Lennox Elite, XP16 Installation Instructions Manual

INSTALLATION

¢>,2008 Lennox industries Inc.

DatIas, Texas, USA

RETAIN THESE INSTRUCTIONS

FOR FUTURE REFERENCE

_, WARNING

AI_CAUTION

INSTRUCTIONS

Elite ® Series XP16 Series
Units

HEAT PUMPS _ Technical
505,329M J_.LLPublications

04/08 LithoU.S.A.
Supersedes 01/08

Shipping and Packing List ...................... 1

XP16 Heat Pumps ............................. 1

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

General Information ........................... 3

Recovering Refrigerant from Existing System ..... 5

Removing Existing Outdoor Unit ................. 6

Positioning New Outdoor Unit ................... 6

Removing and Installing Panels ................. 7

New or Replacement Line Set ................... 9

Brazing Connections ........................... 11

Removing Indoor Unit Metering Device ........... 11

Flushing the System ........................... 12

Installing New Indoor Unit Metering Device ........ 13

Testing for Leaks .............................. 13

Evacuating the System ......................... 15

Servicing Unit Delivered Void of Charge ........... 16

Electrical Connections ......................... 16

Start-Up and Charging Procedures ............... 17

System Operation ............................. 17

Charge using the Subcooling Method ............ 21

System Operation ............................. 21

Defrost System ............................... 21

Maintenance .................................. 25

Homeowner Information ........................ 26

Checklists .................................... 28

A IMPORTANT

A IMPORTANT

04/08

IIIHIIIIII]]IIII]IIIIIIIII]IIIIIIIII]

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

1 -Assembled XP16 outdoor unit

The XP16 Heat Pumps, which will also be referred to in this
instruction as the outdoor unit, uses HFC-410A

refrigerant. This outdoor unit must be installed with a
matching indoor unit and line set as outlined in the Lennox

XP f 6 Engineering Handbook.

This outdoor unit is designed for use in systems that use
check thermal expansion valve (CTXV) refrigerant

metering devices.

Page 1

505,329M

IIII]III]]IIIIIIIII]IIHI]I]IIIIIIIIIIIII]]IIIII

TOP VIEW

q CDISCHARGE AIR t

SUCTION LINE
CONNECTION

LIQUID LINE
CONNECTION

I LIQUID LINE

CAPACITOR

DEFROST

BOARD

CONTACTOR

REVERSING

VALVE

LIQUID LINE

CONNECTIONS

RUN

XP16 PARTS ARRANGEMENT

OUTDOOR FAN

COMPRESSOR
HIGH PRESSURE SWITCH

DRIER

LOW PRESSURE SWITCH

• VAPOR LINE

VAPOR VALVE AND GAUGE

PORT/SUCTION LINE
CONNECTIONS

UNIT SUPPORT

FEETx_

8-1/2
(216)

t

8-3/4
(222)

1

%

SIDE VIEW

(_ 13 1

F -- CONNECTION

//q/

4N/4

L_I ! (108)

(241)

8-1/4
(210)

ELECTRICAL

INLETS

t

t

9N/2

t

f

4-3/4

(121)

[

A

2 (51)

L

tt

1 (25)

UNIT SUPPORT FEET _ _-

D

E

\

I I i i

SIDE VIEW

® @ ®

K

J

XP16-024 BASE SECTION

XP16 A

-024 31 (787)

-036 35 (889)

-048 45 (1143)

-060 39 (991)

505329M 04/08

B C D

27 (686) 28 (711)

30-1/2 (775) 35 (889)

30-1/2 (775) 35 (889)

30-1/2 (775) 35 (889) 16-7/8 (429)

13-7/8 (352)

7-3/4 (197)

8-3/4 (222)

Page 2

3-1/4 (83)

3-1/8 (79)

XP16 BASE WITH ELONGATED LEGS

G H J K

27-1/8 (689)

30-3/4 (781)

3-5/8 (92)

4-5/8 (117)

4-1/2 (114)

3-3/4 (95)

20-5/8 (524)

26-7/8 (683)

WARNING

OPERATING SERVICE VALVES

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

checking charge and charging
Each valve is equipped with a service port which has a

factory-installed valve stem

IMPORTANT

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

who have jurisdiction before installation.

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

Table 1 Torque Requirements

Parts Recommended Torque

Service valve cap 8 ft Ib 11 NM
Sheet metal screws 16 in Ib 2 NM

Machine screws #10 28 in Ib 3 NM
Compressor bolts 90 in Ib 10 NM
Gauge port seal cap 8 ft Ib 11 NM

USING MANIFOLD GAUGE SETS
When checking the system charge only use a manifold

gauge set that features low loss anti-blow back fittings
See figure 2 for a typical manifold gauge connection setup

Manifold gauge sets used with HFC-410A refrigerant
systems must be capable of handling the higher system

operating pressures The gauges should be rated for use

with pressures of 0 - 800 on the high side and a low side of

30" vacuum to 250 psi with dampened speed to 500 psi
Gauge hoses must be rated for use at up to 800 psi of
pressure with a 4000 psi burst rating

I/6 TURN

9

8 4

Figure 1 Cap Tightening Distances

1/12 TURN

IMPORTANT

To Access Angle-Type 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 to the service port
3 When testing iscompleted replace service port cap and

tighten as follows:

• With Torque Wrench: Finger tighten and then
tighten per table 1

• Without Torque Wrench: Finger tighten and use an
appropriately sized wrench to turn an additional

1/6 turn clockwise as illustrated in figure 1

Page 3

XP16 SERIES

DISTRIBUTOR

CBECK REV " sAT:UvA E

EXPANSION VALVE _ \

DR,ER OUTo tOR "-

LOW HIGH MUFFLER

PRESSURE PRESSURE ___ ]

LIOUID *o

Figure 2. Typical Manifold Gauge Connection Setup

To Open and Close Angle-Type Service Valve:

A valve stem cap protects the valve stem from

contamination and assures a leak-free seal,

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,

3. Replace the stem cap and tighten as follows:

• With Torque Wrench: Tighten finger tight and then
tighten per table 1,

• Without Torque Wrench: Finger tighten and use an
appropriately sized wrenched to turn an additional

1/12 turn clockwise as illustrated in figure 1.

SERVICE PORT

SERVICE PORT

VALVE STEM

FRONT-SEATED

TOINDOOR

UNIT

TO OUTDOOR

Figure 3. Angle-Type Service Valve

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

CAP _-

STEM CAP

CLOSED TO BOTHINDOOR

(Font-Seated Closed)

SERVICE PORT

CLOSED) INSERT HEX
WRENCH HERE

AND OUTDOOR UNITS

NOTE - Arrows indicate direction
of refrigerant flow.

INDOOR UNIT

_ CHECK EXPANSION VALVE --

INDOOR

COIL

NOTE- To prevent stripping of the cap, the wrench should
be appropriately sized and fit snugly over the cap before
tightening the cap.

SERVICE PORT CAP

SERVICE PORT SERVICE PORT

CORE

OPEN TO BOTH

INDOOR AND INSERT HEX WRENCH HERE

OUTDOOR UNITS

TO INDOOR

UNIT

TO OUTDOOR UNIT

STEM CAP

(VALVE STEM SHOWN OPEN)

Figure 4. Angle-Type Service Valve

(Back-Seated Opened)

To Access Bali-Type 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 to the service port.

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

• With Torque Wrench: Finger tighten and then
tighten per table 1,

• Without Torque Wrench: Finger tighten and use an
appropriately sized wrench to turn an additional

1/6 turn clockwise as illustrated in figure 1.

505329M 04/08

Page 4

OPEN TO LINE SET WHEN VALVE IS CLOSED,
TO BOTH LINE SET AND UNIT WHEN VALVE IS

OPEN.

TO OPEN ROTATE STEM
COUNTERCLOCKWISE 90 ° .

TO CLOSE ROTATE STEM
CLOCKWISE 90 ° .

TO INDOOR UNIT

BALL (SHOWN
CLOSED)

VALVE
STEM

RECOVERY MACHINE

MANIFOLD GAUGES

CORE

SERVICE PORT CAP

TO OUTDOOR UNIT

STEM CAP

Figure 5. Bali-Type Service Valve

To Open and Close Bali-Type Service Valve:

A valve stem cap protects the valve stem from

contamination and assures a leak-free seal,

1. Remove stem cap with an appropriately sized wrench,

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

rotate stem clockwise 90°.

3. Replace the stem cap and tighten as follows:

• With Torque Wrench: Finger tighten and then
tighten per table 1.

• Without Torque Wrench: Finger tighten and use an
appropriately sized wrench to turn an additional

1/12 turn clockwise as illustrated in figure 1,

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

Remove existing HCFC-22 refrigerant using one of the

following procedures:

METHOD 1:

If the existing outdoor unit is not equipped with shut-off
valves, or if the unit is not operational and you plan to use

the existing HCFC-22 to flush the system,

NOTE - Use recovery machine instructions for specific
setup requirements,

1. Disconnect all power to the existing outdoor unit,

2. Connect to the existing unit a gauge set, clean
recovery cylinder and a recovery machine. Use the
instructions provided with the recovery machine on
how to setup the connections,

3. Remove all HCFC-22 refrigerant from the existing
system, Check gauges after shutdown to confirm that

the entire system is completely void of refrigerant,

/

OUTDOOR UNIT

Figure 6. Typical Refrigerant Recovery

(Method 1)

NOTE - Use recovery machine instructions for specific
setup requirements.

METHOD 2:
Use this method if the existing outdoor unit is equipped

with manual shut-off valves, and plan on using new

HCFC-22 refrigerant to flush the system,
IMPORTANT: Some system configurations may contain

higher than normal refrigerant charge due to either large
internal coil volumes, and/or long line sets, The following

conditions may cause the compressor to stop functioning:
The following devices could prevent full system charge

recovery into the outdoor unit:

• Outdoor unit's high or low-pressure switches (if
applicable) when tripped can cycled the compressor

OFF.

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

• Compressor has internal vacuum protection that is
designed to unload the scrolls (compressor stops

pumping) when the pressure ratio meets a certain
value or when the suction pressure is as high as 20
psig. (Compressor suction pressures should never be

allowed to go into a vacuum, Prolonged operation at
low suction pressures will result in overheating of the
scrolls and permanent damage to the scroll tips, drive

bearings and internal seals),

Once the compressor can not pump down to a lower
pressure due to one of the above system conditions, shut

off the suction valve. Turn OFF the main power to unit and
use a recovery machine to recover any refrigerant left in

the indoor coil and line set.
Perform the following task:

1, Start the existing HCFC-22 system in the cooling

mode and close the liquid line valve.

