Lennox T?CLASS TPA S4 SERIES Information Manual

Page 1

© 2006 Lennox Industries Inc.

Corp. 0632−L6

TPA*S4

Service Literature

3, 3.5, 4 and 5 ton

10.5, 12.3, 14 and 17.6 kW

Revised 05−2009

T−CLASStTPA*S4 COMMERCIAL SERIES UNITS

The TPA*S4 is a HFC−410A commercial split-system
heat pump. The series is designed for use with expansion
valves (TXV). All TPA*S4 units utilize scroll compressors.

TPA*S4 series units are available in 3, 3.5, 4 and 5 ton
capacities. All major components (indoor blower and coil)
must be matched according to Lennox recommendations
for the compressor to be covered under warranty. Refer to
the Engineering Handbook for approved system
matchups.

This manual is divided into sections which discuss the
major components, refrigerant system, charging
procedure, maintenance and operation sequence.

Information contained in this manual is intended for use by
qualified service technicians only. All specifications are subject
to change.

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.

IMPORTANT

This unit must be matched with an indoor coil as
specified in Lennox’ Engineering Handbook. Coils
previously charged with HCFC−22 must be flushed.

Table of Contents

Specifications / Electrical Data Page 2. . . . . . . . .

Optional Accessories Page 3. . . . . . . . . . . . . . . . .

I Unit Components Page 4. . . . . . . . . . . . . . . . . . .

II Refrigerant System Page 8. . . . . . . . . . . . . . . . .

III Charging Page 10. . . . . . . . . . . . . . . . . . . . . . . . .

IV Maintenance Page 16. . . . . . . . . . . . . . . . . . . . . .

V Diagrams Page 17. . . . . . . . . . . . . . . . . . . . . . . . .

MODEL NUMBER IDENTIFICATION

TPA Y1036 S 44 n

Major Design Sequence

A = 1st Generation

B = 2nd Generation

Brand/Family

T = T−Classt Product Line

Unit Type

P = Heat Pump Outdoor Unit

Nominal Cooling Capacity − Tons

036 = 3 Tons

042 = 3.5 Tons

048 = 4 Tons
060 = 5 Tons

Cooling Efficiency

S = Standard Efficiency

Minor Design Sequence

1 = 1st Revision
2 = 2nd Revision
3 = 3rd Revision

Vol ta ge

Y = 208/230V-3 phase-60hz
G = 460V-3 phase-60hz

Refrigerant Type

4 = R−410A

Part Load Capability

N = No part load, single stage compressor

Coil type

4 = Four−sided

Page 2

Revised 05−2009TPA*S4

SPECIFICATIONS

General
Data

Model No. TPA036S4 TPA042S4 TPA048S4 TPA060S4

Nominal Tonnage 3 3.5 4 5

Connections
(sweat)

Liquid line o.d. − in. 3/8 3/8 3/8 3/8

Vapor line o.d. − in. 7/8 7/8 7/8 1-1/8

1

Refrigerant HFC−410A charge furnished 8 lbs. 12 oz. 10 lbs. 10 oz. 13 lbs. 2 oz. 15 lbs. 3 oz.

Outdoor
Coil

Net face area

sq. ft.

Outer coil 15.21 18.66 21.11 29.09

Inner coil 14.50 17.95 20.31 28.16

Tube diameter 5/16 5/16 5/16 5/16

Number of rows 2 2 2 2

Fins per inch 22 22 22 22

Outdoor
Fan

Diameter − in. − No. of Blades 18 − 4 22 − 4 22 − 4 22 − 4

Motor hp 208/230V − 1/5

460V − 1/6

1/3 1/3 1/4

Cfm 2450 3890 3890 3830

Rpm 1100 1080 1085 830

Watts 190 400 375 330

Shipping Data − lbs. 1 package 180 220 250 255

ELECTRICAL DATA

Line voltage data − 60 hz − 3ph 208/230V 460V 208/230V 460V 208/230V 460V 208/230V 460V

