fault conditions in the system. When an abnormal condition is detected, this function communicates the specific condition through system diagnostic LEDs. The function is capable of detecting both mechanical and electrical system problems.

IMPORTANT

DS15 and DS13 compressor LED fault and lockout codes do not provide safety protection. The is a monitoring function only and cannot control or shut down other devices.

RESETTING LED FAULT AND LOCKOUT LED CODES

All LED fault and lockout codes can be reset manually or automatically:

1. Manual Reset

Manual reset can be achieve by one of the following methods:

S Disconnecting R wire from the air conditioner

control’s R terminal.

S Turning the indoor unit off an on again.

Cycle the 24VAC power to air conditioner control off and on. After power up, existing code will display for 60 seconds and then clear.

2. Automatic Reset

After a fault or lockout is detected, the air conditioner control continues to monitor the unit’s system and compressor operations. When/if conditions return to normal, the alert code is turned off automatically.

Page 37

XC21 SERIES

Table 9. System Status, Fault and Lockout LED Codes and Related icomfort Touch® Thermostat Alert Codes

System fault and lockout LED (DS11 / DS14) alarm codes takes precedence over system status LED codes (cooling, heating stages or defrost/dehumidification). Only the latest active LED fault or lockout alarm code if present will be displayed. If no fault or lockout codes are active, then system status LEDs are routinely displayed. See notes 1 and 2 in table below for duration of fast / slow flashes and pause.

Air Conditioner

Control LEDs

DS11

Green

DS14

Red

icomfort Touch

Thermostat

Display

Condition

Possible Cause(s)

SYSTEM STATUS

Solution

Off Off Not applicable Power problem

No power (24V) to control terminals R and C or control failure.

Check control transformer power (24V).

If power is available to control and LED(s) do not light, replace control.

Simultaneous slow flash Not applicable Normal operation Unit operating normally or in standby mode.

Initial power up, safety trip, end of room thermostat

None required (Jumper FIELD TEST pins to override)

demand.

Sensor being detected open or shorted or out of temperature range. control will revert to time/temperature defrost operation. (System will still heat or cool).

This model does not utilize a coil sensor, however this alert indicates either an open or shorted circuit. See if 10K resistor is not damage or missing. Resistor is located in the sensor harness assembly, brown lead.

Indicates that control has internal component failure. Cycle 24 volt power to control. If code does not clear, replace control.

These are codes that show status of operation whether in low stage or high stage, heating or cooling, defrost or in the EDA mode.

Alternating slow flash Not applicable

Simultaneous fast flash

Alternating fast flash

Moderate / Critical

Alert Code 180

Moderate / Critical

Alert Code 417

On On Not applicable

2 fast

flashes

Not applicable Defrost

then pause

1 fast

flashes

Off Not applicable

then pause

2 fast

flashes

Off Not applicable

then pause

5−minute

anti−short−cycle

delay

Ambient sensor

problem

Coil sensor

problem

Air conditioner

control failure

First−stage

compressor

cooling

Second−stage

compressor

cooling

2 fast

flashes

then pause

None None

506587−01

On Not applicable

Moderate Alert

Code 105

Moderate Alert

Code 120

Critical Alert Code

124

Critical Alert Code

125

Moderate / Critical

Alert Code 126

Dehumidification

mode

Device

communication

failure

Unresponsive

device

Active subnet

controller missing

Hardware failure

Internal control communication

failure

These are codes that show status of operation whether in low stage or high stage, heating or cooling, defrost or in the EDA mode.

ALERT STATUS

icomfort Touch® thermostat device is unable to communicate with any other device on the RSBus. Alarm only occurs if a specific device did communicate initially after power up and communication was later lost. Possible causes are lost connection, bus short or open, or other device stop responding.

Message could be sent by any device on RSBus if expected response message is not received from other device. If sent by indoor or outdoor control, device did not get expected response (incorrect or no response at all) from active Subnet controller. If sent by the icomfort Touch® thermostat, and did not get the expected response (incorrect or no response at all) from device. Normally this indicate device malfunction.

Device lost connection to icomfort Touch® thermostat. Thermostat is sending heartbeat message in one minute intervals. Device sets this alarm if no Heartbeat is received for three minutes. Normally this indicate lost connection to thermostat, or thermostat is not working. Alert will clear after valid subnet controller message is received.

Entire or partial system failure. Alert will clear 300 seconds after fault has recovered.

Internal communication on outdoor control. Alert will clear 300 seconds after fault has recovered.

Page 38

Air Conditioner

Control LEDs

DS11

Green

DS14

Red

None None

icomfort Touch

Thermostat

Display

Critical Alert Code

131

Condition

Corrupted control

parameters

Possible

Possible Cause(s)

Cause(s)

Solution

System stored configuration data is corrupted. System will not run. Refer to communicating thermostat for memory corrupt handling.