2, Pump as much of the existing HCFC-22 refrigerant

with the compressor back into the outdoor unit until
you have reached the limitations of the outdoor
system, Turn the outdoor unit main power OFF and

use a recovery machine to remove the remaining
refrigerant in the system,

Page 5

XP16 SERIES

NOTE - It may be necessary to bypass the low pressure
switches if equipped to ensure complete refrigerant

evacuation.

3. When the low side system pressures reach 0 psig,
close the suction line valve,

4. Check gauges after shutdown to confirm that the
valves are not allowing refrigerant to flow back into the

low side of the system.

• Some localities are adopting sound ordinances based
on the unit's sound level registered from the adjacent
property, not from the installation property. Install the

unit as far as possible from the property line,

• When possible, do not install the unit directly outside
a window, Glass has a very high level of sound

transmission, For proper placement of unit in relation
to a window see the provided illustration in figure 8.

Perform the following task at the existing outdoor unit:

• Disconnect line set at the service valves,

• Disconnect electrical service at the disconnect switch.

• Remove old outdoor unit,

A CAUTION

See Unit Dimensions on page 3 for sizing mounting slab,
platforms or supports. Refer to figure 7 for mandatory
installation clearance requirements.

CONTROL PANEL
ACCESS LOCATION

INSTALLUNITAWAY

FROMWINDOWS--------' II--

IIIIIHIlls

Figure 8. Outside Unit Placement

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 9,

NOTE - If necessary for stability, anchor unit to slab as
described in Stabilizing Unit on Uneven Surfaces on page

7,

* SEE NOTES BELOW THIS FIGURE FOR FURTHER DETAILS.

Figure 7. Installation Clearances

NOTES:

• Service clearance of 30 in. (762 mm) must be
maintained on one of the sides adjacent to the control

box.

• Clearance to one of the other three sides must be 36
in, (914 mm).

• Clearance to one of the remaining two sides may be

12 in, (305 mm) and the final side may be 6 in, (152

mm).

• 48 in. (1219 mm) clearance required on top of unit.

• A clearance of 24 in. (610 mm) must be maintained
between two units,

POSITIONING CONSIDERATIONS

Consider the following when positioning the unit:

505329M 04/08

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.

BUILDING

STRUCTURE_-r

MOUNTING

SLAB --T-

GROUNDLEVEL

Figure 9. Slab Mounting at Ground Level

ELEVATING THE UNIT (SMALL-BASE UNITS)

If additional elevation is necessary, raise the unit by

extending the length of the unit support feet. This may be
done by cutting four equal true-cut lengths of Schedule

(SCH) 40, 4" (101.6mm) piping to the height required as
illustrated in figure 10.

Page 6

iL

BASE

LEG DETAIL

4" (101.6MM) SCH 40

Figure 10. Elevated Slab Mounting using Feet

Extenders (Small Base Units)

NOTE - Keep the height of extenders short enough to
ensure a sturdy installation. If it is necessary to extend

further, consider a different type of field-fabricated
framework that is sturdy enough for greater heights.

The inside diameter of the 4" (101.6mm) piping is
approximately 0.25" (6.35mm) greater than the

pre-installed feet on the unit. Devise a shim that will take up
the space and hold the extenders onto the feet during this

procedure. Small strips of 0.125" (3.175mm) thick
adhesive foam may be used. One or two small 1"
(25.4mm) square strips should be adequate to hold the

extender in place.

ELEVATING THE UNIT (LARGER-BASE UNITS)

Unlike the small-base units which use round support feet,
the larger-base units are outfitted with elongated support

feet as illustrated infigure 11which uses a similar method
for elevating the unit.

If additional elevation is necessary, raise the unit by
extending the length of the unit support feet. This may be

achieved by using a 2" SCH 40 female threaded adapter.
The specified coupling will fit snuggly into the recessed

portion of the feet. Use additional 2" SCH 40 male threaded
adaptors which can be threaded into the female threaded

adaptors to make additional adjustments to the level of the
unit.

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

BASE

LEG DETAIL

2" (50.8MM) SCH 40

FEMALE THREADED

ADAPTER

Figure 11. Elevated Slab Mounting using Feet

Extenders (Larger Base Units)

ROOF MOUNTING

Install unit at a minimum of four inches above the surface
of the roof. Care must be taken to ensure weight of unit is

properly distributed over roof joists and rafters. Either
redwood or steel supports are recommended.

CAUTION

Page 7

XP16 SERIES

REMOVING PANELS
Remove the Iouvered panels as follows:

1. Remove two screws, allowing the panel to swing open
slightly as illustrated in figure 12.

NOTE - Hold the panel firmly throughout this procedure

2, Rotate bottom corner of panel away from hinge corner

post until lower three tabs clear the slots as illustrated
in figure 12, detail B.

3, Move panel down until lip of upper tab clears the top

slot in corner post as illustrated in figure 12, detail A,

INSTALLING PANEL
Install the Iouvered panels as follows:

1, Position the panel almost parallel with the unit as

illustrated in figure 13, detail D with the screw side as
close to the unit as possible.

2, With a continuous motion slightly rotate and guide the

lip of top tab inward as illustrated in figure 12, details

A and C, then upward into the top slot of the hinge

corner post.

3, Rotate panel to vertical to fully engage all tabs,

4, Holding the panel's hinged side firmly in place, close

the right-hand side of the panel, aligning the screw
holes.

5, When panel is correctly positioned and aligned, insert

the screws and tighten,

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.

SCREW

LIP

HOLES _

\

MAINTAIN MINIMUM PANEL ANGLE (AS CLOSE TO PARALLEL WITH THE UNIT

AS POSSIBLE) WHILE INSTALLING PANEL.

ANGLE MAY BE TOO SIDE TO MAINTAIN
EXTREME _-_ FULLY-ENGAGED TABS

PREFERRED ANGLE
FOR INSTALLATION _

HOLD DOOR FIRMLY TO THE HINGED

Figure 13. Removing/Installing Louvered Panels

(Detail D)

STABILIZING UNIT ON UNEVEN SURFACES
To help stabilize an outdoor unit, some installations may

require strapping the unit to the pad using brackets and
anchors commonly available in the marketplace,

With unit positioned at installation site, remove two side
Iouvered panels to expose the unit base pan, Install the

brackets as illustrated in figure 14 and using conventional
practices; replace the panels after installation is complete,

Slab Side Mounting

k

#101/2" LONG SELF-

DRILLING

METAL SCREWS

STABILIZING

BRACKET (18 GAUGE

METAL - 2" WIDTH;

HEIGHT AS REQ'D)

#10 lq/4" LONG

HEX HD SCREW

- COIL

BASE PAN

DETAIL

ROTATE IN THIS DIRECTION;

THEN DOWN TO REMOVE

Figure 12. Removing/Installing Louvered Panels

(Details A, B and C)

505329M 04/08

PANEL

Page 8

CONCRETE SLAB - USE PLASTIC
PLASTIC ANCHOR (HOLE DRILL

1/4")PLASTIC SLAB - NO PLASTIC

ANCHOR (HOLE DRILL 1/8")

Mounting

STABILIZING BRACKET MINIMUM 1
(18 GAUGE METAL- 2" PER SIDE _

WIDTH; HEIGHT AS

REOD,;BENDTOFORM

Deck Top

FOR EXTRA

STABILITY

ONE BRACKET PER SIDE (MIN.); FOR EXTRA STABILITY,
2 BRACKETS PER SIDE, 2" FROM EACH CORNER.

liI "

Figure 14. Installing Stabilizer Brackets

J

A IMPORTANT

This section provides information on installation or
replacement of existing line set. If line set are not being

installed then proceed to Brazing Connections on page 11.
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. Also, consider the following when

placing and installing a high-efficiency air conditioner,
REFRIGERANT LINE SET

Field refrigerant piping consists of liquid and suction lines

from the outdoor unit (braze connections) to the indoor unit

coil (flare or sweat connections). Use Lennox L15 (sweat,
non-flare) series line set, or use field-fabricated refrigerant

lines as listed in table 2,

Table 2. Refrigerant Line Set

Field Connections Recommended Line Set

Model

-024 (10 ram) (19 ram) (10 ram) (19 ram) 15 ft. - 50 ft.

-048-036 (10 ram) (22 ram) (10 mm) (22 ram) (4.6 m- 15 m)

-060 (10 ram) (29 ram) (10 ram) (29 ram) Fabricated

NOTE - When installing refrigerant lines longer than 50
feet, see the Lennox Refrigerant Piping Design and
Fabrication Guidelines, or contact Lennox Technical
Support Product Applications for assistance. To obtain the

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

Liquid Suction Liquid Suction

Line Line Line Line L15 Line Set

3/8". 3/4" 3/8" 3/4"

3/8". 718" 3/8" 7/8"

318". 1-1/8". 318" 1-1/8" Field

L15-41

(4.6m - 15 m)
L15-65

15ft,- 50 ft.

MATCHING WITH NEW OR EXISTING INDOOR COIL

AND LINE SET

The RFCl-metering line consisted of a small bore copper
line that ran from condenser to evaporator coil. Refrigerant

was metered into the evaporator by utilizing

temperature/pressure evaporation effects on refrigerant in
the small RFC line. The length and bore of the RFC line

corresponded to the size of cooling unit.
If the XP16 is being used with either a new or existing

indoor coil which is equipped with a liquid line which served
as a metering device (RFCI), the liquid line must be

replaced prior to the installation of the XP16 unit. Typically
a liquid line used to meter flow is 1/4" in diameter and

copper.
INSTALLING LINE SET

Line Set Isolation--This reference illustrates
procedures, which ensure proper refrigerant line set

isolation:

• Installation of line set on horizontal runs is
illustrated in figure 15,

• Installation of a transition from horizontal to
vertical is illustrated in figure 16,

• Installation of line set on vertical runs is illustrated in
figure 17,

TO HANG LINE SET FROM JOIST OR

RAFTER, USE EITHER METAL STRAPPING

MATERIAL OR ANCHORED HEAVY NYLON
WIRE TIES.

STRAPPING MATERIAL

(AROUND SUCTION

LINE ONLY)

METAL

SLEEVE

TAPE OR

WIRE TIE

8 FEET

STRAP THE SUCTION LINE TO
THE JOIST OR RAFTER AT 8 FEET

INTERVALS THEN STRAP THE
LIQUID LINE TO THE SUCTION

LINE.

WIRE TIE
(AROUND

/ SUCTION LINE

ONLY)

TAPE OR

WIRE TIE

• Model (XP16) and size of unit (e,g. -060).