2

Maximum overcurrent protection (amps) 20 15 30 15 30 15 35 15

3

Minimum circuit ampacity 14.2 7.8 18.6 8.3 18.8 8.6 21.3 10.7

Compressor Rated Load Amps

10.4 5.8 13.5 6.0 13.7 6.2 15.6 7.8

Locked Rotor Amps

88 38 88 44 83.1 41 110 52

Power Factor

.85 .84 .83 .81 .90 .92 .90 .91

Outdoor
Fan Motor

Full Load Amps

1.1 .55 1.7 1.0 1.7 1.0 1.7 1.0

Locked Rotor Amps

1.9 1.1 4.1 2.2 4.1 2.2 3.1 2.3

Page 3

Revised 05−2009TPA*S4

OPTIONAL ACCESSORIES − must be ordered extra

Model No. TPA036S4 TPA042S4 TPA048S4 TPA060S4

Compressor Low Ambient Cut−Off 45F08 S S S S

Compressor Sound Cover 69J03 S S S S

Freezestat 3/8 in. tubing 93G35 S S S S

5/8 in. tubing 50A93 S S S S

Hail Guards 92M89 S

92M90 S S

12W21 S

92M94 S

4

Low Ambient Kit 54M89 S S S S

Low Ambient Control Option (down to 30°F) See table below See table below See table below See table below

Mild Weather Kit 33M07 S S S S

Monitor Kit − Service Light 76F53 S S S S

Mounting Base 69J06 S

69J07 S S S

Outdoor
Thermostat
Kit

Thermostat 56A87 S S S S

Mtg. Box 31461 S S S S

Refrigerant
Line Sets

L15−65−30, L15−65−40, or L15−65−50 S S S

Field Fabricate S

Time Delay Relay Kit 58M51 S S S S

Unit Stand−Off Kit 94J45 S S S S

NOTE − Extremes of operating range are plus 10% and minus 5% of line voltage.

1

Refrigerant charge sufficient for 15 ft. length of refrigerant lines.

2

HACR type circuit breaker or fuse.

3

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

4

Freezestat is recommended with Low Ambient Kit.

LOW AMBIENT CONTROL Option (Down to 0°F)

Order one each: Speed Control Kit, Weatherproof Kit, Outdoor Fan Motor and Capacitor

Model No. TPA036S2

TPA048S2 TPA060S2
Speed Control Kit X5867 S S S

Weatherproof Kit 56N41 S S S
Outdoor

Fan Motor

1/2 HP − 230V 69H75 S S S

460V 69H76 S S S

Capacitor with mounting bracket 53H06 S S S

IMPORTANT

The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFCs, HFCs, and HCFCs) as of
July 1, 1992. Approved methods of recovery,
recycling or reclaiming must be followed. Fines
and/or incarceration may be levied for
noncompliance.

CAUTION

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

Page 4

Revised 05−2009TPA*S4

I − UNIT COMPONENTS

Unit components are illustrated in figure 1.

TPA*S4 UNIT COMPONENTS

FIGURE 1

control box

service valves

compressor

reversing valve

condenser fan

drier

muffler

FIGURE 2

CAPACITOR

(C1)

COMPRESSOR

CONTACTOR

(K1)

TPA*S4 UNIT CONTROL BOX

GROUNDING

LUG

DEFROST

CONTROL

(CMC1)

DANGER

Electric Shock Hazard.
May cause injury or death.

Disconnect all remote electrical power
supplies before opening unit panel. Unit
may have multiple power supplies.

A − Control Box (Figure 2)

TPA*S4 units are not equipped with a 24V transformer. All
24 VAC controls are powered by the indoor unit. Refer to
wiring diagram.

Electrical openings are provided under the control box
cover. Field thermostat wiring is made to a 24V terminal
strip located on the defrost control board located in the
control box. See figure 3.

