Lennox XC25-024-230-01, XC25-036-230-01, XC25-048-230-01, XC25-060-230-01 Installation And Service Procedure

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Page 1

INSTALLATION AND SERVICE

PROCEDURE

Service Literature

Dave Lennox Signature

Corp. 1253-L11

July 24, 2013

IMPORTANT

XC25 units have refrigerant piping requirements that are unique to this unit. Size and install the refrigerant piping per table 2 (page 14) to ensure proper unit operation.

IMPORTANT:

Before applying any power (main, solar or low voltage) to the outdoor unit, confirm the iComfort Wi-Fi® thermostat has

software Version 2.1 or higher installed. (Reference the iComfort Wi-Fi® thermostat manual.)

This unit is an integral component of a system that requires an iComfort Wi-Fi or furnace.

thermostat and iComfort™-enabled air handler

Collection XC25 Series Units

TABLE OF CONTENTS

I. OVERVIEW

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

Typical Serial Number Identification 2..............

Specifications 2.................................

Electrical Data 3................................

Unit Dimensions 4..............................

Typical Unit Parts Arrangement 5.................

Operating Service Valves 7.......................

General 7.....................................

II. INSTALLATION

Unit Placement 9...............................

Removing and Installing Panels 12.................

New or Replacement Line Set 13..................

Brazing Connections 16...........................

Flushing the System 19...........................

Leak Testing the System 21.......................

Evacuating the System 21.........................

Electrical 24.....................................

Servicing Unit Delivered Void of Charge 29..........

Unit Start-Up 29.................................

XC25

iComfort Wi-Fi

iComfort™-enabled

air handler or

furnace

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.

WARNING

Electrical Hazard

High Voltage

Wait 5 Minutes

Electrical components may hold charge. Do not remove this panel or service this area for 5 minutes after the power has been removed.

III. SYSTEM OPERATION AND SERVICE

7-Segment Alert and System Status Codes 30.......

Outdoor Control Push-Button Operation 35..........

Configuring Unit 39...............................

Reconfiguring Outdoor Control using iComfort Wi-Fi

Thermostat 40...................................

System Overview 40.............................

Maintenance 41..................................

SunSource

Unit Wiring Diagrams 42..........................

Factory Wiring Diagrams 45.......................

Unit Sequence of Operations 47...................

Component Testing 50............................

System Refrigerant 69............................

Home Energy System 41..............

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.

2013 Lennox Industries Inc.

Page 2

Model Number identification

I. OVERVIEW

− −

C 25 XXX

230

-02

Refrigerant Type

X = R-410A

Unit Type

C = AIR CONDITIONER

Nominal Cooling Capacity

Minor Revision Number

Voltage

230 = 208/230V-1ph-60hz

024 = 2 tons

Series

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

Typical Serial Number Identification

Location Code

19 = Saltillo, Mexico

58 = Marshalltown, IA

Year Code

08 = 2008 09 = 2009 10 = 2010

8 09 C

05716

5 (or 6) Digit Unique Number

Month Code

A = January B = February C = March

Specifications

Unit Outdoor Fan

Model Number

XC25-024-230-01 70 59 13 lbs, 10 oz 5 26

Sound Rating Number (dB) Maximum Minimum

Factory Refrigerant

Charge

Number of Blades Diameter - inches.

Unit Outdoor Fan

Model Number

XC25-036-230-01 73 59 10 lbs, 12 oz 5 26

Model Number

XC25-048-230-01 74 66 14 lbs, 9 oz 5 26

Model Number

XC25-060-230-01 74 64 14 lbs, 8 oz 5 26

Tested according to AHRI Standard 270-2008 test conditions.

Factory refrigerant charge is sufficient for refrigerant line lengths up to 15 feet.

Sound Rating Number (dB) Maximum Minimum

Unit Outdoor Fan

Factory Refrigerant

Charge

Number of Blades Diameter - inches.

XC25

Page 3

Electrical Data

208/230V-60 Hz-1 Ph

Unit Compressor Outdoor Fan (RPM varies with compressor RPM)

Model Number

Maximum

Over-

current

Protection

(amps)

Minimum

Circuity

Ampacity

XC25-024-230-01 25 14.9 10.30 18.0 1/3 3020 1950 500 350 80 32 2.0

Unit Compressor Outdoor Fan (RPM varies with compressor RPM)

Model Number

Maximum

Over-

current

Protection

(amps)

Minimum

Circuity

Ampacity

XC25-036-230-01 30 19.5 14.00 18.0 1/3 4100 1950 650 350 157 32 2.0

Unit Compressor Outdoor Fan (RPM varies with compressor RPM)

Model Number

Maximum

Over-

current

Protection

(amps)

Minimum

Circuity

Ampacity

XC25-048-230-01 50 32.9 24.70 29.0 1/3 4220 3020 675 500 185 82 2.0

Unit Compressor Outdoor Fan (RPM varies with compressor RPM)

Model Number

Maximum

Over-

current

Protection

(amps)

Minimum

Circuity

Ampacity

XC25-060-230-01 50 34.1 25.70 29.0 1/3 4385 3020 700 500 212 82 2.0

HACR type circuit breaker or fuse.

Refer to National or Canadian Electrical Code manual to determine wire, fuse and disconnect size requirements.

Rated

Load

Amps

(RLA)

Locked

Rotor Amps (LRA)

Motor

CFM RPM WATTS

MAX MIN MAX MIN MAX MIN

Load Amps (FLA)

208/230V-60 Hz-1 Ph

Rated

Load

Amps

(RLA)

Locked

Rotor Amps (LRA)

Motor

CFM RPM WATTS

MAX MIN MAX MIN MAX MIN

Load Amps (FLA)

208/230V-60 Hz-1 Ph

Rated

Load

Amps

(RLA)

Locked

Rotor Amps (LRA)

Motor

CFM RPM WATTS

MAX MIN MAX MIN MAX MIN

Load Amps (FLA)

208/230V-60 Hz-1 Ph

Rated

Load

Amps

(RLA)

Locked

Rotor Amps (LRA)

Motor

CFM RPM WATTS

MAX MIN MAX MIN MAX MIN

Load Amps (FLA)

Full

XC25

Page 4

Unit Dimensions -- Inches (mm)

UNIT SUPPORT

FEET

IMPORTANT

This unit must be matched with an indoor coil as specified in Lennox Product Specification bulletin. Coils previously charged with HCFC-22 must be flushed.

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 nearby these areas during installation or while servicing this equipment.

16-7/8

(429)

8-3/4 (222)

3-1/8

(79)

30-3/4

(781)

26-7/8

(683)

3-3/4 (95)

4-5/8 (117)

BASE WITH ELONGATED LEGS

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.

XC25

Page 5

Typical Unit Parts Arrangement

GROUND LUGS

CONTROL PANEL FOR

XC25-024 AND -036

CONTACTOR-SPST

(25FLA/35RES)

INVERTER REACTOR,

GROUND LUGS

230V, 4KW

OUTDOOR

CONTROL

CONTROL PANEL FOR

XC25-048 AND -060

DC INVERTER

CONTROL

INVERTER NOISE FILTER FOR

6KW INVERTER (208/240V,

60HZ, CURRENT RANGE 30A

MAXIMUM, INDUCTANCE

4.3MH)

CONTACTOR-SPST

(35FLA/40RES)

OUTDOOR CONTROL

Figure 1. Control Panel Components

INVERTER REACTOR,

230V, 6KW

DC INVERTER CONTROL

XC25

Page 6

VAPOR VALVE

AND GAUGE

PORT

LIQUID VALVE AND

GAUGE PORT

COMPRESSOR TOP CAP

SWITCH (THERMAL)

Typical Plumbing Components

VARIABLE-CAPACITY COMPRESSOR - HFC-410A, 3-PHASE

LIQUID LINE SENSOR

LIQUID LINE BI-FLOW

FILTER DRIER

(HFC-410A)

LOW PRESSURE SWITCH - NORMALLY OPEN, SWITCH CLOSES WHEN SYSTEM PRESSURES GO ABOVE 90±5, AND OPENS

WHEN SYSTEM PRESSURES DROP BELOW 40±5 PSIG

Figure 2. Plumbing (Component Locations and Specifications)

IMPORTANT

This unit must be matched with an indoor coil as specified in Lennox Product Specification bulletin. Coils previously charged with HCFC-22 must be flushed.

CRANKCASE HEATER THERMOSTAT (S40) OPENS AT 70ºF, CLOSES AT 50ºF

HIGH PRESSURE SWITCH - NORMALLY CLOSED. SWITCH OPENS WHEN SYSTEM PRESSURES REACH 590± SYSTEM PRESSURES DROP BELOW 418±15 PSIG

15, AND CLOSES WHEN

CAUTION

XC25

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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.

General

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

The XC25 is a high-efficiency residential split-system air conditioner, which features a variable-capacity scroll com pressor and uses HFC-410A refrigerant. Units are available in 2, 3, 4 and 5-ton sizes. The series is designed for use with an expansion valve (approved for use with HFC-410A) in the indoor unit only.

USING MANIFOLD GAUGE SET

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

Manifold gauge set used with HFC-410A refrigerant sys tems must be capable of handling higher system operating pressures. The gauges should be rated for use with pres sures 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

TORQUE REQUIREMENTS

When servicing or repairing HVAC components, ensure the fasteners are appropriately tightened. Table 1 lists torque values for fasteners.

Operating Service Valves

The liquid and vapor line service valves are used for re moving refrigerant, flushing, leak testing, evacuating, checking charge and charging.

Each valve is equipped with a service port which has a fac tory-installed valve stem. Figure 3 provides information on how to access and operating both angle and ball service valves.

IMPORTANT

Only use hex 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 a hex 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.

WARNING

The State of California has determined that this product may contain or produce a chemical or chemicals, in very low doses, which may cause serious illness or death. It may also cause cancer, birth defects, or reproductive harm.

IMPORTANT

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

XC25

Page 8

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:

D With torque wrench: Finger tighten and

torque cap per table 1.

D 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:

D With Torque Wrench: Finger tighten and then

torque cap per table 1.

D Without Torque Wrench: Finger tighten and

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

1/6 TURN

1/12 TURN

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

Figure 3. Angle and Ball-Type Service Valves

XC25

Page 9

II. INSTALLATION

Unit Placement

CAUTION

In order to avoid injury, take proper precaution when lift ing heavy objects.

See Unit Dimensions on page 4 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:

D Some localities are adopting sound ordinances based

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

D When possible, do not install the unit directly outside

a window. Glass has a very high level of sound trans mission. For proper placement of unit in relation to a window see 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, de tail B.

NOTE - If necessary for stability, anchor unit to slab as de scribed 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 ex tending the height of the unit support feet. Use a 2-inch (50.8mm) Schedule 40 female threaded adapter to raise the height of the unit.

The specified coupling will fit snugly into the recessed por tion 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 en sure a sturdy installation. If it is necessary to extend the height further than what is stable, consider a different type of field-fabricated framework that is sturdy enough for greater heights.

CLEARANCE ON ALL SIDES — INCHES (MILLIMETERS)

6 (152)

12 (305)

36 (914)

ACCESS PANEL

CONTROL PANEL

ACCESS

LOCATION

30 (762)

LINE SET CONNECTIONS

NOTES:

D CLEARANCE TO ONE OF THE THREE

SIDES MUST BE 36 INCHES (914MM).

D CLEARANCE TO ONE OF THE

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

NOTE - Dimensions are not to scale.

MINIMUM CLEARANCE BETWEEN

TWO UNITS

24 (610)

ACCESS PANEL

LINE SET

CONNECTIONS

MINIMUM CLEARANCE

ABOVE UNIT

48 (1219)

REAR VIEW OF UNIT

Figure 4. Installation Clearances

XC25

Page 10

STABILIZING UNIT ON UNEVEN SURFACES

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.

1. Remove the louvered panel from each side to expose the unit base.

2. Install the brackets as illustrated in figure 5, detail D us ing conventional practices.

3. Replace the panels after installation is complete.

ROOF MOUNTING

Locate the unit above a load-bearing wall or area of the roof that can adequately support the unit. Consult local codes for rooftop applications.

NOTICE

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

rubber roofing material may absorb 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.

XC25

Page 11

DETAIL A DETAIL B

INSTALL UNIT AWAY FROM WINDOWS

TWO 90° ELBOWS INSTALLED IN LINE SET

REDUCES LINE SET VIBRATION.

Outside Unit Placement

INSTALL UNIT LEVEL OR, IF ON A SLOPE, MAINTAIN SLOPE TOLERANCE OF 2 DEGREES (OR 2 INCHES PER 5 FEET [50 MM PER 1.5 M]) AWAY FROM BUILDING STRUCTURE.

GROUND LEVEL

Slab Mounting at Ground Level

BUILDING

STRUCTURE

MOUNTING SLAB

DETAIL C

BASE

LEG DETAIL

2” (50.8MM) SCH 40

FEMALE THREADED

USE ADDITIONAL 2” SCH 40 MALE THREADED ADAPT ERS WHICH CAN BE THREADED INTO THE FEMALE THREADED ADAPTERS TO MAKE ADDITIONAL AD JUSTMENTS TO THE LEVEL OF THE UNIT.

Elevated Slab Mounting using Feet

ADAPTER

2” (50.8MM) SCH 40

MALE THREADED

ADAPTER

Extenders

DETAIL D

Slab Side Mounting

#10 1/2” LONG SELF-DRILLING

SHEET METAL SCREWS

STABILIZING BRACKET (18 GAUGE

METAL — 2” WIDTH; HEIGHT AS

#10 1-1/4” LONG HEX HEAD

SCREW AND FLAT WASHER

CONCRETE SLAB — USE TWO PLASTIC ANCHORS (HOLE DRILL 1/4”)

WOOD OR PLASTIC SLAB — NO PLASTIC ANCHOR (HOLE DRILL 1/8”)

REQUIRED)

CORNER POST

MINIMUM ONE

Deck Top Mounting

STABILIZING BRACKET (18 GAUGE METAL — 2” (50.8MM) WIDTH; HEIGHT AS REQUIRED); BEND TO FORM RIGHT ANGLE

SAME FASTENERS AS SLAB SIDE MOUNTING.

ONE BRACKET PER SIDE (MIN.); FOR EXTRA STABILITY, TWO BRACKETS PER SIDE, 2” (50.8MM) FROM EACH CORNER.

PER SIDE

FOR EXTRA

STABILITY

Stabilizing Unit on Uneven Surfaces

IMPORTANT - To help stabilize an outdoor unit, some installations may require strap

ping the unit to the pad using brackets and anchors commonly available in the marketplace.

COIL

BASE PAN

Figure 5. Placement and Slab Mounting

XC25

Page 12

Removing and Installing Panels

ACCESS PANEL REMOVAL

PANELS

ACCESS AND LOUVERED

REMOVE AND INSTALL THE ACCESS PANEL AS ILLUSTRATED.

WARNING

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

IMPORTANT - Do not allow panels to hang on unit by top tab. Tab is for alignment and not designed to support weight of panel.

PANEL SHOWN SLIGHTLY ROTATED TO ALLOW TOP TAB TO EXIT (OR ENTER) TOP SLOT FOR REMOVING (OR INSTALLING) PANEL.

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.

LIP

SCREW

HOLES

Detail B

Detail A

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

ALIGN PANEL WITH SCREW HOLES. INSTALL SCREWS AND TIGHTEN.

Detail C

MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL WITH THE UNIT AS POSSIBLE) WHILE INSTALLING PANEL.

Figure 6. Removing and Installing Panels

XC25

ANGLE MAY BE TOO EXTREME

PREFERRED ANGLE FOR INSTALLATION

Detail D

ROTATE IN THIS DIRECTION; THEN

DOWN TO REMOVE PANEL

HOLD DOOR FIRMLY ALONG

THE HINGED SIDE TO MAINTAIN

FULLY-ENGAGED TABS

Page 13

New or Replacement Line Set

REFRIGERANT LINE SET

This section provides information on installation or replace

ment of existing line set. If new or replacement line set is

not being installed then proceed to Brazing Connections on

page 16.

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 referenced in table 2, use the procedure outlined under Flushing the System on page 19.

If refrigerant lines are routed through a wall, 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 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 19).

IMPORTANT

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

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

IMPORTANT !

If this unit is being matched with an approved line set or indoor unit coil that 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 system performance and capacity.

Failure to properly flush the system per the XC25 Installation and Service Procedures will void the warranty.

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.

WARNING

Fire, Explosion and Personal Safety Hazard. Failure to follow this warning could result in damage, personal inju ry 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 ex plosion, that could result in property damage, personal injury or death.

WARNING

When using a high pressure gas such as 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).