• Line set diameters for the unit being installed as listed
in table 2 and total length of installation,

• Number of elbows and if there is a rise or drop of the
piping,

Figure 15. Refrigerant Line Set: Installing

Horizontal Runs

Page 9

XP16 SERIES

ANCHOREDHEAVY

NYLONWIRETIE

WALL

.X\ L,QU,DL,NE

METALSLEEVE

AUTOMOTIVE

MUFFLER-TYPEHANGER

WALL

STUD

METALSLEEVE

S; sA cY, o 't

k
\SUCTION LINE - WRAPPED IN

ARMAFLEX

STRAP LIQUID LINE TO
SUCTION LINE

_ LIQUID LINE

x

SUCTION LINE - WRAPPED IN
ARMAFLEX

IMPORTANT - REFRIGERANT LINES MUST NOT CONTACT WALL.

OUTSIDE WALL SUCTION LINE

m

NOTE - SIMILAR INSTALLATION
PRACTICES SHOULD BE USED

IF LINE SET IS TO BE INSTALLED
ON EXTERIOR OF OUTSIDE
WALL.

-- WOOD BLOCK

LIQUID LINE

/ / I/ / / / /

WIRE TIE

INSIDE WALL

STRAP

SLEEVE

WIRE TIE

WIRE TIE

STRAP

IMPORTANT! REFRIGERANT

LINES MUST NOT CONTACT
STRUCTURE,

Figure 16. Refrigerant Line Set: Transition from

Vertical to Horizontal

CUT AND DEBUR

INSTALL CORE ONLY FOR

3OTH SERVICE PORTS after they

have coolED.

1

INDOOR UNIT

REMOVE CAP AND CORE FROM

BOTH LIQUID AND SUCTION

SERVICE PORTS

_. SUCTION LINE _ /VALVE

LIQUID LINE SERVICE_

Figure 18. Brazing Connections

Figure 17. Refrigerant Line Set: Installing Vertical

SERVICE PORT MUST BE

OPEN TO ALLOW EXIT

POINT FOR NITROGEN SERVICE

VALVE

Runs (New Construction Shown)

outdoor

UNIT

505329M 04/08

Page 10

Usethefollowingproceduretobrazethelinesettothenew
airconditionerunit.Figure18is providedas ageneral
guidefor preparingto brazethe line set to the air

conditionerunit.

WARNING

WARNÁNG

_WARNING

NOTE - The RFCIV or TXV metering device at the indoor
unit will allow low pressure nitrogen to flow through the

system.)
NO TE - Use silver alloy brazing rods with five or six percent

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

percent silver alloy for copper-to-brass or copper-to-steel

brazing.

6, Braze the liquid line to the liquid line service valve.

Turn off nitrogen flow. Repeat procedure starting at
paragraph 4 for brazing the suction line to the suction

service valve.

7, After all connections have been brazed, disconnect

manifold gauge set the from service ports and remove
wrapping. Reinstall the service port core for both of the

outdoor unit's service valves,

Remove the existing HCFC-22 refrigerant flow control
orifice or thermal expansion valve from the indoor coil. The

existing indoor unit HCFC-22 metering device is not
approved for use with HFC-410A refrigerant and may

prevent proper flushing.

REPLACEMENT PARTS

If replacement parts are necessary for the indoor unit,
order kit 69J46. The kit includes:

• 10 -- Brass nuts for liquid line assemblies

• 20 -- Teflon rings

• 10 -- Liquid line orifice housings

• 10 -- Liquid line assemblies

LIQUID LINE ORIFICE HOUSINGS (10) / RETAINER

TEFLON RINGS (20)

PISTON

1. Cut ends of the refrigerant lines square (free from
nicks or dents). Debur the ends. The pipe must remain
round, do not pinch end of the line.

2. Remove service cap and core from both the suction
and liquid line service ports.

3. Connect gauge low pressure side to liquid line service
valve.

4. To protect components during brazing, wrap a wet
cloth around the liquid line service valve body and
copper tube stub and use another wet cloth

underneath the valve body to protect the base paint.

Also, shield the light maroon R-410A sticker.

5. Flow regulated nitrogen (at 1 to 2 psig) through the
refrigeration gauge set into the valve stem port

connection on the liquid line service valve and out of

the valve stem port connection on the suction service
valve.

..(_J jBRASS NUTS (10) _

--/"1 .STRANER

,, O%ER

LIQUID LINE ASSEMBLIES

(INCLUDES STRAINER) (10) LIQUID LINE

Figure 19.69J46 Kit Components

TYPICAL FIXED ORIFICE REMOVAL PROCEDURE

1. On fully cased coils, remove the coil access and
plumbing panels.

2. Remove any shipping clamps holding the liquid line
and distributor assembly.

3. Using two wrenches, disconnect liquid line from liquid
line orifice housing. Take care not to twist or damage
distributor tubes during this process.

4. Remove and discard fixed orifice, valve stem
assembly if present and Teflon washer as illustrated in

figure 20.

ASSEMBLY

Page 11

XP16 SERIES

5. Use a field-provided fitting to temporary reconnect the
liquid line to the indoor unit's liquid line orifice housing,

DISTRIBUTOR TUBES

LIQUID LINE ORIFICE HOUSING

TEFLON RING Remove and discard valve

FIXED stem assembly (if present)

BRASS NUT

/

" j ....

4. Remove the suction line sensing bulb.

5. Disconnect the liquid line from the TXV at the liquid line
assembly,

6. Disconnect the TXV from the liquid line orifice housing.
Take care not to twist or damage distributor tubes
during this process,

7. Remove and discard TXV and the two Teflon rings as
illustrated.

8. Use a field-provided fitting to temporary reconnect the
liquid line to the indoor unit's liquid line orifice housing,

VA_ ?'"%%_'2s_ASS_"_T

VALVESTEMCAP (Uncased Coil Shown

Figure 20. Typical Fixed Orifice Removal

TYPICAL TXV REMOVAL PROCEDURE

1. On fully cased coils, remove the coil access and
plumbing panels,

2. Remove any shipping clamps holding the liquid line
and distributor assembly,

3. Disconnect the equalizer line from the TXV equalizer
line fitting on the suction line,

TWO PIECE

PATCH PLATE

UNCASED COIL LIQUID LINE STUB END

ONLY) ORIFICE HOUSING

DISTRIBUTOR TXV

TUBES

(Uncased Coil Shown)

RING

SENSING

LINE

A IMPORTANT

A IMPORTANT

IMPORTANT

MALE EQUALIZER LINE /

FITTING / SUCTION

/

SENSING BULB L_,

Figure 21. Typical TXV Removal

505329M 04/08

LIQUID

LINE

CAUTION

Page 12

Iftheoriginalsystemused:

• HCFC-22refrigerant,thenflushthesystemusingthe
procedureprovidedinthissection,

• HFC-410Arefrigerant,thenproceedtoInstalling New

Refrigerant Metering Device.

INVERTED HCFC-22 CYLINDER

/ CONTAINS CLEAN HCFC-22 TO

BE USED FOR FLUSHING. GAUGE

I PRESSURE PRESSURE

!O_ U'! MANIFOLD

suc t'_

SERVICE VALVE _ _ I : _'_ :I '_J

/\/\ _=n _ _ i-gh,

/ \ _ i I u" w _ ,_ 'U

RECOVERY

CYLINDER

NOTE - THE INVERTED HCFC-22 CYLINDER MUST CONTAIN AT LEAST THE SAME
AMOUNT OF REFRIGERANT AS WAS RECOVERED FROM THE EXISTING SYSTEM,

Figure 22. Typical Flushing Connection

LOW HIGH

OPENEDIIII CLOSED

RECOVERY MACHINE

XP16 units use CTXV for metering refrigerant only. This
section provides instructions on installing CTXV

refrigerant metering device.

1/2 TURN

Figure 23. Tightening Distance

TYPICAL CTXV INSTALLATION PROCEDURE
The CTXV unit can be installed internal or external to the
indoor coil. In applications where an uncased coil is being

installed in a field-provided plenum, install the CTXV in a
manner that will provide access for field servicing of the

CTXV, Refer to Figure 24 for reference during installation
of CTXV unit.

REQUIRED EQUIPMENT

Equipment required to flush the existing line set and indoor
unit coil:

• Two clean HCFC-22 recovery bottles,

• Oilless recovery machine with pump-down feature,

• Two gauge sets (one for HCFC-22; one for
HFC-410A).

FLUSHING PROCEDURE

1. Connect the following:

• HCFC-22 cylinder with clean refrigerant to the

suction service valve,

• HCFC-22 gauge set to the liquid line valve,

• Recovery machine with an empty recovery tank to

the gauge set,

2. Set the recovery machine for liquid recovery and start
the recovery machine. Open the gauge set valves to
allow the recovery machine to pull a vacuum on the
existing system line set and indoor unit coil.

3. Invert the cylinder of clean HCFC-22 and open its
valve to allow liquid refrigerant to flow into the system
through the suction 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.

4. After all of the liquid refrigerant has been recovered,
switch the recovery machine to suction recovery so

that all of the HCFC-22 suction is recovered. Allow the

recovery machine to pull a vacuum on the system,

5. Close the valve on the inverted HCFC-22 drum and
the gauge set valves. Pump the remaining refrigerant

out of the recovery machine and turn the machine off.

TWOPIECE (Uncased Coil Shown)

PATCH PLATE

UNCASED COIL

ONLY) LIQUID LINE

DISTRIBUTOR CTXV

TUBES. -

MALE EQUALIZER LINE
FITTING (SEE FIGURE 26

FOR FURTHER DETAILS)

SENSING BULB INSULATION IS
REQUIRED IF MOUNTED EXTERNAL

TO THE COIL CASING SEE FIGURE 25
FOR BULB POSITIONING.

HOUSING

..'_ORIFICE STUB END

LINE

RING

SENSING

LINE

LIQUID

LINE

Figure 24. Typical CTXV Installation

1, Remove the field-provided fitting that temporary

reconnected the liquid line to the indoor unit's
distributor assembly,

Page13

XP16 SERIES

2. Install one of the provided Teflon rings around the
stubbed end of the CTXV and lightly lubricate the
connector threads and expose surface of the Teflon
ring with refrigerant oil.

3. Attach the stubbed end of the CTXV to the liquid line
orifice housing, Finger tighten and use an appropriately

sized wrench to turn an additional 1/2 turn clockwise
as illustrated in figure 23, or 20 ft-lb,

4. Place the remaining Teflon washer around the other
end of the CTXV. Lightly lubricate connector threads

and expose surface of the Teflon ring with refrigerant
oil,

5. Attach the liquid line assembly to the CTXV. Finger
tighten and use an appropriately sized wrench to turn
an additional 1/2 turn clockwise as illustrated in figure
23, or 20 ft-lb,

6. Attach the suction line sensing bulb in the proper
orientation as illustrated in figure 25 using the clamp

and screws provided,

NOTE - Insulating the sensing bulb once installed may be
required when the bulb location is external to the coil
casing.