24V THERMOSTAT TERMINAL STRIP

FIGURE 3

W1 C L R O Y1

1 − Compressor Contactor K1

The compressor is energized by a contactor located in the
control box. See figure 2. Three−pole contactors are used
in TPA*S4 series units. K1 is energized through the
control board by the indoor thermostat terminal Y1 (24V)
when thermostat demand is present.

2 − Capacitor C1

All units use single−phase PSC outdoor fan motors which
require a run c a p a c i t o r. Ra t i n g s for c a p a c i t o r will be on
fan motor nameplate. C1 aids in the start up of outdoor
fan B4.

3 − Defrost System

The TPA036S4 defrost system includes two components:
a defrost thermostat and a defrost control.

Defrost Thermostat

The defrost thermostat is located on the liquid line between
the check/expansion valve and the distributor. When
defrost thermostat senses 42°F (5.5°C) or cooler, the
thermostat contacts close and send a signal to the defrost
control board to start the defrost timing. It also terminates
defrost when the liquid line warms up to 70°F (21°C).

Page 5

Revised 05−2009TPA*S4

Defrost Control

The defrost control board includes the combined functions
of a time/temperature defrost control, defrost relay,
diagnostic LEDs and terminal strip for field wiring
connections. See figure 4.

The control provides automatic switching from normal
heating operation to defrost mode and back. During
compressor cycle (call for defrost), the control
accumulates compressor run times at 30-, 60-, or
90-minute field−adjustable intervals. If the defrost
thermostat is closed when the selected compressor run
time interval ends, the defrost relay is energized and
defrost begins.

TPA036S4 Outdoor Unit Defrost Control

Board

FIGURE 4

LEDs

24v terminal

strip

Timing

Pins

Test Pins

Compressor

Delay Pins

Reversing

Valve

Low Pressure
Switch (S87)

High Pressure
Switch (S4)

Defrost

Thermostat

Defrost Control Timing Pins

Each timing pin selection provides a different
accumulated compressor run time period for one defrost
cycle. This time period must occur before a defrost cycle
is initiated. The defrost interval can be adjusted to 30
(T1), 60 (T2), or 90 (T3) minutes (see figure 4). The
defrost timing jumper is factory−installed to provide a
90−minute defrost interval. If the timing selector jumper is
not in place, the control defaults to a 90−minute defrost
interval. The maximum defrost period is 14 minutes and
cannot be adjusted.

A TEST option is provided for troubleshooting. The TEST

mode may be started any time the unit is in the heating
mode and the defrost thermostat is closed or
jumpered. If the jumper is in the TEST position at

power-up, the control will ignore the test pins. When the
jumper is placed across the TEST pins for two seconds, the
control will enter the defrost mode. If the jumper is removed
before an additional 5−second period has elapsed (7
seconds total), the unit will remain in defrost mode until the
defrost thermostat opens or 14 minutes have passed. If the
jumper is not removed until after the additional 5−second
period has elapsed, the defrost will terminate and the test
option will not function again until the jumper is removed
and re−applied.

Compressor Delay

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. The compressor will be
cycled off for 30 seconds going in and out of the defrost
mode when the compressor delay jumper is removed.

NOTE − The 30-second off" cycle is not functional when
jumpering the TEST pins.

Time Delay

The timed-off delay is five minutes long. The delay helps to
protect the compressor from short-cycling in case the
power to the unit is interrupted or a pressure switch opens.
The delay is bypassed by placing the timer select jumper
across the TEST pins for 0.5 seconds.

Pressure Switch Circuit

The defrost control incorporates two pressure switch
circuits. The optional high pressure switch (S4) connects to
the board’s HI PS terminals. The board also includes
connections for an optional low pressure, or
loss-of-charge-pressure, switch (S87). See figure 4 for
switch terminal location.

During a single demand cycle, the defrost control will lock
out the unit after the fifth time that the circuit is interrupted
by any pressure switch wired to the control board. In
addition, the diagnostic LEDs will indicate a locked-out
pressure switch after the fifth occurrence of an open
pressure switch (see Table 1). The unit will remain locked
out until power to the board is interrupted, then
re-established or until the jumper is applied to the TEST
pins for 0.5 seconds.