Recommended POE oils are Mobil EAL ARCTIC 22 CC or

ICI EMKARATEt RL32CF.

WARNING

Danger of fire. Bleeding the refrigerant charge from only the high side may result in the low side shell and suction tubing being pressurized. Application of a brazing torch while pressurized may result in ignition of the refrigerant and oil mixture - check the high and low pressures before unbrazing.

IMPORTANT !

Some scroll compressors have an internal vacuum protector that will unload scrolls when suction pres sure 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 COMPRES SOR.

The XC25 is a variable-capacity cooling system utilizing variable-speed compressor technology. With the variablespeed compressor and variable pumping capacity, additional consideration must be given to refrigerant piping sizing and application. The following guidelines are to be used exclusively for the XC25 systems.

XC25

Page 14

COOLING SYSTEM (HFC410A)

D Total equivalent length equals 180 feet (all piping and

fittings included).

NOTE - This is a general guide. Lengths may be more or less, depending on remaining system design factors.

D Maximum linear (actual) length = 150 feet. D Maximum linear liquid lift = 60 feet.

NOTE - Maximum lifts are dependent on total length, num ber of elbows, and other factors that contribute to total pressure drop.

D Maximum linear length of vapor riser = 60 feet. D Size vertical vapor riser per table 3. D Line set lengths up to 50 linear feet: Use rated line

sizes listed in table 2.

D Line set lengths between 51 and 150 linear feet:

Crankcase heater and nonbleed port TXV factory-in

stalled. No additional components required. Vertical vapor riser must be sized to the vapor riser listed in table 3 on systems with line sets longer than 51 feet. Use tables 3 and 4 to determine the correct liquid and vapor line sizes.

D Line set lengths over 150 linear feet: Not recom

mended.

D Additional oil is not required for systems with line

lengths up to 150 feet.

NOTE - Recommended POE oils are Mobil EAL ARCTIC 22 CC or ICI EMKARATEt RL32CF.

SUCTION TRAPS

In systems with the outdoor unit 5 to 60 feet above the in door unit, one trap must be installed at the bottom of the suction riser.

Table 2. Standard Refrigerant Line Set — Up to 50 Linear Feet

Inches (mm)

Model Number (-xx*) Valve Size Connections Recommended Line Sets

Model Number (-xx*)

XC25-024-230-XX XC25-036-230-XX XC25-048-230-XX

XC25-060-230-XX 3/8” (10 mm) 1-1/8” (29 mm) ** Field-fabricated

* Applicable to all minor revision numbers unless otherwise specified. ** Some applications may require a field-provided 1-1/8” to 7/8” adapter.

Liquid Line Suction Line

3/8” (10 mm) 7/8” (22 mm)

L15 Line Set Model

L15-65-30 30 feet (9.1 m) 89J60 L15-65-40 40 feet (12.2 m) 89J61 L15-65-50 50 feet (15.2 m) 89J62

Line Set Length Catalog Number

Table 3. XC25 Piping Guidelines

Model

024 180 150 60 60 7/8” 5/8”

036 180 150 60 60 7/8” 3/4”

048 180 150 60 60 7/8” 7/8”

060 180 150 60 60 7/8” 7/8”

Maximum Total

Equivalent Length (ft)

Maximum Linear

(actual) Length (ft)

Maximum Vapor

Riser (ft)

Maximum

Linear Liquid

Lift (ft)

Preferred Vapor Line

Sizes for Horizontal

Runs

Required Vapor

Riser Size

Table 4. Liquid Line Diameter Selection Table

Total Linear Length (feet)

Unit

024

036

048

060

Line Size

5/16” 25 50 55 48 40 33

3/8” 25 50 60 60 60 60

3/8” 25 50 60 56 51 45

1/2” 25 50 60 60 60 60

3/8” 25 50 50 41 31 22

1/2” 25 50 60 60 60 60

3/8” 25 50 36 22 8 NR

1/2”

25 50 75 100 125 150

50 60 60 60 59

Note  Shaded rows indicate rated liquid line size.

1. Find your unit on the left side of the table.

2. Start with the rated liquid line size (shaded row) for the outdoor unit.

3. Select the actual total linear length of your system shown at the top of the table.

4. The elevation listed in the table is the maximum allowed for the liquid line listed.

5. Consider the larger liquid line size shown in the table if the elevation does not meet your requirements.

Max. Elevation

(ft)

XC25

Page 15

LINE SET

INSTALLATION

LINE SET ISOLATION — THE FOLLOWING ILLUSTRATIONS ARE EXAM

PLES OF PROPER REFRIGERANT LINE SET ISOLATION:

REFRIGERANT LINE SET — TRANSITION

FROM VERTICAL TO HORIZONTAL

ANCHORED HEAVY NYLON WIRE TIE OR AUTOMOTIVE

MUFFLER‐TYPE HANGER

AUTOMOTIVE

MUFFLER‐TYPE HANGER

IMPORTANT - Refrigerant lines must not contact structure.

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.

IMPORTANT - Refrigerant lines must not contact wall

OUTSIDE WALL

VAPOR LINE

LIQUID LINE

WALL STUD

STRAP LIQUID LINE TO VAPOR LINE

LIQUID LINE

NON-CORROSIVE

METAL SLEEVE

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

WIRE TIE

INSIDE WALL

WOOD BLOCK

BETWEEN

STUDS

SLEEVE

VAPOR LINE WRAPPED

WITH ARMAFLEX

OUTSIDE

WALL

PVC

PIPE

FIBERGLASS

INSULATION

NOTE - SIMILAR INSTALLATION PRACTICES SHOULD BE USED IF LINE SET IS TO BE INSTALLED ON EXTERIOR OF OUTSIDE WALL.

CAULK

STRAP

NON-CORROSIVE METAL SLEEVE

WIRE TIE

WOOD BLOCK

WIRE TIE

STRAP

LIQUID LINE

FLOOR JOIST OR

ROOF RAFTER

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.

Figure 7. Line Set Installation

XC25

Page 16

Brazing Connections

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

WARNING

IMPORTANT

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

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.

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.

WARNING

Fire, Explosion and Personal Safety Hazard.

Failure to follow this warning could re sult 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 a fire and/or an explosion, that could result in property damage, per sonal injury or death.

XC25

Page 17

PIPING PANEL REMOVAL AND LINE SET PREPARATION

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 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 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 line service

port, nitrogen flow will have an exit point.

SUCTION SERVICE PORT MUST BE OPEN AND

SERVICE PORT CORE REMOVED TO ALLOW

EXIT POINT FOR NITROGEN FLOW

SUCTION LINE

INDOOR

UNIT

SUCTION LINE

SERVICE VALVE

SUCTION LINE SERVICE

VALV E

LOW

ATTACH

GAUGES

OUTDOOR

UNIT

HIGH

SERVICE PORT CORE

SERVICE PORT CAP

LIQUID LINE

LIQUID LINE SERVICE

VALV E

Figure 8. Brazing Procedures

NITROGEN

XC25

Page 18

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

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.

IMPORTANT !

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

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

SUCTION / VAPOR SERVICE PORT

MUST BE OPEN AND SERVICE PORT

CORE REMOVED TO ALLOW EXIT

POINT FOR NITROGEN FLOW

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.

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)

XC25

Page 19

Flushing the System

LINE SET AND INDOOR COIL (1 OF 2)

TYPICAL EXISTING FIXED ORIFICE REMOVAL PROCEDURE (UNCASED COIL

DISTRIBUTOR

ASSEMBLY

A. ON FULLY CASED COILS, REMOVE THE COIL ACCESS AND PLUMBING

PANELS.

B. REMOVE ANY SHIPPING CLAMPS HOLDING THE LIQUID LINE AND DIS

TRIBUTOR ASSEMBLY.

C. USING TWO WRENCHES, DISCONNECT LIQUID LINE FROM LIQUID LINE

ORIFICE HOUSING. TAKE CARE NOT TO TWIST OR DAMAGE DISTRIBU TOR TUBES DURING THIS PROCESS.

D. REMOVE AND DISCARD FIXED ORIFICE, VALVE STEM ASSEMBLY (IF

PRESENT) AND TEFLON

E. USE A FIELD-PROVIDED FITTING TO TEMPORARILY RECONNECT THE

LIQUID LINE TO THE INDOOR UNIT'S LIQUID LINE ORIFICE HOUSING.

SHOWN)

DISTRIBUTOR TUBES

REMOVE AND DISCARD

WHITE TEFLON

LIQUID LINE ORIFICE HOUSING

TEFLON® RING

FIXED ORIFICE

BRASS NUT

(IF PRESENT)

WASHER AS ILLUSTRATED ABOVE.

SEAL

LIQUID LINE ASSEMBLY

(INCLUDES STRAINER)

CONNECT GAUGES AND EQUIPMENT FOR FLUSHING PROCEDURE

INV ERT ED HCFC-22 CYLINDER CONTAINS CLE AN HCFC-22 TO B E USED FOR FLUSHING.

VAPOR LINE

SERVICE VALVE

EXISTING

INDOOR

UNIT

LIQUID LINE SERVICE

RECOVERY

CYLINDER

VALV E

VAPOR

LIQUID

OUTDOOR

NEW

UNIT

OPENED

RECOVERY MACHINE

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.

MANIFOLD

LOW

TANK RETURN

INLET

DISCHARGE

GAUGE

TWO PIECE PATCH PLATE

HIGH

CLOSED

TYPICAL EXISTING EXPANSION VALVE REMOVAL PROCEDURE (UNCASED COIL SHOWN)

(UNCASED COIL ONLY)

DISTRIBUTOR

TUBES

A. ON FULLY CASED COILS, REMOVE THE COIL ACCESS AND PLUMBING

B. REMOVE ANY SHIPPING CLAMPS HOLDING THE LIQUID LINE AND DIS

C. DISCONNECT THE EQUALIZER LINE FROM THE CHECK EXPANSION

D. REMOVE THE VAPOR LINE SENSING BULB.

E. DISCONNECT THE LIQUID LINE FROM THE CHECK EXPANSION VALVE

F. DISCONNECT THE CHECK EXPANSION VALVE FROM THE LIQUID LINE

G. REMOVE AND DISCARD CHECK EXPANSION VALVE AND THE TWO TEF

H. USE A FIELD-PROVIDED FITTING TO TEMPORARILY RECONNECT THE

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER

LINE FITTING

PANELS.

TRIBUTOR ASSEMBLY.

VALVE EQUALIZER LINE FITTING ON THE VAPOR LINE.

AT THE LIQUID LINE ASSEMBLY.

ORIFICE HOUSING. TAKE CARE NOT TO TWIST OR DAMAGE DISTRIBU TOR TUBES DURING THIS PROCESS.

RINGS.

LON

LIQUID LINE TO THE INDOOR UNIT'S LIQUID LINE ORIFICE HOUSING.

LIQUID LINE

SENSING BULB

ORIFICE

HOUSING

EQUALIZER LINE

STUB END

TEFLON RING

VAPOR

CHECK

EXPANSION

VALV E

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

LINE

TEFLON

RING

SENSING

FLUSHING LINE SET

CAUTION -This procedure should not be performed on systems

which contain contaminants (Example, compressor burn out).

THE LINE SET AND INDOOR UNIT COIL MUST BE FLUSHED WITH AT LEAST THE SAME AMOUNT OF CLEAN REFRIGERANT THAT PRE VIOUSLY 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 VACU UM 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 RECOV

ERED, SWITCH THE RECOVERY MACHINE TO VAPOR RECOVERY SO THAT ALL OF THE HCFC-22 VAPOR IS RECOVERED. ALLOW THE RECOVERY MACHINE TO PULL SYSTEM DOWN TO 0.

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 OFF THE MACHINE.

LINE

LIQUID

LINE

XC25

Page 20

FLUSHING LINE SET AND INDOOR COIL (2 OF 2)

TYPICAL NEW CHECK EXPANSION VALVE INSTALLATION PROCEDURE

THIS OUTDOOR UNIT IS DESIGNED FOR USE IN SYSTEMS THAT USE A CHECK EXPANSION VALVE METERING DEVICE. SEE LENNOX XC25 PRODUCT SPECIFICATIONS FOR APPROVED EXPANSION VALVE KIT MATCH-UPS AND APPLICATION INFORMATION.

THE EXPANSION VALVE UNIT CAN BE INSTALLED INTERNAL OR EXTERNAL TO THE INDOOR COIL. IN APPLICATIONS WHERE AN

TWO PIECE

PATCH PLATE

(UNCASED

COIL ONLY)

DISTRIBUTOR

TUBES

DISTRIBUTOR

ASSEMBLY

MALE EQUALIZER LINE

FITTING (SEE

EQUALIZER LINE

INSTALLATION FOR

FURTHER DETAILS)

SENSING BULB INSULATION IS REQUIRED IF MOUNTED EXTERNAL TO THE COIL CASING. SEE SENSING BULB INSTALLATION FOR BULB POSITIONING.

(Uncased Coil Shown)

LIQUID LINE

ORIFICE

HOUSING

STUB

END

TEFLON RING

EQUALIZER LINE

EXPANSION

VALV E

LIQUID LINE

ASSEMBLY WITH

BRASS NUT

VAPOR

LINE

UNCASED COIL IS BEING INSTALLED IN A FIELD-PROVIDED PLENUM, INSTALL THE CHECK EXPANSION VALVE IN A MANNER THAT WILL PROVIDE ACCESS FOR FIELD SERVICING OF THE EXPANSION VALVE. REFER TO BELOW ILLUSTRATION FOR REFERENCE DURING INSTALLATION OF EXPANSION VALVE UNIT.

TEFLON

RING

A. REMOVE THE FIELD-PROVIDED FITTING THAT TEMPORARILY RECON

NECTED THE LIQUID LINE TO THE INDOOR UNIT'S DISTRIBUTOR AS

SENSING

LINE

LIQUID LINE

SEMBLY.

B. INSTALL ONE OF THE PROVIDED TEFLON

STUBBED END OF THE 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 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 IL LUSTRATED IN THE FIGURE ABOVE, OR 20 FT-LB.

D. PLACE THE REMAINING TEFLON

OF THE EXPANSION VALVE. LIGHTLY LUBRICATE CONNECTOR THREADS AND EXPOSE SURFACE OF THE TEFLON FRIGERANT OIL.

E. ATTACH THE LIQUID LINE ASSEMBLY TO THE EXPANSION VALVE. FIN

GER 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.

9 O'CLOCK TO

3 O'CLOCK

BULB

WASHER AROUND THE OTHER END

RINGS AROUND THE

ON LINES SMALLER THAN 7/8”, MOUNT SENSING BULB BETWEEN THE 9 AND 3 O'CLOCK POSITIONS.

SENSING BULB INSTALLATION

VAPOR LINE

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 INSU LATING THE SENSING BULB ONCE INSTALLED.

B. CONNECT THE EQUALIZER LINE

FROM THE EXPANSION VALVE TO THE EQUALIZER VAPOR PORT ON THE VAPOR LINE. FINGER TIGHTEN THE FLARE NUT PLUS 1/8 TURN (7 FT-LBS) AS ILLUS TRATED BELOW.

1/8 TURN

VAPOR LINE

BULB

FLARE SEAL CAP

ON 7/8” AND LARGER LINES, MOUNT SENSING BULB AT EITHER THE 4 OR 8 O'CLOCK POSITION. NEVER MOUNT

BULB

NOTE - NEVER MOUNT THE SENSING BULB ON

BOTTOM OF LINE.

THE SENSING BULB ON BOTTOM OF LINE.

FLARE NUT

1/2 TURN

RING WITH RE

EQUALIZER LINE INSTALLATION

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.

XC25

COPPER FLARE SEAL BONNET

MALE BRASS EQUALIZER LINE FITTING

VAPOR LINE

Page 21

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 PROVIDED FOR THE LIQUID AND SUCTION LINE PIPE PANEL PASS THROUGH.

REAR VIEW OF UNIT EXTERIOR

PIPING PANEL

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.

Leak Testing the System

IMPORTANT

Figure 10. Isolation Grommets

IMPORTANT

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.

Leak detector must be capable of sensing HFC refrigerant.

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.

XC25

Page 22

LEAK TEST

LINE SET AND INDOOR COIL

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.

LOW

HIGH

CONNECT GAUGE SET

A. CONNECT AN HFC-410A MANIFOLD GAUGE SET HIGH PRESSURE

HOSE TO THE VAPOR VALVE SERVICE PORT.

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.

NITROGEN

TEST FOR LEAKS

AFTER THE LINE SET HAS BEEN CONNECTED TO THE INDOOR AND OUTDOOR UNITS, CHECK THE LINE SET CON NECTIONS 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) PRES SURE]. 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.