None None

Off Slow flash

Off On

Slow flash Off

On Off

Slow flash On

Fast flash On

OFF Fast flash

Critical Alert Code

132

Moderate Alert

Code 410

Critical Alert Code

411

Moderate Alert

Code 412

Critical Alert Code

413

Moderate Alert

Code 414

Critical Alert Code

415

Moderate / Critical

Alert Code 417

Failed flash CRC

check.

Low pressure

fault

Low pressure

switch lockout

High pressure

fault

High pressure switch lockout

Discharge line

temperature fault

Discharge line

temperature

lockout

Discharge sensor

fault

No operations, A175 control enters boot loader mode. Alarm will clear after reset.

Restricted air flow over indoor or outdoor coil.

Improper refrigerant charge in system.

Improper metering device installed or incorrect operation of metering device.

Incorrect or

Remove any blockages or restrictions from coils and/or fans. Check indoor and outdoor fan motor for proper current draws.

Check system charge using approach and subcooling temperatures.

Check system operating pressures and compare to unit charging charts.

Make sure all pressure switches and sensors have secure connections to system to prevent refrigerant leaks

or errors in pressure and temperature measurements. improper sensor location or connection to system.

This code detects high discharge temperatures. If the discharge line temperature exceeds a temperature of 279ºF (137ºC) during compressor operation, the control will de−energize the compressor contactor output (and the defrost output if active). The compressor will remain off until the discharge temperature has dropped below 225ºF (107ºC). See figure 29 for further details concerning lockouts and reset procedures.

The A175 control detects open or short sensor or out of temperature sensor range. This fault is detected by allowing the unit to run for 90 seconds before checking sensor resistance. If the sensor resistance is not within range after 90 seconds, the control will raise the alarm.

Simultaneous Fast flash

None

then Pause

Fast simultaneous flashing of DS11, DS13,

Second−stage

heat lock−in

OEM mode Factory Test Mode.

If the unit is in non−communicating mode and it goes to second stage due to ambient temperature being below second stage lock−in setting (E48).

DS14 and DS15

1. Pause duration is two (2) seconds.

2. Fast flash duration is 1/2 second. Slow flash duration is one (1) second.

Page 39

XC21 SERIES

Table 10. Compressor Fault and Lockout LED Codes and Related icomfort Touch® Thermostat Alert Codes

NOTE  See notes 1 and 2 in table below for duration of fast / slow flashes and pause.

Air Conditioner

Control LEDs

DS15

Yellow

Off On

1 flash

then pause

2 flashes

then pause

3 flashes

then pause

DS13

Red

Off

icomfort

Touch

Thermostat

Display

Moderate/

Critical Alert

400

Critical Alert

Code 401

(outdoor

control part#

101798−03)

Moderate

Alert Code

401

(outdoor

control part#

101798−04)

Critical Alert

Code 402

Moderate

Alert Code

403

Condition

Compressor

internal

overload trip

Long run time.

System

pressure trip

Short cycling

Possible Cause(s)

Thermostat demand signal Y1 is present, but compressor not running

Compressor is running extremely long run cycles.

Indicates the compressor protector is open or missing supply power to the compressor.

Compressor is running less than three minutes.

Solution

Compressor protector is open.

S Check for high head pressure S Check compressor supply voltage

Outdoor unit power disconnect is open.

Compressor circuit breaker or fuse(s) is open.

Broken wire or connector is not making contact.

Low or high pressure switch open if present in the system.

Compressor contactor has failed to close.

Low refrigerant charge.

Evaporator blower is not running.

S Check blower relay coil and contacts S Check blower motor capacitor S Check blower motor for failure or blockage S Check evaporator blower wiring and

connectors

S Check indoor blower control S Check thermostat wiring for open circuit

Evaporator coil is frozen.

S Check for low suction pressure S Check for excessively low thermostat

setting

S Check evaporator airflow (coil blockages or

return air filter)

S Check ductwork or registers for blockage.

Faulty metering device.

S Check TXV bulb installation (size, location

and contact)

S Check if TXV/fixed orifice is stuck closed or

defective

Condenser coil is dirty

Liquid line restriction (filter drier blocked if

present)

Thermostat is malfunctioning

S Check thermostat sub−base or wiring for

short circuit

S Check thermostat installation (location and

level)

High head pressure.

S Check high pressure switch if present in

system

S Check if system is overcharged with

refrigerant

S Check for non−condensable in system

Condenser coil poor air circulation (dirty, blocked, damaged).

Condenser fan is not running.

S Check fan capacitor S Check fan wiring and connectors S Check fan motor for failure or blockage

Return air duct has substantial leakage.

Thermostat demand signal is intermittent.

Time delay relay or Air Conditioner Control is defective.