SUCTION LINE 7/8", MOUNT SENSING BULB

ON LINES SMALLER THAN

AT EITHER THE 3 OR 9

'X_L,,'*"L_"

BULB\_

FLARE SEAL_

CAP

÷

OR --FLARE SEAL

J_ FLARE NUT

X COPPER

BONNET

J

•_MALE BRASS EQUALIZER
LINE FITTING

SUCTION LINE

Figure 26. Copper Flare Seal Bonnet Removal

8. Connect the equalizer line from the CTXV to the
equalizer suction port on the suction line. Finger

tighten the flare nut plus 1/8 turn (7 ft-lbs) as illustrated
in figure 23,

NOTE - To prevent any possibility of water damage,
properly insulate all parts of the CTXV assembly that may
sweat due to temperature differences between the valve
and its surrounding ambient temperatures,

See the Lennox XP16 Engineering Handbook for
approved CTXV kit match-ups and application

information.
The reference CTXV kits include:

'Lr"* _,,,_ __,_,"_ __CK POSITION.

SUCTION LINE

ON 7/8" AND LARGER LINES,
MOUNT SENSING BULB AT

EITHER THE 4 OR 8 O'CLOCK

'TO%M%EVL%MOUNT

(BULB .

NOTE - NEVER MOUNT ON BOTTOM OF LINE.

Figure 25. TXV Sensing Bulb Installation

7. Remove and discard either the flare seal cap or flare
nut with copper flare seal bonnet from the equalizer

line port on the suction line as illustrated in figure 26.

A IMPORTANT

O_TEFLON

RINGS (2) _ I_

STRAP (1)

Figure 27. CTXV Kit Components

After the line set has been connected tothe indoor unit and
air conditioner, check the line set connections and indoor

unit for leaks. Use the following procedure to test for leaks:

IMPORTANT

505329M 04/08

Page 14

,A WARNING

,WARNING

,WARNING

7. After leak testing disconnect gauges from service
ports.

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

defined as any gas that will not condense under
temperatures and pressures present during operation of

an air conditioning system. Non-condensables and water
suction combine with refrigerant to produce substances

that corrode copper piping and compressor parts.

,A WARNING

IMPORTANT

1. Connect an HFC-410A manifold gauge set high
pressure hose to the suction valve service port.

(Normally, the high pressure hose is connected to the

liquid line port; however, connecting it to the suction
port better protects the manifold gauge set from high
pressure damage.)

2. 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 (suction only).

3. Open the high pressure side of the manifold to allow
HFC-410A into the line set and indoor unit, Weigh in

a trace amount of HFC-410A, [A trace amount is a

maximum of two ounces (57 g) refrigerant or three

pounds (31 kPa) pressure]. Close the valve on the

HFC-410A cylinder and the valve on the high pressure

side of the manifold gauge set, Disconnect the

HFC-410A cylinder.

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

gauge set,

5. Adjust dry nitrogen pressure to 150 psig (1034 kPa).
Open the valve on the high side d the manifold gauge

set in order to pressurize the line set and the indoor unit,

6. 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.

1. Connect manifold gauge set to the service valve ports
as follows:

• low pressure gauge to suction line service valve

• high pressure gauge to liquid line service valve

2. Connect micron gauge.

3. Connect the vacuum pump (with vacuum gauge) to
the center port of the manifold gauge set,

4. Open both manifold valves and start the vacuum
pump.

5. 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 to
determine if there is a rapid rise in sure indicates a
relatively large leak. If this occurs, repeat the leak testing

procedure.

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

pressure.

6. 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.

Page15

XP16 SERIES

7, 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,

8, Reconnect the manifold gauge to the vacuum pump,

turn the pump on, and continue to evacuate the line set
and indoor unit until the absolute pressure does not
rise above 500 microns (29.9 inches of mercury) within
a 20-minute period after shutting off the vacuum pump
and closing the manifold gauge valves.

9, When the absolute pressure requirement above has

been met, disconnect the manifold hose from the
vacuum pump and connect it to an upright cylinder d

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,

10. Close manifold gauge valves and shut off the
HFC-410A cylinder and remove the manifold gauge

set,

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

1, Use nitrogen to pressurize the system and check for

leaks. Repair all leaks,

2, Evacuate the system to remove as much of the

moisture as possible,

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

4, Evacuate the system again. Then, weigh the

appropriate amount of HFC-410A refrigerant as listed
on unit nameplate into the system.

5, Monitor the system to determine the amount of

moisture remaining in the oil. It may be necessary to
replace the filter drier several times to achieve the

required dryness level. If system dryness is not
verified, the compressor will fail in the future.

determine transformer loading. If loading exceeds the
factory-provided transformer capacity, a larger

field-provided transformer will need to be installed in the
system.

_WARNING

WIRING CONNECTIONS

1, Install line voltage power supply to unit from a properly

sized disconnect switch.

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

ground.

NOTE - Connect conduit to the unit using a proper conduit
fitting. Units are approved for use only with copper
conductors. See figure 28 for high voltage field wiring

diagram. A complete unit wiring diagram is located on the
back side of the unit's access panel.

AI_

OEFROST

CONTROL

E

LUG

GROUND_

CONTACTOR

m

GROUND

mlmLZ

mLI

z_

208 =
60/I

Old'DOOR

FAN

ro--oq

K31

i__..._._I_WlIN

LLII_LE-CAPAC ][TOR

CIZ

OUAL

CAPACITOR

LINE VOLTAGE

FIELD INSTALLED

ohvo_l

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

wiring must conform with current local codes and the current

Canadian Electrical Code (CEC),
Refer to the furnace or blower coil installation instructions

for additional wiring application diagrams and refer to unit

nameplate for minimum circuit ampacity and maximum
overcurrent protection size,

230VAC SUPPLY VOLTAGE

The XP16 outdoor unit is rated for 230VAC applications
only, A hard-start kit is required for applications where the

supply voltage is less than 230VAC,

24VAC TRANSFORMER

Use the transformer provided with the furnace or coil
blower for low-voltage control power (24VAC - 40 VA

minimum)

NOTE - The addition of accessories to the system could
exceed the 40 VA power requirement of the
factory-provided transformer, Measure the system's
current and voltage after installation is complete to

505329M 04/08

Page 16

z_ NOTE-

FOR USE WITH COPPER CONDUCTORS ONLY, REFER TO UNIT RATING PLATE FOR

MINZMUM CZRCUIT AMPACITY AN0 MAXIMUM 0VER-CURRENT PROTECTION SIZE

Figure 28. Outdoor Unit Typical Field Wiring

NOTE - For proper voltages, select thermostat wire
gauge per the following chart:

Table 3. Wire Run Length

Wire run length AWG # Insulation type

less than 100' (30m) 18 color-coded, temperature
more than 100' (30m) 16 rating 35°C minimum

3, Install room thermostat (ordered separately) on an

inside wall approximately in the center of the
conditioned area and 5 feet (1.5 m) from the floor,

NOTE -Thermostat should not be installed on an outside

wall or where it can be effected by sunlight, drafts or
vibrations,

4. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit (figures 29 and 30),

NOTE - 24VAC, Class II circuit connections are made in
the low voltage junction box,

SOME CONNECTIONS MAY NOT APPLY. REFER TO SPECIFIC THERMOSTAT

( ANDINDOORUNIT.)

OUTDOORUNITq ] NDOOR UN T TB11

A2 THERMOSTAT

I_11 i L_I"- i

I It t E_ t

Id_Pt- i- q_]- 4

ivl t t E_l t

@

ILSLFt--i---_4- 4

1@4-t- t _ a
I_1t t E_-,L_J

ou, _Lt --t 4

t _ J I J

SOME CONNECTIONS MAY NOT APPLY. REFER TO SPECIFIC THERMOSTAT

{

A_J_J _N R HT_N

rc_3-1_vT-_x_TM_,S,GNATURESTAT

OUTDOOR UNIT 1 I TB1 I A2 THERMOSTAT

[ L_

I-- __ I -- _y1) I OUTDOOR

-_ i I _ _ i SENSOR; USE

I -- -- TWISTED PAIR

, !

I-- Qg)_---I-- _ 1

/

[ I L J

Figure 29. Outdoor Unit and Blower Unit

Thermostat Designations

SA HIGH

PRESS_E

SWITCH L Ii

SB7 LOW
PRESSURE

SWITCH

C12 B4

DUAL FAN

CAPACITOR

©

LI _

REVERSING z_-

VALVE_

®

RT13 A_BIENT

SENGDE

®

RT21 DEFROST

COlLSENGOR

®

RT28

DISCHARRE
SENSOR

@

/i',ROTE-

FOR USE WITH COPPER CO_DBCTORSONLY.
REFER TO UNIT RATING PLATE FOR

MINIMUM CIRCUIT AMPACITY AND
MAXIMUM OVER-CURRENT PROTECTION SIZE

A REFER TO COMPRESSORIN UNIT

FOR ACTUAL TERMINAL ARRANGE_NT,

Z_ WARNING-

ELECTRIC SHOCKHAZARD,CANCAUSE INJURY
OR DEATH.UNIT MUSTBE OROUNOEDIN

ACCORDANCE WITH RATIONAL AND LOCAL CODES, /_ Gll- AND KSR ARE OPTIONAL LOW AMBIENT CONTROLS

L2

Z_ REMOVE3UMPORFOR TWO STAGE COOL
Z_ RYI4 SENSOR,OUTDOORTENP (OPTIONAL}

OPTIONAL HARO START KIT MAY DE REUUIREO ON
APPLICATIONGWHERE VOLTASES ARE LESS THAN
EGOVOLT. KIT INCLUDES K31 AND C7 WITH
ALL NECESSARYWIRING.

Figure 30. Outdoor Unit and CB31MV/CBX32MV

Thermostat Designations

JZ [[_@ BLUE cWRIIRMEpED

w

TERM,NAL

•-- --J II DEFROSTBOARDDETAIL

il

i

/_k L34 SECONDSTAGE, SOLENOID IS LOCATEDIN

COI_RESSOR. COIL IS 25VOC, 00 NOT CONNECT

24VAC TO COIL TERMINALS.