HFC-410A

MANIFOLD GAUGE SET

TO VAPOR

SERVICE VALVE

OUTDOOR UNIT

XC25

Figure 11. System Leak Test

Page 23

Evacuating the System

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 TO AN

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 IS USED LATER FOR BOTH THE AND NITROGEN CONTAINERS.

OUTDOOR

UNIT

A34000 1/4 SAE TEE WITH SWIVEL COUPLER

500

MICRON

GAUGE

LOW

TO VAPOR

SERVICE VALVE

MANIFOLD

GAUGE SET

HIGH

HFC-410A

TO LIQUID LINE SERVICE VALVE

VACUUM PUMP

NITROGEN

RECOMMEND

MINIMUM 3/8” HOSE

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 REFERS TO THE TOTAL ACTUAL PRESSURE (ABOVE ABSOLUTE ZERO) WITHIN A GIVEN VOLUME OR SYSTEM. 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), CLOSE THE MANIFOLD GAUGE VALVES, TURN

OFF THE VACUUM PUMP AND DISCONNECT THE MANIFOLD GAUGE CENTER PORT HOSE FROM VACUUM PUMP. ATTACH THE MANIFOLD CENTER PORT HOSE TO A DRY NITROGEN CYLINDER WITH PRESSURE REGULATOR SET TO 150 PSIG (1034 KPA) AND PURGE THE HOSE. OPEN THE MANIFOLD GAUGE VALVES TO BREAK THE VACUUM IN THE LINE SET AND INDOOR UNIT. CLOSE THE 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 IN

DOOR 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:

1. Close manifold gauge valves.

. Shut off HFC-410A cylinder. . Reinstall service valve cores by removing manifold hose from service valve. Quickly install cores with core

tool while maintaining a positive system pressure.

. Replace the stem caps and secure finger tight, then tighten an additional one-sixth (1/6) of a turn as illus

trated.

1/6 TURN

Figure 12. Evacuating System

XC25

Page 24

IMPORTANT

Load Shedding

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 temperat ures and pressures present during operation of an air conditioning system. Non-condensables combined with re frigerant 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 air handler installation instructions for additional wiring application diagrams. Refer to unit nameplate for minimum circuit ampacity and maximum over-current protection size.

24VAC TRANSFORMER

Use the transformer provided with the furnace or air hand ler for low‐voltage control power (24VAC - 40 VA minimum).

Utility Load Shedding Mode ACTIVATED (Utility Cycled Unit OFF) – The normally closed set of

contacts in the utility load shedding control receiver OPEN. This removes 24VAC from the coil of the field-provided re lay (catalog # 69J79). The relay contacts close (terminal 7 to terminal 2), completing the circuit between terminals R and L on the outdoor control. The 24VAC input to terminal L activates the load shedding mode in the outdoor control, cycling the outdoor unit OFF. The 7-Segment display on the outdoor control displays a load shedding alert code (E600) and an alert appears on the display of the iComfort

thermostat. The customer receives email notifica

Wi-Fi tions when the alert occurs, if the option to receive notifications is selected.

Utility Load Shedding Mode DEACTIVATED (Normal Equipment Operation) – When load shedding is

not required, the contacts in the utility load control receiver are closed. This provides 24VAC to the coil of the fieldprovided relay (catalog # 69J79).The relay contacts OPEN (terminal 7 to terminal 2) removing 24VAC from the L ter minal on the outdoor control. This deactivates the load shedding mode in the outdoor control. The outdoor unit re turns to normal operation and alert code clears once load shedding mode is deactivated.

For more information, see the Load Shedding Feature Wir ing Diagram on page 44.

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.

Figure 13. Electrical Installation

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 CON TROL BOX.

XC25

Page 25

ROUTE CONTROL WIRES

Maximum length of wiring (18 gauge) for all connections on

the RSBus is 1500 feet (457 meters). Wires should be col or-coded, with a temperature rating of 95 mum, and solid-core (Class II Rated Wiring). All low volt age wiring must enter unit through the provided fieldinstalled busing installed in the electrical inlet.

The iComfort Wi-Fi wires between the thermostat and the furnace / air handler

™

iComfort and the furnace/air handler iComfort™ control. When a thermostat cable with more than four wires is used, the ex tra wires must be properly connected to avoid electrical noise (see below).

Use a wire nut to bundle the four unused wires at each end of the cable. Each bundle should also include an additional wire that should be connected on each end to the C termi nal as shown in the figure below.

control and four wires between the outdoor unit

thermostat requires four thermostat

F (35ºC) mini

ELECTRICAL (CONTROL WIRING)

AND LINE SET INLETS USE BUSHING AND GROMMETS

PROVIDED IN BAG

BUSHING

GROMMETS

Indoor Control

TYPICAL CONTROL BOX

CONTROL WIRING ROUTE (LOW VOLTAGE)

OUTDOOR CONTROL

Outdoor Control

PROVIDED RAST

6-PIN CONNECTOR

Single Wire To

C Terminal

Unused Wires

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 side panel of the control box. Connect conduit to the control box using a proper conduit fitting.

ELECTRICAL INLET

(HIGH VOLTAGE)

Single Wire To C Terminal

Unused Wires

GROUND LUGS

CONTACTOR

iComfort Wi-Fi

thermostat

WATERTIGHT FLEX

IBLE CONDUIT

TO SERVICE

DISCONNECT BOX

Figure 14. Electrical Installation (Continued)

XC25

Page 26

CAUTION

Electrostatic discharge can affect electronic components. Take precautions

ELECTROSTATIC DISCHARGE

(ESD)

Precautions and Procedures

STEP 3 -- ELECTRICAL (Continued) -- Outdoor Control Unit

during unit installation and service to protect the unit's electronic controls. Precautions will help to avoid control exposure to electrostatic discharge by putting the unit, the control and the technician at the same electrostatic potential. Neutralize electrostatic charge by touching hand and all tools on an unpainted unit surface before performing any service procedure.

NOTE - The green LED located on the outdoor control flashes when communication occurs between the outdoor control and either the thermostat or the inverter.

XC25

PUMP DOWN - WHEN THE UNIT IS IN PUMP DOWN MODE,  IS

TO ACTIVATE PUMP DOWN MODE, REFER TO PUMP DOWN

SHOWN ON THE 7-SEGMENT DISPLAY.

Figure 15. Outdoor Control Unit

7-SEGMENT

PUSH

BUTTON

CYCLE SEQUENCE ON PAGE 36.

DISPLAY

Page 27

TABLE 5

Outdoor Control Terminal Designations and Input /Outputs (see figure 15 for terminal locations)

Designator Description Input Output Common

O OUT

LO PS Low pressure switch N/A 5ma @18VAC N/A LO PS Low pressure switch sensing connection 5ma @18VAC N/A N/A Hi PS High pressure switch N/A 24VAC nominal N/A Hi PS High pressure switch sensing connection 24VAC nominal N/A N/A

TP Top cap thermostat switch sensing connection 24VAC nominal N/A N/A

Cntctr

Cntctr Contactor common N/A 24VAC common

Fan PWM PWM fan output N/A

COM PWM fan common connection N/A N/A

Fan Park

Unused on XC25, for heat pump applications only.

Top cap thermostat switch (in series with the HI PS)

Control (inverter power) contactor switched out put (in series with the HI PS and TC)

PWM fan parking spot for unused terminal, not connected.

N/A

N/A N/A 24VAC common

N/A 24VAC nominal N/A

N/A

N/A N/A N/A

Switched 24VAC nominal

Switched 24VAC Nominal

1097% duty cycle, 1923 VDC peak

N/A

Fan PWM com mon

P2 Terminal Designations

Y1 Y1 emergency input

C 24VAC nominal power return. N/A N/A 24VAC common i Low data line. Data Data N/A i+ High data line. Data Data N/A

R 24VAC nominal power input.

DF OEM test N/A N/A N/A

TOUT

TST

Unused on XC25, for heat pump applications only.

26Vdc transistor output to Lennox factory OEM tester

OEM test pin. In each terminal box:

P2  Terminal 1  TEST P2  Terminal 2  TOUT P2  Terminal 3  DF P2  Terminal 4  R

24VAC nominal from ther mostat and loaded to draw 17ma at 30VAC

24VAC nominal board main power input.

N/A N/A N/A

24VAC nominal 17ma @ 30VAC

N/A N/A

XC25

Page 28

Table 5 continued.

Outdoor Control Terminal Designations and Input /Outputs

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

local codes. The 4 pins in P6 have the potential of transferring up to 250 volts to the unit cabinet ground.

Designator Description Input Output Common

Outdoor control

communication

transmit pin.

Inverter common.

P6 - Pin 1 Tx

P6 - Pin 2

Inverter

Common

Transmit data to inverter, connects to Rx of inverter.

Inverter common

NOTE - This is a signal reference point and not an earth ground.

Outdoor control

communication

receive pin.

P6 - Pin 3 Rx

Receive data from the inverter. Connects to Tx of inverter.

P6 - Pin 4 Inv 5V Inverter 5VDC volts. Inverter 5VDC volts

LIQ

Liquid line temperature sensor sup ply.

N/A N/A N/A

• Pin 1 to pin 2 should read 4.5 to 5.5 VDC when not communicating.

• Pin 3 to pin 2 should read 4.5 to 5.5 VDC when not communicating.

• Pin 4 to pin 2 should read 4.5 to 5.5 VDC.

NOTE - Communication signals switch off and on rapidly. This may cause volt meter readings to fluctuate. This is normal. Communication signals will switch between this 5V and common (Pin 2).

LIQ Liquid line temperature sensor return. N/A N/A N/A

AMB

COIL

Pump Down

Outdoor ambient temperature sensor supply.

Outdoor ambient temperature sensor return.

Outdoor coil temperature sensor sup ply.

Outdoor coil temperature sensor re turn.

To initiate pump down function, place jumper in the ON position. (See PUMP DOWN MODE OPERATION on page 37.)

1. Place the jumper in the ON position to

activate pump down mode.

2. Place the jumper in the OFF position to

deactivate pump down mode.

NOTE -If the pump down jumper is in the ON position during power-up, it is ignored.

NOTE - The outdoor control stays in pump down mode for five minutes control initiates a compressor shutdown sequence.

, after which the outdoor

N/A N/A N/A

PUMP

DOWN

OFF

PUMP

DOWN

OFF

24VAC input to L en

L Load shedding input

ergizes load shed

N/A N/A

ding feature.

Load shedding input reference. Refer

to wiring of load shedding terminals

N/A N/A

located on page 44.

24VAC

common

XC25

Page 29

Servicing Units Delivered Void of Charge

If the outdoor unit is void of refrigerant, clean the system us ing the procedure described below.

1. Leak test the system using the procedure outlined on page 22.

2. Evacuate the system using procedure outlined on page 23.

3. Use nitrogen to break the vacuum and install a new fil ter drier in the system.

4. Evacuate the system again using procedure outlined on page 23.

5. Weigh in refrigerant using procedure outlined in figure

57.

6. Monitor the system to determine the amount of mois ture remaining in the oil. It may be necessary to replace the filter drier several times to achieve the required dry ness level. If system dryness is not verified, the

compressor will fail in the future.

Unit Start-Up

IMPORTANT

1. Rotate fan to check for binding.

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

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 unit and close the outdoor unit dis connect switch to start the unit.

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

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.

8. Check system for sufficient refrigerant by using the procedures listed in the System Refrigerant section on

page 69.

XC25

Page 30

III. SYSTEM OPERATION AND SERVICE

7-Segment Alert and System Status Codes

Alert codes are displayed using the 7-segment display loc ated on the outdoor control.

NOTE - System fault and lockout codes take precedence over system status codes (cooling, heating operating per centages or defrost/dehumidification).

The 7-segment will display an abnormal condition (error code) when detected in the system. A list of the codes are shown in table 6.

RESETTING ALERT CODES

Alert codes can be reset manually or automatically:

1. Manual Reset

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

Table 6. Outdoor Control 7-Segment Display Alert Codes and Inverter LED Flash Codes

NOTE - System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or defrost/dehumidification). Only the latest active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Inverter LED Flash

Alert

Codes

N/A N/A ON OFF N/A XC/XP 25-024 and -036 only: Indicates inverter is operating normally.

N/A N/A ON ON N/A XC/XP 25-048 and -060 only: Indicates inverter is operating normally.

N/A N/A OFF OFF N/A Indicates inverter is NOT energized.

E 105 N/A N/A N/A Moderate

E 120 N/A N/A N/A Moderate

E 124 N/A N/A N/A Critical

E 125 N/A N/A N/A Critical

E 131 N/A N/A N/A Critical

E 132 N/A N/A N/A Critical

E 180 N/A N/A N/A Critical

Inverter

Code

Code (number of

flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

The outdoor control has lost communic ation with either the thermostat or in door unit.

There is a delay in the outdoor unit re sponding to the system.

The iComfort WiFi thermostat has lost communication with the outdoor unit for more than 3 minutes.

There is a hardware problem with the outdoor control.

The outdoor unit con trol parameters are corrupted.

Internal software er ror.

The outdoor unit am bient temperature sensor has malfunc tioned. As a result the outdoor unit con trol will not perform low ambient cooling.

• Disconnecting R wire from the outdoor control R

terminal.

• Turning the indoor unit off and back on again

After power up, all currently displayed codes are cleared.

2. Automatic Reset

After an alert is detected, the outdoor control continues to monitor the unit's system and compressor opera tions. When/if conditions return to normal, the alert code is turned off automatically.

NOTE - Error codes can be recalled by following in formation shown in the table on page 35.

thermostat.

Equipment is unable to communicate. Indicates numerous message errors. In most cases errors are related to electrical noise. Make sure high voltage power is separated from RS Bus. Check for miswired and/or loose connections between the stat, indoor unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault clears after commu nication is restored.

Typically, this alarm/code does not cause any issues and clears on its own. The alarm / code is usually caused by a delay in the outdoor unit responding to the thermostat. Check all wiring connections. Cleared after unresponsive device re sponds to any inquiry.

Equipment lost communication with the thermostat. Check the wiring connections, ohm wires and cycle power. The alarm stops all associated HVAC operations and waits for a heartbeat message from the unit that's not communicating. The alarm / fault clears after communication is reestablished.

There is a control hardware problem. Replace the outdoor con trol if the problem prevents operation and is persistent. The alarm / fault is cleared 300 seconds after the fault recovers.

Reconfigure the system. Replace the control if heating or cool ing is not available.

Replace outdoor control.

In normal operation, after outdoor control recognizes sensors, the alarm is sent if valid temperature reading is lost. Compare outdoor sensor resistance to temperature/resistance charts in unit installation instructions. Replace sensor pack if necessary. At the beginning of (any) configuration, furnace or airhandler control detects the presence of the sensor(s). If detected (read ing in range), appropriate feature is shown in the iComfort

WiFi

thermostat About screen. The alarm / fault clears upon

configuration, or when normal values are sensed.

XC25

Page 31

Table 6 continued

Inverter LED Flash

Alert

Codes

E 345

E 409 N/A N/A N/A Moderate

E 410 N/A N/A N/A Moderate

E 411 N/A N/A N/A Critical

E 412 N/A N/A N/A Moderate

E 413 N/A N/A N/A Critical

E 416 N/A N/A N/A

E 422 N/A N/A N/A Moderate

E 423 40 4 flashes OFF

E 424 N/A N/A N/A Moderate

Inverter

Code

N/A

Code (number of

flashes)

Priority

Red LED Green LED

N/A N/A Critical

Moderate / Critical

Moderate

/ Critical

Alarm Description Possible Causes and Clearing Alarm

The O relay on the airhandler or outdoor unit has failed. Either the pilot relay contacts did not close or the relay coil did not energize.

Outdoor control sec ondary voltage is 18VAC or less.

The outdoor unit low pressure switch has closed.

The low pressure switch has opened 5 times within one hour. As a result, the out door unit is locked out

The outdoor unit high pressure switch has opened.

The high pressure switch has opened 5 times within one hour. As a result, the out door unit is locked out

The outdoor coil sensor has malfunc tioned. As a result the outdoor unit control will not perform defrost.

Compressor top cap switch exceeding thermal limit.

The inverter has de tected a circuit prob

lem

The liquid line tem perature sensor has malfunctioned.

O relay / Sage 1 failed. Pilot relay contacts did not close or the relay coil did not energize. Replace control. Fault clears after a power re set.

Secondary voltage is below 18VAC. After 10 minutes, operation is discontinued. Check the indoor line voltage and transformer output voltage. The alarm clears after the voltage is higher than 20VAC for 2 seconds or after a power reset.