If high pressure switch is present, see flash Code 2 information.

Clearing Status

Clears the error after current is sensed in the run and start winding for two seconds, service removed or power reset.

Clears the error after 30 consecutive normal run cycles, or after power reset.

Clears after four consecutive normal compressor run cycles, or after power reset.

506587−01

Page 40

Air Conditioner

Control LEDs

DS15

Yellow

4 flashes

then pause

5 flashes

then pause

6 flashes

then pause

7 flashes

then pause

8 flashes

then pause

9 flashes

then pause

DS13

Red

Off

icomfort

Touch

Thermostat

Display

Critical Alert

Code 404

Critical Alert

Code 405

Critical Alert

Code 406

Critical Alert

Code 407

Critical Alert

Code 408

Moderate/

Critical Alert

Code 409

Condition

Locked rotor

Open circuit

Open start

circuit

Open run

circuit

Welded

contactor

Secondary low

voltage

Possible

Possible Cause(s)

Cause(s)

Compressor has a locked out due to run capacitor short, bearings are seized, excessive liquid refrigerant.

Compressor has an open circuit due to power disconnection, fuse is open or other similar conditions.

Current not sensed by Start transformer.

Current not sensed by run transformer.

Compressor always runs

24VAC is below 18VAC.

Solution

Run capacitor has failed.

Low line voltage (contact utility if voltage at disconnect is low).

S Check wiring connections

Excessive liquid refrigerant in the compressor.

Compressor bearings are seized.

Outdoor unit power disconnect is open.

Unit circuit breaker or fuse(s) is open.

Unit contactor has failed to close.

S Check compressor contactor wiring and

connectors

S Check for compressor contactor failure

(burned, pitted or open)

S Check wiring and connectors between

supply and compressor

S Check for low pilot voltage at compressor

contactor coil

High pressure switch is open and requires manual reset.

Open circuit in compressor supply wiring or connections.

Unusually long compressor protector reset time due to extreme ambient temperature.

Compressor windings are damaged.

S Check compressor motor winding

resistance

Run capacitor has failed.

Open circuit in compressor start wiring or connections.

S Check wiring and connectors between

supply and the compressor S terminal

Compressor start winding is damaged.

S Check compressor motor winding

resistance

Open circuit in compressor start wiring or connections.

S Check wiring and connectors between

supply and the compressor R terminal

Compressor start winding is damaged.

S Check compressor motor winding

resistance

Compressor contactor failed to open.

Thermostat demand signal not connected to module.

Control circuit transformer is overloaded.

Low line voltage (contact utility if voltage at disconnect is low).

S Check wiring connections

Clearing Status

Clears after power reset or four normal compressor cycles.

Clears after one normal compressor run cycle or power reset.

Clears when amperage is detected in RUN and START sensors, or after power reset.

Clears after one normal compressor run cycle or after power reset.

Clears after voltage is higher than 20VAC for two seconds, or after power reset.

Fast simultaneous flashing of DS11,

OEM mode Factory test mode.

DS13, DS14 and DS15

1. Pause duration is two (2) seconds.

2. Fast flash duration is 1/2 second. Slow flash duration is one (1) second.

3. Initially a moderate status is displayed and is escalated to critical if alarm exists for more than 10 minutes.

Page 41

XC21 SERIES

Field Configuration and Testing

This section provides procedures for configuring, adjusting and testing various components of this unit.

S Fan Motor (B4) Test Procedure

S Fan Motor Control (A177) Configuration and Testing

S Top Grille and Fan Motor Mounting Adjustment (Fan

Clearance)

S Heat Pump Control (A175) Unit Nominal Capacity

Code configuration

FAN MOTOR (B4) TEST PROCEDURE

The following procedure can be used to test the fan motor operation. A fully charged 9V battery will be required for this procedure. See figure 30 for complete test procedure.

This is a test that will verify that the motor does operate.

1. Verify main (240 volt) power if OFF to unit.

2. Remove both wires (brown and black) from the J2 terminal on the fan motor control (A177).

3. Room thermostat should be in OFF position (unit in idle mode − no heating or cooling demands)

4. Turn main power (240 volt) On to unit.

5. Connect 9 Volt battery to fan motor plugs as noted in picture below.

6. Fan motor should run at a reduced fan speed.

7. If fan motor does not run, then replace fan motor assembly.

FAN MOTOR CONTROL (A177) LED CODES AND SEQUENCE OF OPERATION

This section provides information concerning operation and testing of the fan control.

Fan Motor Control Sequence of Operation

During start up, the following sequence is followed:

1. Display error conditions (see table 12), if present

2. If no errors are detected, then the LED code indicating stage operation (see table 13) will display the applicable code and then a long pause.