Z_ S4O _ NRI ARE USED ON 04G AND 060 UNITS ONLY

SHIPPEDASSHOWNABOVEWITHTERMINAL

CRIMPED TO BLUE WIRE; USE TERMINAL OR
CUT OFF TERMINAL AND SPLICE BLUE WIRE

WITH Y2 WIRE TO INDOOR UNIT,

DENOTESOPTIONAL CONPONENTS

J J J CLASS II VOLTAGEFIELD INSTALLED

LINE VOLTAGE FIELD INSTALLED

IMPORTANT

1. Rotate fan to check for binding.

Figure 31. XP16 Wiring

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

Page 17

XP16 SERIES

have consulted with the power company and the
voltage condition has been corrected.

6, Set the thermostat for a cooling demand. Turn on

power to the indoor indoor unit and close the outdoor
unit disconnect switch to start the unit.

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

8, Check system for sufficient refrigerate by using the

procedures listed under Testing and Charging

System,

TESTING AND CHARGING SYSTEM
This system uses HFC-410A refrigerant which operates at

much higher pressures than HCFC-22. The pre-installed
liquid line filter drier is approved for use with HFC-410A

only. Do not replace it with components designed for use

with HCFC-22, This unit is NOT approved for use with coils
which use capillary tubes as a refrigerant metering device.

SETTING UP TO CHECK CHARGE

1. Close manifold gauge set valves. Connect the center
manifold hose to an upright cylinder of HFC-410A,

2, Connect the manifold gauge set to the unit's service

ports as illustrated in figure 2.

• low pressure gauge to vapor service port

• high pressure gauge to liquid service port

COOLING MODE INDOOR AIRFLOW CHECK
Check airflow using the Delta-T (DT) process using the

illustration in figure 32,

HEATING MODE INDOOR AIRFLOW CHECK
Blower airflow (CFM) may be calculated by energizing

electric heat and measuring:

• Temperature rise between the return air and supply air
temperatures at the indoor coil blower unit,

• Measuring voltage supplied to the unit,

• Measuring amperage being drawn by the heat unit(s).

Then, apply the measurements taken in following formula
to determine CFM:

CFM =

Amps x Volts x 3.41

1.98 x Temperature rise (F)

CALCULATING CHARGE

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

Amount Adjust amount, for specified per

specified variation in line set indoor unit

on length listed on table match-up listed in Total

nameplate in figure 33. tables 4 through 7. charge

+ + =

Additional charge

Temp. } DT
ofair 180 24 24 24 23 23 22 22 22 20 19 18 17 16 15

entering.._178 23 23 23 22 22 21 21 20 19 18 17 16 15 14
indoor _ I _

coilOF _l.u 22 22 22 21 21 20 19 19 18 17 16 15 14 13

I _'174 21 21 21 20 19 19 18 17 16 16 15 14 13 12
_[72 20 20 19 18 17 17 16,/_15 14 13 12 11 10

Wet-bulb°F 57 58 59 60 61 62 63 64 65 66 67 68 69 70 [

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

n

DRY

BULB

90

All temperatures are iNDOOR WET
expressed in °F COiL BULB

Figure 32. Checking Indoor Airflow over Evaporator Coil using Delta-T Chart

WEIGH

Refrigerant Charge per Line Set Length

Liquid Line Ounces per 5 feet (g per 1.5 m)

Set Diameter adjust from 15 feet (4.6 m) line set*

3/8" (9.5 mm) 3 ounce per 5' (85 g per 1.5 m)

NOTE - *If line length is greater than 15 ft. (4.6 m), add this

amount. If line length is less than !5 ft. (4.6 m), subtract this
amount.

Step 1. Determine the desired DT--Measure entering air tempera-
ture using dry bulb (A) and wet bulb (B). DT is the intersecting value of

A and B in the table (see triangle).
Step 2. Find temperature drop across coil--Measure the coil's dry

bulb entering and leaving air temperatures (A and C). Temperature
Drop Formula: (TDrop) = A minus C.

Step 3. Determine if fan needs adjustment--If the difference be-
tween the measured TDrop and the desired DT (TDropiDT) is within

±3°, no adjustment is needed, See examples: Assume DT = 15 and A
temp. = 72°, these C temperatures would necessitate stated actions:

C° TDrop- DT = °F ACTION

53° 19 - 15 = 4 Increase the airflow
58° 14 - 15 = -1 (within +3° range) nochange

62° 10 - 15 = -5 Decrease the airflow
Step 4. Adjust the fan speed--See indoor unit instructions to in-

crease/decrease fan speed.

Changing air flow affects all temperatures; recheck temperatures to

confirm that the temperature drop and DT are within +3°.

LENNOX

_i|m[IWiIiiiHi

1. Check Liquid and suction line pressures

2. Compare unit pressures with tables 8 and
9, Normal Operating Pressures.

3. Conduct leak check; evacuate as
previously outlined,

4. Weigh in the unit nameplate charge plus
any charge required for line set differences

over feet,

This nameplate isfor illustration purposes
only. Go to actual nameplate on outdoor

unit for charge information.

505329M 04/08

Figure 33. Using Weigh In Method

Page 18

8UBCOOLING

USE COOLING

MODE

60°F (15 °) --

USE HEATING

MODE

%

SATo
LIQo -

SCo =

Check the airflow as illustrated in figure 32 to be sure the indoor airflow is as required.
(Make any air flow adjustments before continuing with the following procedure0

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 tables 8 and 9 (second stage - high capacity),

NOTE - The reference table is a general guide. Expect m#nor pressure variations. Significant
differences may mean improper charge or other system problem.

5 Set thermostat for heat/cool demand, depending on mode being used:

Using cooling mode--When the outdoor ambient temperature is 60°F (15°C) and above.

Target subcooling values (second stage - high capacity) in table 8 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 68°F (20°C) which should

call for second stage (high capacity) 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 table 9 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 77°F (25°C) which should call for second stage

(high capacity) heating. When pressures have stabilized, continue with step 6.
6 Read the liquid line temperature; record in the LIQ° space.

7 Read the liquid line pressure; then find its corresponding temperature in the temperature/

pressure chart listed in table 10and record it in the SAT °space.
8 Subtract LIQ° temp. from SAT °temp. to determine subcooling; record it in SC °space.
9 Compare SC° results with table below, being sure to note any additional charge for line set

and/or match-up.

10 If subcooling value is greater than shown in tables 4 through 7 for the applicable unit, remove

refrigerant; if less than shown, add refrigerant.

11 If refrigerant is added or removed, repeat steps 4 through 10 to verify charge.

Figure 34. Using Subcooling Method -- Second Stage (High Capacity)

Table 4. XP16-024

INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge

CBX26UH-018 20 8 1 5
CBX26UH-024 20 8 1 5
CB27UH-024 12 6 O 12

CB27UH-030 13 9 1 12
CB3OU 21/26 12 6 O 12
CB3OU 31 13 9 1 12
CBX32M-018/024 12 6 O 12
CBX32M-030 13 9 1 12

CBX32MV 024/030 13 9 1 12
CBX32MV 036 12 9 O 10
CH33-25B 17 4 O O
CH33-36A-2F 12 6 O 10
CH3_36B_F 17 4 O O

CH33 36C 2F 12 7 1 2
CR33-24A/B-F 20 4 O O
CR33-3O/36A/B/C-F 20 8 1 6
CR33 48 21 9 O 3
CX34_5A/_6F 12 6 O 12

CX34-31A/B-6F 20 9 1 12
CX34-36A/B/C-6F 17 5 O 5
CX34 38A/B 6F SerialNo#before6007K 31 7 O 8
CX34_8A/_6F SerialNo#6007Kandafter 10 8 O 11
CX34-19 18 4 O 1

Target

(+5°F) (+I°F)

Table 5. XP16-036

INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge

CH23_1 17 7 O 13
CH23-65 12 8 1 10

CBX26UHq330 25 8 1 14
CBX26UH 036 25 8 1 14
CB27UH-036 17 8 2 4

CB27UH-042 17 8 2 4
CB3OU_I 17 6 O O

CB3OU-41/46 17 8 2 4
CBX32M-030 17 6 O O
CBX32M-036 17 8 2 4

CBX32MV-024/030 17 6 O O
CBX32MV 036 17 8 2 4
C33 44C 17 8 1 14

CH33-42B-2F 17 7 O 13
CH33_44/48_2F 12 8 1 8

CH33_48C_F 10 8 1 6
CH33-43B 9 10 1 6

CH33_49C 9 10 1 6
CR33_48B/C_ 25 8 2 O
CR33-50/60C-F 25 9 0 14

CX34 38A/B_F se.al No#before6007K 31 7 1 5
CX34 38A/B 6FSet_alNo#6OOTKandafter 10 8 1 12

CX34-43B/C-6F 10 8 1 6
CX34 6OD 9 9 O 14

**Amount of charge required in additional to charge shown on unit nameplate.

(Remember to consider Iine set length difference.)

ililili'11" .....

Target

(*5°F) (*I°F)

Page 19

XP16 SERIES

Table 6. XP16-048

INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge

CH23 68 15 13 0 7
CB27UH-048 17 7 0 0
CB27UH-060 17 7 0 0
CB30U 51, 65 17 7 0 0

CBX32M-048, -060 17 7 0 0
CBX32MV-068 16 10 0 3

CH33 60D 2F 18 4 0 2
CH33-62D-2F 15 10 0 4

CR33-60 40 4 0 2
CX34 60D 6F 18 4 0 2

CX34-62D-6F 16 8 0 2

Target

(+5°F) (+I°F)

Table 7. XP16-060

INDOOR HEAT Subcooling **Add
MATCHUP PUMP Heat Cool charge

CH23 68 13 14 3 3
CH23-65 18 2 0 0

CBX26UH-060 13 14 3 5
CB27UH-060 13 10 2 1

CBX32M-060 13 10 2 1
CBX32MV-068 13 12 2 9

CH33 60D 2F 15 6 1 3
CH33-62D-2F 13 12 2 10
CR33-50/60C-F 30 6 1 3

CR33 60D F 30 6 1 3
CX34-49C-6F 13 9 1 14
CX34-60D-6F 15 6 1 3

CX34 62C 6F 13 11 2 6
CX34-62D-6F 13 11 2 5

Target

(+5°F) (+I°F)

NOTE - Use the tables 8 and 9 to perform maintenance
checks; it is not a procedure for charging the system. Minor
variations in these pressures may be due to differences in
installations. Significant deviations could mean that the
system is not properly charged or that a problem exists
with some component in the system.