Unit pressure is below the lower limit. The system is shutdown. The low pressure switch opens at 25PSIG and closes at 40PSIG. Con firm that the system is properly charged with refrigerant. Check TXV, indoor unit blower motor, dirty filters or clogged refrigerant fil ter. Confirm that the evaporator coil is clean. The alarm clears after the pressure switch opens or after a power reset.

Low pressure switch error count reached 5 strikes. The low pres sure switch for HFC410A opens at 40PSIG and resets at 90PSIG. Confirm that the system is properly charged with refrigerant. Check for clogged TXV, blockage to indoor unit blower motor, dirty filters or clogged refrigerant filter. Confirm that the evaporator coil is clean.

The alarm clears after a power reset.

Unit pressure is above the upper limit. System is shut down. The high pressure switch opens at 590PSIG and closes at 418PSIG. Confirm that the system is properly charged with refrigerant. Check for clogged TXV, blockage to indoor unit blower motor, clogged refri gerant filter. Confirm that the outdoor unit is clean. The alarm clears after the pressure switch closes or a power reset.

For heating, indoor CFM may be set too low. For zoning system, zone CFM may be set too low.

Open high pressure switch error count reached 5 strikes. System is shut down. The high pressure switch for HFC410A opens at 590PSIG and closes at 418PSIG. Confirm that the system is prop erly charged with refrigerant. Check condenser fan motor, for clogged TXV, for blockage to indoor unit blower motor, for stuck re versing valve or clogged refrigerant filter. Confirm that the outdoor unit is clean. The alarm clears after a power reset.

For heating, indoor CFM may be set too low. For zoning system, zone CFM may be set too low.

Coil sensor being detected open or shorted, or temperature is out of coil sensor range. Outdoor unit control will not perform demand or time/temperature defrost operation. System is still able heat and cool. Check the resistance of the coil sensor and compare to tem perature resistance chart. Replace coil sensor if needed. The alarm clears when outdoor unit control detects proper coil sensor readings or after a power reset.

Check condenser fan motor, TXV, indoor unit blower motor, stuck reversing valve, clogged refrigerant filter or undercharge. When error occurs with inverter slowdown errors, check for system over charge. Automatically clears when error is corrected.

Control locks out after 10 strikes within an hour. To clear, disconnect power to outdoor unit and restart.

In normal operation, after outdoor control recognizes sensors, the alarm is sent if valid temperature reading is lost. Compare liquid line sensor resistance to temperature/resistance charts in unit installation instructions. Replace sensor pack if necessary. At the beginning of (any) configuration, furnace or airhandler control detects the pres ence of the sensor(s). If detected (reading in range), appropriate fea ture is shown in the iComfort WiFi alarm / fault clears upon configuration, or when normal values are sensed.

thermostat About screen. The

XC25

Page 32

Table 6 continued

Inverter LED Flash

Alert

Codes

Inverter

Code

E 425 N/A N/A N/A Minor

E 426 N/A N/A N/A Critical

E 427 21 2 flashes 1 flash

E 428 22 2 flashes 2 flashes

E 429 23 2 flashes 3 flashes

E 430 26 2 flashes 6 flashes

E 431 27 2 flashes 7 flashes

E 432 28 2 flashes 8 flashes

E 433 29 2 flashes 9 flashes

E 434 53 5 flashes 3 flashes

Code (number of flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

Moderate

/ Critical

Moderate

/ Critical

Moderate

/ Critical

Moderate

/ Critical

Moderate

/ Critical

Moderate

/ Critical

Moderate

/ Critical

Moderate / Critical

Outdoor control has increased minimum compressor speed to allow for proper oil return due to low ambient temperat ure.

Excessive inverter alarms

The inverter has de tected a DC peak fault condition

The inverter has de tected a high main input current condi tion

The inverter has de tected a DC link low voltage condition

Compressor start failure

The inverter has de tected a PFC circuit over-current condi tion

The inverter has de tected a DC link high voltage condition.

The inverter has de tected a compressor over-current condi tion

Outdoor control has lost communica tions with the invert er for greater than 3 minutes.

Outdoor ambient temperature is below system limit. Control at tempts to run at lowest allowed compressor speed to allow for proper oil return. Automatically clears when outdoor ambient temperature rises above limit for more than 5 minutes.

After ten faults within one hour, control is locked out, indicating poor system operation. Review history of alarms to resolve sys tem setup. Check condenser fan motor, TXV, indoor unit blower motor, over-charge, undercharge, or clogged refrigerant filter. To clear error, disconnect power to outdoor unit and restart. In verter alarms 12 to 14 and 53 do not count toward this lock out condition.

If condition (55A or higher) is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If peak current (55A or higher) occurs 10 times within an hour, system is locked out. Indicates high pressure, condenser fan failure, locked com pressor rotor or overcharge. To clear, disconnect power to outdoor unit and restart.

If condition is detected, is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 5 times within an hour, system is locked out. Indicates high pressure, condenser fan failure or overcharge. To clear, disconnect power to outdoor unit and restart.

Error occurs when DC link voltage drops below 14VDC. If condi tion is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 10 times within an hour, sys tem is locked out. Indicates power interruption, brownout, poor electrical connec tion or loose inverter input wire. To clear, disconnect power to outdoor unit and restart.

If condition is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 10 times within an hour, system is locked out. Indicates poor connection at compressor harness, improper winding resistance, locked compressor rotor, or flooded com pressor. To clear, disconnect power to outdoor unit and restart.

Error occurs when PFC detects a over-current condition of 100A peak. If condition is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 10 times within an hour, system is locked out. Indicates high pressure, condenser fan failure, locked com pressor rotor or overcharge. To clear, disconnect power to outdoor unit and restart.

Error occurs when the DC link capacitor voltage is greater than 480VDC. If condition is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 10 times within an hour, system is locked out. System stops. To clear, dis connect power to outdoor unit and restart.

Error occurs when compressor peak phase current is greater than 28A. Inverter issues code 14 first and slows down to try to reduce the current. If the current remains high, outdoor unit com pressor and fan stop. Antishort cycle is initiated. If condition oc curs 5 times within an hour, system is locked out. To clear discon nect power to outdoor unit and restart.

Error occurs when communication a checksum error occurs for 3 minutes. Outdoor control stops all compressor demands. Re cycle power to the inverter by deenergizing the contactor for 2 minutes.

XC25

Page 33

Table 6 continued

Inverter LED Flash

Alert

Codes

Inverter

Code

E 435 60 6 flashes OFF

E 436 62 6 flashes 2 flashes

E 437 65 6 flashes 5 flashes

E 438 73 7 flashes 3 flashes

E 439 12 1 flash 2 flashes Moderate

E 440 13 1 flash 3 flashes Moderate

E 441 14 1 flash 4 flashes Moderate

E 442 N/A N/A N/A Critical

E 443 N/A N/A N/A Critical

E 600 N/A N/A N/A Critical

E 601 N/A N/A N/A Critical

Code (number of

flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

Moderate / Critical

Inverter internal er ror.

Inverter heat sink temperature ex ceeded limit

Heat sink temperat ure sensor fault has occurred (temperat ure less than 4 ºF or greater than 264ºF after 10 minutes of operation)

The inverter has de tected a PFC circuit over-current condi tion

Compressor slow down due to high in put current.

Compressor slow down due to high heatsink temperat ure.

Compressor slow down due to high compressor current.

The top cap switch has opened 5 times within one hour. As a result, the outdoor unit is locked out

Incorrect appliance unit size code selec ted.

Compressor has been cycled OFF on utility load shedding.

Outdoor unit has been cycled OFF on low temperature protection.

When this error occurs, the outdoor control cycles power to the inverter by opening the contactor for 2 minutes. Check that the EEPROM is properly seated. After power is cycled to the inverter 3 times, the outdoor unit is locked out

Occurs when the heat sink temperature exceeds the inverter limit. Inverter issues code 13 first, then slows down to allow the heat sink to cool. If temperature remains high, outdoor unit stops (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, system is locked out. To clear, disconnect power to outdoor unit and restart.

Occurs when the temperature sensor detects a temperature less than 0.4ºF or greater than 264ºF after 10 minutes of op eration. If condition is detected, outdoor unit will stop (com pressor and fan). Antishort cycle is initiated. If condition oc curs 5 times within an hour, system will lock out. To clear dis connect power to outdoor unit and restart. If problem persists, replace inverter.

Occurs when PFC detects an input over-current condition of 35A peak. If condition is detected, outdoor unit will stop (com pressor and fan). Antishort cycle is initiated. If condition oc curs 10 times within an hour, system will lock out. Indicates high pressure, condenser fan failure, or locked compressor rotor. To clear, disconnect power to outdoor unit and restart.

Input current is approaching a high limit. Compressor speed automatically slows. The control continues sending the in verter speed demanded by the thermostat. The control sets indoor CFM and outdoor RPM to values according to demand percentage rather than the actual Hz. Alarm is automatically cleared.

Heat sink temperature is approaching limit. The compressor speed automatically slows to reduce heatsink temperature. The control sets indoor CFM and outdoor RPM to values ac cording to demand percentage rather than the actual Hz. Alarm is automatically cleared.

Compressor current is approaching high limit. The com pressor speed automatically slows. The control will set in door CFM and outdoor RPM to values according to demand percentage rather than the actual Hz. Alarm is automatically cleared.

When compressor thermal protection sensor opens 5 times within 1 hour, outdoor stops working. To clear, disconnect power to outdoor unit and restart.

Check for proper configuring of unit size codes for outdoor unit in configuration guide or in installation instructions. If replacing inverter, verify inverter model matches unit size. The alarm/fault clears after the correct match is detected following a reset. Remove the thermostat from the system while applying power and reprogramming.

Load shedding function: Provides a method for a local utility company to limit the maximum power level usage of the out door unit. The feature is activated by applying 24 volts AC power to the L and C terminals on the outdoor control.

Low temperature protection: Outdoor unit will not operate when the outdoor temperature is at or below 4°F (20°C). If the unit is operating and the outdoor temperature drops be low 4°F (20°C), the unit continues to operate until the room thermostat is satisfied or the outdoor temperature drops to 15°F (26°C). Outdoor unit ambient sensor provides tem perature readings.

XC25

Page 34

POWER-UP / RESET:

7-SEGMENT POWER-UP DISPLAY STRING

FIRMWARE VERSION: During initial power-up or reset, the first item displayed is the outdoor control firmware version. Example to the right shows firmware version 2.3.

UNIT TYPE: The next item displayed is the self discovery unit type. AC = air conditioner and HP = heat pump. If the unit type cannot be determined, three bars appear.

UNIT NOMINAL CAPACITY: The next item to be displayed is the self-discovery unit nominal capacity. Valid capacities are 24 for 2-ton, 36 for 3-ton, 48 for 4-ton and 60 for 5-ton units. If the unit type cannot be determined, three bars ap pear.

UNIT CODE: The next item to be displayed is the self discov ery unit code. (may be a single character or two characters). If the unit code cannot be determined, three bars appear.

UNIT CODE



  

UNIT TYPE, SIZE AND MODEL

NOT PROGRAMMED

2-TON HEAT PUMP, XP25-024

3-TON HEAT PUMP, XP25-036

4-TON HEAT PUMP, XP25-048

5-TON HEAT PUMP, XP25-060





THROUGH



(These are just examples of firmware version, unit type,



FIRMWARE

VERSION

unit nominal capacity and unit codes.)

7-SEGMENT POWER-UP DISPLAY STRING EXAMPLE



UNIT

TYPE













UNIT

CAPACITY



UNIT

CODE



IDLE MODE





 



Description Example of Display

Idle Mode: Decimal point flashes at 1 Hz.

Soft Disabled: Top and bottom horizontal line and decimal point

flash at 1 Hz.

O.E.M. Test Mode

Anti-Short Cycle Delay

Cooling Cycle: Shows current percentage of maximum cooling

capacity. Example to the right indicates a cooling demand of 50 percent and a outdoor fan speed of 700 RPM.

2-TON AIR CONDITIONER, XC25-024

3-TON AIR CONDITIONER, XC25-036

4-TON AIR CONDITIONER, XC25-048

5-TON AIR CONDITIONER, XC25-060

Figure 16. Outdoor Control 7-Segment Unit Status Displays

Table 7. Outdoor Control 7-Segment Unit Status Displays

Idle Mode: Decimal point flashes at 1 Hz (0.5 second on, 0.5 second off). Display OFF.

Soft Disabled: Top and bottom horizontal line and decimal point flash at 1 Hz (0.5 second on, 0.5 second off). NOTE - Control should be replaced.

All segments flashing at 2 Hz (unless error is detected) NOTE - Control

should be replaced.

The middle line flashes at 1 Hz for 2 seconds, followed by a 2-second dis play of the number of minutes left on the timer (value is rounded up: 2 min. 1 sec. is displayed as 3). If activated, the anti-short cycle delay time remain ing is displayed (default is 300 sec./5 min.).

The demand percentage is displayed first, followed by a pause, then the outdoor fan speed and the ambient temperature.

   pause     pause   

XC25

Page 35

Table 6 continued

Description Example of Display

Diagnostic recall: Shows the last 10 stored diagnostic error

codes.

Fault memory clears

Active error in outdoor control Idle mode: Show all active

error(s) codes.

Active error in run mode: Show current status and all active error(s) codes.

Outdoor Ambient Temperature (OAT): Any time OAT is within operating range, value is displayed if unit is in diagnostic and non-diagnostic modes.

Outdoor Coil Temperature (OCT): Any time OCT is sensed in operating range, value is displayed if unit is in diagnostic mode or manually enabled for non-diagnostic modes.

Liquid Line Temperature (LIQ): Any time LIQ is sensed in oper ating range, value is displayed if unit is in diagnostic mode or manually enabled for non-diagnostic modes.

Pump Down Mode: While the unit is in pump down mode,   is displayed repeatedly. Errors are shown if they exist.

If first error is    , second     pause     pause

   

Next codes (up to 10) are show using same method.

If there are no error codes stored:  pause    . After the fault memory is cleared, the following display string will displayed with 0.5 seconds char acter ON / OFF time:

    pause

Following display string is repeated if Error E 125 and E 201 are present:

    pause    

Following display string is repeated if Error E 440 is present while outdoor fan speed at 700RPM:

    pause    

Following display string is repeated if cooling is active with outdoor fan speed set at 650 RPM and OAT is 104

   pause     pause     pause

Following display string is repeated if heat is active with outdoor fan speed set at 550 RPM and OCT is 25

   pause     pause    pause

Following display string is repeated if cooling is active with outdoor fan speed set at 650 RPM and LIQ is 105

   pause     pause     pause

Following display string is repeated:

  pause  

 

pause     pause   pause    

PUSH−BUTTON OPERATION

Allows field access to Diagnostic, Fan, Defrost and Error Code Re call modes.

To enter mode options, push and hold button next to 7seg ment display until DASH symbol appears. Immediately re lease the button. Once dash starts flashing, proceed to next step.

Push and hold button until the selection stops flashing, then release button. The 7 seg ment display shows the selected mode and the control performs the selected function.

Outdoor control must be in IDLE mode (no heating or cooling operation).

NOTE - See table 6 for explanation of codes.

Push and hold button until mode selection displays on the 7seg

ment display (, ,    ,  or ). Immediately release the button,

proceed to next step.



Figure 17. Push-Button Operation

Unit Selection Code for Outdoor Control

If the single-character display shows three (3) horizontal lines, the unit selection code needs to be programmed. Press and hold the button until the   menu option is displayed, release button. The singlecharacter display displays the selected mode per example in figure 16 on page 34. When the desired unit selection code appears, press and hold the button until it stops flashing, then release.

Unit Code Unit Type Unit Model

  





 

2-ton heat pump XP25-024

3-ton heat pump XP25-036

4-ton heat pump XP25-048

5-ton heat pump XP25-060

2-ton air conditioner XC25-024

3-ton air conditioner XC25-036

4-ton air conditioner XC25-048

5-ton air conditioner XC25-060

XC25

Page 36

Idle mode — System is energized with no demand — Decimal flashes at 1 Hertz > 0.5 second ON, 0.5 second OFF.

Display Symbol or Character

Displayed

during start-up

or power

recycling.

Display Fan Test and Display String Option

Display string shows outdoor control firmware version    > pause>   or   unit >pause>unit capacity in BTUs>pause >unit code. If 3 horizontal bars are displayed during any sequence of this display string, it indicates that the specific parameter is not configured.

Idle mode — decimal flashes at 1 Hertz > 0.5 second ON, 0.5 second OFF

 or  Indicates either cooling () or heating () mode and demand percentage.

 





Error Code Recall Mode (NOTE - control must be in idle mode)



—



Code displays when system is in defrost mode. To enter defrost mode, unit must be running in heating mode, outdoor ambient must be below 65F and outdoor coil temperature must be below defrost termination temperature.

