Lennox HP21, HP21−411, HP21−413, HP21−511, HP21−513 Unit Information

...

Corp. 9434−L12

Service Literature

Revised 07−2007

HP21 SERIES UNITS INCLUDING TSC−2, TSC−3 AND TSC-6

The HP21 is a high efficiency residential split-system heat pump with a two-speed compressor. Early models include HP21−411, −511 and −651. Late models built after March 1, 2000 include HP21−36, −48 and −60. All models are available in sizes ranging from 3 through 5 tons in either single or three-phase configuration. Early and late models feature solid-state two-speed control and new solid-state demand defrost control. The two-speed control regulates compressor speed in response to thermostat demand during cooling mode. Compressor speed is regulated by outdoor air temperature during heating mode. The defrost control monitors outdoor air temperature and liquid line temperature to determine when defrost is needed. The series uses conventional heat pump circuitry with expansion valves in the outdoor and indoor units.

This manual is divided into sections which discuss the components, refrigerant system, charging procedures, maintenance and operation sequences. All specifications in this manual are subject to change.

DANGER

HP21

EARLY/LATE MODEL

TABLE OF CONTENTS

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

Electric Shock Hazard. May cause injury or death.

Line voltage is present at all components when unit is not in operation on units with single pole contactors.

Disconnect all remote electrical power supplies before opening unit panel.

Unit may have multiple power supplies.

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Installation and service must be performed by a qualified installer or service agency.

WARNING

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

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

Specifications / Electrical 2. . . . . . . . . . . . . . . . . . . . . .

I Application 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

II Unit Components 3. . . . . . . . . . . . . . . . . . . . . . . . . . .

TSC−2 Control 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TSC−3 Control 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TSC−6 Control 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

III Refrigerant System 20. . . . . . . . . . . . . . . . . . . . . . . . .

IV Charging 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

V Maintenance 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VI Miscellaneous 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VII Wiring Diagrams and Operating Sequence 27. . . .

Page 1

SPECIFICATIONS

Model No.

Face area (sq.ft.) outside / inside

Outdoor Coil

Outdoor Fan

Refrigerant−22 (charge furnished) Liquid line connection (sweat) Vapor line connection (sweat)

Tube diameter (in.)

No. of Rows Fins per inch

Diameter (in.) No. of Blades

Motor hp Cfm Rpm

Watts

HP21−411 HP21−413

HP21−36−230 HP21−36−233

18.22/

17.53

3/8 3/8 3/8

222

18 18 20 24 24 24

334

1/10 1/6 1/4

3120 3200 4200

820 815 815

13lbs. 10oz. 15lbs. 5oz. 18lbs. 10oz.

3/8 3/8 3/8 3/4 7/8 1−1/8

ELECTRICAL DATA

Model No.

Line voltage data − 60hz.

Rated load amps

Compressor

Outdoor Coil Fan Motor

Max fuse or circuit breaker size (amps) *Minimum circuit ampacity

*Refer to National Electrical Code Manual to determine wire, fuse and disconnect size requirements.

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

Power factor Locked rotor amps

Full load amps Locked rotor amps

HP21−411

HP21−36−230

208/230/1ph 208/230/3ph208/230/3ph 208/230/1ph208/230/1ph 208/230/3ph

17.6 12.7 17.6 12.7 30.8 19.9 .98 .90 .98 .90 .92 .90

90.0 60.0 90.0 60.0 141.0 91.0

0.7 0.7 1.0 1.0 1.7 1.7

1.2 1.2 1.9 1.9 2.9 2.9

40 25 40 25 60 45

22.7 16.6 23.0 16.9 40.2 27.0

HP21−413

HP21−36−233

HP21−511

HP21−513

HP21−511

HP21−48−230

HP21−48−230 HP21−48−233

21.64/

20.81

200 310155

HP21−513

HP21−48−233

HP21−651 HP21−653

HP21−651

HP21−60−230

HP21−60−230 HP21−60−233

23.92/

23.01

HP21−653

HP21−60−233

Page 2

UNIT CONTROL

DEFROST CONTROL

LIQUID LINE SENSOR

REVERSING VALVE

AND SOLENOID L1

HP21 ELECTRICAL COMPONENTS

COMPRESSOR

TERMINAL BOX

HIGH PRESSURE

SWITCH S4

SERVICE LIGHT

THERMOSTAT S54

FIGURE 1

I−APPLICATION

All major components (indoor blower/coils) must be matched according to Lennox recommendations for the compressor to be covered under warranty. Refer to Engineering Handbook for approved system matchups. A misapplied system will cause erratic operation and can result in early failure of compressor or other components.

II−UNIT COMPONENTS

A−Control Transformer T19

All units are equipped with a line voltage to 24VAC transformer which supplies power to unit controls as shown in table 1. Refer to unit wiring diagram for detailed information regarding unit wiring.

B−Contactors K1 and K69

The compressor is energized by a set of contactors located in the control box. Contactors in HP21 units are energized as shown in table 2.