3. The fan motor speed / RPM (revolutions per minute) indicator is displayed next (see table 11).

4. There is a short pause.

The above sequence will continue to repeat if a thermostat demand is present. See figure 31 for LED sequence. See table 13 for description of flash and pause durations.

REMOVE BOTH LEADS

FROM J2 TERMINALS

BLACK LEAD

BROWN LEAD

COM

PARK

FAN PWM OUT

FAN MOTOR CONTROL

BLACK LEAD

CONNECT B4 FAN

MOTOR BLACK COMMON

WIRE TO 9V BATTERY

NEGATIVE TERMINAL

FULLY CHARGED

9V BATTERY

BLACK LEAD

BROWN LEAD

CONNECT B4 FAN MOTOR WIRE TO 9V BATTERY

POSITIVE TERMINAL

506587−01

Figure 30. Fan Motor (B4) Test

Page 42

Table 11. Two Stage  Fan Motor Control RPM, LED Code and DC Voltage Output

CFM Profile Pin Select

Application

4 3 2 1 RPM

XC21−024 On On OFF OFF 475 6 15.1 550 8 17.6 200 3 6.3

XC21−036 On OFF On On 525 7 16.8 600 8 19.2 225 3 7.0

XC21−048 and −060 On OFF OFF On 600 8 19.2 675 9 21.6 225 3 7.0

* LED Code indicates Fan Motor Control LED flash sequence. For example, LED Code 9 indicates 9 slow flashes and pause.

Low Stage  ECM1/Y1

Only

LED

Code

DC Volt RPM

Table 12. Fan Motor Control Error/Fault LED Codes

Unit Status

Mismatched RPM

CRC Failure Constant On.

Fan Motor Control

LED

Fast flash with no

pause

Possible Cause

Internal feedback, PWM does not match target.

Microcontroller CRC failure.

Table 13. Fan Motor Control Stage LED Indicator

Codes

Unit Status Unit Status Motor Control LED

Two Stage Operation

Low Stage  ECM1/Y1 OnLY

High Stage  ECM1/Y1 and ECM2/Y2

EDA Operation  ECM2/Y2 OnLY

One slow flash, then short pause

Two slow flash, then short pause

Three slow flash, then short pause

Table 14. Fan Motor Control flash and Pause

Durations

flash or Pause State Duration

flash flash Three flashes per second

Slow flash One flash per second

Short Pause Two seconds of OFF time

Long Pause Five seconds of OFF time

Testing

Use the following subsections to verify and test the fan motor control (A177).

Verifying Jumper Settings (J2)

The unit is shipped from the factory with the default motor RPM setting required for the specific model size. Use the table 11 for two−stage operation to verify that jumpers are set correctly for the specific size unit.

During start up, the fan motor control LED will display any error conditions. If error conditions exist then no other codes will display. If no error conditions are present, then the stage status and and RPM indicator are displayed. Two−stage units have various fan motor

speed operations available (see table 11).

The following three methods can be used to determine whether the fan motor (B4) is operating at the correct RPMs based on unit size.

1. Use the information provided in table 11 to verify that all four jumper terminals are set correctly for the specific size unit.

2. Verify LED RPM indicator is displaying the correct flash sequence for the applicable size unit (see table table 11).

3. Test DC voltage output on the fan motor control’s J2 terminals (see figure 32) while under full load and verify the voltage read to the voltage listed in table 11 for the applicable size unit.

4. If no voltage is detected at the J2 terminals, verify there is a Y1 demand at the thermostat and applicable voltages detected all fan motor control voltage inputs, see table 15.

If there is a demand, proceed to the next section for further testing.

Verifying Correct Input Voltage  (ECM/Y1, ECM/Y2,

Using a volt meter, check voltages on the following fan motor control inputs using table 15. Voltage will only be present during a thermostat demand. See figure 33 for test example.

If correct voltages are detected at applicable inputs during a demand, and no voltage is present at the J2 terminals, then fan motor control should be replaced.

High Stage  ECM1/Y1

and ECM2/Y2

LED

Code

DC Volt RPM

Verifying LED Status Codes

Verifying Correct DC Output Voltage (J2)

ECM C and EXT ECM/R)

EDA Operation 

ECM2/Y2 Only

LED

Code

Table 15. Fan Motor Control Voltage Inputs

Input Thermostat Demand Voltage Present

ECM/Y1 and ECM C (Low Stage)

ECM/Y1 − ECM/Y2 and ECM C (High Stage)

ECM/Y2 and ECM C (EDA Operation)

EXT ECM/R and ECM C

YES Between 24VDC and 32 VDC

NO NOnE

YES Between 24VDC and 32 VDC at each input

NO NOnE at each input

YES Between 24VDC and 32 VDC

NO NOnE

YES 24VAC

NO NOnE

DC Volt

Page 43

XC21 SERIES

DEMAND

BEGINS

MISMATCHED

RPM

CRC

FAILURE

ONE STAGE

(LOW)