Table 8. Normal Operating Pressures - Cooling 1

XP 16 -024 -036 -048 -060

°F (°C) 2 Liq I Vap Liq I Vap Liq IVap Liq I Vap

First Stage (Low Capacity) Pressure 3

65 (18.3} 232 146 225 144 235 144 225 138
75 (23.9} 264 148 261 147 268 145 264 141

85 (29.4) 307 149 302 149 310 147 305 142
95 (35.6) 353 151 349 151 356 148 352 146

165 (46.6) 403 153 397 153 407 150 405 148
115(46.1) 460 155 461 157 466 152 459 150

Second Stage (High Capacity) Pressure 3

65 (18.3) 240 143 239 139 244 140 241 134
75 (23.9) 279 145 278 141 283 141 280 136
85 (29.4) 322 147 322 143 326 144 324 137

95 (35.6) 371 149 367 146 374 147 373 138

165 (46.6) 423 151 426 148 427 148 425 142
115(46.1) 485 154 489 151 491 151 486 146

Table 9. Normal Operating Pressures - Heating 1

XP 16 -024 -036 -048 -060

°F (°C) 2 Liq I Vap Liq IVap Liq IVap Liq I Vap

First Stage (Low Capacity) Pressure 3

46 (4.4) 337 93 328 98 369 75 351 63

50 (16) 322 117 333 118 366 114 335 92

Second Stage (High Capacity) Pressure 3

26 (-7.0) 279 62 296 62 311 58 308 59
36 (-1.6) 288 76 309 75 334 72 323 70

46 (4.4) 302 93 322 92 354 89 318 69
56(16) 306 112 336 113 381 108 329 82

1 Most-popular-match-up pressures. Indoor match up, indoor air quality, and indoor load
cause pressures to vary.

2 Temperature of the air entering the outdoor coil.
3 Liquid -+10& Vapor -+5psig.

Table 10. HFC-410A Temp. (°F) - Pressure (Psig)

°F Psig °F Psig °F Psig °F Psig

32 100.8 63 178.5 94 290.8 125 445.9
33 102.9 64 181.6 95 295.1 126 451.8

34 105.0 65 184.3 96 299.4 127 457.6
35 107.1 66 187.7 97 303.8 128 463.5
36 109.2 67 190.9 98 308.2 129 469.5

37 111.4 68 194.1 99 312.7 130 475.6
38 113.6 69 197.3 100 317.2 131 481.6

39 115.8 70 200.6 101 321.8 132 487.8
40 118.0 71 203.9 102 326.4 133 494.0
41 120.3 72 207.2 103 331.0 134 500.2
42 122.6 73 210.6 104 335.7 135 506.5
43 125.0 74 214.0 105 340.5 136 512.9
44 127.3 75 217.4 106 345.3 137 519.3
45 129.7 76 220.9 107 350.1 138 525.8
46 132.2 77 224.4 108 355.0 139 532.4
47 134.6 78 228.0 109 360.0 140 539.0
48 137.1 79 231.6 110 365.0 141 545.6
49 139.6 80 235.3 111 370.0 142 552.3
50 142.2 81 239.0 112 375.1 143 559.1
51 144.8 82 242.7 113 380.2 144 565.9
52 147.4 83 246.5 114 385.4 145 572.8
53 150.1 84 250.3 115 390.7 146 579.8
54 152.8 85 254.1 116 396.0 147 586.8
55 155.5 86 258.0 117 401.3 148 593.8
56 158.2 87 262.0 118 406.7 149 601.0
57 161.0 88 266.0 119 412.2 150 608.1
58 163.9 89 270.0 120 417.7 151 615.4
59 166.7 90 274.1 121 423.2 152 622.7
60 169.6 91 278.2 122 428.8 153 630.1
61 172.6 92 282.3 123 434.5 154 637.5
62 175.4 93 286.5 124 440.2 155 645.0

INSTALLING SERVICE VALVE CAPS

Disconnect gauge set and re-install both the liquid and

suction service valve caps,

INSTALL CAPS

OUTDOOR UNIT /

SERVICE VALVES_

Figure 35. Installing Service Valve Caps

505329M 04/08

Page 20

Theoutdoorunitandindoorblowercycleondemandfrom
theroomthermostat.Whenthethermostatblowerswitch

is in the ON position,the indoorbloweroperates
continuously.

THERMOSTATOPERATION
Someindoorthermostatsincorporateisolatingcontacts

andanemergencyheatfunction(whichincludesanamber
indicatinglight).Thethermostatisnotincludedwiththe

unitandmustbepurchasedseparately.

EMERGENCY HEAT (AMBER LIGHT)

An emergency heat function is designed into some room

thermostats. This feature is applicable when isolation of the
outdoor unit is required, or when auxiliary electric heat is

staged by outdoor thermostats. When the room thermostat is
placed in the emergency heat position, the outdoor unit

control circuit is isolated from power and field-provided relays
bypass the outdoor thermostats. An amber indicating light
simultaneously comes on to remind the homeowner that he

is operating in the emergency heat mode.
Emergency heat is usually used during an outdoor unit

shutdown, but it should also be used following a power
outage if power has been off for over an hour and the

outdoor temperature is below 50°F (10°C). System should
be left in the emergency heat mode at least six hours to

allow the crankcase heater sufficient time to prevent
compressor slugging.

FILTER DRIER
The unit is equipped with a large-capacity bifiow filter drier

which keeps the system clean and dry. If replacement is

necessary, order another of like design and capacity. The
replacement filter drier must be suitable for use with

HFC-410A refrigerant.

DEFROST SYSTEM DESCRIPTION

The demand defrost controller measures differential
temperatures to detect when the system is performing

poorly because of ice build-up on the outdoor coil. The
controller self-calibrates when the defrost system starts

and after each system defrost cycle. The defrost control
board components are shown in figure 36.

The control monitors ambient temperature, outdoor coil
temperature, and total run time to determine when a

defrost cycle is required. The coil temperature probe is
designed with a spring clip to allow mounting to the outside

coil tubing. The location of the coil sensor is important for
proper defrost operation.

NOTE - The demand defrost board accurately measures
the performance of the system as frost accumulates on the
outdoor coil. This typically will translate into longer running
time between defrost cycles as more frost accumulates on
the outdoor coil before the board initiates defrost cycles.

TEST PINS --

DEFROST

TERMINATION

PIN SETTINGS

SENSOR

PLUG IN

(COIL &

AMBIENT

SENSORS)

DELAY

REVERSING

VALVE

PRESSURE/

SWITCH

CIRCUIT X

CONNECTIONS

PINS

LOW
AMBIENT

THERMOSTAT
PINS

-- DIAGNOSTIC
LEDS

24V TERMINAL
STRIP

CONNECTIONS

Note - Compo-
nent locations

vary by board

manufacturer,

Figure 36. Defrost Control Board

DEFROST BOARD DIAGNOSTIC LEDS

The state (Off, On, Flashing) of two LEDs on the defrost
board (DSl [Red] and DS2 [Green])indicate diagnostics

conditions that are described in table 12 on page 24,

DEFROST BOARD PRESSURE SWITCH
CONNECTIONS

The unit's automatic reset pressure switches (LOPS - $87
and HI PS - $4) are factory-wired into the defrost board on

the LO-PS and HI-PS terminals, respectively.
Low Pressure Switch (LO-PS)--When the low pressure

switch trips, the defrost board will cycle off the compressor,
and the strike counter in the board will count one strike.

The low pressure switch is ignored under the following
conditions:

• During the defrost cycle and 90 seconds after the
termination of defrost

• When the average ambient sensor temperature is
below 15° F (-9°C)

• For 90 seconds following the start up of the
compressor

• During test mode

High Pressure Switch (HI-PS)--When the high pressure
switch trips, the defrost board will cycle off the compressor,

and the strike counter in the board will count one strike.
DEFROST BOARD PRESSURE SWITCH SETTINGS

High Pressure (auto reset) - trip at 590 psig, reset at 418.
Low Pressure (auto reset) - trip at 25 psig; reset at 55.
PRESSURE SWITCH 5-STRIKE LOCKOUT

The internal control logic of the board counts the pressure
switch trips only while the Y1 (Input) line is active. If a

pressure switch opens and closes four times during a Y1
(Input), the control logic will reset the pressure switch trip

counter to zero at the end of the Y1 (Input). If the pressure
switch opens for a fifth time during the current Y1 (Input),

the control will enter a lockout condition.

Page 21

XP16 SERIES

The 5-strike pressure switch lockout condition can be reset
by cycling OFF the 24-volt power to the control board or by

shorting the TEST pins between 1 to 2 seconds. All timer

functions (run times) will also be reset.

If a pressure switch opens while the Y1 Out line is
engaged, a 5-minute short cycle will occur after the switch
closes.

DEFROST SYSTEM SENSORS

Sensors connect to the defrost board through a

field-replaceable harness assembly that plugs into the

board as illustrated in figure 39 on page 23. Through the
sensors, the board detects outdoor ambient, coil, and

discharge temperature fault conditions. As the detected
temperature changes, the resistance across the sensor

changes. Sensor resistance values can be checked by
ohming across pins shown in table 11.

Table 11. Sensor Temperature/Resistance Range

Pins/W

Sensor Range °F (°C) range (ohms) Color

Outdoor -35 (-37) to 120 (48) 280,000 to 3750 3 & 4

Coil -35 (-37) to 120 (48) 280,000 to 3750 5 & 6

Discharge (if 24 (-4) to 350 (176) 41,000 to 103 1 & 2

applicable) (Yellow)

Note: Sensor resistance increases as sensed temperature decreases.

Temperature Resistance values ire

(Black)

(Brown)

Figure 37 shows how the resistance varies as the
temperature changes for both type of sensors.

NOTE - When checking the ohms across a sensor, be
aware that a sensor showing a resistance value that is not

within the range shown in table 11, maybe 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.

1 ml157_O

I

mMm7450

19275

11775

B 15425

_ 19975

26200

[] 34375

mm46275

I 62700 85300

10000 30000 50000 70000 90000

RESISTANCE (OHMS)

i

Figure 37. Temperature/Resistance Chart

(Ambient and Coil Sensors)

m
m250
roll

m325
m
m425

m
m600

m
m825

m1175

WOO

_025

"500

3000

3750

4650 5825

1000 2000 3000 4000 5000 6000

RESISTANCE (OHMS)

Figure 38. Temperature/Resistance Chart

(Discharge Sensor)
Ambient Sensor--The ambient sensor considers
outdoor temperatures below -35°F (-37°C) or above 120°F

(48°C) as a fault. Ifthe ambient sensor is detected as being
open, shorted or out of the temperature range of the
sensor, the board will not perform demand defrost

operation. The board will revert to time/temperature
defrost operation and will display the appropriate fault

code. Heating and cooling operation will be allowed in this
fault condition.