CRANKCASE

THERMOSTAT S40

COMPRESSOR B1

AMBIENT AIR PORT

(DEFROST CONTROL

AMBIENT SENSOR)

TABLE 1

HP21 Component Source of Power

Two-Speed Control A14

Contactor K1

Contactor K69

High Pressure Limit S4

Crankcase Thermostat S40

Defrost Control CMC1

Defrost Relay K4

Speed Control Thermostat S55

Service Light Thermostat S54

Ambient Thermistor RT3

Potential Relay K31

Crankcase Heater HR1

Compressor Run Capacitor C5

Compressor Start Capacitor C7

Bleed Resistor R21

Fan Capacitor C1

Compressor B1

Outdoor Fan B4

24VAC from

Outdoor Unit

Transformer T19

24VAC from

Indoor Unit

Transformer T1

Line Voltage

Page 3

START CAPACITOR C7

(single-phase only)

OUTDOOR FAN CAPACITOR C1

(three-phase only)

DUAL CAPACITOR C12

(single−phase)

EARLY HP21 -1 / -2 / -3 SINGLE PHASE SERIES UNITS USE FAN

CAPACITOR C1 AND COMPRESSOR CAPACITOR C5 IN PLACE OF

START RELAY K31 (single-phase only)

C12

HP21 CONTROL BOX COMPONENTS

Contactor K1

CONTACTOR K69

DEFROST RELAY

FIGURE 2

CONTACTOR K1

TRANSFORMER

T19

DEFROST CONTROL

CMC1

SPEED CONTROL

THERMOSTAT S55

TWO-SPEED CONTROL

A14

24V TERMINAL

STRIP TB15

Contactor Operation: Single-Phase Units

Contactor K1 energizes low speed compressor operation in all units (single-phase and three-phase.) In single−phase units K1 is a two pole contactor with two sets of normally open contacts and in three−phase units K1 is a five pole contactor with three sets of normally open contacts and two sets of normally closed contacts. K1 is also equipped with a set of single-pole double-throw auxiliary contacts located on the side of the contactor. The contactor is energized in response to low speed thermostat demand (from twospeed control jackplug J44/P44 pin 9.)

TABLE 2

Compressor Speed

Low

High

Contactors Energized

Single-Phase Three-Phase

K1 K1

K1 & K69 K69

In single-phase units, K1 also de-energizes the crankcase heater during compressor operation.

Contactor K69

Contactor K69 energizes high speed operation in all units (single-phase and three-phase.) In single−phase units K69 is a five−pole contactor with three sets of normally open contacts and two sets of normally closed contacts. In three− phase units K69 is a three−pole contactor with three sets of normally open contacts.This contact arrangement provides unique switching characteristics for two-speed operation. K69 is also equipped with a set of single-pole double-throw auxiliary contacts located on the side of the contactor. The contactor is energized in response to high speed thermostat demand from JP44-8 (two-speed control jackplug J44/P44 pin 8.)

Low speed demand energizes K1. K1 de-energizes the crankcase heater and energizes the compressor. High speed demand energizes both contactors K1 and K69. K69 N.O. contacts close to redirect the circuit to the high speed start windings and the N.C. contacts open to de-energize the low speed start windings. K69 N.C. contacts also switch whenever K69 is energized to ensure that K1 is energized with K69 during high speed operation (refer to unit wiring diagram).

Contactor Operation: Three-Phase Units

Low speed demand energizes K1. K1 energizes the compressor and locks out contactor K69. High speed demand de−energizes K1 and energizes contactor K69. K69 locks out K1 and energizes the compressor on high speed. K1 is wired so that when de−energized, the contactor forms a parallel common connection to the motor windings for high speed forming a parallel Delta" connection for Copeland compressors. When K1 is energized, the contactor forms a series Delta connection to the compressor windings. Refer to operation sequence in back of this manual for more information.

C−Defrost Relay K4

All HP21 units are equipped with a defrost relay located in the unit control box which controls defrost. The relay is a 3PDT relay powered 24 VAC from the thermostat. K4 is enabled during both cooling and heating modes (except emergency heat). It is only powered when the defrost control is calling for defrost. When energized, the reversing valve and indoor auxiliary heat are energized. Simultaneously, the outdoor fan is de-energized. K4 latches in for the duration of the defrost period.

Page 4

D−Hard Start Relay K31 (single-phase only)

All single-phase HP21 units are equipped with a hard start relay located in the unit control box which controls the operation of the compressor starting circuit. The relay is normally closed when the compressor (contactor K1) is de-energized. Capacitor (C7) is connected in series to a set of normally closed K31 contacts and assists the compressor in starting. When K1 energizes, the compressor immediately begins startup. K31 remains de-energized during compressor start-up and the start capacitor (C7) remains in the circuit. As the compressor gains speed K31 is energized by electromotive forces generated by the compressor. When K31 energizes, its contacts open to take the start capacitor out of the circuit.

E−Terminal Strip TB15

All HP21 units are equipped with a low voltage terminal strip located in the unit control box for making up thermostat wiring connections (refer to figure 2).

F−Compressor B1

See ELECTRICAL DATA or compressor nameplate for specifications. Figure 3 shows the compressor terminal box. All compressors are equipped with internal pressure relief valves set at 450+50 psig. Compressors in all units use insertion type crankcase heaters which are regulated by relays in the HP21.

frost relay is energized. In three-phase units, the outdoor fan is controlled by contactor K10 and is de-energized when the defrost relay is energized. See figure 4 if outdoor fan motor replacment is necessary.

1/4"

Condenser fan and motor

FAN GUARD

Wiring

Drip loop

FIGURE 4

H−High Pressure Limit S4

All units are equipped with a high pressure limit mounted on the compressor discharge line. The switch can be manually reset and has a cutout" point of 410+10 psig. The switch is electrically connected in series with crankcase thermostat S40 in the two-speed control’s safety circuit. When tripped, the TSC interrupts unit operation. If the high pressure switch trips" three times within the same thermostat demand, the two-speed control locks out and the contactor cannot energize.

TYPICAL TWO-SPEED COMPRESSOR

TERMINAL BOX

COPELAND SINGLE-PHASE SHOWN

T3 T8 T1 T7

SINGLE

PHASE

S1 S2

FIGURE 3

G−Outdoor Fan Motor B4

The specifications table on page 1 of this manual shows the specifications of outdoor fans used in all HP21 units. In single-phase units, the outdoor fan is controlled by the compressor contactor and is de−energized when the de-

Although the high pressure limit must be reset manually, if the two-speed control is locked out it must be reset before the unit can operate. To reset the control, break and remake thermostat demand.