DEMAND

ENDED

TWO STAGE

(HIGH)

YES

DEFAULT

FAN MOTOR

SPEED USED

DEFAULT FAN

MOTOR

SPEED USED

ECM1/Y1

ONLY

ECM1/Y1

ONLY AND

EMC2/Y2

FAN MOTOR

RPM SET PER

JUMPER

SETTINGS

FAN MOTOR

RPM SET PER

JUMPER

SETTINGS

LED CONTINUOUS FAST

FLASH

LED CONSTANT ON

LED STAGE INDICATOR: OnE slow FLASH AND ONE SHORT PAUSE

REPLACE FAN MOTOR

CONTROL BOARD

REPLACE FAN MOTOR

CONTROL BOARD

LED RPM INDICATOR: EXAMPLE: (2−TOn) – 5 slow FLASHES AND LONG PAUSE

LED STAGE INDICATOR: TWO slow FLASHES AND ONE SHORT PAUSE

LED RPM INDICATOR:

DEMAND

ENDED

EDA

OPERATIOn

DEMAND

ENDED

YES

ECM2/Y2

ONLY

FAN MOTOR

RPM SET PER

JUMPER

SETTINGS

EXAMPLE: (2−TOn) – 5 slow FLASHES AND LOnG PAUSE

LED STAGE INDICATOR: THREE slow FLASHES AND OnE SHORT PAUSE

LED RPM INDICATOR: EXAMPLE: (2−TOn – 3 slow FLASHES AND LOnG PAUSE

Figure 31. Fan Motor Control One/Two Stage and EDA LED Sequence of Operation

506587−01

Page 44

FAN MOTOR CONTROL (A177) 

PULSE−WIDTH MODULATION (PWM)

CFM Profile Pin Select

AIR

CONDITIONER

CONTROL (A175)

CONTROL PANEL

VERIFY DC VOLTAGE OUTPUT USING FAN PWM OUT AND COM TERMINALS. SEE TABLE 11 FOR OPTIMAL DC VOLTAGE BASED ON CFM PROFILE USED.

COM

PARK

JUMPER

OFF

JUMPER

LED

GREEN

YELLOW

FAN PWM OUT

RED

YELLOW

HIGH PRESSURE SWITCH (S4)

AIR CONDITIONER CONTROL (A175)

YELLOW

BLUE

BLACK

YELLOW

FAN MOTOR

CONTROL

SEE TABLE 11 FOR CFM PROFILE SELECTION OPTIONS.

Figure 32. Fan Control, Wiring, Jumper Settings, Testing and LED Location

GREEN

RED RED

BLACK

BROWN

FAN MOTOR

(B4)

Page 45

XC21 SERIES

FAN MOTOR CONTROL (A177) 

PULSE−WIDTH MODULATION (PWM)

CONTROL PANEL

INPUT VOLTAGES DURING DEMAND

ECM/Y1 ONLY − 24VDC BOTH ECM/Y1 AND ECM/Y2 − 24VDC AT EACH INPUT ECM/Y2 ONLY − 24VDC

AIR

CONDITIONER

CONTROL (A175)

BLUE WIRE

BLACK WIRE

VDC

VAC

ONE YELLOW WIRE FROM PS (E24) TERMINAL ON AIR

CONDITIONER CONTROL. AND SECOND YELLOW WIRES ON

PIGGYBACK TERMINALS GOES TO S4 HIGH PRESSURE SWITCH.

GREEN

RED

YELLOW

S4 HIGH PRESSURE SWITCH

YELLOW

YELLOW WIRE

EXT PWR/R (24VAC INPUT

DURING DEMAND ONLY)

YELLOW

BLUE

BLACK

YELLOW

MOTOR

CONTROL

GREEN

RED RED

B4 FAN

BLACK

BROWN

SEE TABLE 11 FOR CFM PROFILE SELECTION OPTIONS.

MOTOR

Figure 33. Testing for External Power to Fan Motor Control

506587−01

AIR CONDITIONER CONTROL (A175)

Page 46

TOP GRILLE OR FAN MOTOR MOUNT ADJUSTMENT FOR FAN CLEARANCE

Sometimes during shipping, either the fan motor mounting or top grille may become out of alignment. This may cause the fan motor blade to not clear the orifice ring. If this situation occurs, simply adjust either or both the fan motor mount or top grille positions to allow proper clearance. The top grille four fastener insertion points to the plastic top and motor mount locations are larger than the fasteners used to secure the grille and fan motor mounts. Use the procedures provided in figure 34 to adjust for fan clearance.