Coil Sensor--The coil temperature sensor considers
outdoor temperatures below -35°F (-37°C) or above 120°F

(48°C) as afault. If the coil temperature sensor is detected
as being open, shorted or out of the temperature range of

the sensor, the board will not perform demand or
time/temperature defrost operation and will display the

appropriate fault code. Heating and cooling operation will
be allowed in this fault condition.

Discharge Line Sensor--If the discharge line
temperature exceeds a temperature of 300°F (148°C)
during compressor operation, the board will de-energize

the compressor contactor output (and the defrost output, if
active). The compressor will remain off until the discharge

temperature has dropped below 225°F (107°C) and the
5-minute anti-short cycle delay has been satisfied. This

sensor has two fault and lockout codes:

.

If the board recognizes five high discharge line
temperature faults during a single (Y1) compressor
demand, it reverts to a lockout mode and displays the
appropriate code. This code detects shorted sensor or
high discharge temperatures. (Code on board is
"Discharge Line Temperature Fault and Lockout").

,

If the board recognizes five temperature sensor range
faults during a single (Y1) compressor demand, it

reverts to a lockout mode and displays the appropriate
code. The board detects open sensor or
out-of-temperature sensor range. This fault is
detected by allowing the unit to run for 90 seconds
before checking sensor resistance. If the sensor
resistance is not within range after 90 seconds, the
board will count one fault. After five faults, the board
will lockout. (Code on board is "Discharge Sensor

Fault and Lockout").

505329M 04/08

Page 22

DEFROST BOARD

DEFROST SENSOR

HARNESS

COIL SENSOR - 12

TUBES UP FROM
BOTTOM (11-1/2")

SENSOR

EAR _LY- -

I
= ON LATER MODELS

= DISCHARGE LINE SENSOR
I

L ..... ,

ON

MODELS

LOCATIONS

COIL SENSOR -
APPLY GREASE BETWEEN

RETURN BEND AND SENSOR

Figure 39. Sensor Locations

The discharge line sensor, which covers a range of 150°F
(65°C) to 350°F (176°C), is designed to mount on a V2"

refrigerant discharge line.

NOTE - Within a single room thermostat demand, if
5-strikes occur, the board will lockout the uniL Defrost

board 24 volt power R must be cycled OFF or the TEST

pins on board must be shorted between I to 2 seconds to

reset the board.

Second-Stage Operation--If the board receives a call for
second-stage compressor operation Y2 in heating or

cooling mode and the first-stage compressor output is
active, the second-stage compressor solenoid output will
be energized.

If first-stage compressor output is active in heating mode
and the outdoor ambient temperature is below the selected

compressor lock-in temperature, the second-stage
compressor solenoid output will be energized without the
Y2 input. If the jumper is not connected to one of the

temperature selection pins on P3 (40, 45, 50, 55°F), the
default Iockqn temperature of 40°F (4.5°C) will be used.

The board de-energizes the second-stage compressor
solenoid output immediately when the Y2 signal is

removed or the outdoor ambient temperature is 5°F above
the selected compressor lock-in temperature, or the

first-stage compressor output is de-energized for any

reason.

Defrost Temperature Termination Shunt (Jumper)

Pins--The defrost board selections are: 50, 70, 90, and
100°F (10, 21, 32 and 38°C). The shunt termination pin is

factory set at 50°F (10°C). If temperature shunt is not

installed, default termination temperature is 90°F (32°C).

XP16-048

COIL SENSOR -
13 TUBES UP FROM
BOTTOM (12-1/2")

DELAY MODE

The defrost board has a field-selectable function to reduce
occasional sounds that may occur while the unit is cycling

in and out of the defrost mode. When a jumper is installed
on the DELAY pins, the compressor will be cycled off for 30

seconds going in and out of the defrost mode. Units are
shipped with jumper installed on DELAY pins.

NOTE - The 30 second off cycle is NOTfunctional when

jumpering the TEST pins.

OPERATIONAL DESCRIPTION
The defrost control board has three basic operational

modes: normal, defrost, and calibration.

• Normal Mode--The demand defrost board monitors
the O line, to determine the system operating mode

(heat/cool), outdoor ambient temperature, coil
temperature (outdoor coil) and compressor run time to

determine when a defrost cycle is required.

• Calibration Mode--The board is considered
uncalibrated when power is applied to the board, after

cool mode operation, or if the coil temperature
exceeds the termination temperature when it is in heat
mode.

Calibration of the board occurs after a defrost cycle to
ensure that there is no ice on the coil. During
calibration, the temperature of both the coil and the

ambient sensor are measured to establish the
temperature differential which is required to allow a

defrost cycle.

• Defrost Mode--The following paragraphs provide a
detailed description of the defrost system operation.

Page 23

XP16 SERIES

Table 12. Defrost Control Board Diagnostic LEDs

DS2 DS1
Green Red Condition/Code Possible Cause(s) Solution

OFF OFF Power problem No power (24V) to board terminals 1 Check control transformer power (24V).

R & C or board failure. 2 If power is available to board and LED(s) do

not light, replace board.

Simultaneous Normal operation Unit operating normally or in stand- None required.
SLOW Flash by mode.

Alternating SLOW 5-minute anti-short cycle Initial power up, safety trip, end of None required (Jumper TEST pins to override)

Flash delay room thermostat demand.
Simultaneous Ambient Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will revert to

FAST Flash time/temperature defrost operation. (System will still heat or cool).

Alternating Coil Sensor Problem Sensor being detected open or shorted or out of temperature range. Board will not per-

FAST Flash form demand or time/temperature defrost operation. (System will still heat or cool).

ON ON Circuit Board Failure doeslndicateSnotclear,thatboardreplacehaSboard.internalcomponent failure. Cycle 24 volt power to board. If code

Table 13. Defrost Control Board Diagnostic Fault and Lockout Codes

DS2 DS1
Green Red Condition/Code Possible Cause(s) Solution

(Each fault adds 1 strike to that code's counter; 5 strikes per code = LOCKOUT)

OFF

OFF

SLOW
Flash

ON

SLOW ON Discharge Line Temperature
Flash Fault

FAST
Flash

OFF Fast Discharge Sensor Fault

Fast OFF Discharge Sensor
Flash LOCKOUT

SLOW Low Pressure Fault

Flash

ON Low Pressure LOCKOUT

OFF High Pressure Fault

OFF High Pressure LOCKOUT

ON Discharge Line Tempera-

ture LOCKOUT

Flash

1Restricted air flow over indoor or

outdoor coil.

2 Improper refrigerant charge in

system.

3 Improper metering device

installed or incorrect operation

of metering device.

4 Incorrect or improper sensor

location or connection to sys-

tem.

1Remove any blockages or restrictions from

coils and/or fans. Check indoor and outdoor

fan motor for proper current draws.

2Check system charge using approach and

subcooling temperatures.

3Check system operating pressures and

compare to unit charging charts.

4 Make sure all pressure switches and sensors

have secure connections to system to prevent
refrigerant leaks or errors in pressure and
temperature measurements.

This code detects shorted sensor or high discharge temperatures. If the discharge line
temperature exceeds a temperature of 300°F (148°C) during compressor operation, the

board will de-energize the compressor contactor output (and the defrost output if active).
The compressor will remain off until the discharge temperature has dropped below 225°F

(107°C).
The board detects open sensor or out of temperature sensor range. This fault is detected

by allowing the unit to run for 90 seconds before checking sensor resistance. If the sen-
sor resistance is not within range after 90 seconds, the board will count one fault. After 5
faults, the board will lockout.

DETAILED DEFROST SYSTEM OPERATION

The demand defrost control board initiates a defrost cycle
based on either frost detection or time.

Frost Detection--If the compressor runs longer than 34
minutes and the actual difference between the clear coil

and frosted coil temperatures exceeds the maximum
difference allowed by the control, a defrost cycle will be
initiated.

IMPORTANT- The demand defrost control board will allow
a greater accumulation of frost and will initiate fewer

defrost cycles than a time/temperature defrost system.

505329M 0_08

Time--If six hours of heating mode compressor run time
has elapsed since the last defrost cycle while the coil

temperature remains below 35°F (2°C), the demand
defrost control will initiate a defrost cycle.

Actuation--When the reversing valve is de-energized,
the Y1 circuit is energized, and the coil temperature is

below 35°F (2°C), the board logs the compressor run time.

If the board is not calibrated, a defrost cycle will be initiated

after 34 minutes of heating mode compressor run time,
The control will attempt to self-calibrate after this (and all

other) defrost cycle(s),

Page 24

Y1 Active ("0" line inactive) /

I

1

/

Short test pins for longer than

1second but less than 2.0

seconds

Clear any short cycle

lockout and/or 5-strike

fault lockout function, if

applicable. No other func-
tions will be executed and

unit will continue in the
mode it was operating,

Test pin short REMAINS in place for more than 5 seconds

I If in COOLING Mode

No further test

mode operation will

be executed until

the test short is re-

moved and reap-

plied.

Clear any short cycle lockout or 5-strike fault lock-

The controller will check for ambient and coil

faults (open or shorted) If a fault exists, the

unit will remain in Heat Mode and no further

test mode operation will be executed until the

test short is removed and re applied. If no

fault exists, the unit will go into Defrost mode.

t

The unit will return to Heat mode uncalibrated with defrost timer set for

34 minutes. No further test mode operation will be executed until the

test short is removed and re applied.

Figure 40. Test Mode

Calibration success depends on stable system
temperatures during the 20-minute calibration period. If

the board fails to calibrate, another defrost cycle will be
initiated after 90 minutes of heating mode compressor run

time. Once the defrost board is calibrated, it initiates a
demand defrost cycle when the difference between the

clear coil and frosted coil temperatures exceeds the
maximum difference allowed by the control or after six

hours of heating mode compressor run time has been
logged since the last defrost cycle.

Termination--The defrost cycle ends when the coil
temperature exceeds the termination temperature or after

14 minutes of defrost operation, If the defrost is terminated
by the 14-minute timer, another defrost cycle will be

initiated after 34 minutes of run time,
Test Mode--When Y1 is energized and 24V power is

being applied to the board, a test cycle can be initiated by
placing the termination temperature jumper across the
"Test" pins for 2 to 5 seconds, Ifthe jumper remains across

the "Test" pins longer than five seconds, the control will
ignore the test pins and revert to normal operation, The

jumper will initiate one cycle per test,

Enter the TEST mode by placing a shunt (jumper) across
the TEST pins on the board after power-up. (The TEST

pins are ignored and the test function is locked out if the
shunt is applied on the TEST pins before power-up). Board

timings are reduced, the low-pressure switch is ignored
and the board will clear any active lockout condition,

Each test pin shorting will result in one test event. For
each TEST the shunt (jumper) must be removed for at

least one second and reapplied, Refer to flow chart (figure

40) for TEST operation,

Note: The Y1 input must be active (ON) and the 0 room
thermostat terminal into board must be inactive.