I−Crankcase Thermostat S40

Crankcase thermostat S40 is electrically connected in series with high pressure limit S4 in the two-speed control’s safety circuit. It is used in all units to monitor the temperature of the compressor. The switch is a N.C. SPST belly-band" thermostat strapped to the compressor. The switch is factory preset to trip at 190°F+5°F on a temperature rise. When tripped, the TSC interrupts unit operation. The crankcase thermostat automatically resets when the compressor crankcase drops below 110°F+7°F. If the crankcase thermostat trips" three times within the same thermostat demand, the two-speed control locks out and the contactor cannot energize. If the two-speed control is locked out it must be reset before the unit can operate. To reset the control, break and remake thermostat demand.

Page 5

J−Service Light Thermostat S54

All units are equipped with a service light thermostat mounted on the compressor discharge line. The switch is electrically connected to the service light in the indoor thermostat. When compressor discharge line temperature reaches 130+5°F, the switch opens. If discharge line temperature drops below 110+5°F during unit operation (indicating a problem in the system), the switch closes. If thermostat demand is present when S54 closes, the service light is powered to indicate service is needed.

K−Start Capacitor C7

All single-phase HP21 units are equipped with a start capacitor connected in parallel with the run capacitor. The capacitor is switched off by the potential relay when the compressor nears full speed. The start capacitor is rated 145−175mfd. @ 330VAC in all single-phase units.

Three-phase HP21 units do not use start capacitors.

L−Bleed Resistor R21

All single-phase HP21 units are equipped with a bleed resistor connected in parallel with start capacitor C7. The resistor is used to slowly discharge the capacitor when not in use. R21 is a 15,000 ohm 2 watt resistor.

M−Run Capacitor C5

All single-phase early model HP21 -1 / -2 / -3 units use a compressor run capacitor to maximize motor efficiency. The run capacitor is located in the unit control box and is electrically connected as shown in the unit wiring diagram. Run capacitors are wired in parallel with the start capacitor. See side of capacitor for ratings.

O−Dual Capacitor C12

HP21-4 / -5 and late model single-phase units use a single dual capacitor to maximize motor efficiency in both the fan motor and the compressor, which use PSC motors. A dual capacitor has two independent capacitors inside one can. Each side of the capacitor has different ratings . See side of capacitor for ratings. The dual capacitor is wired in parallel with the start capacitor and is electrically connected as shown in the unit wiring diagram.

P− Two-Speed Controls

ELECTROSTATIC DISCHARGE (ESD)

Precautions and Procedures

CAUTION

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

TSC−2 Two-Speed Control

The TSC two-speed control (figure 5) is a Lennox built control designed for use with two-speed condensing units and heat pumps. The control provides automatic switching from low speed to high speed operation and back. The TSC−2 is designed for use with Bristol and Copeland compressors. All HP21 series units use Copeland compressors. All early model HP21−1 units use the TSC−2 controls.

N−Fan Capacitor C1

All early model HP21 -1 / -2 / -3 single phase and all HP21 three−phase series units (regardless of dash number) use single-phase PSC outdoor fan motors which require an external run capacitor. The fan capacitor is located inside the unit control box. See side of fan capacitor for ratings.

The TSC two-speed control contains relays which energize compressor operation in response to thermostat demand. High speed operation can be energized and de−energized without passing through low speed. The control also contains safety timed−off delays and compressor over−temperature sensing which help protect the compressor.

Page 6

JP44−1 24VAC POWER (INPUT) JP44−2 24VAC NEUTRAL (GROUND) JP44−3 NOT USED JP44−4 2nd STAGE THERMOSTAT DEMAND JP44−5 THERMOSTAT COMMON (C) JP44−6 1st STAGE THERMOSTAT DEMAND JP44−7 24VAC FROM SAFETY SWITCHES

TO INTERNAL CONTACTOR COIL (INPUT) JP44−8 HIGH SPEED (24VAC OUTPUT) JP44−9 LOW SPEED (24VAC INPUT)

TSC-2 TWO-SPEED CONTROL

S1 and S2

TO COMPRESSOR WINDING

TEMPERATURE SENSORS

S1 MANUAL OVERRIDE

OF 5 MINUTE DELAY

RED DIAGNOSTIC LED

JP44

123

456

789

FIGURE 5

JP44

TOP VIEW

A timed−off delay in the control prevents the compressor

from operating for five minutes after the end of a thermostat

demand or after a power failure to prevent short cycling

(see miscellaneous section.) The control also counts unit

fault conditions." Whenever the compressor stops due to a

safety limit trip or if the compressor winding temperature

becomes too hot, the control’s internal cycle counter accu-

mulates one fault. If three unit faults are counted during the

same thermostat demand, the control locks out" and stops

all unit operation. The control can be reset by breaking and

remaking thermostat demand. Also, unit faults are erased

when power is interrupted. When thermostat demand

changes stages, compressor operation stops for approxi-

mately one minute to allow refrigerant pressure to equalize

in the system.

In order to aid servicing and troubleshooting, a manual

override button has been placed on the control. The manu-

al override button, when pressed and released, bypasses

the five minute delay so low speed or high speed operation

can be immediately energized.

A red LED located on the face of the control can be used for

diagnostics. The control continually self-tests its internal

circuits and uses the diagnostic LED to indicate control fail-

ure or Safety Dormant Lockout. A Safety Dormant Lockout

is caused by abnormal line voltage (such as a lightning

strike near the unit).

Normal Operation Sequence

1− General Operation

On power−up, the control begins a ten second initial power−up delay.

2− The control then begins a five minute delay during

which the unit is not operational (control and outdoor unit do not respond to thermostat demand.) Once the five minute delay is complete, the control waits in OFF mode for thermostat demand.

3− After receiving a thermostat demand, the TSC delays

three seconds before responding.