Control must be in Idle mode: To enter fan test option -  mode, push and hold button until solid – appears, release button. Display begins flashing. Within 10 seconds, push and

Indicates outdoor fan RPM speed.

 in the display string represents the

ambient temperature in F at the sensor on the outdoor unit. In display configuration mode, it also repres ents the option for enabling both coil and liquid line temperature on the 7-segment display string.

To enter error code recall mode, push and hold button until solid  appears, then release button. Control displays up to 10 error codes stored in memory. If     is displayed, there are no stored error codes.

To exit error code recall mode, push and hold button until solid three horizontal bars appear, then release button. Note - Error codes are not

cleared.

To clear error codes stored in memory, continue to hold button while the 3 horizontal bars are displayed. Release button when solid  is displayed.

Push and hold for one (1) second, release button. 7-Segment displays     and exits error recall mode.

hold button until required symbol  displays, release button. Display begins flashing. With in 10 seconds, push and hold button until display stops flashing, release button. Control outputs DC voltage on PWM and COM terminals. Outdoor fan cycles ON for 10 minutes at 490 RPM. To exit test – Push and hold button until three horizontal bars display. Release button, outdoor fan cycles OFF.

Control can be in Idle or demand mode: To enter display configuration option -  mode, push and hold button until solid – appears, release button. Display begins flashing. Within 10 sec onds, push and hold button until required symbol flashing. Within 10 seconds, push and hold button until display stops flashing, release button. Display shows error () code(s), ambient (), outdoor coil ( ) and liquid () temperatures in Fahrenheit.

NOTE - If button is not pushed in the 10-second time period, the control exits the test mode. If this occurs, test mode must be repeated.

 displays, release button. Display begins

FIELD TEST MODE OPERATION

The field test mode allows the unit to be put into diagnostic mode and allows the installer to perform multiple tests on the control / unit.

Diagnostic Mode

Diagnostic mode is only available when the system is idle or during an active / suspended call for heating or cooling. Diagnostic mode is terminated when the exit command is given, the button is pressed and released without entering the diagnostic menu or 10 minutes has passed, whichever comes first.

When this mode is selected all installed temperature sensor valves (non-open and non-short) are shown on the 7-segment display. The following system status codes are displayed:

D Cooling D Percentage demand operation D Outdoor fan RPM D Active error codes

Outdoor Fan Mode

Diagnostic mode is only available while the system is in idle mode. This mode can be exited with the proper command or after 10 minutes has passed.

In diagnostic mode, the control ,energizes the outdoor fan at the highest speed. The control continuously displays the fan RPM on the 7-segment display.

PUMP DOWN MODE OPERATION

1. Turn room thermostat OFF.

2. Install a set of refrigerant gauges on the system to monitor the pressure.

NOTE - All operation monitoring devices: High pressure switch, low pressure switch and compressor internal vacu um protection remain active in the system. This will prevent the compressor from recovering all the system refrigerant into the outdoor unit.

NOTE - If the pump down jumper is in the ON position dur ing power-up, it is ignored.

3. Move the Pump Down jumper (page 26 for location) from the OFF position to the ON position.

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Page 37

6. Monitor the low-side pressure at the outdoor unit. The internal vacuum protection in the compressor and/or

PUMP DOWN

OFF

PUMP DOWN

OFF

one of the pressure switches prevents full recovery of the refrigerant into the outdoor unit. When the system reaches this condition, the suction line service valve should be shut off and the Pump Down Jumper moved back to the OFF position.

Figure 18. Pump Down Jumper

4. Shut off the liquid line service valve to stop the flow of refrigerant into the indoor coil.

NOTE - The outdoor control will stay in pump down mode for five minutes

, after which the outdoor control initiates a

compressor shutdown sequence.

5. After a three-second delay, the compressor and out door fan will ramp up to 100% capacity. (Indoor fan will remain OFF.)

7. Use a refrigerant recovery machine to recover the re maining refrigerant on the indoor side of the system.

Table 8. Field Test, Diagnostic Recall and Program Menu Options

Display

No Change - idle (*)

Solid . Solid  Solid  Solid  Solid 

String  

*No change indicates the display will continue to show whatever is currently being displayed for normal operations.

**Note once the error history is deleted it cannot be recovered. After the history is deleted, the unit will reset itself.

Display and action (normal operation)

No Change - idle (*)

Enter or exit field test and program mode.

Puts unit in diagnostic mode. (Displays ambient, coil, liquid sensor temperatures and any active error codes.)

Clears error history (**)

Enter diagnostic recall mode. Displays up to 10 error codes in memory.

Starts outdoor fan.

Enter unit code programming.

Table 9. Normal Operation Character Display String

Display

 

Display and action (normal operation) Display and action (configuration and test mode)

Idle mode — decimal flashes at 1 Hertz > 0.5 second ON, 0.5 second OFF

Cooling operation. Shows  and the cooling demand percentage. Example:    pause     pause   

Fan RPM. Shows  and the current fan RPM. Example:    pause     pause   

  in the display string represents the active error code(s) in the outdoor unit.

Example:    pause     pause     pause     pause    pause

  in the display string represents the outdoor ambient temperature in F at the outdoor sensor on the outdoor unit.

Example:    pause     pause   

 If enabled,  in the display string represents the outdoor coil temperature in F at the sensor on the outdoor unit.

Example:    pause     pause    pause    pause. Air conditioning units do not require an outdoor coil sensor. A 10K resistor, across pins 5 and 6 on the outdoor control sensor harness, prevents false outdoor coil sensor codes. The 10K resistor causes the 7-segment display to show a constant 77ºF coil (c) temperature value.

 If enabled,  in the display string represents the outdoor liquid line temperature in F at the sensor on the outdoor unit.

Example:    pause     pause    pause    pause pause     pause

 

 

COOLING AT

50% DEMAND

BY DEFAULT, COOLING OR HEATING, DEMAND, OUTDOOR FAN RPM, ACTIVE ERROR CODES

  displays when system is in pump down mode.

TYPICAL 7-SEGMENT ACTIVE COOLING OR HEATING DEMAND DISPLAY STRING





OUTDOOR

FAN RPM

AND OUTDOOR AMBIENT TEMPERATURE ARE DISPLAYED.

ACTIVE ERROR

CODE (IF PRESENT)



 

OUTDOOR

AMBIENT AIR

TEMP

STRING REVERTS BACK TO DEFAULT (SEE FIGURE 20 TO ENABLE)





OUTDOOR

COIL TEMP(*)

OUTDOOR COIL AND LIQUID LINE TEMPERATURES CAN BE

MANUALLY ENABLED. IF SYSTEM POWER IS RECYCLED, DISPLAY





OUTDOOR LIQUID

LINE TEMP





* Air conditioning units do not require an outdoor coil sensor. A 10K resistor, across pins 5 and 6 on the outdoor control sensor harness, prevents false outdoor coil sensor codes. The 10K resistor causes the 7-segment display to show a constant 77ºF coil (c) temperature value.

Figure 19. Typical 7-Segment Demand Display String

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Page 38

How to enable liquid line temperature information on a 7-segment display

Both coil and liquid line temperatures can be enabled for display either during normal demand operation or while in idle mode.

NOTE - If system power is recycled, display string reverts back to

default. Repeat the procedure which enables the outdoor coil and

liquid line temperature information. All temperatures are dis

played in Fahrenheit.

Yes

To enable temperature display, push and hold button next to 7-segment display until dash symbol appears and immediately release button. Once dash starts flashing, proceed to next step.

Push and hold the button until the solid

 appears on the 7-segment display.

Then, immediately release the button.

During thermostat demand of the outdoor control, the 7-segment display shows the cooling or heating (percent demand), fan RPM, error codes if present, and outdoor ambient, Coil and liquid line temperatures need to be manually enabled to be displayed.





PERCENTAGE OF

MAXIMUM CAPACITY

NOTE - The coil and liquid line temperature readings are temporarily shown on the outdoor 7-segment display when the iComfort Wi-Fi® diagnostic screen is accessed.



FAN RPM





 

ACTIVE ERRORS

Outdoor control is either in IDLE

mode or heating / cooling

demand)



ONLY

OUTDOOR

Push and hold button until the flashing release button. The display shows the coil and liquid line temperature if there is an active demand running.

AMBIENT

 stops flashing then







OUTDOOR COIL

TEMP (*)

Wait until unit returns to a active demand or

idle mode.



 

OUTDOOR LIQUID

LINE TEMP



Figure 20. Enabling Liquid Line Temperature Information

XC25

Page 39

Configuring Unit

When installing a replacement outdoor control, the unit selection code may have to be manually assigned using the 7-seg ment display and push button on the control. The unit code sets unit type, capacity and outdoor fan RPM.

Configuring Unit Selection Code

Power-up - Unit selection code (two-digit number) displayed

represents unit size code (outdoor unit capacity). During initial power-up, firmware version, unit type, unit capacity and unit selection code will appear on the 7-segment display.

If three horizontal bars are shown in the 7-segment display during power-up, the outdoor control did not store the last configuration setting. If this happens, the configuration se quence for that setting must be repeated.

−

To enter unit selection mode, push and hold the

button next to the 7-segment display until dash symbol appears and immediately release button. Once dash starts flashing, proceed to next step.

Push and hold button until the solid  sequence is displayed on the 7-segment display then immediately release the button. This configuration sequence allows the installer to select unit selection code (number combination) that matches the outdoor unit type and inverter.

Press and hold the button during the  cycling display.

NOTE - Either the PU sequence will repeat 5 times and if a selection is not made the control will return to idle mode.

Yes

UNIT SELECTION

CODE



NOT

SELECTED

Outdoor control is in IDLE mode

(No heating or cooling demand)



Turn room thermostat

to OFF

1. When the correct unit section code is displayed, release but ton immediately. [Display flashes.]

2. Push and hold button until selection stops flashing during one of the three cycles. [Release push button]

3. If selection is not made during those three cycles the control returns to idle mode.

UNIT SELECTION

CODES

2-TON HEAT PUMP (XP25-024)

3-TON HEAT PUMP (XP25-036)

4-TON HEAT PUMP (XP25-048)

5-TON HEAT PUMP (XP25-060)

2-TON AIR CONDITIONER (XC25-024)

3-TON AIR CONDITIONER (XC25-036)

4-TON AIR CONDITIONER (XC25-048)

5-TON AIR CONDITIONER (XC25-060)

UNIT

SELECTED

NOT

SELECTED

If three horizontal bars display in any part of the 7-segment display string during power-up, the outdoor control did not store the unit selection code. If this occurs, the configuration sequence for that section of the display string must be repeated.

−

The outdoor control stores the unit type, automatically exits the con figuration mode and resets.

EXAMPLE 7-SEGMENT DISPLAY STRING



FIRMWARE

VERSION





UNIT

TYPE



UNIT

CAPACITY

Figure 21. Configuring Unit Selection Code





UNIT

CODE



IDLE MODE

(NO DEMAND)

XC25

Page 40

Reconfiguring Outdoor Control using

iComfort Wi-Fi

Thermostat

If any component of the HVAC system is changed, e.g. re placing an outdoor sensor, reconfiguring the system is required. To begin reconfiguring a system, select the

Setup tab.

System Overview

Refer to the iComfort Wi-Fi® Thermostat Installer Setup Guide for configuration procedures.

IMPORTANT

Some scroll compressors have internal vacuum protector that will unload the 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 outdoor control provides the following functions:

D Internal switching of outputs D Compressor anti-short-cycle delay (adjustable

through the thermostat interface.

D Five-strike lockout function D High (S4) and low (S87) pressure switches

D Ambient (RT13) and liquid line (RT36) temperatures

monitoring and protection.

COMPRESSOR PROTECTION — FIVE-STRIKE LOCKOUT

The five-strike lockout function is designed to protect the compressor from damage. The five-strike feature is used for both high (S4) and low (S87) pressure switches.

Resetting Five-Strike Lockout

Once the condition has been rectified, power to the outdoor control R terminal must be cycled OFF.

Diagnostic Information

The following diagnostic information is available through the thermostat's user interface. Refer to the iComfort

Installer's System Setup Guide.

Wi-Fi

D Compressor anti-short cycle delay timer status D Cooling rate D Compressor shift delay timer status D High pressure switch status D Low pressure switch status D Compressor top cap switch status D Liquid line temperature D Outdoor ambient temperature D Outdoor fan RPM D Compressor active alarm D Compressor Hz D Inverter compressor short cycle D Heat sink temperature

Installer Test

Verify the proper operation of the system by running the In staller Test feature through the thermostat interface. Refer to the iComfort Wi-Fi

COMPRESSOR SHORT CYCLING DELAY

The outdoor control protects the compressor from:

D Short cycling (five minutes) when during initial power-

D Interruption in power to the unit D Pressure or sensor trips D Delay after demand is removed

The delay is set by default for 300 seconds (five minutes) but can be changed through the thermostat interface.

Available settings are 60, 120, 180, 240 and 300 seconds.

CRANKCASE HEATER (HR1)

Compressors in all units are equipped with a 40-watt bellyband-type crankcase heater. HR1 prevents liquid from accumulating in the compressor. HR1 is controlled by the crankcase heater thermostat.

CRANKCASE HEATER THERMOSTAT (S40)

Thermostat S40 controls the crankcase heater in all units. S40 is located on the liquid line. When liquid line temperat ure drops below 50°F, thermostat S40 closes, energizing HR1. The thermostat opens, de-energizing HR1, once li quid line temperature reaches 70°F.

Installer System Setup Guide.

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Page 41

Maintenance

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

2. Outdoor unit fan motor is pre-lubricated and sealed. No further lubrication is needed.

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

4. Check all wiring for loose connections.

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

6. Check amp draw on outdoor fan motor.

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

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

Outdoor Coil

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

D Outdoor Coil — The outdoor coil may be flushed with

a water hose.

D Outdoor Coil (Coastal Area) — Moist air in ocean loca

tions 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 includ ing the outdoor coil. Consult your installing contractor for proper intervals/procedures for your geographic area or service contract.

Indoor Unit

1. Clean or change filters.

2. Lennox blower motors are pre-lubricated and perman ently 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. Check all wiring for loose connections.

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

6. Check amp draw on blower motor.

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.

Locations with Possibility of Heavy Snow or

Freezing Rain Accumulation

Heavy snow and/or freezing rain can interfere with the per formance of the outdoor fan assembly. Lennox recommends use of the optional snow guard (X8782) in these areas.

Figure 22. Snow Guard Top Cover — X8782

SunSource® Home Energy System

This Dave Lennox Signature® Collection air conditioner is factory-equipped with components that make it Sun Source solar modules and other optional equipment so that they can become part of a SunSource

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 de mands. 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 com pany for a possible credit. Check with your local utility company for availability.

Solar-Ready. These units can be matched with

Home Energy System.

XC25

Page 42

Unit Wiring Diagrams

The following wiring diagrams were used during various stages of unit production. Service technician will need to visually inspect the unit being serviced to determine which wiring diagram is applicable. Quick verification can usually be made by comparing the wiring diagram located on the unit access panel to the following diagrams.

Figure 23. Typical Unit Wiring (XC25-024 and -036)

XC25

Page 43

Figure 24. Typical Unit Wiring (XC25-048 and -060)

XC25

Page 44

NOTE - For more information on Load Shedding, see Electrical on page 24.

Figure 25. Load Shedding Feature Wiring Diagram

XC25

Page 45

Factory Wiring Diagrams

INVERTER

REACTOR

INVERTER

Figure 26. Typical Factory Wiring (XC25-024 and -036)

CONTROL

OUTDOOR

XC25

Page 46

REACTOR

INVERTER

NOISE FILTER

INVERTER

CONTROL

OUTDOOR

Figure 27. Typical Factory Wiring (XC25-048 and -060)

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Page 47

Unit Sequence of Operation

The following figures illustrated the overall unit sequence of operation along with the operation of various pressure switches and temperature sensors. The figures also illustration the use of the compressor anti-short cycle function in relations to unit Status, Fault and lock out LED Codes system operations interaction.

On 24 VAC power-up or outdoor reset, the outdoor control shall perform the following tasks:

1. Start the anti-short cycle 3-minute delay in the outdoor control.

2. Check status of the temperature sensor and pressure devices.

3. If the outdoor control does not detect any error codes, outdoor control sends 24 volts out on the

CNTCTR terminals to pull in the contactor coil. (Note - These checks take about 60 seconds).

4. The contactor contacts pull IN and main power is applied to the compressor inverter.

From idle mode

Room thermostat is sending a cooling percent age of maximum capacity demand to the main control board in the outdoor unit.