Short test pins for more than 2.0 seconds

out function, if applicable.

i

If in HEATING Mode I I If in DEFROST Mode

The unit will terminate defrost and

enter Heat Mode uncalibrated with

defrost timer set for 34 minute

test. No further test mode opera-

tion will be executed until the test

short is removed and reapplied.

I

Test pins short REMOVEDof5 secondsbef°re a maximum

The unit will remain in Defrost mode until ter-

mination on time or temperature

DEFROST BOARD DIAGNOSTICS

See table 12 on page 24 to determine defrost board
operational conditions and to diagnose cause and solution

to problems,

kWARNING

Before the start of each heating and cooling season, the

following service checks should be performed by a

qualified service technician. First, turn off electrical power
to the unit prior to performing unit maintenance.

• Inspect and clean the outdoor and indoor coils. The
outdoor coil may be flushed with a water hose.

NOTE - It may be necessary to flush the outdoor coil
more frequently if it is exposed to substances which

are corrosive or which block airflow across the coil
(e.g., pet urine, cottonwood seeds, etc.)

• Visually inspect the refrigerant lines and coils for leaks.

• Check wiring for loose connections.

• Check voltage at the indoor and outdoor units (with
units operating).

• Check the amperage draw at the outdoor fan motor,
compressor, and indoor blower motor. Values should

be compared with those given on unit nameplate.

• Check, clean (or replace) indoor unit filters.

• Check the charge and gauge the system pressures.

Page25

XP16 SERIES

• Check the condensate drain line for free and
unobstructed flow; clean, if necessary

• Adjust blower speed for cooling Measure the pressure
drop over the coil to determine the correct blower CFM

Refer tothe unit information service manual for pressure
drop tables and procedure

• Check drive belt for wear and proper tension

NOTE - if owner reports insufficient cooling, the unit
should be gauged and refrigerant charge checked
Refer to section on refrigerant charging in this

instruction

IMPORTANT

11 Iftemperatures and pressures change in the direction

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

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

In order to ensure peak performance, your system must be

properly maintained Clogged filters and blocked airflow
prevent your unit from operating at its most efficient level

1 Air Filter--Ask your Lennox dealer to show you where

your indoor unit's filter is located Itwill be either at the
indoor unit (installed internal or external to the cabinet)

or behind a return air grille in the wall or ceiling Check
the filter monthly and clean or replace it as needed

2 Disposable Filter--Disposable filters should be

replaced with a filter of the same type and size

NOTE - If you are unsure about the filter required for
your system, call your Lennox dealer for assistance

,& IMPORTANT

Use this check-out procedure (see checklist immediately

following) to verify part-load and full-load capacity

operation of two-stage modulation compressors
TOOLS REQUIRED

Refrigeration gauge set
Digital volt/amp meter
Electronic temperature thermometer

On-off toggle switch

PROCEDURE

NOTE - Block outdoor coil to maintain a minimum of 375

psig during testing)

1 Turn main power OFF to outdoor unit

2 Adjust room thermostat set point 5°F above the room

temperature

3 Remove control access panel Install refrigeration

gauges on unit Attach the amp meter to the common
(black wire) wire of the compressor harness Attach

thermometer to discharge line as close as possible to
the compressor

4 Turn toggle switch OFF and install switch in series with

Y2 wire from room thermostat

5 Cycle main power ON

6 Allow pressures and temperatures to stabilize before

taking measurements (may take up to 10 minutes)

7 Record all of the readings for the Y1 demand
8 Close switch to energize Y2 demand Verify power is

going to compressor solenoid

9 Allow pressures and temperatures to stabilize before

taking measurements (may take up to 10 minutes)

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

3 Reusable Filter--Many indoor units are equipped

with reusable foam filters Clean foam filters with a
mild soap and water solution; rinse thoroughly; allow

filter to dry completely before returning it to the unit or
grille

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

4, Electronic Air Cleaner--Some systems are

equipped with an electronic air cleaner, designed to
remove airborne particles from the air passing through
the cleaner. If your system is so equipped, ask your

dealer for maintenance instructions,

5, Indoor Unit--The indoor unit's evaporator coil is

equipped with a drain pan to collect condensate
formed as your system removes humidity from the
inside air. Have your dealer show you the location of
the drain line and how to check for obstructions. (This

would also apply to an auxiliary drain, if installed,)

IMPORTANT

6 Outdoor Unit--Make sure no obstructions restrict

airflow to the outdoor unit Leaves, trash or shrubs
crowding the unit cause the outdoor unit to work harder

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and use more energy. Keep shrubbery trimmed away
from the unit and periodically check for debris which

collects around the unit.

When removing debris from around the unit, be aware
of metal edges on parts and screws. Although special

care has been taken to keep exposed edges to a
minimum, physical contact with metal edges and
corners while applying excessive force or rapid motion
can result in personal injury.

Cleaning of the outdoor unit's coil should be performed
by a trained service technician. Contact your dealer

and set up a schedule (preferably twice a year, but at

least once a year) to inspect and service your air
conditioning or heat pump system.

HEAT PUMP OPERATION

Your new Lennox heat pump has several characteristics
that you should be aware of:

• Heat pumps satisfy heating demand by delivering
large amounts of warm air into the living space. This

is quite different from gas- or oil-fired furnaces or an

electric furnace which deliver lower volumes of

considerably hotter air to heat the space.

• Do not be alarmed if you notice frost on the outdoor coil
in the winter months. Frost develops on the outdoor

coil during the heating cycle when temperatures are
below 45°F (7°C). An electronic control activates a

defrost cycle lasting 5 to 15 minutes at preset intervals
to clear the outdoor coil of the frost.

• During the defrost cycle, you may notice steam rising

from the outdoor unit. This is a normal occurrence. The
thermostat may engage auxiliary heat during the

defrost cycle to satisfy a heating demand: however,
the unit will return to normal operation at the

conclusion of the defrost cycle.

EXTENDED POWER OUTAGE

The heat pump is equipped with a compressor crankcase
heater which protects the compressor from refrigerant

slugging during cold weather operation.
If power to your unit has been interrupted for several hours

or more, set the room thermostat selector to the
Emergency Heat setting to obtain temporary heat without

the risk of serious damage to the heat pump.
In Emergency Heat mode, all heating demand is satisfied

by auxiliary heat; heat pump operation is locked out. After a
six-hour compressor crankcase warm-up period, the

thermostat can be switched to the HEAT setting and
normal heat pump operation may resume.

THERMOSTAT OPERATIONS

Though your thermostat may vary somewhat from the
description below, its operation will be similar.

Temperature Setting Levers

Most heat pump thermostats have two temperature
selector levers: one for heating and one for cooling. Set the

levers or dials to the desired temperature setpoints for both
heating and cooling. Avoid frequent temperature

adjustment; turning the unit off and back on before
pressures equalize puts stress on the unit compressor.

Fan Switch

In AUTO or INT (intermittent) mode, the blower operates
only when the thermostat calls for heating or cooling. This

mode is generally preferred when humidity control is a
priority. The ON or CONT mode provides continuous

indoor blower operation, regardless of whether the
compressor or auxiliary heat are operating. This mode is

required when constant air circulation or filtering is desired.
System Switch
Set the system switch for heating, cooling or auto

operation. The auto mode allows the heat pump to
automatically switch from heating mode to cooling mode to

maintain predetermined comfort settings. Many heat
pump thermostats are also equipped with an emergency

heat mode which locks out heat pump operation and
provides temporary heat supplied by the auxiliary heat.

Indicating Light
Most heat pump thermostats have an amber light which

indicates when the heat pump is operating in the
emergency heat mode.

Temperature Indicator
The temperature indicator displays the actual room

temperature.
PROGRAMMABLE THERMOSTATS
Your Lennox system may be controlled by a

programmable thermostat. These thermostats provide the
added feature of programmable time-of-day setpoints for

both heating and cooling. Refer to the user's information
manual provided with your particular thermostat for
operation details.

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

• Check to see that all electrical disconnect switches are
ON.

• Make sure the room thermostat temperature selector
is properly set.

• Make sure the room thermostat system switch is
properly set.

• If you discover any blown fuses or tripped circuit
breakers, call your Lennox dealer for assistance.

• Make sure unit access panels are in place.

• Make sure air filter is clean.

• Locate unit model number and have it handy before
calling.

OPTIONAL ACCESSORIES
Refer to the Lennox XPf6 Engineering Handbook for

optional accessories that may apply to this unit. The

following may or may not apply:

• Compressor monitor

• Compressor crankcase heater

• Mounting bases

• Stand-off kit

• Sound cover

• Low ambient kit

• Mild ambient kit

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XP16 SERIES

• Monitor kit • Two-stage Lennox room thermostat

!!! !!!!!!!!!!!!!!!!!!

Expected results during Y2

Unit Readings Y1 - First-Stage demand (Toggle switch On) Y2 - Second-Stage

COMPRESSOR

Voltage Same
Amperage Higher

OUTDOOR UNIT FAN
MOTOR

Amperage Same or Higher

TEMPERATURE

Ambient Same

Outdoor Coil Discharge Air Higher
Compressor Discharge Line Higher

Indoor Return Air Same
Indoor Coil Discharge Air Lower

PRESSURES

Suction (Vapor) Lower
Liquid Higher

Customer Address
Indoor Unit Model Serial

Outdoor Unit Model Serial
Notes:

START UP CHECKS

Refrigerant Type:
1st Stage: Rated Load Amps

2nd Stage: Rated Load Amps
Outdoor Unit Fan Full Load Amps

COOLING MODE

Suction Pressure: 1st Stage:

Liquid Pressure: 1st Stage:

Supply Air Temperature: 1st Stage:

Temperature: Ambient:

System Refrigerant Charge (Refer to manufacturer's information on unit or installation instructions for required sub-
cooling and approach temperatures,)

Subcooling: A B SUBCOOLING

Saturated Condensing Temperature (A) -- =

minus Liquid Line Temperature (B)

Approach: A B APPROACH

Liquid Line Temperature (A) minus -- =

Outdoor Air Temperature (B)

Indoor Coil Temperature Drop (18 to 22°F) A B COIL TEMP DROP

Return Air Temperature (A) minus -- =

Supply Air Temperature (B)

Actual Amps Rated Volts Actual Volts
Actual Amps Rated Volts Actual Volts

Actual Amps: 1st Stage 2nd Stage

2nd Stage:
2nd Stage:

2nd Stage:

Return Air:

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