4− Low speed demand (JP44−6) energizes low speed op-

eration (JP44−9) OR high speed demand (JP44−4) energizes high speed operation (JP44−8.)

5− During unit operation, if low speed demand changes to

high speed demand or if high speed demand changes to low speed, the control delays three seconds before responding. Then, all unit operation stops for 60+5 seconds (control de−energizes JP44−8 and JP44−9.) This allows refrigerant pressure to equalize in the system. At the end of the 60+5 second delay, the control responds to whatever thermostat demand is present. If no thermostat demand is present, the control resets (see unit fault conditions section) and the control returns to step 2 above.

6− If thermostat demand stops compressor operation, all

unit operation stops after a three second delay (control de−energizes JP44−8 and JP44−9,) the control resets (see unit fault conditions section) and the control returns to step two.

Page 7

Two-Speed Control Fault Conditions

If the control is in low speed operation, high speed operation, OFF" mode or speed change delay, the control counts" or accumulates faults on an internal cycle counter. Only faults which occur during compressor operation and which cause the compressor to shut off are counted. After a fault is counted, the control stops unit operation, resets and begins a five minute time delay (step 2, operation sequence). If the control senses a fault at the end of five minutes, the unit will not restart. If the control counts three faults during the same thermostat demand, the control locks out unit operation.

NOTE−If the control locks out, it can be reset by breaking thermostat demand for about five seconds then remaking thermostat demand. Also, anytime thermostat demand is removed or power is interrupted, the control resets to zero faults.

It is likely that the control could count three unit faults from the crankcase temperature switch during a single thermostat demand since this switch resets automatically. However, the cycle counter can only count unit faults from the high pressure switch if the reset button is pushed without interrupting thermostat demand.

2− On all units using the TSC two-speed control, terminals

S1 and S2 on the control are connected to temperature sensors (thermistors) which monitor the temperature of the compressor motor windings. The two-speed control measures the resistance through the sensors. The sensors increase their resistance as temperature increases (for example, too much superheat). When the resistance through the sensors increases above a preset limit, the control stops compressor operation. As the compressor windings cool, the resistance through the sensors drops below the reset limit, the control resets automatically and one fault is counted.

A fault occurs when

1− Compressor operation is monitored by high pressure

switch and crankcase temperature thermostat. These controls are wired in series. If either one trips, compressor operation is interrupted and one fault is counted. High pressure switch must be reset manually but crankcase temperature switch resets automatically.

IMPORTANT-If the cycle counter counts three faults during the same thermostat demand, the control locks out. The outdoor unit remains inoperable until thermostat demand is broken. This indicates further troubleshooting is needed. Though the control can be reset by breaking thermostat demand, the unit may remain inoperable. The high pressure or high temperature conditions may still exist and must be located and corrected before the unit can be placed back in service.

NOTE-Intermittent continuity (bad connection or failing components) can cause false lockout or lit LED. Check all electrical connections thoroughly.

The sensors can be checked by measuring resistance (ohms) through the sensors with the wires disconnected from the control (unit not running). The sensor wires are not polarity sensitive. Table 3 shows winding temperature sensor resistance values which will cause the TSC to lock out. When the unit is operating normally, the resistance through the sensors should be below the trip value shown in table 3.

The control can be checked by comparing the resistance measured through the sensors to the voltage measured across the sensor terminals with the unit running. Table 4 shows voltage measured across twospeed control terminals S1 and S2 with the compressor running.

Page 8

Compressor Winding

Temperature Sensor

TSC−2 Bristol or Copeland

Compressor

Two-Speed Control Manual Override

TABLE 3

Trip Ohms

Temp. Rise

25K to 35K 8.4K to 10K

Reset Ohms

Temp. Fall

tion). If compressor starts, the control is good and should not be replaced. Proceed through the troubleshooting flowchart in the Unit Information Manual to locate the source of the lockout. If the compressor does not start, a problem probably exists elsewhere in the unit. Check the unit voltage and proceed through the unit troubleshooting flowchart in the Unit Information Manual.

The manual override button is designed to be an aid in servicing and troubleshooting the control or the unit. When the button is pushed and then released, the control bypasses the five minute override delay.

TABLE 4

COMPRESSOR WINDING SENSOR

OPERATING RANGE

Resistance Through

Compressor Winding

Temperature Sensor

K-ohms (ohms x 1000)

1.0

5.5

6.9

8.4

10.0

16.0

20.0

24.0

25.0

30.0

35.0

+−

DC volts

Measured with unit running.

Voltage Across TSC Ter-

minals S1 and S2 with

Unit Running

DC Volts +.15

.02 .92

3.4

3.9

4.3

4.7

5.6

6.0

---

6.3

6.8

7.0

Reset

Range

Trip

Range

LED ON"

MEANS TSC FAULT" CONDITION

If the unit will not run and the LED is lit, the TSC may be in Safety Dormant Lockout (a lockout caused by self-test failure or high voltage spike).

To determine if the control is in Safety Dormant Lockout, briefly turn off power at the disconnect. When power is restored, check the LED. If the LED is lit, the control is damaged and must be replaced. If the LED is not lit, the control is probably good and should not be replaced until eliminated by all other checks. Confirm this by activating the compressor (press and release the override button with thermostat demand present). If the compressor starts, the control was in safety dormant lockout (due to high voltage spike or self-test failure) and the control should not be replaced. If the compressor does not start, the control is probably good and the problem is located elsewhere in the unit. Proceed through the troubleshooting flowchart to locate the problem. Start by checking all manually reset controls (high pressure switch etc...)

Service Instructions:

Do not use the override button for eleven seconds after power-up. If the button is pushed during the ten second power-up delay, the button has no effect. The control completes the five minute delay.