Yes

All switches closed

and sensors in operat

ing range.

Yes

Outdoor Control

1. Sends a demand to the compressor inverter to start and run the compressor up to the requested pumping capacity (Frequency in hertz).

2. Outputs a DC voltage on the DAN PWM and COM terminals to start and run the outdoor fan motor at the demand RPM.

3. Sends a communication signal into the indoor unit to start and run the supply fan motor at the demand air volume (CFM).

Check for status or

fault codes in the

outdoor control or

room thermostat.

(NOTE - Refer to low

pressure and high pressure switch flow charts for sequence

of operation.

Diagnostic Screen

1. View the AIR CONDITIONING screen for current compressor frequency in hertz.

2. View the OUTDOOR CONTROL 7-Segment display to read the RPM of the outdoor fan motor.

3. View the AIR HANDLER screen for actual CFM of the indoor blower motor.

Figure 28. 24 Volt Power-Up or Outdoor Reset

XC25

Page 48

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

CLOSED

CONTACTOR

ENERGIZED

INITIAL TRIP

SWITCH IS

IGNORED FOR

90 SECONDS

OPEN

CONTACTOR

DE-ENERGIZED

ANTI-SHORT

CYCLE TIMER

BEGINS

INCREMENT

5-STRIKE

COUNTER

LED ALERT

CODE / OR

MODERATE

ALERT 410

DISPLAYED

LOW

PRESSURE

SWITCH (S87)

The thermostat terminates demand when the contactor

CLOSED

SWITCH IS CLOSED OR OUTDOOR

AMBIENT TEMPERATURE IS 15ºF

OR BELOW

is de-energized. If demand is satisfied when alarm is not active, the 5-strike counter resets.

2. Lockouts can be reset by cycling power off to the out

door control (A175) R terminal.

3. The low pressure switch is ignored by the system when

the outdoor temperature is below 15°F.

5-STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

LOCKOUT

XC25

SERVICE

REQUIRED

OPEN

CLOSED

LED ALERT

CODE / OR

CRITICAL

ALERT 411

DISPLAYED

LED ALERT CODE / OR

MODERATE

ALERT 410

DISPLAYED

SERVICE

REQUIRED

NORMAL

OPERATION

ANTI-SHORT

CYCLE TIMER

ENDS

CONTACTOR

ENERGIZED

LOW

PRESSURE

SWITCH (S87)

WAITING FOR

PRESSURE

SWITCH TO

CLOSED

Figure 29. Low Pressure Switch (S87) Sequence of Operation (All Versions)

Page 49

Y1 DEMAND

OPEN

HIGH

PRESSURE

SWITCH (S4)

OPEN

CONTACTOR

DE-ENERGIZED

ANTI-SHORT

CYCLE TIMER

BEGINS

INCREMENT

5-STRIKE

COUNTER

CLOSED

HIGH

PRESSURE

SWITCH (S4)

1. The thermostat terminates demand when the contactor is

TOP CAP

SWITCH (S173)

CLOSED

de-energized. If demand is satisfied when alarm is not active, the 5-strike counter resets.

2. Lockouts can be reset by cycling power off to the outdoor control

(A175) R terminal.

5-STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

CONTACTOR

ENERGIZED

SERVICE

REQUIRED

OPEN

LED ALERT

CODE / OR

MODERATE

ALERT 412

DISPLAYED

ANTI-SHORT

CYCLE TIMER

ENDS

HIGH

PRESSURE

SWITCH (S4)

WAITING FOR

PRESSURE SWITCH TO

CLOSED

HIGH

PRESSURE

SWITCH (S4)

LOCKOUT

LED ALERT

CODE / OR

CRITICAL

ALERT 413

CLEARED

LED ALERT

MODERATE

DISPLAYED

CODE / OR

ALERT 412

SERVICE

REQUIRED

NORMAL

OPERATION

Figure 30. High Pressure Switch (S4) Sequence of Operation (All Versions)

XC25

Page 50

Component Testing

Component Testing Table of Contents

Verifying High Pressure and Low Pressure Switch Oper

ation 50.........................................

Compressor Operation, Checkout and Status / Error

Line Filter (Electromagnetic Compatibility Circuit - EMC) Operations, Checkout and Status / Error Codes 59...

Outdoor Fan Operation and Checkout 60...........

Codes 53.......................................

Crankcase Heater, Checkout and Status / Error Codes

55..................................

Compressor Sound Cover 56......................

Liquid Filter Drier (Heat Pumps only) 56.............

Ferrites 61......................................

Outdoor Control Operation, Checkout and Status / Error

Codes 62.......................................

Unit Sensor Operations, Checkout and Status / Error

Codes 63.......................................

Top Cap Switch Operation, Checkout and Status / Error

Codes 57.......................................

DC Inverter Control Operation, Checkout and Status /

Error Codes 66..................................

Reactor Operations, Checkout and Status /

Error Codes 58..................................

Emergency 24VAC Operation 69...................

Verifying High and Low Pressure Switch Operation

OPERATION :

The unit's pressure switches (LO PS - S87 and HI PS - S4) are factory-wired into the control on the LO-PS and HI-PS termin als, respectively.

Low Pressure Switch (LO-PS) — See figure 29 for low pressure switch sequence of operation.

High Pressure Switch (HI-PS) — See figure 30 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:

D High Pressure (auto-reset) - trip at 590 psig; reset at 418. D Low Pressure (auto-reset) - trip at 40 psig; reset at 90.

CHECKOUT

Using a multimeter set to ohms with the terminals disconnected from the control board, check the resistance between the two terminals of the pressure switch. If the resistance reading is 0 ohms, the switch is closed.

Figure 31. Verifying High Pressure and Low Pressure Switch Operation

XC25

S4 HIGH PRESSURE SWITCH

S87 LOW PRESSURE SWITCH

Page 51

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

CLOSED

CONTACTOR

ENERGIZED

INITIAL TRIP

SWITCH IS

IGNORED FOR

90 SECONDS

OPEN

CONTACTOR

DE-ENERGIZED

ANTI-SHORT

CYCLE TIMER

BEGINS

INCREMENT

5-STRIKE

COUNTER

LED ALERT CODE / OR

MODERATE

ALERT 410

DISPLAYED

LOW

PRESSURE

SWITCH (S87)

CLOSED

SWITCH IS CLOSED OR OUTDOOR

AMBIENT TEMPERATURE IS 15ºF

1. The thermostat will terminate demand when the contactor is de-energized. If demand is satisfied when alarm is not active, the 5-strike counter will reset.

2. Lockouts can be reset by cycling power off to the outdoor control's

(A175) R terminal.

3. The low pressure switch is ignored by the system when the outdoor temperature is below 15°F.

5-STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

LOW

PRESSURE

SWITCH (S87)

LOCKOUT

OR BELOW

SERVICE

REQUIRED

OPEN

ANTI-SHORT

CYCLE TIMER

ENDS

LED ALERT

CODE / OR

CRITICAL

ALERT 411

SERVICE

REQUIRED

DISPLAYED

CONTACTOR

ENERGIZED

LOW

PRESSURE

SWITCH (S87)

CLOSED

LED ALERT

CODE / OR

MODERATE

ALERT 410

NORMAL

OPERATION

DISPLAYED

WAITING FOR

PRESSURE SWITCH TO

CLOSED

Figure 32. Low Pressure Switch (S87) Sequence of Operation (All Versions)

XC25

Page 52

Y1 DEMAND

OPEN

HIGH

PRESSURE

SWITCH (S4)

OPEN

CONTACTOR

DE-ENERGIZED

ANTI-SHORT

CYCLE TIMER

BEGINS

INCREMENT

5-STRIKE

COUNTER

CLOSED

HIGH

PRESSURE

SWITCH (S4)

1. The thermostat will terminate demand when the contactor is de-energized. If demand is satisfied when alarm is not active, the 5-strike counter will reset.

2. Lockouts can be reset by cycling power off to the outdoor control's

(A175) R terminal.

5-STRIKE

COUNTER

REACHES 5

WITHIN A SINGLE

Y1 DEMAND

TOP CAP

SWITCH (S173)

CLOSED

CONTACTOR

ENERGIZED

SERVICE

REQUIRED

OPEN

LED ALERT CODE / OR

MODERATE

ALERT 412

DISPLAYED

ANTI-SHORT

CYCLE TIMER

ENDS

HIGH

PRESSURE

SWITCH (S4)

WAITING FOR

PRESSURE SWITCH TO

CLOSED

HIGH

PRESSURE

SWITCH (S4)

LOCKOUT

LED ALERT

CODE / OR

CRITICAL

ALERT 413

CLEARED

MODERATE

DISPLAYED

LED ALERT

CODE / OR

ALERT 412

SERVICE

REQUIRED

NORMAL

OPERATION

Figure 33. High Pressure Switch (S4) Sequence of Operation (All Versions)

XC25

Page 53

High and Low Pressure Switch Errors

Table 10. Outdoor Control 7-Segment Display Alert Codes - High and Low Pressure Switches

System fault and lockout codes take precedence over system status codes (cooling, heating operating percentages or de frost/dehumidification). Only the latest active fault or lockout codes are displayed (if present). If no fault or lockout codes are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Alert

Codes

E 410 Moderate

E 411 Critical

E 412 Moderate

E 413 Critical

Priority Alarm Description Possible Causes and Clearing Alarm

Unit pressure is below the lower limit. The system is shutdown. The low pressure

The outdoor unit low pressure switch has closed.

The low pressure switch has opened 5 times within one hour. As a result, the outdoor unit is locked out

The outdoor unit high pressure switch has opened.

The high pressure switch has opened 5 times within one hour. As a result, the outdoor unit is locked out

NOTE - Unused on XC25. Used for heat pump applications only.

switch opens at 25PSIG and closes at 40PSIG. Confirm that the system is properly charged with refrigerant. Check TXV, indoor unit blower motor, dirty filters or clogged refrigerant filter. Confirm that the evaporator coil is clean. The alarm clears after the pressure switch opens or after a power reset.

Low pressure switch error count reached 5 strikes. The low pressure switch for HFC410A opens at 40PSIG and resets at 90PSIG. Confirm that the system is prop erly charged with refrigerant. Check for clogged TXV, blockage to indoor unit blower motor, dirty filters or clogged refrigerant filter. Confirm that the evaporator coil is clean. The alarm clears after a power reset.

Unit pressure is above the upper limit. System is shut down. The high pressure switch opens at 590PSIG and closes at 418PSIG. Confirm that the system is prop erly charged with refrigerant. Check for clogged TXV, blockage to indoor unit blower motor, clogged refrigerant filter. Confirm that the outdoor unit is clean. The alarm clears after the pressure switch closes or a power reset.

For heating, indoor CFM may be set too low. For zoning system, zone CFM may be set too low.

Open high pressure switch error count reached 5 strikes. System is shut down. The high pressure switch for HFC410A will open at 590PSIG and close at 418PSIG. Confirm that the system is properly charged with refrigerant. Check condenser fan motor, clogged TXV, blockage to indoor unit blower motor, stuck reversing valve or clogged refrigerant filter. Confirm that the outdoor unit is clean. The alarm clears after a power reset.

For heating, indoor CFM may be set too low. For zoning system, zone CFM may be set too low.

thermostat.

Compressor Operation, Checkout and Status / Error Codes

OPERATION:

The compressor is a 380VAC three-phase variable-capacity scroll compressor that is approved for use with HFC410A refri gerant. The compressor, when connected to an inverter, is capable of operating in a running frequency range from 22 hertz up to a maximum of 70 Hertz (maximum hertz is dependent on compressor size). The compressor speed is determined by demand from the room thermostat.

CHECKOUT:

Figure 34. Compressor Operation, Checkout and Status/Error Codes

IMPORTANT: If compressor replacement is required, remove the compressor through the top of the unit. Removal through

the access panel is not possible.

XC25

Page 54

STATUS CODES:

When the compressor is running, the 7segment display on the outdoor control sends the current compressor demand (as a percentage) to the room thermostat. (Example: C 5 0 – compressor is running at 50% of maximum speed.)

Figure 35. Compressor Operation, Checkout and Status/Error Codes

ERROR CODES:

Table 11. Outdoor Control 7-Segment Display Alert Codes - Compressor

Inverter LED Flash

Alert

Codes

E 430 26 2 flashes 6 flashes

E 433 29 2 flashes 9 flashes

E 439 12 1 flash 2 flashes Moderate

Inverter

Code

Code (number of

flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

If condition is detected, outdoor unit compressor and fan stop. Antishort cycle is initiated. If condition occurs 10 times within an

Moderate / Critical

Compressor start failure

The inverter has de tected a compressor over-current condi tion

Compressor slow down due to high in put current.

hour, system is locked out. Indicates poor connection at compressor harness, improper winding resistance, locked compressor rotor, or flooded com pressor. To clear, disconnect power to outdoor unit and restart. Error occurs when compressor peak phase current is greater than 28A. Inverter issues code 14 first and slows down to try to reduce the current. If the current remains high, outdoor unit com pressor and fan stop. Antishort cycle is initiated. If condition oc curs 5 times within an hour, system is locked out. To clear discon nect power to outdoor unit and restart. Input current is approaching a high limit. Compressor speed automatically slows. The control continues sending the inverter speed demanded by the thermostat. The control sets indoor CFM and outdoor RPM to values according to demand percent age rather than the actual Hz. Alarm is automatically clear.

thermostat..

XC25

Page 55

Table 11 continued

Inverter LED Flash

Alert

Codes

E 440 13 1 flash 3 flashes Moderate

E 441 14 1 flash 4 flashes Moderate

E 600 N/A N/A N/A Critical

Inverter

Code

Code (number of flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

Compressor slow down due to high heatsink temperat ure.

Compressor slow down due to high compressor current.

Compressor has been cycled OFF on utility load shedding.

Heat sink temperature is approaching limit. The compressor speed automatically slows to reduce heatsink temperature. The control sets indoor CFM and outdoor RPM to values according to demand percentage rather than the actual Hz. Alarm is automat ically cleared. Compressor current is approaching high limit. The compressor speed automatically slows. The control will set indoor CFM and outdoor RPM to values according to demand percentage rather than the actual Hz. Alarm is automatically cleared. Load shedding function: Provides a method for a local utility company to limit the maximum power level usage of the outdoor unit. The feature is activated by applying 24 volts AC power to the L and C terminals on the outdoor control.

Crankcase Heater, Checkout and Status / Error Codes

OPERATION:

CRANKCASE HEATER (HR1)

Compressors in all units are equipped with a 40 or 70 watt (depending on unit size) belly-band type crankcase heater. The heater prevents liquid from accumulating in the compressor. The heater is controlled by the crankcase heater thermostat.

CRANKCASE HEATER THERMOSTAT (S40)

Crankcase heater thermostat S40 controls the crankcase heater in all units and is located on the liquid line (see figure 2 for location).

1. When liquid line temperature drops below 50°F the thermostat closes which results in the heater being energized.

2. When liquid line temperature rises above 70°F the thermostat opens which results in the heater being de-energized.

Crankcase Heater Thermostat

Figure 36. Belly-Band Crankcase Heater Thermostat

CHECKOUT:

Belly-Band Crankcase Heater: Using meter set on ohms, check crankcase heater resistance. If resistance is 0 ohms or

infinite, replace the crankcase heater.

Belly-Band Crankcase Heater - 240VAC, Watts

40 or 70

XC25

Page 56

Figure 37. Checking Belly-Band Crankcase Heater

Crankcase Heater Thermostat: As the detected temperature changes, the resistance across the sensor changes. Table 15 on page 65 shows how the resistance varies as the temperature changes for this sensor.

NOTE - When checking the ohms across a sensor, be aware that a sensor showing a resistance value that is not range shown in table 15 on page 65, may be performing as designed. However, if a shorted or open circuit is detected, the sensor is faulty; the sensor needs to be replaced.

Figure 38. Checking Crankcase Heater Thermostat

STATUS CODE:

None

ERROR CODES:

None

within the

Compressor Sound Cover

All units come with a soft-sided polyethylene molded outer shell compressor sound cover. The cover helps reduce any un wanted operating sounds from the compressor. The cover features a hook/loop closure system for ease of installation on the compressor.

Liquid Line Filter Drier

A filter drier designed for all XC25 series model units is factory-installed in the liquid line. The filter drier is designed to remove moisture and foreign matter, which can lead to compressor failure.