PUSH

FORWARD

GRILLE MOUNTING

POINTS

PUSH

FORWARD

FASTENER INSERTION POINT

FAN MOTOR MOUNTING POINTS

The four mounting point holes that secure the top grille to the plastic top are larger than the fasteners used to secure the grille. this is also true for the four fasteners securing the fan motor to the top grille. To provide more clearance, preform either or both of the following procedures.

TOP GRILLE ADJUSTMENT

1. loosen the four grille mounting fasteners and push the grille forward. tighten mounting hardware. if there is still insufficient clearance proceed to step 2.

FAN MOTOR POSITION ADJUSTMENT

2. loosen the four fan motor grille mounting fasteners and push the fan motor forward. tighten mounting hardware.

GRILLE MOUNTING POINTS

Figure 34. Fan Blade Clearance Adjustment

ORIFICE RING

Page 47

XC21 SERIES

AIR CONDITIONER CONTROL (A175) UNIT NOMINAL CAPACITY CODE CONFIGURATION

In a communicating system, if the room thermostat is indicating either a error code 313, indoor and outdoor unit capacity mismatch error code, or error code 34, must program unit capacity for outdoor unit (see figure 35).

Set room thermostat

Go to control terminal

Remove R wire

from control (24 volt

AC power)

icomfort

enabled 

Remove control

wires from i+ and

i− terminals

START

to OFF

strip

Non − icomfort

enabled 

Remove control

wire from Y1

terminal

DS14 (Red)

DS11 (Green)

Field Test

(E33)

DS12

Communicating

Status Indicator

TERMINAL STRIP

Sensor harness must be attached to air conditioner control.

FINISH

Connect R wire to

control (24 volt AC

power)

Reconnect any control

wiring previously

removed.

Remove R wire from

air conditioner control

(24 volt AC power)

Place jumper on

FIELD TEST

(E33 pins)

Connect R wire to control

(24 volt AC power)

Status LED lights DS11 and DS14 will blink and then on continuously. Once both LEDs are on continuously then remove jumper immediately from E33.

If jumper is not removed immediately from E33, then DS11 and DS14 LEDs will resume blinking again.

YES

successfully

Remove R wire

from control (24 volt

AC power)

Jumper

removed

Place jumper on FIELD

TEST (E33 pins) within 2 to 4

seconds after removal

The control´s DS11 and DS14 LEDs will start blinking the Unit Nominal Code at three (3) second intervals starting at 1−ton through to 6−ton. If a code is not selected, the control will cycle one more time through the codes before defaulting back to the idle mode (simultaneous slow flash).

Long blink ON red LED (DS14) to indicate tonnage and solid ON green LED (DS11) to indicate ½ tonnage.

When the required Unit Capacity Code is displaying on the LEDs, remove FIELD TEST jumper from pins (E33). LEDs will continue to display the selected unit capacity code for two (2) minutes before defaulting back to the idle mode {simultaneous slow flash}, or until the 24 volt

power is cycled to the air conditioner control.

Model

−012

−018

−024

−030

−036

−042

−048

−054

−060

−066

−072

Size

1−ton

1.5−ton

2−ton

2.5−ton

3−ton

3.5−ton

4−ton

4.5−ton

5−ton

5.5−ton

6.0−ton

DS11 Green LED

OFF

DS14 Red LED

1 long flash

2 long flashes

3 long flashes

4 long flashes

5 long flashes

6 long flashes

Figure 35. Air Conditioner Control (A175) Unit Nominal Capacity Code Configuration

506587−01

Page 48

Maintenance

WARNING

This product and/or the indoor unit it is matched with may contain fiberglass wool.

Disturbing the insulation during installation, maintenance, or repair will expose you to fiberglass wool dust. Breathing this may cause lung cancer. (Fiberglass wool is known to the State of California to cause cancer.)

Fiberglass wool may also cause respiratory, skin, and eye irritation.

To reduce exposure to this substance or for further information, consult material safety data sheets available from address shown below, or contact your supervisor.

Lennox Industries Inc. P.O. Box 799900 Dallas, TX 75379−9900

INDOOR UNIT MAINTENANCE

Indoor Unit

1. Clean or change filters.

2. Lennox blower motors are prelubricated and permanently sealed. No more lubrication is needed.

3. Adjust blower speed for cooling. Measure the pressure drop over the coil to determine the correct blower CFM. Refer to the unit information service manual for pressure drop tables and procedure.

4. Belt Drive Blowers − Check belt for wear and proper tension.

5. Check all wiring for loose connections.

6. Check for correct voltage at unit. (blower operating)

7. Check amperage draw on blower motor.

Motor Nameplate:_________ Actual:__________.