LED OFF"

MAY MEAN UNIT FAULT" CONDITION

If the unit will not run and the LED is not lit, a unit lockout condition is indicated. Breaking and remaking thermostat demand will reset the control. Activate the compressor by pressing and releasing the override button (see illustra-

1− If light comes on and stays lit, turn off power at dis-

connect for at least 3 seconds.

NOTE−Breaking thermostat demand will not reset the control if the control is in a Safety Dormant Lockout.

2− If LED is on when power is restored, replace TSC.

3− If light goes out see troubleshooting flowchart in

Unit Information Manual.

Page 9

TSC-3 Two-Speed Control

All early model HP21 -2 series units (single and three phase) are equipped with a TSC-3 two-speed control. The speed-control thermostat (formerly key number S55) has been removed from the unit and incorporated into the circuitry of the TSC-3 control (see figure 6). The function and operating sequence are otherwise identical to the TSC-2 plus the separate thermostat used in previous HP21 units.

The purpose of the speed control thermostat is to force the compressor to operate on high speed when outdoor temperature is low. It initiates a speed change delay and automatically energizes high speed when temperature drops below the setpoint. The setpoint is factory preset and can be field adjusted.

TSC-3 TWO-SPEED CONTROL

(with built in speed control thermostat)

TSC

TWO-SPEED CONTROL

When temperature rises above the setpoint, the control initiates a speed change delay and automatically energizes low speed.

The setpoint can be changed by adjusting the potentiometer shown in figure 6. The potentiometer is factory set as shown in table 5.

TABLE 5

Speed Control Thermostat

Adjustable Range

Cut-In

(Close on Temperature Drop)

Cut-Out

(Open on Temperature Rise)

Min.

37+2°F 42+2°F 55+2°F

47+2°F 52+2°F 65+2°F

46+2°F

56+2°F

Mid.

Factory

Setting

Max

To adjust the speed control thermostat, insert a small slot screwdriver into the potentiometer as shown in figures 6 and 7. To lower the setpoint, turn the potentiometer counter-clockwise. To raise the setpoint, turn the potentiometer clockwise. Do not force the potentiometer to turn past its stops; the potentiometer will be damaged.

SENSOR

TEMPERATURE

ADJUSTMENT (potentiometer)

FIGURE 6

J44

SCREWDRIVER

TSC-3 TWO-SPEED CONTROL

WINDING TEMPERATURE

SENSOR TERMINALS

OVERRIDE

BUTTON

(5 minute delay)

TEMPERATURE

SENSOR

TEMPERATURE ADJUSTMENT

(shown in factory position)

FIGURE 7

The unit wiring diagrams have been revised to reflect the changes for the HP21-2 (TSC-3), and are shown in section VII−Wiring Diagrams and Operation Sequence.

Page 10

TSC-6 Two-Speed Control

HP21 -4 and -5 and late model HP21 units (single and three phase) are equipped with a TSC-6 two-speed control. The TSC-6 (A14) two-speed control contains relays which energize compressor operation in response to thermostat demand. High speed operation can be energized and de-energized without passing through low speed. The control also contains safety timed-off delays and compressor over-temperature sensing which protect the compressor. The control has an external temperature probe to lock out low speed during low temperatures, plus a potentiometer used for setting the low speed lock out temperature. The adjustment range is 38° F (3.3° C) to 55° F (12.7° C) ±2° F (1.1° C). This lock out will occur in both heating and cooling modes.

TSC-6 SHOWN

A timed-off delay in the control prevents short cycling by locking out compressor operation for five minutes after the end of a thermostat demand or after a power failure. The control also counts unit fault conditions." When the compressor stops due to a safety limit trip, or if the compressor winding temperature becomes too hot, the control’s internal cycle counter accumulates one fault. If three unit faults are counted during the same thermostat demand, the control locks out" and stops all unit operation. The control can be reset by breaking and remaking thermostat demand. Unit faults are erased when power is interrupted. When thermostat demand changes stages, compressor operation stops for approximately one minute to allow refrigerant pressure to equalize in the system.

A manual override button aids servicing and troubleshooting, on the control. The manual override button, when pressed and released, bypasses the five-minute delay so low speed or high speed operation can be immediately energized. However, the control provides a one-minute delay between speed changes, which cannot be bypassed.

Do not use the override button immediately after powerup. If the button is pushed during the ten-second power-up delay, it has no effect. The control completes the five-minute delay.

The control continually self-tests its internal circuits and uses the diagnostic lights to indicate control failure.

Normal Operation Sequence

1− After self-test, the control begins a five-minute delay dur-

ing which the unit is not operational (control and outdoor unit do not respond to thermostat demand). Once the fiveminute delay is complete, the control waits in OFF mode for thermostat demand.

2− After receiving a thermostat demand, the TSC de-

lays three seconds before responding.

3− Low speed demand (JP44-9) energizes low speed

operation OR high speed demand (JP44-8) energizes high speed operation.

4− During unit operation, if low speed demand changes

to high speed demand or if high speed demand changes to low speed, the control delays three seconds before responding. Then, all unit operation stops for 60+5 seconds (control de-energizes JP44-8 and JP44-9). This allows refrigerant pressure to equalize in the system. At the end of the 60+5 second delay, the control responds to whatever thermostat demand is present. If no thermostat demand is present, the control resets (see unit fault conditions section) and returns to step 2 above.

5− When thermostat demand is satisfied, all unit opera-

tion stops after a three-second delay (control de-energizes JP44-8 and JP44-9), the control resets (see unit fault conditions section) and returns to step two.

6− General Operation

On power-up, the control begins a ten-second initial delay.