XC25

Figure 39. Compressor Sound Cover

Page 57

Figure 40. Liquid Line Filter Drier

Top Cap Switch Operation, Checkout and Status / Error Codes

OPERATION:

Top Cap Thermal Sensor Switch (S173)

Some units are equipped with a compressor-mounted normally closed temperature switch that prevents compressor dam age due to overheating caused by internal friction. The switch is located on top of the compressor casing. This switch senses the compressor casing temperature and opens at 239-257°F to shut off compressor operation. The auto-reset switch closes when the compressor casing temperature falls to 151-187°F, and the compressor is re-energized. This single-pole, singlethrow (SPST) bi-metallic switch.

COMPRESSOR TOP CAP SWITCH

(SPST BI-METALIC SWITCH,

NORMALLY OPENS AT 239-257ºF,

AND CLOSES AT 151-187ºF

SWITCH COVER

TOP OF COMPRESS0R

Figure 41. Top Cap Thermal Sensor Switch

CHECKOUT:

Using a multimeter set to ohms, with the terminals disconnected from the system, check the resistance between the two terminals of the top cap switch. If the resistance reading is 0 ohms, the switch is closed.

Figure 42. Verifying Top Cap Thermal Sensor Switch

STATUS:

None

XC25

Page 58

ERROR:

Table 12. Outdoor Control 7-Segment Display Alert Codes - Top Cap Switch

are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Alert

Codes

E 422 Moderate

E 442 Critical

Priority Alarm Description Possible Causes and Clearing Alarm

Compressor top cap switch ex ceeding thermal limit.

The top cap switch has opened 5 times within one hour. As a result, the outdoor unit is locked out

Check condenser fan motor, TXV, indoor unit blower motor, stuck reversing valve, clogged refrigerant filter or undercharge. When error occurs with inverter slowdown errors, check for system overcharge. Automatically clears when error is corrected.

When compressor thermal protection sensor opens 5 times within 1 hour, outdoor stops working. To clear, disconnect power to outdoor unit and restart.

thermostat.

Reactor Operations, Checkout and Status / Error Codes

OPERATION:

Reactor (Inductor or choke) is a passive twoterminal electrical component that stores energy in its magnetic field. Reactors are one of the basic components used in electronics where current and voltage change with time, due to the ability of induct ors to delay and reshape alternating currents.

CHECKOUT: Main Power ON – Voltage IN reactor should be the same as the voltage OUT. With main power OFF and reactor disconnec

ted from system; resistance between leads should be the same (brown IN to brown OUT, blue IN to blue OUT).

STATUS CODES:

None

ERROR CODES:

None

Voltage “IN” same as Voltage “OUT”

Figure 43. XC/XP 25-024 and -036 Reactor

208/240 Voltage “IN”

Figure 44. XC/XP 25-048 and -060 Reactor

XC25

208/240 Voltage “OUT”

Page 59

Line Filter (Electromagnetic Compatibility Circuit - EMC) Operations, Checkout and Status / Error Codes

OPERATION:

The line filter reduces the unintentional conducted emission from the equipment, to a level sufficient to pass regulatory limits (such as FCC part 15).

The filter is rated at 208/230 volt, 30 amp maximum, 60 Hertz.

NOTE - The 2- and 3-ton inverters have the EMC builtin. The 4- and 5-ton units have an external device (see illustration below).

NOTE - A line filter is an electronic filter which is placed between electronic equipment and an external power source in order to attenuate conducted radio frequency interference (RFI). RFI is also known as electromagnetic interference (EMI).

CHECKOUT:

Voltage IN should read the same value as the Voltage OUT. With filter isolated from system, resistance between L1 and L2 should be the same as resistance between N1 and N2.

STATUS CODES:

None

ERROR CODES:

None

208/240

Voltage IN

208/240

Voltage OUT

Figure 45. XC25 4- and 5-ton filter board (EMC)

XC25

Page 60

Outdoor Fan Operation and Checkout

OPERATION:

These units use an integrated control and motor that is programmed for variable-capacity operation. The fan speed is

controlled by the iComfort Wi-Fi

CHECKOUT:

VAC Voltage Check

Check for 208/240 VAC power at inverter contactor (red wires) (see figure 46).

With unit operating, check for main VAC to motor and outdoor control VDC output to motor:

1. No voltage present – Check main power

2. Voltage present – Perform DC volt checks (19 -23 VDC between FAN PWM and COM) (see figure 46)

thermostat.

Perform DC volt checks (19 -23 VDC between FAN PWM and COM).

Figure 46. VAC Voltage Check

XC25

Page 61

VDC Voltage Check: Check for VDC out of Fan PWM and COM. VDC output reading is determined by the percentage of room thermostat de mand.

1. No voltage present – Remove wires from control and check for VDC. If there is no voltage present, then replace out door control.

2. Voltage present – Perform a 9-volt battery test on motor (see figure 47).

BLACK LEAD

CONNECT B4 FAN MOTOR BLACK

COMMON WIRE TO 9V BATTERY

NEGATIVE TERMINAL

NEGATIVE TERMINAL POSITIVE TERMINAL

FULLY CHARGED 9V BATTERY

BROWN LEAD

CONNECT B4 FAN MOTOR WIRE TO 9V BATTERY POSITIVE

TERMINAL

Figure 47. VDC Voltage Check

STATUS OR ERROR CODES:

There is no feedback from the outdoor fan motor to the outdoor control therefore no status or error codes are displayed on

either the outdoor control or iComfort Wi-Fi

room thermostat.

NOTE - If the outdoor fan does not operate at the correct RPM, or does not start, the system will shut be down by other protection components such as the high and low pressure switches which will generate error code(s).

Ferrites

Electronic cabling and wires, by virtue of their lengthtowidth ratios, are perfect natural antennas. In the presence of highspeed microprocessor signals, cables will conduct, radiate, and receive unwanted highfrequency signals. Use an in sertion-loss device, such as a ferrite suppressor as shown below, to control radio-frequency (RF) interference.

Ferrites are consistently stable over time and over wide temperature ranges, and provide RF suppression without causing large current losses.

Figure 48. Ferrites

XC25

Page 62

Outdoor Control Operation, Checkout and Status / Error Codes

OPERATION:

The outdoor control is a microprocessor-based device for use with variable-capacity compressors up to 5-tons in capacity operating on 24VAC residential power. The outdoor control integrates the functionality of maintaining compressor speed, demand, defrost and fan PWM controls. The outdoor control is self-configuring. During start-up the outdoor control selects one of two configurations  variable-capacity air conditioner or variable-capacity heat pump.

7-SEGMENT

DISPLAY

PUSH

BUTTON

NOTE - The green LED located on the outdoor control flashes when communication occurs between the outdoor control and either the thermostat or the inverter.

PUMP DOWN - WHEN UNIT IS IN PUMP DOWN MODE,  WILL BE

TO ACTIVATE PUMP DOWN MODE, REFER TO PUMP DOWN

DISPLAYED ON 7-SEGMENT.

CYCLE SEQUENCE ON PAGE 36.

Figure 49. Outdoor Control Unit

STATUS CODES:

Table 13. Outdoor Control 7-Segment Display Alert Codes - Outdoor Control Status

Alert Codes

E 600 Critical

E 601 Critical

Priority Alarm Description Possible Causes and Clearing Alarm

Compressor has been cycled OFF on utility load shedding.

Outdoor unit has been cycled OFF on low temperature protection.

thermostat.

Load shedding function: Provides a method for a local utility company to limit the maximum power level usage of the outdoor unit. The feature is activated by applying 24 volts AC power to the L and C terminals on the outdoor control. Low temperature Protection: Outdoor unit will not operate when the outdoor temperature is at or below 4°F (20°C). If the unit is operating and the outdoor temperature drops below 4°F (20°C), the unit will continue to operate until the room thermostat is satisfied or the outdoor temperature drops to 15°F (26°C). (Outdoor unit ambient sensor provides temperature readings.)

XC25

Page 63

ERROR CODES:

Table 14. Outdoor Control 7-Segment Display Alert Codes - Outdoor Control Errors

are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Alert

Codes

E 105 Moderate

E 120 Moderate

E 124 Critical

E 125 Critical

E 131 Critical

E 132 Critical Internal software error. Replace outdoor control.

Priority Alarm Description Possible Causes and Clearing Alarm

Equipment is unable to communicate. Indicates numerous message errors. In most The outdoor control has lost com munication with either the thermo stat or indoor unit.

There is a delay in the outdoor unit responding to the system.

The iComfort WiFi® thermostat has lost communication with the outdoor unit for more than 3 minutes.

There is a hardware problem with the outdoor control.

The outdoor unit control parameters are corrupted

cases errors are related to electrical noise. Make sure high voltage power is separated

from RSBus. Check for miswired and/or loose connections between the stat, indoor

unit and outdoor unit. Check for a high voltage source of noise close to the system. Fault

clears after communication is restored.

Typically, this alarm/code does not cause any issues and will clear on its own. The alarm

/ code is usually caused by a delay in the outdoor unit responding to the thermostat.

Check all wiring connections. Cleared after unresponsive device responds to any in

quiry.

Equipment lost communication with the thermostat. Check the wiring connections, ohm

wires and cycle power. The alarm stops all associated HVAC operations and waits for

a heartbeat message from the unit that's not communicating. The alarm / fault clears

after communication is reestablished.

There is a control hardware problem. Replace the outdoor control if the problem pre

vents operation and is persistent. The alarm / fault is cleared 300 seconds after the fault

recovers.

Reconfigure the system. Replace the control if heating or cooling is not available.

thermostat.

Unit Sensor Operations, Checkout and Status / Error Codes

OPERATION

Pins 5 and 6 (No Sensor)

There is no sensor located on positions 5 and 6 of the connector. A resistor installed between pins 5 and 6 on the cable harness provides continuity for this circuit. This resistor (location shown in figure 51) provides resistance value between 314669 and 3779 ohms the coil temperature sensor is out of range or faulty (see table 15 on page 65). If resistor is damaged or missing, order re placement harness assembly (101334-05).

Ambient temperatures, as read by the ambient temperature sensor (shown in figure 51) which are below -35°F (-37°C) or above 120°F (48°C) trigger a fault condition. If the ambient sensor is open, shorted, or out of the temperature range of the sensor, the control does not perform demand defrost operation. The control reverts to time/temperature defrost operation and displays the appropriate alert code (see table 15 on page 65). Heating and cooling operation is allowed in this fault condition.

Liquid line temperatures below -40°F (-40°C) or above 140°F (60°C) trigger a fault condition and result in the appropriate alarm code (see table15 on page 65). The outdoor control uses the liquid line sensor to change the fan speed, allowing cooling operation at lowered ambient temperatures.

. If the resistor becomes damaged or lost, the outdoor control generates a false error code indicating

Ambient Temperature Sensor (RT13)

Liquid Line Temperature Sensor (RT36)

XC25

Page 64

SENSOR

NONE

TEMP RANGE ºF

(ºC)

N/A

RESISTANCE VALUES

RANGE (OHMS)

314669 and 3779

PIN# / WIRE

SLEEVE COLOR

6 AND 5

OUTDOOR

AMBIENT

LIQUID LINE

OUTDOOR

AMBIENT

LIQUID LINE

-40 (-40) TO 140 (60)

BLACK WIRES WITH

BLACK SLEEVE

BLACK WIRES WITH

YELL0W SLEEVE

336,000 to 2,487 (see table 15 on page 65 for exact temperature to ohm readings).

4 AND 3

(BLACK)

2 AND 1

(YELLOW)

TEMPERATURE

SENSOR HARNESS

Figure 50. Temperature Sensor Specifications

CHECKOUT

Sensors connect to the outdoor control through a field‐replaceable harness assembly that plugs into the outdoor control. Through the sensors, the control detects outdoor ambient, coil and liquid temperature fault conditions. As the detected tem perature changes, the resistance across the sensor changes. Check sensor operation by reading ohms across pins shown in figure 50.

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 figure 50, 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.

XC25

OUTDOOR AMBIENT

TEMPERATURE

SENSOR

LIQUID LINE SENSOR

CRANKCASE HEATER

THERMOSTAT (S40) OPENS AT

70ºF, CLOSES AT 50ºF

Figure 51. Temperature Sensor Locations

Page 65

Degrees Fahr enheit

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 Fahr enheit

Resistance

Degrees Fahr enheit

Resistance

Degrees Fahr enheit

Resistance

Table 15. Ambient and Liquid Line Sensors Temperature / Resistance Range

XC25

Page 66

ERROR CCOCODES:

Table 16. Outdoor Control 7-Segment Display Alert Codes - Outdoor Control Errors

are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Alert

Codes

E 180 Critical

E 416

E 424 Moderate Faulty outdoor liquid line sensor Sensor is open or shorted. Replace the sensor.

Priority Alarm Description Possible Causes and Clearing Alarm

During normal operation, after the outdoor control recognizes sensors, the alarm will be sent only if valid temperature reading is lost. Compare outdoor sensor resistance to temperature/resistance charts in unit installation instructions. Replace sensor pack if necessary. At the beginning of (any) configuration, furnace or air-handler control will detect the presence of the sensor(s). If detected (reading in range), appropriate feature will be set as 'installed' and shown in the iComfort Wi-Fi screen. The alarm / fault will clear upon configuration, or sensing normal values.

Coil sensor is detected as open or shorted, or temperature is out of coil sensor range. Outdoor unit control will not perform demand or time/temperature defrost operation. System will still heat or cool. Check the resistance of the coil sensor and compare to temperature resistance chart. Replace coil sensor if needed. The alarm clears when outdoor unit control detects proper coil sensor readings or after a power reset.

Moderate /

Critical

The iComfort Wi-Fi® thermostat has found a problem with the outdoor unit's ambient temperature sensor.

The outdoor coil sensor is either open, short-circuited or the temperature is out of sensor range. As a result the outdoor unit control will not perform defrost.

thermostat.

thermostat 'About'

DC Inverter Control Operation, Checkout, Status / Error Codes

OPERATION OF COMPONENTS:

Electromagnetic compatibility circuit (EMC): EMC ensures the correct operation of different equipment items which use or respond to electromagnetic phenomena. It also helps to negate the effects of interference. NOTE - The 2- and 3-ton inverter

has an EMC builtin. The 4- and 5-ton units have an external inverter.

CONVERTER:

Converts AC (alternating current) to DC (direct current).

POWER FACTOR CORRECTION (PFC) CIRCUIT:

The PFC module is an integrated part of the outdoor inverter that monitors the DC bus for high, low and abnormal voltage conditions. If any of these conditions are detected, the PFC function and compressor will stop.

INTELLIGENT (INVERTER) POWER MODULE (IPM): The IPM converts DC power into AC power. The control method is known as pulse width modulation (PWM). This means the

DC is switched on and off very quickly (chopped) by the transistor switches to make simulated AC at required frequency and voltage.

COMMUNICATION CONTROL CIRCUIT:

Receives and sends message between the inverter and the outdoor control.

Power Factor Correction Circuit

Converter

Intelligent Power Module

XC25

Electromagnetic Compatibility Circuits

Communication Control

Figure 52. 2- and 3-Ton Unit Inverter

Page 67

Heat Sink

Converter

Power Factor Correction Circuit

Intelligent Power Module

Communication Control

Figure 53. 4- and 5-Ton Unit Inverter

STATUS CODES:

Table 17. Outdoor Control 7-segment Display Alert Codes and Inverter LED Flash Codes

thermostat.

Inverter LED Flash

Alert

Codes

N/A ON OFF N/A XC 25-024 and -036 only: Indicates inverter is operating normally.

N/A ON ON N/A XC 25-048 and -060 only: Indicates inverter is operating normally.

N/A OFF OFF N/A Indicates inverter is NOT energized.

Code (number of flashes)

Red LED

Green

LED

Priority Alarm Description Possible Causes and Clearing Alarm

ERROR CODES:

Table 18. Outdoor Control 7-Segment Display Alert Codes and Inverter LED Flash Codes

are active, then system status codes are displayed. Alert codes are also displayed on the iComfort Wi-Fi

Inverter LED Flash

Alert

Codes

E 423 40 4 flashes OFF

E 426 N/A N/A N/A Critical

Inverter

Code

Code (number of

flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

Moderate /

Critical

The inverter has de tected a circuit prob lem.

Excessive inverter alarms

Control will lock out after 10 strikes within an hour. To clear disconnect power to outdoor unit and restart.

After ten faults within one hour, control will lock out. Indicates poor system operation. Review history of alarms to resolve system setup. Check condenser fan motor, TXV, indoor unit blower motor, stuck reversing valve, over-charge, undercharge, and clogged refrigerant filter. To clear error, disconnect power to outdoor unit and restart. Inverter alarms 12 to 14 and 53 do not count towards this lock out condition.

thermostat.