Indoor Coil

1. Clean coil if necessary.

2. Check connecting lines, joints and coil for evidence of oil leaks.

3. Check condensate line and clean if necessary.

DEALER

Outdoor Unit

Maintenance and service must be performed by a qualified installer or service agency. At the beginning of each cooling season, the system should be checked as follows:

1. Outdoor unit fan motor is pre−lubricated and sealed. No further lubrication is needed.

2. Visually inspect all connecting lines, joints and coils for evidence of oil leaks.

3. Check all wiring for loose connections.

4. Check for correct voltage at unit (unit operating).

5. Check amperage draw on outdoor fan motor.

Motor Nameplate:_________ Actual:__________.

6. Inspect drain holes in coil compartment base and clean if necessary.

NOTE - If insufficient cooling occurs, the unit should be gauged and refrigerant charge should be checked.

Outdoor Coil

Clean and inspect outdoor coil (may be flushed with a water hose). Ensure power is off before cleaning.

NOTE  It may be necessary to flush the outdoor coil more frequently if it is exposed to substances which are corrosive or which block airflow across the coil (e.g., pet urine, cottonwood seeds, fertilizers, fluids that may contain high levels of corrosive chemicals such as salts)

Sea Coast  Moist air in ocean locations can carry salt, which is corrosive to most metal. Units that are located near the ocean require frequent inspections and maintenance. These inspections will determine the necessary need to wash the unit including the outdoor coil. Consult your installing contractor for proper intervals/procedures for your geographic area or service contract.

HOMEOWNER

Cleaning of the outdoor unit’s coil should be performed by a trained service technician. Contact your dealer and set up a schedule (preferably twice a year, but at least once a year) to inspect and service your outdoor unit. The following maintenance may be performed by the homeowner.

CAUTION

IMPORTANT

Sprinklers and soaker hoses should not be installed where they could cause prolonged exposure to the outdoor unit by treated water. Prolonged exposure of the unit to treated water (i.e., sprinkler systems, soakers, waste water, etc.) will corrode the surface of steel and aluminum parts and diminish performance and longevity of the unit.

Outdoor Coil

The outdoor unit must be properly maintained to ensure its proper operation.

S Please contact your dealer to schedule proper

inspection and maintenance for your equipment.

S Make sure no obstructions restrict airflow to the

outdoor unit.

S Grass clippings, leaves, or shrubs crowding the unit

can cause the unit to work harder and use more energy.

Page 49

XC21 SERIES

S Keep shrubbery trimmed away from the unit and

periodically check for debris which collects around the unit.

Routine Maintenance

In order to ensure peak performance, your system must be properly maintained. Clogged filters and blocked airflow prevent your unit from operating at its most efficient level.

1. Air Filter  Ask your Lennox dealer to show you

where your indoor unit’s filter is located. It will be either at the indoor unit (installed internal or external to the cabinet) or behind a return air grille in the wall or ceiling. Check the filter monthly and clean or replace it as needed.

2. Disposable Filter  Disposable filters should be

replaced with a filter of the same type and size.

 If you are unsure about the filter required for your

NOTE system, call your Lennox dealer for assistance.

3. Reusable Filter  Many indoor units are equipped

with reusable foam filters. Clean foam filters with a mild soap and water solution; rinse thoroughly; allow filter to dry completely before returning it to the unit or grille.

NOTE  The filter and all access panels must be in place any time the unit is in operation.

4. Lennox Branded Air Filters  are designed to

remove airborne particles from the air passing through the filter.

5. Indoor Unit  The indoor unit’s evaporator coil is

equipped with a drain pan to collect condensate formed as your system removes humidity from the inside air. Have your dealer show you the location of the drain line and how to check for obstructions. (This would also apply to an auxiliary drain, if installed.)

Thermostat Operation

See the ComfortSense® 7000 or icomfort Touch thermostat homeowner manual for instructions on how to operate your thermostat.

Preservice Check

If your system fails to operate, check the following before calling for service:

S Verify room thermostat settings are correct.

S Verify that all electrical disconnect switches are On.

S Check for any blown fuses or tripped circuit breakers.

S Verify unit access panels are in place.

S Verify air filter is clean.

S If service is needed, locate and write down the unit

model number and have it handy before calling.

Accessories

For update−to−date information, see any of the following publications:

S Lennox XC21 Engineering Handbook

S Lennox Product Catalog S Lennox Price Book

506587−01

Page 50

SunSource® Home Energy System

This Dave Lennox Signature® Collection heat pump is factory−equipped with components that make it SunSource with solar modules and other optional equipment so that they can become part of a SunSource System.

Units can be upgraded for use with solar equipment at the time of installation or in the future.

Solar energy is first used to meet cooling/heating demands. When the outdoor unit is not operating, the system powers lighting, appliances and other electronic devices in the home. Any surplus power is sent back to the utility company for a possible credit (check with your local utility company for availability).