Page 11

MANUAL

OVERRIDE

BUTTON

COMPRESSOR

SENSOR

CONNECTORS

HEARTBEAT

LED

MODE

SELECTION

JUMPERS

TSC-6 (A14) TWO-SPEED CONTROL COMPONENTS

OPTION 1 ENABLE

JUMPER

OPTION 2 ENABLE

JUMPER

DIAGNOSTIC LEDs

D8, D4, D2, D1

Y1 LED

LOW SPEED lock out TEMP. ADJUSTMENT

OUTDOOR

TEMP. SENSOR

CONNECTOR

OPTION 1

CONNECTOR

JP44-1 24VAC POWER (INPUT) JP44-2 24VAC COMMON JP44-3 24VAC (SPARE, NOT USED) JP44-4 2nd STAGE THERMOSTAT DEMAND JP44-5 THERMOSTAT COMMON (C) JP44-6 1st STAGE THERMOSTAT DEMAND JP44-7 24VAC FROM SAFETY SWITCHES

TO INTERNAL CONTACTOR COIL (INPUT) JP44-8 HIGH SPEED (24VAC OUTPUT) JP44-9 LOW SPEED (24VAC OUTPUT)

OPTION 2

CONNECTOR

SERVICE RELAY

CONNECTORS

LOW SPEED

LED

HIGH SPEED

FIGURE 8

TSC-6 (A14) MAIN CONTROL PLUG

JP44

456

789

Y2 LED

MAIN CONTROL

PLUG

LED

Two-Speed Control Fault Conditions

If the control is in low speed operation, high speed operation, OFF" mode or speed change delay, the control counts" or accumulates faults on an internal cycle counter. Only faults which occur during compressor operation and which cause the compressor to shut off are counted. After a fault is counted, the control stops unit operation, resets and begins a five-minute time delay (step 2, operation sequence). If the control senses a fault at the end of five minutes, the unit will not restart. If the control counts three faults during the same thermostat demand, the control locks out unit operation.

FIGURE 9

IMPORTANT

If the cycle counter counts three faults during the same thermostat demand, the control locks out. The outdoor unit remains inoperable until thermostat demand is broken. This indicates further troubleshooting is needed. Though the control can be reset by breaking thermostat demand, the unit may remain inoperable. The high pressure or low pressure conditions may still exist and must be located and corrected before the unit can be placed back in service. See diagnostic codes to determine problem.

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IMPORTANT

If the control locks out, it can be reset by breaking thermostat demand for about five seconds then remaking thermostat demand. Also, anytime thermostat demand is removed or power is interrupted, the control resets to zero faults.

A fault occurs when:

1− Compressor operation is monitored by high and low pres-

sure switches. These controls are wired in series. If either one trips, compressor operation is interrupted and one fault is counted. The control locks out compressor operation for a minimum of five minutes when a safety device terminates operation. High pressure switch must be reset manually but low pressure switch resets automatically.

It is likely that the control could count three unit faults from the low pressure switch during a single thermostat demand since this switch resets automatically. However, the cycle counter can only count unit faults from the high pressure switch if the reset button is pushed without interrupting thermostat demand.

2− On all units using the TSC two-speed control, terminals

S1 and S2 on the control are connected to temperature sensors (thermistors) which monitor the temperature of the compressor motor windings. The two-speed control measures the resistance through the sensors. The sensors increase their resistance as temperature increases (for example, too much superheat). When the resistance through the sensors increases above a preset limit, the control stops compressor operation for a minimum of five minutes. As the compressor windings cool, the resistance through the sensors drops below the reset limit, the control resets automatically and one fault is counted.

Check sensors by measuring resistance (ohms) through the sensors with the wires disconnected from the control (unit not running). The sensor wires are not polarity sensitive. Table 6 shows winding temperature sensor resistance values which will cause the TSC to lock out. When unit is operating normally, resistance through the sensors should be below the trip value shown in table 6.

TABLE 6

Compressor Winding Temperature Sensor

TSC−6 Copeland Compressor 90 − 7800 25K − 35K 8.4K − 10K

IMPORTANT − Normal resistance values of these compressors are above 200 ohms but can read 90 ohms during certain ambient temperatures. Ohm value below 200 ohms will cause the two−speed control to cycle the compressor "off" and will not allow the compressor to cycle back "on" until the ohm values are above 200 ohms. To prevent this issue, the field can install a 150 ohm − 1/4

Normal Ohms

Trip Ohms Temp R i s e

Reset Ohms Temp F a l l

watt resistor in series with one of the sensor connections on the two−speed control. (The resistor can be found at electronic stores such as Radio Shack). Table 7 shows the resistor in series with the control and compressor.

The control can be checked by comparing the resistance measured through the sensors to the voltage measured across the sensor terminals with the unit running. Table 7shows voltage measured across twospeed control terminals S1 and S2 with the compressor running.

TABLE 7

COMPRESSOR WINDING SENSOR

OPERATING RANGE

Resistance Through

Compressor Winding

Temperature Sensor

K-ohms (ohms x 1000)

.090 − .200

1.0

5.5

6.9

8.4

10.0

16.0

20.0

24.0

25.0

30.0

35.0

DC volts

Measured with unit running.

Resistor

Compressor

Voltage Across TSC-6

compressor sensor terminals

with Unit Running DC Volts

1.70 − 1.82

6.07 − 6.48

6.86 − 7.33

7.55 − 8.07

8.16 − 8.72

9.69 − 10.36

10.34 − 11.05

10.82 − 11.57

10.93 − 11.68

11.35 − 12.14

11.68 − 12.48

Short in Sensor

Reset

Range

Trip

Range

MODE SELECTION JUMPERS

The control has six mode selection jumpers for selection of operating modes and problem code recall or test. Choose one of the first four modes for operation.

Normal: Normal operation (default mode). Unit

runs on high or low speed as the indoor thermostat load demands.

Latch 1: After high speed demand is met, the unit remains in high speed until the low speed demand is satisfied.

Page 13

Latch 2: After the unit operates in low speed for 15 minutes consecutively, it switches to high speed until low speed demand is satisfied.

Latch 3: After the unit operates in low speed for 30 minutes consecutively, it switches to high speed until low speed demand is satisfied.