XC25

Page 68

Table Table 18 continued

Inverter LED Flash

Alert

Codes

E 427 21 2 flashes 1 flash

E 428 22 2 flashes 2 flashes

E 429 23 2 flashes 3 flashes

E 430 26 2 flashes 6 flashes

E 431 27 2 flashes 7 flashes

E 432 28 2 flashes 8 flashes

E 433 29 2 flashes 9 flashes

E 434 53 5 flashes 3 flashes

E 435 60 6 flashes OFF

E 436 62 6 flashes 2 flashes

E 437 65 6 flashes 5 flashes

E 438 73 7 flashes 3 flashes

E 439 12 1 flash 2 flashes Moderate

E 440 13 1 flash 3 flashes Moderate

E 441 14 1 flash 4 flashes Moderate

Inverter

Code

Code (number of

flashes)

Red LED Green LED

Priority Alarm Description Possible Causes and Clearing Alarm

Moderate / Critical

The inverter has de tected a DC peak fault condition

The inverter has de tected a high main in put current condition

The inverter has de tected a DC link low voltage condition

Compressor start

The inverter has de tected a PFC circuit over-current condition.

The inverter has de tected a DC link high voltage condition.

The inverter has de tected a compressor over-current condi tion.

Outdoor control has lost communications with the inverter for greater than 3 minutes.

Inverter internal er ror.

Inverter heat sink temperature ex ceeded limit

Heat sink temperat ure sensor fault has occurred (temperat ure less than 4 ºF or greater than 264ºF after 10 minutes of operation).

The inverter has de tected a PFC circuit over-current condi

tion

Compressor slow down due to high in put current.

Compressor slow down due to high heatsink temperat ure.

Compressor slow down due to high compressor current.

failure

If condition (55A or higher) is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If peak current (55A or higher) occurs 10 times within an hour, system will lock out. Indicates high pressure, condenser fan failure, locked compressor rotor or over charge. To clear, disconnect power to outdoor unit and restart.

If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, system will lock out. Indicates high pressure, condenser fan failure or overcharge.

To clear, disconnect power to outdoor unit and restart.

Error occurs when DC link voltage drops below 14VDC. If condition is detected, out door unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 10 times within an hour, system will lock out. Indicates power interruption, brownout, poor electrical connection or loose inverter in put wire. To clear, disconnect power to outdoor unit and restart.

If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 10 times within an hour, system will lock out. Indicates poor connection at compressor harness, improper winding resistance, locked compressor rotor, or flooded compressor. To clear, disconnect power to outdoor unit and restart.

Error occurs when PFC detects a over-current condition of 100A peak. If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 10 times within an hour, system will lock out. Indicates high pressure, condenser fan failure, locked compressor rotor or over charge. To clear, disconnect power to outdoor unit and restart.

Error occurs when the DC link capacitor voltage is greater than 480VDC. If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 10 times within an hour, system will lock out. System will stop. To clear, disconnect power to outdoor unit and restart.

Error occurs when compressor peak phase current is greater than 28A. Inverter will issue code 14 first and slow down to try to reduce the current. If the current remains high, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condi tion occurs 5 times within an hour, system will lock out. To clear disconnect power to outdoor unit and restart.

Error occurs when communication a checksum error occurs for 3 minutes. Outdoor control stops all compressor demands. Recycle power to the inverter by deenergiz ing the contactor for 2 minutes.

When this error occurs, the outdoor control will cycle power to the inverter by opening

the contactor for 2 minutes. Check that the EEPROM is properly seated. After power is

cycled to the inverter 3 times, the outdoor unit is locked out.

This occurs when the temperature sensor detects a temperature less than 0.4ºF or greater than 264ºF after 10 minutes of operation. If condition is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initiated. If condition occurs 5 times within an hour, system will lock out. To clear disconnect power to outdoor unit and re start. If problem persists, replace inverter.

Error occurs when PFC detects an input over-current condition of 35A peak. If condi tion is detected, outdoor unit will stop (compressor and fan). Antishort cycle is initi ated. If condition occurs 10 times within an hour, system will lock out. Indicates high pressure, condenser fan failure, or locked compressor rotor. To clear, disconnect power to outdoor unit and restart.

Input current is approaching a high limit. Compressor speed will automatically slow down. The control continues sending the inverter speed demanded by the thermostat. The control will set indoor CFM and outdoor RPM to values according to demand per centage rather than the actual Hz. Alarm is automatically clear.

Heat sink temperature is approaching limit. The compressor speed will automatically slow down to reduce heatsink temperature. The control will set indoor CFM and out door RPM to values according to demand percentage rather than the actual Hz. Alarm is automatically cleared.

Compressor current is approaching high limit. The compressor speed will automatic ally slow down. The control will set indoor CFM and outdoor RPM to values according to demand percentage rather than the actual Hz. Alarm is automatically cleared.

XC25

Page 69

Emergency 24VAC System Operation

The Y terminal located on the outdoor control allows the outdoor unit to be cycled ON and OFF using 24VAC inputs. The outdoor unit will operate at 100% capacity in this configuration.

The following wiring diagrams display the wiring changes needed to switch a full communicating system to a non-communic ating system with the XC25 running in emergency mode (24VAC inputs to outdoor unit).

IComfort Wi-Fi



Thermostat,

Communicating Air Handler and XC25

Communicating Air

Handler or

Furnance

24VAC Thermostat

Communicating Air

Handler or

Furnance

(Non−Communicating Mode)

Emergency 24VAC

IComfort ® Wi-Fi



THERMOSTAT

RSBus

XC25 UNIT

NOTES:

1. Move one wire on both indoor and outdoor controls from terminals i+ to Y1 for 24VAC operation on air conditioner and indoor unit.

2. Disconnect the i- wire from terminal strip and tape.

3. Do not disconnect wires form the XC25 R and C terminals, both are required.

Figure 54. Emergency 24VAC System Operation

System Refrigerant

IMPORTANT !

The system must be operating at full capacity during charging. Increase (heat) or decrease (cooling) the thermostat setting by 5°F to create system demand. Confirm outdoor unit running capacity on the display on the outdoor control. Value should be 100%.

This section outlines the procedures to:

1. Connect a gauge set for testing and charging as illustrated in fig

ure 55.

2. Check and adjust indoor airflow as described in figure 56.

3. Add or remove refrigerant using the weigh-in method shown in

figure 57.

NOTE 1 and 2

XC25 UNIT

NOTE 3

4. Verify the charge using the subcooling method described in fig

ure 58.

IMPORTANT: Unit must be operating at 100% input to be charged

properly.

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.

INDOOR AIRFLOW CHECK

Check airflow using the Delta-T (DT) process using the illustration in figure 56.

The diagnostic screen on the thermostat or outdoor control 7-seg ment display shows indoor and outdoor motor CFMs or RPMs.

XC25

Page 70

MANIFOLD GAUGE SET

GAUGE SET

LOW

HIGH

CONNECTIONS FOR TESTING AND CHARGING

TRUE SUCTION PORT

CONNECTION

OUTDOOR UNIT

REFRIGERANT TANK

CHARGE IN

LIQUID PHASE

DIGITAL SCALE

INSIDE OUTDOOR UNIT

TEMPERATURE

SENSOR

A. CLOSE MANIFOLD GAUGE SET VALVES AND CONNECT THE CENTER HOSE TO A CYLINDER OF HFC-410A SET FOR LIQUID PHASE CHARGING.

B. CONNECT THE MANIFOLD GAUGE SET'S LOW PRESSURE SIDE TO THE TRUE SUCTION PORT.

C. CONNECT THE MANIFOLD GAUGE SET'S HIGH PRESSURE SIDE TO THE LIQUID LINE SERVICE PORT.

D. POSITION TEMPERATURE SENSOR ON LIQUID LINE NEAR LIQUID LINE SERVICE PORT.

TO LIQUID

LINE SERVICE

VALV E

TEMPERATURE SENSOR

(LIQUID LINE)

Figure 55. Gauge Set Connections

TEMPERATURE OF AIR ENTERING INDOOR COIL ºF

AIRFLOW

INDOOR COIL

DRY

BULB

53º

ALL TEMPERATURES ARE EXPRESSED IN ºF

ASSUME DT = 15 AND A TEMP. = 72º, BELOW C TEMPERATURES REQUIRE ACTION:

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

DROP

19º

AIR FLOW

– DT = ºF ACTION

DROP

INDOOR COIL

AIR FLOW

64º

WET

BULB

72º

DRY BULB

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

WET-BULB ºF

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

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

THE DRY BULB AIR TEMPERATURE ENTERING AND LEAV ING THE COIL (A AND C). TEMPERATURE DROP FORMULA:

) = A MINUS C.

DROP

3. DETERMINE IF FAN NEEDS ADJUSTMENT — IF THE DIF

FERENCE BETWEEN THE MEASURED T SIRED DT (T NEEDED. SEE EXAMPLE AT LEFT:

4. ADJUST THE FAN SPEED — SEE INDOOR UNIT INSTRUC

TIONS TO INCREASE/DECREASE FAN SPEED.

NOTE - CHANGING AIR FLOW AFFECTS ALL TEMPERA TURES; RECHECK TEMPERATURES TO CONFIRM THAT THE TEMPERATURE DROP AND DT ARE WITHIN +

–DT) IS WITHIN +3º, NO ADJUSTMENT IS

DROP

— MEASURE

AND THE DE

DROP

3º.

Figure 56. Checking Indoor Airflow over Evaporator Coil using Delta-T Chart

XC25

Page 71

Use the WEIGH-IN method for adding initial refrigerant charge, and then use SUBCOOLING method for for verifying refrigerant charge.

WEIGH-IN

64ºF (17.7ºC) and Below

Amount specified

on nameplate

SUBCOOLING

COOLING

HEATING

SATº LIQº – SCº =

CHARGING METHOD

Adjust amount for variation in line set length and liquid line diameter using table below.

Liquid Line

Set Diameter

5/16”

3/8”

1/2”

HFC-410A

(ounces per foot)

0.40

0.60

1.00

Total charge

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.

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

Charging Formula for Liquid Line Charge Adjustments

[(Line set oz./ft. x total length)  (factory charge for line set)] = charge adjustment

Example: Units are factorycharged for 15 feet (4.6 meters) of 3/8" line set. Factory charge for 3/8" is 0.60 oz/ft x 15 = 9.0 ounces.

Figure 57. Using HFC-410A Weigh-In Method

CHARGING METHOD

1. THE DIAGNOSTIC SCREEN ON THE THERMOSTAT OR OUTDOOR CONTROL 7-SEGMENT DISPLAY WILL SHOW INDOOR AND OUTDOOR MOTOR CFMS OR RPMS.

2. MEASURE OUTDOOR AMBIENT TEMPERATURE; DETERMINE WHETHER TO USE COOLING MODE OR HEATING MODE TO CHECK CHARGE.

3. CONNECT GAUGE SET.

4. CHECK LIQUID AND VAPOR LINE PRESSURES. COMPARE PRESSURES WITH EITHER HEAT OR COOLING MODE NORMAL OPERATING PRESSURES IN THE APPLICABLE CHARGING STICKER, NORMAL OPERATING PRESSURES, HIGH STAGE.

NOTE

- THE REFERENCE TABLE IS A GENERAL GUIDE. EXPECT MINOR PRESSURE VARIATIONS. SIGNIFICANT

DIFFERENCES MAY MEAN IMPROPER CHARGE OR OTHER SYSTEM PROBLEM.

5. SET THERMOSTAT FOR HEAT/COOL DEMAND, DEPENDING ON MODE BEING USED:

USE

MODE

60ºF

(15ºC)

USE

MODE

USING COOLING MODE — WHEN THE OUTDOOR AMBIENT TEMPERATURE IS 60°F (15°C) AND ABOVE. TARGET

SUBCOOLING VALUES (SECOND STAGE - HIGH CAPACITY) IN APPLICABLE CHARGING STICKER ARE BASED ON 70 TO 80°F (21-27°C) INDOOR RETURN AIR TEMPERATURE; IF NECESSARY, OPERATE HEATING TO REACH THAT TEMPERATURE RANGE; THEN SET THERMOSTAT TO COOLING MODE SETPOINT TO 68ºF (20ºC) WHICH SHOULD CALL FOR SECOND-STAGE (HIGH STAGE) COOLING. WHEN PRESSURES HAVE STABILIZED, CONTINUE WITH STEP 6.

USING HEATING MODE — WHEN THE OUTDOOR AMBIENT TEMPERATURE IS BELOW 60°F (15°C). TARGET

SUBCOOLING VALUES (SECOND-STAGE - HIGH CAPACITY) IN APPLICABLE CHARGING STICKER ARE BASED ON 65-75°F (18-24°C) INDOOR RETURN AIR TEMPERATURE; IF NECESSARY, OPERATE COOLING TO REACH THAT TEMPERATURE RANGE; THEN SET THERMOSTAT TO HEATING MODE SETPOINT TO 77ºF (25ºC) WHICH SHOULD CALL FOR SECOND-STAGE (HIGH STAGE) HEATING. WHEN PRESSURES HAVE STABILIZED, CONTINUE WITH STEP 6.

6. READ THE LIQUID LINE TEMPERATURE; RECORD IN THE LIQº SPACE.

7. READ THE LIQUID LINE PRESSURE; THEN FIND ITS CORRESPONDING TEMPERATURE IN THE TEMPERATURE/ PRESSURE CHART LISTED IN THE APPLICABLE CHARGING STICKER AND RECORD IT IN THE SATº SPACE.

8. SUBTRACT LIQº TEMPERATURE FROM SATº TEMPERATURE TO DETERMINE SUBCOOLING; RECORD IT IN SCº SPACE.

9. COMPARE SCº RESULTS WITH APPLICABLE CHARGING STICKER, BEING SURE TO NOTE ANY ADDITIONAL CHARGE FOR LINE SET AND/OR MATCH-UP.

10. IF SUBCOOLING VALUE IS GREATER THAN SHOWN IN APPLICABLE CHARGING STICKER FOR THE APPLICABLE UNIT, REMOVE REFRIGERANT; IF LESS THAN SHOWN, ADD REFRIGERANT.

11. IF REFRIGERANT IS ADDED OR REMOVED, REPEAT STEPS 6 THROUGH 10 TO VERIFY CHARGE.

12. DISCONNECT GAUGE SET AND RE-INSTALL BOTH THE LIQUID AND SUCTION SERVICE VALVE CAPS.

(All charging MUST be performed while system is operating

either at maximum speed or 100% demand.)

Figure 58. Using HFC-410A Subcooling Method - High Speed (High Capacity)

Table 19. HFC-410A Temperature (°F) - Pressure (Psig)

°F Psig °F Psig °F Psig °F Psig °F Psig °F Psig °F Psig °F Psig

32 100.8 48 137.1 63 178.5 79 231.6 94 290.8 11 0 365.0

33 102.9 49 139.6 64 181.6 80 235.3 95 295.1 111 370.0 126 451.8 142 552.3

34 105.0 50 142.2 65 184.3 81 239.0 96 299.4 11 2 375.1 127 457.6 143 559.1

35 107.1 51 144.8 66 187.7 82 242.7 97 303.8 11 3 380.2 128 463.5 144 565.9

36 109.2 52 147.4 67 190.9 83 246.5 98 308.2 11 4 385.4 129 469.5 145 572.8

37 111.4 53 150.1 68 194.1 84 250.3 99 312.7 11 5 390.7 130 475.6 146 579.8

38 113.6 54 152.8 69 197.3 85 254.1 100 317.2 11 6 396.0 131 481.6 147 586.8

39 115.8 55 155.5 70 200.6 86 258.0 101 321.8 11 7 401.3 132 487.8 148 593.8

40 118.0 56 158.2 71 203.9 87 262.0 102 326.4 11 8 406.7 133 494.0 149 601.0

41 120.3 57 161.0 72 207.2 88 266.0 103 331.0 11 9 412.2 134 500.2 150 608.1

42 122.6 58 163.9 73 210.6 89 270.0 104 335.7 120 417.7 135 506.5 151 615.4

43 125.0 59 166.7 74 214.0 90 274.1 105 340.5 121 423.2 136 512.9 152 622.7

44 127.3 60 169.6 75 217.4 91 278.2 106 345.3 122 428.8 137 519.3 153 630.1

45 129.7 61 172.6 76 220.9 92 282.3 107 350.1 123 434.5 138 525.8 154 637.5

46 132.2 62 175.4 77 224.4 93 286.5 108 355.0 124 440.2 139 532.4 155 645.0

47 134.6 78 228.0 109 360.0 140 539.0

125 445.9

141 545.6

XC25

Page 72

Figure 59. XC25 Charging Sticker

XC25

Lennox XC25-024-230-01, XC25-036-230-01, XC25-048-230-01, XC25-060-230-01 Installation And Service Procedure

Specifications and Main Features

Frequently Asked Questions

User Manual