The SolarSynct package consists of the following components:

S Lennox

Signature

unit.

solar−ready. These units can be matched

Home Energy

Solar Subpanel installed in a Dave Lennox

Collection air conditioner or heat pump

S Solar modules (1 to 15 may be used to vary the

amount of electricity generated).

S Envoy Communications Gateway monitors solar

power performance.

All components must be ordered separately. See the Lennox XC21 Engineering Handbook for SunSource Home Energy System component ordering.

Wiring runs from the roof−mounted solar modules to the outdoor unit. From there, power travels to the home electrical service panel using the existing outdoor unit power wiring.

Checklists

TWO  STAGE COMPRESSOR CHECKOUT

Use this check-out procedure to verify part- and full-load capacity operation of two-stage modulation compressor.

IMPORTANT

This performance check is OnLY valid on systems that have clean indoor and outdoor coils, proper airflow over coils, and correct system refrigerant charge. All components in the system must be functioning proper to correctly perform compressor modulation operational check. (Accurate measurements are critical to this test as indoor system loading and outdoor ambient can affect variations between low and high capacity readings).

TOOLS REQUIRED

S Refrigeration gauge set S Digital volt/amp meter S Electronic temperature thermometer S On-off toggle switch

PROCEDURE

1. Turn main power OFF to outdoor unit.

2. Adjust room thermostat set point 5ºF above (heating operation) or 5ºF below (cooling operation) the room temperature.

3. Remove control access panel. Install refrigeration gauges on unit. Attach the amp meter to the common (black wire) wire of the compressor harness. Attach thermometer to discharge line as close as possible to the compressor.

4. Turn toggle switch OFF. Install switch in series with Y2 wire from room thermostat (see note ** in the Field Operational Checklist on page 51).

5. Cycle main power On.

6. Allow pressures and temperatures to stabilize before taking any measured reading (may take up to 10 minutes).

7. Record all of the readings for the Y1 demand.

XC21 Field Operational Checklist

Cooling*** Heating***

8. Close switch to energize Y2 demand. Verify power is going to compressor solenoid (see note ** in the Field Operational Checklist on page 51).

9. Allow pressures and temperatures to stabilize before taking any measured reading (this may take up to 10 minutes).

10. Record all of the readings with the Y1 and Y2 demand.

11. If temperatures and pressures change in the direction noted in chart, the compressor is properly modulating from low to high capacity. (If no amperage, pressures or temperature readings change when this test is performed, the compressor is not switching between low and high capacity and replacement is necessary).

12. After testing is complete, return unit to original set up.

Unit Readings

Compressor

Voltage Same Same

Amperage Higher Higher

Condenser Fan motor

Amperage Same or Higher Same or Higher

Temperature

Ambient Same Same

Outdoor Coil Discharge Air Higher Lower

Compressor Discharge Line Higher Higher

Indoor Return Air Same Same

Indoor Coil Discharge Air Lower Higher

Pressures

First

Stage

Expected results

during Y2 demand

(Toggle switch On)

Second

Stage

First Stage

Expected results

during Y2 demand

(Toggle switch On)

Y2 Second

Stage

Suction (Vapor) Lower Down

Liquid Higher Higher

Note − Heat pump may have a low ambient control or Control that locks in second−stage below its set point. It may be necessary to remove a wire

from the control when performing this check out. ** On the XC21 units, the System Operation Monitor controls the second−stage solenoid coil in compressor. *** Cooling Mode Operation − Block outdoor coil to maintain a minimum of 375 psig during testing.

Heating Mode Operation − Block indoor coil to maintain a minimum of 375 psig during testing.

Page 51

XC21 SERIES

XC21 Start−Up and Performance Checklist

Customer Address

Indoor Unit Model Serial

Outdoor Unit Model Serial

Notes:

START UP CHECKS

Refrigerant Type:

First Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts

Second Stage: Rated Load Amps Actual Amps Rated Volts Actual Volts

Condenser Fan Full Load Amps Actual Amps: First Stage Second Stage

COOLING MODE

Suction Pressure: First Stage: Second Stage:

Liquid Pressure: First Stage: Second Stage:

Supply Air Temperature: First Stage: Second Stage:

Temperature: Ambient: Return Air:

System Refrigerant Charge (Refer to manufacturer’s information on unit or installation instructions for required subcooling and approach temperatures.)

Subcooling: A

Saturated Condensing Temperature (A) minus Liquid

Line Temperature (B)

Approach: A

Liquid Line Temperature (A)

minus Outdoor Air Temperature (B)

Indoor Coil Temperature Drop (18 to 22°F) A

Return Air Temperature (A)

minus Supply Air Temperature (B)



SUBCOOLING

APPROACH

COIL TEMP DROP

506587−01

Page 52

Lennox Collection XC21 System Installation Instructions Manual

Specifications and Main Features

Frequently Asked Questions

User Manual