Recall: Used in conjunction with the bypass button to recall the stored problem codes.

Test: Used in conjunction with the control button to start test mode.

Latch 2 or 3 modes are recommended in high humidity areas. If the jumper falls off or is removed, the control will continue to operate in the previously set mode until the control is reset due to loss of power, then the control will default to the Normal mode.

TEST MODE

The control has a test mode. To initiate this mode, move the jumper to the test position and push the control button. The unit will operate in low speed for 10 seconds, turn off for ten seconds, then operate in high speed for 10 seconds. The control will only go into the test mode if there is no thermostat demand and 5 minutes has elapsed since the unit ran. The indoor blower does not run during this mode. The test mode cannot run more than once every 5 minutes.

LED LIGHTS

Y1 and Y2 lights are connected directly to the inputs from the thermostat. They indicate low and high speed demand, respectively.

The HI and LO lights are connected directly across the contactor coils. They indicate if the high and low speed contactors are energized.

The HEARTBEAT light is connected to the microcontroller unit (MCU). It indicates when the control’s MCU is operating correctly, and also when the control is in delay mode. It blinks at a rate of four times a second when the MCU is operating properly and at a rate of once every two seconds when in the delay mode (such as the 1 or 5 minute delay). If the LED is continuously on or off (assuming the power is on), the MCU is not operating properly and the control needs to be replaced.

The D1, D2, D4, and D8 (see figure 8) diagnostic lights display diagnostic codes to aid in unit troubleshooting. Refer to Diagnostic Code Table (table 8).

Diagnostic Code Display

A problem code is normally displayed only for the duration of the error. There is one exception. During a lock out, the code for the problem causing the lock out flashes once a second even if the problem condition no longer exists. If other problems occur during a lock out condition, the codes for those problems will be saved in memory, but not displayed. The stored problem codes are displayed by recalling them from memory. The diagnostic codes can be re-displayed by setting the jumper to the recall position. The stored codes are dis-

played by pushing the push button. As previously mentioned, the push button is used to bypass the five-minute delay and to initiate the test mode. In addition, the button is used to step back through the stored diagnostic codes and erase the diagnostic code memory. Diagnostic codes are recalled in the reverse order of actual occurrence. Each subsequent button push will display additional codes until the last one, which will stay on with additional button pushes. Hold the button down until the lights go off (approximately five seconds) to erase the memory. The control has a nonvolatile memory that stores the 63 most recent diagnostic codes. These codes are stored in memory, even in the event of a power loss.

Not all codes cause lock outs or indicate problems. The purpose of the diagnostic lights is to let the installer or service technician know what is going on with the entire system, not just the two−speed control. Some codes do indicate malfunctions or problems with either the control or the HP21, while others inform the technician of the unit’s status. All codes, except for three, are stored in memory and may be recalled.

Code 1 − Power Loss for Two Electrical Cycles

This code indicates that the unit’s power skipped two electrical cycles (33−40 milliseconds). It may suggest that power to the unit is dirty" or is of low quality. Code 1 is stored.

Code 2 − Input Indication

This code indicates that a change has been made and that the control acknowledges the change. It does not indicate a problem condition. It indicates activity such as jumper setting changes, delay overrides, or addition of an optional safety device to Option 1 or 2. Code 2 is not stored.

Code 3 − Unsteady Thermostat Input

Code 3 indicates intermittent inputs from the room thermostat. Most likely, there is a loose connection at the thermostat when this condition appears. Code 3 is stored.

Code 4 − Pressure Switch Opens < Two Minutes

If the low or high pressure switch opens after the compressor has run for less than two minutes, Code 4 will be displayed. This may indicate blockage or fan failure. Code 4 is stored. If the unit still operates after code is displayed, the low pressure switch stops operation (low pressure is auto−reset). Check for low system charge.

Code 5 − Pressure Switch Opens > Two Minutes

If the low or high pressure switch opens after the compressor has run for more than two minutes, Code 5 is displayed. This may indicate an improper charge or coil obstruction. Code 5 is stored. If the unit still operates after code is displayed, the low pressure switch stops operation (low pressure is auto−reset). Check for low system charge.

Code 6 − Hot Compressor < Five Minutes

Code 6 indicates the compressor temperature exceeded its limit after running less than five minutes. Code 6 is stored.

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TSC-6 DIAGNOSTICS CODES

CODE

TABLE 8

CODE

NUMBER

1 Power loss for two

2 Input Indication OFF OFF ON OFF

3 Unsteady Input OFF OFF ON ON

4 Pressure Switch Open

5 Pressure Switch Open

6 Hot Compressor < 5

7 Hot Compressor > 5 min.

8 Option 1 < 5 minutes ON OFF OFF OFF

9 Option 1 > 5 minutes ON OFF OFF ON

10 Option 2 Open ON OFF ON OFF

11 Compressor Temp.

12 Outdoor temperature

13 Not Used ON ON OFF

14 Test Mode ON ON ON OFF

15 No Jumper in place

CONDITION

cycles

<2 minutes

> 2 minutes

min. (or open sensor)

(or open sensor)

Sensor Problem

Sensor

Indication

DISPLAY LIGHTS

8 4 2 1

OFF OFF OFF ON

OFF ON OFF OFF

OFF ON OFF ON

OFF ON ON OFF

OFF ON ON ON

ON OFF ON ON

ON ON OFF OFF

ON ON

Code 7 − Hot Compressor > Five Minutes

Code 7 indicates the compressor temperature exceeded its limit after running more than five minutes. Code 7 is stored.

Code 8 − Option 1 < Five Minutes

Code 8 occurs if the Option 1 safety device switch opens after the compressor runs less than five minutes. Code 8 is stored.

Code 9 − Option 1 > Five Minutes

Code 9 occurs if the Option 1 safety device switch opens after the compressor runs more than five minutes. Code 9 is stored.