NOTE  The defrost control board ignores input from the
low-pressure switch terminals as follows:

S during the TEST mode,

S during the defrost cycle,

S during the 90-second start-up period,

S and for the first 90 seconds each time the reversing

valve switches heat/cool modes. If the TEST pins are
jumpered and the 5-minute delay is being
bypassed, the LO PS terminal signal is not ignored
during the 90-second start-up period.

Page 6

Revised 05−2009TPA*S4

Diagnostic LEDs

The defrost board uses two LEDs for diagnostics. The LEDs
flash a specific sequence according to the condition.

TABLE 1

Defrost Control Board Diagnostic LED

Mode Green LED (DS2)

Red LED
(DS1)

No power to control OFF OFF

Normal operation /
power to control

Simultaneous Slow FLASH

Anti-short cycle lock­out

Alternating Slow FLASH

Low pressure switch
fault (Optional)

OFF Slow FLASH

Low pressure switch
lockout (Optional)

OFF ON

High pressure switch
fault (Optional)

Slow FLASH OFF

High pressure switch
lockout (Optional)

ON OFF

B − Compressor

All TPA*S4 units utilize a scroll compressor. The scroll
compressor design is simple, efficient and requires few
moving parts. A cutaway diagram of the scroll compressor is
shown in figure 5. The scrolls are located in the top of the
compressor can and the motor is located just below. The oil
level is immediately below the motor.

The scroll is a simple compression concept centered around
the unique spiral shape of the scroll and its inherent properties.
Figure 6 shows the basic scroll form. Two identical scrolls are
mated together forming concentric spiral shapes (figure 7).
One scroll remains stationary, while the other is allowed to
"orbit" (figure 8). Note that the orbiting scroll does not rotate or
turn but merely orbits the stationary scroll.

FIGURE 5

SCROLL COMPRESSOR

DISCHARGE

SUCTION

NOTE − During operation, the head of a scroll compressor may
be hot since it is in constant contact with discharge gas.

FIGURE 6

SCROLL FORM

FIGURE 7

STATIONARY SCROLL

ORBITING SCROLL

DISCHARGE

SUCTION

CROSS−SECTION OF SCROLLS

TIPS SEALED BY
DISCHARGE PRESSURE

DISCHARGE
PRESSURE

The counterclockwise orbiting scroll draws gas into the outer
crescent shaped gas pocket created by the two scrolls (figure
8 − 1). The centrifugal action of the orbiting scroll seals off the
flanks of the scrolls (figure 8 − 2). As the orbiting motion
continues, the gas is forced toward the center of the scroll and
the gas pocket becomes compressed (figure 8 − 3). When the
compressed gas reaches the center, it is discharged vertically
into a chamber and discharge port in the top of the compressor
(figure 7). The discharge pressure forcing down on the top
scroll helps seal off the upper and lower edges (tips) of the
scrolls (figure 7). During a single orbit, several pockets of gas
are compressed simultaneously providing smooth continuous
compression.

The scroll compressor is tolerant to the effects of liquid return.
If liquid enters the scrolls, the orbiting scroll is allowed to
separate from the stationary scroll. The liquid is worked toward
the center of the scroll and is discharged. If the compressor is
replaced, conventional Lennox cleanup practices must be
used.

Due to its efficiency, the scroll compressor is capable of
drawing a much deeper vacuum than reciprocating
compressors. Deep vacuum operation can cause
internal fusite arcing resulting in damaged internal parts
and will result in compressor failure. Never use a scroll
compressor for evacuating or pumping−down" the
system. This type of damage can be detected and will
result in denial of warranty claims.

The scroll compressor is quieter than a reciprocating
compressor, however, the two compressors have much
different sound characteristics. The sounds made by a
scroll compressor do not affect system reliability,
performance, or indicate damage.

See compressor nameplate and ELECTRICAL DATA
table on page 2 for compressor specifications.