Code 10 − Option 2

Code 10 is displayed if the Option 2 safety device switch opens. Code 10 is stored.

Code 11 − Compressor Temperature Sensor Shorted

This code indicates that the compressor temperature sensor wires have shorted together. Code 11 is stored.

Code 12 − Outdoor Temperature Sensor

This code indicates a problem with the operation of the outdoor temperature sensor. Code 12 is stored.

Code 13 − Not Used

This code may be used in future models of the two−speed control, but at this time has no function and, therefore, is not stored.

Code 14 − Test Mode

Code 14 does not indicate a problem. The control is in TEST mode when this code is displayed. See Mode Jumper Selections section.

Code 15 − No Jumper in Place

Code 15 is displayed when the mode jumper is not in place. Make sure jumper is placed securely across the selected set of pins for the appropriate mode of operation.

SERVICE RELAY

The control has a built-in service relay. This relay controls the thermostat service light or communicates with an alarm device. The relay signals the alarm device in such a manner that the alarm device can distinguish between a lock out and a nonlock out condition. The relay contacts are normally open when no problems or lock out conditions occur. A non-lock out condition is reported by closing the contacts for the duration of the next no-demand period. If the control goes into a lock out state, the relay will close and remain closed until the next loss of demand. If the service light on the room thermostat is connected to the service relay, the light will turn on if the control is in a lock out. It will not turn on if the control is detecting non-lock out problems. In order for the service relay to indicate only a lock out condition, one side of the relay must be wired to the alarm and the other side to Y2. During a simultaneous Y1, Y2 demand with a non-lock out condition, the alarm will energize for a very short duration (.2 seconds). If both an alarm device and thermostat service lights are used, an additional external relay may be required depending on thermostat used.

OPTIONAL INPUTS

The control has two optional inputs for additional protection devices. If options 1 or 2 are going to be used, move the three pin mini-jumper to the YES side. OPT 1 input will lock out the compressor on the third count. OPT 2 input will not lock out the compressor at any time, but will display and store the problem code (see Diagnostic code Table). These inputs are designed for normally closed switches connected to 24VAC.

CAUTION

Do not remove the jumpers unless additional protection controls are going to be installed. If OPT 1 jumper is not connected to the NO pin, the control will lock out the compressor. If OPT 2 is not connected to the NO pin, the display only shows the problem code.

The unit wiring diagrams have been revised to reflect the changes for the HP21-4/-5 (TSC-6), and are shown in section VII−Wiring Diagrams and Operation Sequence.

Page 15

Q−Speed Control Thermostat S55 (Early Model HP21 −1 series units only)

The indoor thermostat regulates compressor speed when the unit is operating in cooling mode. When the unit is oper-

ating in heating mode, speed control thermostat S55 regulates compressor speed.

ADJUSTING SPEED CONTROL THERMOSTAT

Adjustment screw can be accessed by inserting screwdriver through slot in underside of control box.

1st stage heating demand from the indoor thermostat ener-

gizes the compressor (Y1 demand). Speed control thermostat S55 controls compressor speed. Additional

heating demand from the indoor thermostat (W1 demand) energizes the indoor auxiliary heat.

Speed control thermostat S55 (figure 10) is a SPST thermostat located in the unit control box. The control uses a

cap-tube sensor to monitor the temperature inside the control box. The cap-tube sensor is coiled adjacent to the

control.

SPEED CONTROL THERMOSTAT S55

Temperature Sensor

(Cap-Tube)

FIGURE 10

S55 continually monitors the temperature inside the control

box. When control box temperature drops below the control setpoint, the control closes. When the control closes,

the contacts shunt across Y1 and Y2 inside the unit. When heating demand is present and S55 is closed, the two-

speed control electrically sees a high speed demand. The compressor operates at high speed until control box warms

and S55 opens.

TABLE 9

Speed Control Thermostat

Adjustable Range

Cut-In

(Close on Temperature Drop)

Cut-Out

(Open on Temperature Rise)

Min

37+2°F 40+2°F 55+2°F

47+2°F 50+2°F 65+2°F

Factory

Setting

Max

S55 has field adjustable setpoints. Temperature differential (difference between cut-in and cut-out) is fixed and cannot

be adjusted. Table 9 shows S55 control setpoints.The control is factory set to close at 40+2°F on a temperature drop

and reset at 50+2°F on a temperature rise.

Turn screw clockwise to increase

switchover temperature.

FIGURE 11

Regional climatic conditions may require the control to be adjusted to a different setting. The adjustment screw is located on the bottom of the control. A hole cut into the bottom shelf of the control box provides access to the speed control from the compressor compartment (see figure 11). Figure 12 shows the adjustment range of the control. Turn adjustment screw clockwise to raise the switchover temperature and counterclockwise to lower the switchover temperature.

SPEED CONTROL THERMOSTAT

*HP21 FACTORY

SETTINGS

*40

ADJUSTMENT

SCREW

FIGURE 12

R−Reversing Valve and Solenoid L1

A refrigerant reversing valve with electromechanical solenoid is used to reverse refrigerant flow during unit operation. The reversing valve is energized during cooling demand and during defrost.

S−Ambient Compensation Thermistor RT3

HP21 units are equipped with an ambient compensation thermistor (RT3) attached to the outdoor fan motor bracket. The thermistor is connected in series with the heat anticipation resistor inside the indoor thermostat. The thermistor helps to prevent abnormal droop caused by the anticipation resistors. RT3 is a NTC thermistor (negative temperature coefficient; increase in temperature equals decrease in resistance). As outdoor temperature increases, the resistance through RT3 drops. As the resistance across RT3 drops, the current through the heat anticipation resistor increases. Therefore, heat anticipation increases as outdoor temperature decreases. RT3 resistance values are shown in table 10.

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